Polishing pads and methods of forming the same

Abstract

Embodiments of the present disclosure relate to advanced polishing pads with tunable chemical, material and structural properties, and new methods of manufacturing the same. According to one or more embodiments of the disclosure, it has been discovered that a polishing pad with improved properties may be produced by an additive manufacturing process, such as a three-dimensional (3D) printing process. Embodiments of the present disclosure thus may provide an advanced polishing pad that has discrete features and geometries, formed from at least two different materials that include functional polymers, functional oligomers, reactive diluents, addition polymer precursor compounds, catalysts, and curing agents. For example, the advanced polishing pad may be formed from a plurality of polymeric layers, by the automated sequential deposition of at least one polymer precursor composition followed by at least one curing step, wherein each layer may represent at least one polymer composition, and / or regions of different compositions. Embodiments of the disclosure further provide a polishing pad with polymeric layers that may be interpenetrating polymer networks.

Description

[Technical Field]

[0001] The embodiments disclosed herein generally relate to polished objects and methods of manufacturing polished objects for polishing processes. More specifically, the embodiments disclosed herein relate to polishing pads produced by processes that generate improved polishing pad characteristics and performance (including tunable performance). [Previous Technology]

[0002] Chemical mechanical polishing (CMP) is a well-known process used in many different industries for planarizing substrate surfaces. In the semiconductor industry, the uniformity of polishing and planarization becomes increasingly important as the feature size of devices continues to shrink. During the CMP process, a substrate, such as a silicon wafer, is mounted on a carrier head, with the device surface placed against a rotating polishing pad. The carrier head provides a controlled load on the substrate to push the device surface against the polishing pad. A polishing liquid, such as a slurry containing abrasive particles, is typically supplied to the surface of the moving polishing pad and the polishing head. The polishing pad and polishing head apply mechanical energy to the substrate, while the pad also helps control the delivery of the slurry that interacts with the substrate during the polishing process. Since polishing pads are typically made of viscoelastic polymers, the mechanical properties of the polishing pad (e.g., elasticity, resilience, hardness, and stiffness) and CMP processing conditions have a significant impact on CMP polishing performance at both the IC grain level (micro / nanoscale) and the wafer or overall level (macroscale). For example, CMP process forces and conditions (such as pad compression, pad rebound, friction, and temperature changes during processing) and abrasive water-based slurry chemicals will affect the characteristics of the polishing pad and thus affect CMP performance.

[0003] A chemical mechanical polishing process performed in a polishing system typically includes multiple polishing pads performing different parts of the overall polishing process. The polishing system typically includes a first polishing pad mounted on a first platform, which produces a first material removal rate and a first surface finish and a first flatness on the substrate surface. This first polishing step is typically referred to as a roughing polishing step and is typically performed at a higher polishing rate. The system will also typically include at least one additional polishing pad mounted on at least one additional platform, which produces a second material removal rate and a second surface finish and flatness on the substrate surface. This second polishing step is typically referred to as a fine polishing step and is typically performed at a lower rate than the roughing polishing step. In some configurations, the system also includes a third polishing pad mounted on a third platform, which produces a third material removal rate and a third surface finish and flatness on the substrate surface. This third polishing step is typically referred to as a material cleaning or buffing step. Multi-pad polishing processes can be used in multi-step processes where the pads have different polishing properties and the substrate undergoes progressively finer polishing or the polishing properties are adjusted to compensate for different layers encountered during polishing, such as metal lines under an oxide surface.

[0004] During each CMP process step, the polishing pads are exposed to compression and springback cycles, heating and cooling cycles, and abrasive slurry chemicals. Eventually, the polishing pads become worn or "polished" after polishing a certain number of substrates and subsequently require replacement or repair.

[0005] Polishing pads are typically made of polymeric materials, including polyurethane, through molding, casting, or sintering. In the case of molding, the polishing pad can be manufactured in one step, for example, by injection molding. In the case of casting, a liquid precursor is cast and solidified into a cake shape, which is then cut into individual pads. These pads can then be processed to their final thickness. Pad surface features, including grooves that facilitate slurry transport, can be machined into the polishing surface or formed as part of the injection molding process. These methods of manufacturing polishing pads are expensive and time-consuming, and often result in uneven polishing results due to difficulties in producing and controlling the dimensions of the pad surface features. Non-uniformity is becoming increasingly important as the dimensions of IC chips and features continue to shrink.

[0006] Current pad materials and methods for producing such pad materials limit the manipulation and fine control of bulk pad properties, such as storage modulus (E') and loss modulus (E”), which play a crucial role in pad performance. Therefore, uniform CMP requires pad materials and surface features, such as grooves and channels, that possess a predictable and finely controlled balance of storage modulus E' and loss modulus E”, which are further maintained within, for example, a CMP processing temperature range of approximately 30°C to approximately 90°C. Unfortunately, conventional pad production via traditional monolithic polymerization and casting and molding techniques offers only limited control over pad properties (e.g., modulus) because the pad is a random mixture of phase-separated macromolecular domains subjected to intramolecular repulsive and attractive forces and variable polymer chain entanglement. For example, the presence of phase-separated micro and macro structural domains in the substrate can lead to the additive combination of nonlinear material reactions, such as the hysteresis phenomenon of the energy storage modulus E' during multiple heating and cooling cycles. These multiple heating and cooling cycles usually occur during the CMP process of multiple batches of substrates, which can lead to polishing non-uniformity and unpredictable performance of different batches of substrates.

[0007] Due to the drawbacks associated with conventional polishing pads and their manufacturing methods, there is a need for new polishing pad materials and new methods for manufacturing polishing pads that provide control over the geometry of the pad's characteristic structure and fine control over the pad material's chemical and physical properties. These improvements are expected to produce improved polishing uniformity at both the microscopic and macroscopic levels (such as across the entire substrate). [Summary of the Invention]

[0008] Embodiments of this disclosure may provide a polished object including a first polishing element comprising a plurality of continuously formed layers. The continuously formed layers may include a first layer comprising a first pattern of pore-forming regions disposed on a surface on which the first layer is formed, and a first structural material region disposed on the surface and located between pore-forming regions adjacent to the first pattern. The continuously formed layer may also include a second layer disposed on the surface of the first layer, wherein the second layer includes a second pattern of pore-forming regions disposed on the surface of the first layer, and a second structural material region disposed on the surface of the first layer and located between pore-forming regions adjacent to the second pattern. The first and second patterns of the pore-forming regions may each further include a pore-forming material that degrades upon exposure to an aqueous solution, and the pore-forming material may further include acrylate.

[0009] Embodiments of this disclosure may further provide a method for forming a polished object, including the continuous formation of a plurality of polymer layers. The method may include: forming a first layer of a plurality of first polishing elements of the polished object, wherein forming the first layer includes forming a first pattern containing pore-forming agent regions on a surface on which the first layer is formed, and forming a first structural material region, wherein the first structural material region is disposed on the surface and located between pore-forming agent regions adjacent to the first pattern. Subsequently, forming a second layer of the plurality of first polishing elements, wherein forming the second layer is disposed on the surface of the first layer and includes forming a second pattern containing pore-forming agent regions on the surface of the first layer, and forming a second structural material region, wherein the second structural material region is disposed on the surface of the first layer and located between pore-forming agent regions adjacent to the second pattern.

[0010] Embodiments of this disclosure may provide a polishing pad having a polishing surface configured to polish the surface of a substrate. The polishing pad includes: a plurality of first polishing elements, each comprising a plurality of first polymer layers, wherein at least one of the plurality of first polymer layers forms the polishing surface; and a plurality of second polishing elements, each comprising one or more of a plurality of second polymer layers, wherein at least a region of each of the one or more second polishing elements is disposed between at least one of the plurality of first polishing elements and a support surface of the polishing pad. In some configurations, the plurality of first polymer layers comprises a first polymer composition, and the plurality of second polymer layers comprises a second polymer composition. The first polymer composition may be formed from a first droplet composition, and the second polymer composition may be formed from a second droplet composition. In some embodiments, the second droplet composition may contain a larger amount of resin precursor composition material than the first droplet composition, and the glass transition temperature of the resin precursor composition material may be less than or equal to about 40°C, such as less than or equal to 30°C. In some embodiments, the first drop composition comprises a larger amount of oligomer and resin precursor composition material than the second drop composition, wherein the functionality of the oligomer and resin precursor composition material is greater than or equal to 2. In some embodiments, the first drop composition comprises oligomer and resin precursor composition material with a functionality greater than or equal to 2, and the second drop composition comprises resin precursor composition material with a functionality less than or equal to 2.

[0011] Embodiments of this disclosure may further provide a polishing pad having a polishing surface configured to polish the surface of a substrate, comprising a plurality of first polishing elements, each comprising a plurality of first polymer layers, the first polymer layers comprising a first polymer material, wherein at least one of the plurality of first polymer layers forms the polishing surface; and a base region disposed between at least one of the plurality of first polishing elements and a polishing pad support surface, wherein the base region comprises a plurality of layers, each comprising a plurality of cured droplets of a first resin precursor composition material and a plurality of cured droplets of a second resin precursor composition material.

[0012] Embodiments of this disclosure may further provide a method for forming a polished object, comprising forming a plurality of polyurethane acrylate polymer layers, wherein forming the plurality of polyurethane acrylate polymer layers comprises applying a plurality of drops of a first precursor formulation in a first pattern to the surface of a polishing body comprising a first material composition, wherein the first precursor formulation comprises a first multifunctional polyurethane acrylate oligomer, a first amount of the first multifunctional acrylate precursor, and a first amount of the first curing agent; applying a plurality of drops of a second precursor formulation in a second pattern to the surface of the polishing body, wherein the second precursor formulation comprises the first multifunctional polyurethane acrylate oligomer and / or the first multifunctional acrylate precursor; and exposing the dispensed droplets of the first precursor formulation and the dispensed droplets of the second precursor formulation to electromagnetic radiation for a first time period, thereby partially curing the drops of the first precursor formulation and the drops of the second precursor formulation.

[0013] Embodiments of this disclosure may provide a polished object having a polished surface configured to polish the surface of a substrate, comprising a plurality of first polishing elements, each comprising a plurality of first polymer layers, wherein at least one of the plurality of first polymer layers forms a polished surface; and a plurality of second polishing elements, each comprising one or more second polymer layers, wherein at least a region of each of the one or more second polishing elements is disposed between at least one of the plurality of first polishing elements and a support surface of the polished object, wherein the plurality of first polymer layers comprises a first polymer composition and the plurality of second polymer layers comprises a second polymer composition, each of the plurality of first polishing elements having an exposed portion and a non-exposed portion, the non-exposed portion of the first polishing element being disposed within a portion of one or more of the second polishing elements, the exposed portion having an exposed surface region including a polished surface and an exposed surface area to volume ratio less than about 20 mm⁻¹. In some configurations, the exposed surface area to volume ratio is less than about 15 mm⁻¹ or less than about 10 mm⁻¹.

[0014] Embodiments of this disclosure may further provide a polished object having a polished surface configured to polish the surface of a substrate, comprising a plurality of first polishing elements, each comprising a plurality of first polymer layers, wherein at least one of the plurality of first polymer layers forms the polished surface; and a plurality of second polishing elements, each comprising one or more of a plurality of second polymer layers, wherein at least a region of each of the one or more second polishing elements is disposed between the at least one of the plurality of first polishing elements and a support surface of a polishing pad, wherein the plurality of first polymer layers comprises a first polymer composition and the plurality of second polymer layers comprises a second polymer composition, and wherein at least one first polymer layer on the polished surface has a dynamic contact angle of less than about 60°.

[0015] Embodiments of this disclosure may further provide a polished object having a polished surface configured to polish the surface of a substrate, comprising a plurality of first polishing elements, each comprising a plurality of first polymer layers, wherein at least one of the plurality of first polymer layers forms the polished surface; and a plurality of second polishing elements, each comprising one or more of a plurality of second polymer layers, wherein at least a region of each of the one or more second polishing elements is disposed between the at least one of the plurality of first polishing elements and a support surface of the polished object, wherein the plurality of first polymer layers comprises a first polymer composition and the plurality of second polymer layers comprises a second polymer composition; and wherein the second polymer layers have a Shore A hardness of less than 90.

[0016] Embodiments of this disclosure may further provide a polished object having a polished surface configured to polish the surface of a substrate, comprising a plurality of first polishing elements, each comprising a plurality of first polymer layers, wherein at least one of the plurality of first polymer layers forms the polished surface; and a plurality of second polishing elements, each comprising one or more of a plurality of second polymer layers, wherein at least a region of each of the one or more second polishing elements is disposed between the at least one of the plurality of first polishing elements and a support surface of the polished object, wherein the plurality of first polymer layers comprises a first polymer composition and the plurality of second polymer layers comprises a second polymer composition, and wherein the thermal diffusivity of the first polymer layer is less than about 6E-6 m2 / s.

[0017] Embodiments of this disclosure may further provide a polished object having a polished surface configured to polish the surface of a substrate, comprising a plurality of first polishing elements, each comprising a plurality of first polymer layers, wherein at least one of the plurality of first polymer layers forms the polished surface; and each comprising one or more second polishing elements comprising a plurality of second polymer layers, wherein at least a region of each of the one or more second polishing elements is disposed between at least one of the plurality of first polishing elements and a support surface of the polished object, wherein the plurality of first polymer layers comprises a first polymer composition and the plurality of second polymer layers comprises a second polymer composition; and wherein one or more of the second polymer layers have a tan δ of at least 0.25 in a temperature range of 25°C and 90°C.

[0018] Embodiments of this disclosure may further provide a method for forming a polished object, comprising continuously forming a plurality of polymer layers, wherein forming the plurality of polymer layers comprises: (a) applying a certain amount of a first addition polymer precursor formulation to a first region of a surface using a lamination process, wherein the first addition polymer precursor formulation comprises a certain amount of a first addition polymer precursor component and a second amount of a second addition polymer precursor component, the second addition polymer precursor component having a viscosity that enables the first addition polymer precursor formulation to be applied using a lamination process; (b) applying a certain amount of a second addition polymer precursor formulation to a second region of a surface using a lamination process, wherein the second addition polymer… The precursor formulation comprises a third amount of a third addition polymer precursor component and a fourth amount of a fourth addition polymer precursor component, the fourth addition polymer precursor component having a viscosity that enables the second addition polymer precursor formulation to be applied using a multilayer process; (c) exposing the applied amount of the first addition polymer precursor formulation and the applied amount of the second addition polymer precursor formulation to electromagnetic radiation for a first time period to partially cure the first amount of the first addition polymer precursor formulation and the second amount of the second addition polymer precursor formulation; and (d) repeating (a)-(c) to form a plurality of first polishing elements, each of the first polishing elements having an exposed portion having an exposed surface area including a polished surface and an exposed surface area to volume ratio of less than about 20 mm⁻¹.

[0019] Embodiments of this disclosure may further provide a method for forming a polished object, including continuously forming a plurality of polymer layers, wherein forming the plurality of polymer layers includes: forming a plurality of first polishing elements, including: (a) applying a first amount of a first addition polymer precursor formulation to a first region of a surface using a lamination process, wherein the first addition polymer precursor formulation includes a certain amount of a first addition polymer precursor component and a second amount of a second addition polymer precursor component, the second addition polymer precursor component having a viscosity that enables the first addition polymer precursor formulation to be applied using a lamination process; (b) applying a second amount of the second addition polymer precursor formulation to a second region of a surface using a lamination process, wherein the second addition polymer precursor formulation includes a third amount of a third addition polymer precursor component and a fourth amount of a fourth addition polymer precursor component, the fourth addition polymer precursor component having a viscosity that enables the second addition polymer precursor formulation to be applied using a lamination process; (c) applying the applied... The process involves: (a) exposing a first amount of a first addition polymer precursor formulation and a second amount of a second addition polymer precursor formulation to electromagnetic radiation for a first time period to partially cure the first amount of the first addition polymer precursor formulation and the second amount of the second addition polymer precursor formulation; (d) repeating (a)-(c); and forming a second polishing element, including: (e) applying a third amount of the first addition polymer precursor formulation to a third region of the surface by using a build-up process; (f) applying a fourth amount of the second addition polymer precursor formulation to a fourth region of the surface by using a build-up process; (g) exposing the third amount of the first addition polymer precursor formulation and the fourth amount of the second addition polymer precursor formulation to electromagnetic radiation for a second time period to partially cure the third amount of the first addition polymer precursor formulation and the fourth amount of the second addition polymer precursor formulation; and (h) repeating (e)-(g); wherein each of the formed first polishing elements has an exposed portion having an exposed surface area including a polished surface.

[0020] Embodiments of this disclosure may further provide a method for forming a polished object, comprising applying a first drop of a first liquid to a surface of a portion of a polishing body, wherein the surface comprises a first material formed by the following steps: curing a certain amount of the first liquid; and exposing the applied first drop of the first liquid to electromagnetic radiation for a first time period to partially cure the material within the first drop, wherein the exposure of the applied first drop of the first liquid is performed after a second time period, and the second time period begins when the first drop is placed on the surface. The first drop may comprise a polyurethane acrylate, a surface-curing photoinitiator, and a bulk-curing photoinitiator, wherein the bulk-curing photoinitiator comprises a material selected from the group consisting of benzoin ether, benzyl ketal, acetophenone, alkyl phenyl ketone, and phosphine oxide, and the surface-curing photoinitiator comprises a material selected from the group consisting of diphenyl ketone compounds and thioxanthone compounds.

[0021] Embodiments of this disclosure may further provide a polishing pad having a polishing surface configured to polish a substrate, comprising: a plurality of first polishing elements arranged in a pattern relative to the polishing surface, wherein each first polishing element includes a plurality of first polymer layers comprising a first polymer material, and at least one of the plurality of first polymer layers of each of the first polishing elements forms a portion of the polishing surface; and a base region disposed between each of the plurality of first polishing elements and a support surface of the polishing pad, the base region comprising a second polymer material. The first polymer material may have a first E'30 / E'90 ratio, and the second polymer material may have a second E'30 / E'90 ratio different from the first E'30 / E'90 ratio. The base region may include a plurality of layers, each comprising a plurality of cured droplets of the first polymer material and a plurality of cured droplets of the second polymer material. Each of the first polymer layers composed of the first polymer material may comprise a plurality of cured droplets of a first droplet composition. In some configurations, the first polymer material has a first E'30 / E90 ratio greater than 6. The first polymer material in the polishing pad may have a first storage modulus, and the second polymer material may have a second storage modulus, wherein the first storage modulus is greater than the second storage modulus, and the substrate region may further comprise a larger volume percentage of the second polymer material compared to the first polymer material. In some embodiments, the first polishing element may further comprise a larger volume percentage of the first polymer material compared to the second polymer material.

[0022] Several embodiments of this disclosure may further provide a method for forming a polishing pad, comprising sequentially repeating the following steps: dispensing a plurality of drops of a pore-forming agent and a plurality of drops of a polymer precursor formulation onto a surface according to a predetermined droplet dispense pattern; and at least partially polymerizing the dispensed plurality of drops of the polymer precursor formulation to form a layer of structural material, wherein the dispensed plurality of drops of the pore-forming agent form a plurality of pore-forming agent-containing features; the plurality of pore-forming agent-containing features are distributed across an XY plane parallel to a support surface of the polishing pad; and at least a plurality of portions of the layer of structural material are interposed between individual pore-forming agent-containing features. In one embodiment of this disclosure, the polymer precursor formulation comprises an aliphatic multifunctional polyurethane acrylate with a functionality greater than or equal to 2.

[0023] Several embodiments of this disclosure may further provide a polishing pad formed by sequentially repeating the following steps: applying a plurality of drops of a pore-forming agent and a plurality of drops of a polymer precursor formulation to a surface according to a predetermined drop application pattern; and at least partially polymerizing the applied plurality of drops of the polymer precursor formulation to form a layer of structural material, wherein the applied plurality of drops of the pore-forming agent form a plurality of pore-forming agent-containing features; the plurality of pore-forming agent-containing features are distributed throughout an XY plane parallel to a support surface of the polishing pad; and at least a plurality of portions of the layer of structural material are interposed between individual pore-forming agent-containing features. In one embodiment of this disclosure, the polymer precursor formulation comprises an aliphatic multifunctional polyurethane acrylate with a functionality greater than or equal to 2.

Implementation Method

[0064] This disclosure relates to advanced polishing objects or advanced polishing pads having tunable chemical, material, and structural properties, and novel methods for manufacturing such polishing pads. According to one or more embodiments of this disclosure, polishing pads with improved properties have been found to be produced by a lamination process such as a three-dimensional (3D) printing process. Embodiments of this disclosure provide an advanced polishing pad having discrete features and geometries, formed from at least two different materials. These different materials are formed from precursors or resin precursor compositions containing "resin precursor components," including but not limited to functional polymers, functional oligomers, monomers, reactive diluents, flow additives, curing agents, photoinitiators, and curing synergies. The resin precursor components may also include chemically active materials and / or compounds, such as functional polymers, functional oligomers, monomers, and reactive diluents, which may be at least monofunctional and may undergo polymerization upon exposure to free radicals, Lewis acids, and / or electromagnetic radiation. As an example, an advanced polishing pad can be formed from a plurality of polymeric layers by automated, continuous deposition of at least one resin precursor composition, followed by at least one curing step, wherein each layer may represent at least one polymeric composition and / or regions of different compositions. In some embodiments, the layers and / or regions of the advanced polishing pad may include composite material structures, such as radiation-cured polymers containing at least one filler (such as metal, half-metal oxide, carbide, nitride, and / or polymer particles). In some embodiments, the filler may be used to increase abrasion resistance, reduce friction, resist wear, improve crosslinking and / or thermal conductivity of the entire pad or certain regions of the pad. Thus, an advanced polishing pad, including the pad body and discrete features generated above, on, and within the pad body, can be simultaneously formed from a plurality of different materials and / or compositions of materials, thereby achieving micron-level control over the pad's structure and properties.

[0065] Furthermore, a polishing pad is provided that includes the desired pad polishing characteristics throughout the entire polishing process. Typical polishing pad characteristics include the static and dynamic characteristics of the polishing pad, which are influenced by the combined characteristics of the individual materials within the polishing pad and the overall polishing pad structure. Advanced polishing pads may include regions containing a plurality of discrete materials and / or regions containing material composition gradients in one or more directions within the polishing pad. Examples of mechanical properties of advanced polishing pads that can be adjusted to achieve the desired polishing performance within the polishing process range include, but are not limited to, storage modulus E', loss modulus E'", hardness, yield strength, ultimate tensile strength, elongation, thermal conductivity, zeta potential, mass density, surface tension, Pascal's ratio, fracture toughness, surface roughness (Ra), and other related properties. Examples of dynamic properties that can be adjusted within advanced polishing pads include, but are not limited to, tan δ (tan δ), storage modulus ratio (or E'30 / E'90 ratio), and other related parameters such as the energy loss factor (KEL). The energy loss factor (KEL) relates to the elastic rebound and damping effect of the pad material. KEL can be defined by the following equation: KEL = tan δ * 10¹² / [E' * (1 + (tan δ)²)], where the unit of E' is Pascal. KEL is typically determined using Dynamic Mechanical Analysis (DMI). DMA (Discharge Damage) measurements are performed at a temperature of 40°C and a frequency of 1 Hz or 1.6 Hz. Unless otherwise specified, the energy storage modulus E', E'30 / E'90 ratio, and restitution rate measurements provided herein are performed using a DMA test method executed at a frequency of approximately 1 Hz and a temperature change rate of approximately 5°C / min. By controlling one or more pad characteristics, improved polishing process performance, improved polishing pad life, and improved polishing process repeatability can be achieved. Examples of pad configurations exhibiting one or more of these characteristics will be further discussed below in conjunction with one or more embodiments discussed herein.

[0066] As will be discussed in more detail below, the storage modulus E' is an important factor in ensuring uniform polishing results on a substrate and is therefore a useful measure of polishing pad performance. The storage modulus E' is typically calculated by dividing the tensile stress applied on the elastic linear portion of the stress-strain curve by the tensile strain (e.g., the slope or Δy / Δx). Similarly, the ratio of viscous stress to viscous strain is used to define the loss modulus E'. It should be noted that both the storage modulus E' and the loss modulus E' are inherent material properties resulting from intermolecular and intramolecular chemical bonds within the material. The storage modulus can be measured at the desired temperature using material testing techniques such as dynamic mechanical analysis (DMA) (e.g., ASTM D 4065, D4440, and D5279). When comparing the properties of different materials, the storage modulus E' is typically measured at a single temperature, within a range between 25°C and 40°C, such as at 40°C.

[0067] Another relevant measure of polishing pad performance and uniformity is the measure of the material's damping capacity, such as the compressive and rebound damping characteristics of the polishing pad. A common method for measuring damping is to calculate the material's tan δ (tan δ) at the desired temperature, where tan δ = loss modulus / storage modulus = E” / E'. When comparing the properties of different materials, the tan δ measurements are usually compared at a single temperature such as 40°C. Unless otherwise specified, the tan δ measurements provided herein are performed using a DMA test method performed at a frequency of 1 Hz and a temperature rate of approximately 5°C / min. tan δ is generally a measure of how the "viscous" chemical structure in a material responds to applied cyclic strain (e.g., bond rotation, polymer chain slippage and movement), such as the flexibility and coiling of aliphatic polymer chains as they recover to a better low-energy structure upon release of force. For example, when cyclic loading is applied, the less elastic the material, the more the viscous molecular segments react will lag behind the elastic molecular segments (phase shift), generating heat. The heat generated in the polishing pad during substrate processing can affect the polishing process outcome (e.g., polishing uniformity) and therefore should be controlled and / or compensated for by the judicious selection of pad materials.

[0068] The hardness of the material in the polishing pad affects the polishing uniformity and material removal rate observed on the substrate after polishing. Material hardness is often measured using Rockwell, ball bearing, or Shore hardness scales to measure indentation resistance and provide empirical hardness values ​​that can be tracked or increase with increasing storage modulus E'. Pad materials are typically measured using the Shore hardness scale, usually using ASTM D2240 technology. Generally, the hardness characteristics of pad materials are measured on the Shore A or Shore D scales, which are typically used for softer or low storage modulus E' polymers, such as polyolefins. Rockwell hardness (e.g., ASTM D785) testing can also be used to test the hardness of "hard" rigid engineering polymers, such as thermoplastics and thermosets. Polishing Pad Equipment and Polishing Methods

[0069] Figure 1A is a schematic cross-sectional view of a polishing table 100 that can be placed within a larger chemical mechanical polishing (CMP) system containing multiple polishing tables 100. The polishing table 100 includes a platform 102. The platform 102 is rotatable about a central axis 104. A polishing pad 106 can be placed on the platform 102. Typically, the polishing pad 106 covers the upper surface of the platform 102, and the platform is at least one to two times larger than the size (e.g., the diameter of the substrate 110) to be processed in the polishing table 100. In one example, the diameters of the polishing pad 106 and the platform 102 are between about 6 inches (150 mm) and about 40 inches (1,016 mm). The polishing pad 106 includes a polishing surface 112 configured to contact and process one or more substrates 110 and a support surface 103 placed on the surface of the platform 102. The platform 102 supports the polishing pad 106 and allows the polishing pad 106 to rotate during polishing. The support head 108 holds the substrate 110 against the polishing surface 112 of the polishing pad 106. The support head 108 typically includes a flexible partition 111 for pushing the substrate 110 against the polishing pad 106 and a retainer 109 for correcting inherent non-uniform pressure distribution on the substrate surface during the polishing process. The support head 108 can rotate about a central axis 114 and / or move in a sweeping motion, thereby generating relative movement between the substrate 110 and the polishing pad 106.

[0070] Delivery arm 118 delivers polishing fluid 116, such as an abrasive slurry, supplied to the polishing surface 112 during polishing. Polishing fluid 116 may contain abrasive particles, pH adjusters, and / or chemically active components to achieve chemical mechanical polishing of the substrate. The slurry chemicals of polishing fluid 116 are designed to polish wafer surfaces and / or features that may include metals, metal oxides, and half-metal oxides. Polishing stage 100 typically also includes pad adjustment assembly 120, which includes adjustment arms 122 and actuators 124 and 126, which are configured to push and sweep the polishing surface 112 against the pad adjustment disk 128 (e.g., a diamond-set disk) at different times during the polishing process cycle, thereby abrading and renewing the surface 112 of the polishing pad 106.

[0071] Figures 1B to 1C are schematic cross-sectional views of a portion of the carrier head 108 placed in the polishing table 100 and a portion of the conventional "hard" or high energy storage modulus E' polishing pad 106A. Figures 1D to 1E are schematic cross-sectional views of a portion of the carrier head 108 placed in the polishing table 100 and a portion of the conventional soft or low energy storage modulus E' polishing pad 106B. Figures 1F to 1G are schematic cross-sectional views of a portion of one embodiment of the carrier head 108 placed in the polishing table 100 and the advanced polishing pad 200 further described below. For clarity, the upper portion of the flexible partition 111 and the carrier head 108 is omitted in Figures 1B to 1G. During operation, a flexible partition 111 (Figure 1A) is placed to push the substrate 110 against polishing pads 106A, 106B, or advanced polishing pad 200. A carrier head actuator (not shown), coupled to the mounting portion (not shown) of the carrier head 108, is configured to push the carrier head 108 and the retaining ring 109 against the surfaces of polishing pads 106A, 106B, or advanced polishing pad 200, respectively. As shown in Figures 1C, 1E, and 1F, the flexible partition 111 is configured to apply pressure to the back of the substrate 110, as illustrated by the applied force F2, and the carrier head actuator is configured to apply a force F1 to the retaining ring 109.

[0072] Figure 1B illustrates a portion of the edge of the substrate 110 placed within the carrier head 108 and on a portion of a conventional "hard" or high energy storage modulus E' polishing pad 106A before a polishing process is performed on the substrate 110. The substrate 110 includes a layer 110A having one or more element features 110B (Figure 1H), which will be removed and / or planarized during a subsequent CMP process. Figure 1C illustrates the substrate 110 using the conventional "hard" polishing pad 106A illustrated in Figure 1B during the polishing process. It has been found that CMP processes using "hard" polishing pads are prone to non-uniform planarization results due to edge effects present at the edges of the substrate 110, which are specifically related to the need to apply a force F1 to the retainer 109 to compensate for the larger inherent polishing non-uniformity found at the edges of the substrate 110 during the CMP process. In other words, the high energy storage modulus E' and rigid or hard properties of the material used to form the "hard" polishing pad cause pad rebound or protrusions 107A to form when a force F1 is applied to the "hard" polishing pad 106A by the retainer 109. The formation of protrusions 107A is generally related to the deformation 107B of the "hard" polishing pad 106A due to the applied force F1, resulting in faster polishing of the edges of the substrate 110 than the center of the substrate 110. The higher polishing rate at the edges of the substrate 110 leads to "overall" CMP planarization non-uniformity (e.g., non-uniformity throughout the substrate).

[0073] Figure 1H is a schematic cross-sectional view of a portion of substrate 110 polished using a conventional "hard" polishing pad 106A. As shown, substrate 110 includes a plurality of features 110B formed within layer 110A and removed and / or planarized during the CMP process. In this example, the high energy storage modulus E', rigidity, and / or hardness of the material used to form the "hard" polishing pad 106A will prevent it from significantly deforming on a microscale (e.g., 10 nm to 1000 nm feature spacing) when a force F2 is applied to substrate 110 by flexible spacer 111. In this case, the "hard" polishing pad 106A will generally deliver an acceptable amount of planarization and planarization efficiency on a microscale, but achieves poor overall planarization results for the reasons discussed above.

[0074] Figure 1D illustrates a portion of the edge of a conventional soft or low energy storage modulus E' polishing pad 106B placed within a carrier head 108 and positioned on a portion of the substrate 110 before a polishing process is performed on the substrate 110. The substrate 110 includes a layer 110A having one or more element features 110B (Figure 1I), which will be removed and planarized during a subsequent CMP process. Figure 1E illustrates the substrate 110 using the conventional soft or low energy storage modulus E' polishing pad 106B illustrated in Figure 1D during the polishing process. It has been found that CMP processes using soft or low energy storage modulus E' polishing pads are prone to non-uniform planarization results because the soft or low energy storage modulus E' polishing pad is relatively easily deformed during the CMP process under the force F1 applied by the retainer 109 and the force F2 applied by the flexible partition 111. In other words, the softness, flexibility, and low energy modulus E' properties of the material used to form the soft or low energy modulus E' polishing pad 106B allow for a minimized effect of the force F1 supplied by the retainer 109, improving the pad's ability to compensate for the downward pressure on the retainer 109. The compressive response of this low elastic modulus material allows for rapid recovery from retainer compression, and a more consistent polishing rate is visible between the center and edges of the substrate during the polishing process. Therefore, using a soft or low energy modulus E' polishing pad will contribute to greater overall CMP planarization uniformity.

[0075] Figure 1I is a schematic cross-sectional view of a portion of a substrate polished using a conventional soft or low energy storage modulus E' polishing pad 106B. In this example, the flexibility or soft or low energy storage modulus E' property of the material used to form the soft or low energy storage modulus E' polishing pad 106B allows the material to deform within a microscale (e.g., 10 nm to 1000 nm feature pitch) when a force F2 is applied to the substrate 110 by the flexible spacer 111. As shown in Figure 1I, the material in the soft or low energy storage modulus E' polishing pad 106B can deform and subsequently contact and polish the region in layer 110A between element features 110B. Simultaneously polishing the top of feature 110B and the portion of the region between feature 110B will cause planarization non-uniformity and other planarization problems. In this case, the soft or low energy storage modulus E' polishing pad 106B generally delivers an acceptable amount of overall planarization, but achieves poor planarization efficiency and provides poor recessed results. Polishing pads with low energy storage modulus offer microscale benefits in improving scratch performance because they allow hard defects that can be placed between the pad surface and the substrate surface to be compressed and / or received within the pad matrix, rather than being forced against the substrate surface by materials with higher energy storage modulus. Advanced polishing pads

[0076] Embodiments of this disclosure generally provide an advanced polishing pad 200 that can be formed using a multilayer process. The advanced polishing pad has a pad body that typically includes discrete features or regions formed from at least two different material compositions. Figures 1F to 1G are schematic cross-sectional views of a portion of the carrier head 108 and pad body 202 of the advanced polishing pad 200 placed in a polishing table 100. Generally, it is necessary to form an advanced polishing pad 200 configured such that the load applied during the polishing process is distributed over regions in the polishing body 202 comprising two or more material compositions, thereby improving the mechanical, structural, and / or dynamic characteristics of the advanced pad. In one embodiment, the pad body 202 may include at least one first polishing element 204 formed from a first energy storage modulus E' material (e.g., a high energy storage modulus E' material) and a second polishing element 206 formed from a second energy storage modulus E' material (e.g., a medium or low energy storage modulus E' material). In one configuration, the height 150 of the first polishing element 204 above the support surface 203 is greater than the height 151 of the second polishing element 206 above the support surface 203, thus the upper surface 208 of the first polishing element 204 protrudes above the second polishing element 206. In one example, as shown in Figure 1G, a force F2 is delivered via a flexible partition 111 through the first polishing element 204 to the second polishing element 206 supported by a support member such as the platform 102 shown in Figure 1A, thereby forming an advanced polishing pad with the desired mechanical and dynamic characteristics derived from the combination of materials in each polishing element. By separating the higher energy storage modulus polishing features from the lower energy storage modulus support features, the advanced polishing pad provides the benefit of improved overall flatness while maintaining the benefit of improved modulus and array level flatness provided by the higher energy storage modulus top pad.

[0077] Figure 1J is a schematic cross-sectional view of a portion of a substrate polished using an advanced polishing pad 200 according to one embodiment of the present disclosure. As illustrated in Figure 1J, in some embodiments, a first polishing element 204 is formed within the polishing body 202 such that it is large enough to span the distance between at least two or more element features 110B (e.g., integrated circuit elements) formed on the surface of the substrate 110. In some embodiments, one or more first polishing elements 204 are sized to be smaller than the major dimensions of the substrate (e.g., the radius of a circular substrate), but larger than the smallest element feature size found on the substrate 110. In some embodiments, each of the plurality of first polishing elements 204 has a lateral dimension 208L parallel to the polishing surface, the dimension being between about 250 micrometers and about 3 millimeters. In one example, when the first polishing element 204 has a circular, square, rectangular, or triangular cross-section on the polishing surface 208, the lateral dimension (e.g., length 208L) may be the diameter or side of the square, rectangle, or triangle of the first polishing element 204. In another example, when the first polishing element 204 is helical or arc-shaped on the polishing surface 208, the lateral dimension (e.g., width 214) can be the thickness of the helix or arc when measured along its radius, or even, in some cases, the outer diameter of the helix. Therefore, the combination of the first polishing element 204 with one or more second polishing elements 206 can be used to adjust the characteristics and performance of the advanced polishing pad, thereby improving the results of polishing processes performed on substrates using the advanced polishing pad, as will be further discussed below.

[0078] In some embodiments, the advanced polishing pad 200 may contain at least one high energy storage modulus E', medium energy storage modulus E', and / or low energy storage modulus E' polishing element and / or chemical structural feature. For example, the high energy storage modulus E' material composition may be at least one or a mixture of chemical groups and / or structural features including aromatic rings and some aliphatic chains. In some cases, the crosslinking density of the high energy storage modulus E' material is greater than 2%. The high energy storage modulus E' composition may be the most rigid element in the advanced polishing pad and have a high hardness value and exhibit minimum elongation. The medium energy storage modulus E' composition may contain a mixture of aromatic rings and crosslinking agents, but may contain a greater amount of aliphatic chains, ether segments, and / or polyurethane segments than the high energy storage modulus E' composition. The medium energy storage modulus E' composition may have intermediate stiffness and hardness, and exhibit a greater elongation than the high energy storage modulus E' material. The low energy storage modulus E' composition may contain aliphatic chains, ether segments, and / or polyurethane segments, and may have a minimum amount or no aromatic rings or crosslinking agents. The low energy storage modulus E' composition may be flexible, soft, and / or rubbery.

[0079] Table 1 summarizes materials (E'30) that possess the required low, medium, and / or high energy storage modulus E' at a temperature of 30°C: Table 1 Low modulus components Medium Modulus Components High modulus components E'30 5 MPa - 100 MPa 100 MPa - 500 MPa 500 MPa - 3000 MPa

[0080] In one embodiment and referring to Table 1, the polishing pad body 202 may be formed of at least one viscoelastic material having different storage moduli E' and / or loss moduli E'". Therefore, the pad body may include a first material or a first material composition having a first storage moduli E' and a loss moduli E'", and a second material or a second material composition having a second storage moduli E' and a loss moduli E' different from the first storage moduli E' and loss moduli E'". In some embodiments, the polishing pad surface features may include a plurality of features having one or more shape factors or dimensions, and are a mixture of features having different mechanical properties, thermal properties, interfacial properties, and chemical properties. For example, pad surface features such as grooves, recesses, and / or protrusions disposed above, on, and within the pad body may include a higher storage moduli E' characteristic derived from the first material or the first material composition and a lower storage moduli E' characteristic derived from a second material or the second material composition that is more elastic than the first material or the first material composition.

[0081] As used herein, the term Advanced Polishing Pad 200 is intended to broadly describe an advanced polishing pad containing one or more of the properties, materials, features, and / or characteristics further discussed above and below. Specific configurations of the advanced polishing pad will be discussed in conjunction with the examples illustrated in Figures 2A through 2K. Unless otherwise specified, the terms First Polishing Element 204 and Second Polishing Element 206 are intended to broadly describe portions, areas, and / or features within the polishing body of the advanced polishing pad 200. Specific examples of different advanced polishing pad configurations shown in Figures 2A through 2K are not intended to limit the scope of the disclosure provided herein, as other similar configurations may be formed using one or more of the build-up processes described herein.

[0082] An advanced polishing pad can be formed by automatically and continuously depositing at least one resin precursor composition layer by layer, followed by at least one curing step, wherein each layer may represent at least one polymer composition and / or regions of different compositions. The compositions may include functional polymers, functional oligomers, reactive diluents, and curing agents. The functional polymers may include multifunctional acrylate precursor components. To form a plurality of solid polymer layers, one or more curing steps may be used, such as exposing one or more compositions to UV radiation and / or heat. In this manner, the entire polishing pad can be formed from a plurality of polymer layers by 3D printing. The thickness of the cured layer can be from about 0.1 micrometers to about 1 millimeter, such as from 5 micrometers to about 100 micrometers and such as from 25 micrometers to about 30 micrometers.

[0083] The polishing pad according to this disclosure may have different mechanical properties on the pad body 202, such as energy storage modulus E' and loss modulus E'", as reflected by at least one compositional gradient between polishing elements. The mechanical properties on the polishing pad 200 may be symmetrical or asymmetrical, uniform or non-uniform, thereby achieving target polishing pad properties, which may include static mechanical properties, dynamic mechanical properties, and wear properties. To achieve the target properties including energy storage modulus E' and loss modulus E'" on the polishing pad, the pattern of any polishing element 204, 206 on the pad body 202 may be radial, concentric, rectangular, spiral, fractal, or arbitrary. Advantageously, the 3D printing process enables the specific placement of material components with desired properties in specific pad areas or on larger areas of the pad, thus combining these properties and representing a larger average characteristic or a "composite characteristic" of these properties. Examples of advanced polishing pad configurations.

[0084] Figure 2A is a schematic perspective cross-sectional view of an advanced polishing pad 200a according to one embodiment of the present disclosure. One or more first polishing elements 204a may be formed in an interlocking concentric ring coupled to one or more second polishing elements 206a, thereby forming a circular pad body 202. In one embodiment, the height 210 of the first polishing element 204a from the support surface 203 is higher than the height 212 of the second polishing element 206a from the support surface 203, so that the upper surface 208 of the first polishing element 204a protrudes above the second polishing element 206a. In one embodiment, the first polishing element 204 is disposed above a portion 212A of the second polishing element 206a. A groove 218 or trench is formed between the first polishing elements 204a and includes at least a portion of the second polishing element 206a. During polishing, the upper surface 208 of the first polishing element 204a forms a polishing surface that contacts the substrate, while the groove 218 retains and guides polishing fluid. In one embodiment, the first polishing element 204a is thicker than the second polishing element 206a in a plane direction perpendicular to the polishing surface or upper surface 208 of the pad body 202 (i.e., the Z direction in Figure 2A), so that a groove or recess 218 is formed on the top surface of the pad body 202.

[0085] In one embodiment, the width 214 of the first polishing element 204a may be between about 250 micrometers and about 5 millimeters. The spacing 216 between the hard first polishing elements 204a may be between about 0.5 millimeters and about 5 millimeters. Each first polishing element 204a may have a width ranging from about 250 micrometers to about 2 millimeters. The width 214 and / or the spacing 216 may vary along the radius of the advanced polishing pad 200 to define areas with different hardness.

[0086] Figure 2B is a schematic partial top view of an advanced polishing pad 200b according to one embodiment of the present disclosure. The advanced polishing pad 200b is similar to the advanced polishing pad 200 of Figure 2A, except that the advanced polishing pad 200b includes interlocking first polishing elements 204b and second polishing elements 206b. The first polishing elements 204b and second polishing elements 206b form a plurality of concentric rings. The first polishing element 204b may include a protruding vertical protrusion 220, and the second polishing element 206b may include a vertical recess 222 receiving the vertical protrusion 220. Alternatively, the second polishing element 206b may include a protruding protrusion, while the first polishing element 204b includes a recess. By interlocking the second polishing element 206b with the first polishing element 204b, the advanced polishing pad 200b will be mechanically stronger when dealing with applied shear forces generated during CMP processes and / or material handling. In one embodiment, the first polishing element and the second polishing element can be interlocked to improve the strength and physical integrity of the polishing pad. The interlocking of the features can be attributed to physical and / or chemical forces.

[0087] Figure 2C is a schematic perspective cross-sectional view of an advanced polishing pad 200c according to one embodiment of the present disclosure. The polishing pad 200c includes a plurality of first polishing elements 204c, such as second polishing elements 206c, extending from a substrate material layer. An upper surface 208 of the first polishing elements 204c is formed as a polishing surface for contacting the substrate during polishing. The first polishing elements 204c and the second polishing elements 206c have different material and structural properties. For example, the first polishing elements 204c may be formed of a rigid material, while the second polishing elements 206c may be formed of a soft or low energy storage modulus E' material. Similar to the advanced polishing pad 200, the polishing pad 200c is formed by 3D printing.

[0088] The first polishing element 204c may have substantially the same size, or its size may vary to produce different mechanical properties on the polishing pad 200c, such as different energy storage modulus E' and / or different loss modulus E'. The first polishing element 204c may be uniformly distributed on the polishing pad 200c or may be arranged in a non-uniform pattern, thereby achieving the target characteristics in the advanced polishing pad 200c.

[0089] In Figure 2C, the first polishing element 204c is shown as a cylinder extending from the second polishing element 206c. Alternatively, the first polishing element 204c may have any suitable cross-sectional shape, such as a cylinder having annular, partially annular (e.g., arc), elliptical, square, rectangular, triangular, polygonal, or other irregular cross-sectional shapes or combinations thereof. In one embodiment, the first polishing element 204c may have different cross-sectional shapes to tune the hardness, mechanical strength, or other desired properties of the advanced polishing pad 200c.

[0090] Figure 2D is a schematic partial side cross-sectional view of the polishing body 202 of an advanced polishing pad 200c according to one embodiment of the present disclosure. The advanced polishing pad 200d is similar to the advanced polishing pads 200a, 200b, or 200c of Figures 2A to 2C, except that the advanced polishing pad 200d includes an interlocking first polishing element 204d and a second polishing element 206d. The first polishing element 204d and the second polishing element 206d may include a plurality of concentric rings and / or discrete elements forming portions of the pad body 202 illustrated, for example, in Figures 2A, 2B, or 2C. In one embodiment, the first polishing element 204d may include a protruding sidewall 224, and the second polishing element 206d may include a region 225 to receive the protruding sidewall 224 of the first polishing element 204d. Alternatively, the second polishing element 206d may include a protruding sidewall, and the first polishing element 204d may include a region configured to receive the protruding sidewall. By interlocking the second polishing element 206c and the first polishing element 204d, the advanced polishing pad 200d can exhibit increased tensile strength, compressive strength, and / or shear strength. Additionally, the interlocking sidewalls prevent the advanced polishing pad 200d from tearing.

[0091] In one embodiment, the boundary between the first polishing element 204d and the second polishing element 206d includes a cohesive transition from at least one material composition to another, such as a transition or compositional gradient from a first composition used to form the first polishing element 204d and a second composition used to form the second polishing element 206d. The cohesiveness of the materials is a direct result of the layering process described herein, which enables micron-level control and close mixing of two or more chemical compositions in layer-by-layer structure formation.

[0092] Figure 2E is a schematic partial cross-sectional view of a polishing pad according to one embodiment of the present disclosure. The advanced polishing pad 200e is similar to the advanced polishing pad 200d of Figure 2D, except that the advanced polishing pad 200e includes interlocking features in a different configuration. The advanced polishing pad 200e may include a first polishing element 204e and a second polishing element 206e having a plurality of concentric rings and / or discrete elements. In one embodiment, the first polishing element 204e may include a horizontal protrusion 226, and the second polishing element 206e may include a horizontal recess 227 to receive the horizontal protrusion 226 of the first polishing element 204e. Alternatively, the second polishing element 206e may include a horizontal protrusion, and the first polishing element 204e may include a horizontal recess. In one embodiment, vertical interlocking features such as those in Figure 2B and horizontal interlocking features such as those in Figures 2D and 2E may be combined to form the advanced polishing pad.

[0093] Figures 2F to 2K are schematic plan views of various polishing pad designs according to embodiments of the present disclosure. Each of Figures 2F to 2K includes a pixel map with white areas (areas within white pixels) representing first polishing elements 204f-204k for contacting and polishing the substrate; and black areas (areas within black pixels) representing second polishing elements 206f-206k. As similarly discussed herein, the white areas generally protrude from the black areas, thus trenches are formed in the black areas between the white areas. In one example, the pixels in the pixel map are arranged in a rectangular pattern (such as an X and Y oriented array) to define the positions of various materials within a layer or portion of a layer of the advanced polishing pad. In another example, the pixels in the graph map are arranged in a hexagonal close-packed array pattern (e.g., a pixel surrounded by six nearest neighbor pixels) to define the positions of various materials within a layer or portion of a layer of the polishing pad. Polishing slurry may flow through and remain in the trenches during polishing. The polishing pads shown in Figures 2F through 2K are formed using a stacking process by depositing a plurality of material layers. Each of these layers may include two or more materials to form the first polishing elements 204f-204k and the second polishing elements 206f-206k. In one embodiment, the first polishing elements 204f-204k may be thicker than the second polishing elements 206f-206k in a direction perpendicular to the plane of the material layers, thus forming grooves and / or trenches on the top surface of the polishing pad.

[0094] Figure 2F is a schematic pixel diagram of an advanced polishing pad design 200f having a plurality of concentric polishing features 204f. The polishing features 204f may be concentric circles of equal width. In one embodiment, the second polishing elements 206f may also have equal width, thus the distance between the first polishing elements 204f is constant along the radial direction. During polishing, the grooves between the first polishing elements 204f retain the polishing slurry and prevent rapid loss of the polishing slurry due to the centrifugal force generated by the rotation of the polishing pad around its central axis (i.e., the center of the concentric circles).

[0095] Figure 2G is a schematic pixel diagram of a polishing pad design 200g having a plurality of segmented first polishing elements 204g arranged in concentric circles. In one embodiment, the segmented first polishing elements 204g may have substantially equal lengths. The segmented first polishing elements 204g may form a plurality of concentric circles. In each circle, the segmented first polishing elements 204g may be evenly distributed within each concentric circle. In one embodiment, the segmented first polishing elements 204g may have equal widths in the radial direction. In some embodiments, regardless of the radius of the concentric circles, the segmented first polishing elements 204g have substantially equal lengths (e.g., equal arc lengths excluding the central area of ​​the polishing pad). In one embodiment, second polishing elements 206g are disposed between the plurality of concentric circles and have equal widths, so the distance between the concentric circles is constant. In one embodiment, the gaps between the segmented first polishing elements 204g may be staggered between the circles to prevent polishing slurry from flowing directly out of the polishing pad under the centrifugal force generated by the rotation of the polishing pad around its central axis.

[0096] Figure 2H is a schematic pixel diagram of a polishing pad design 200h having a spiral first polishing element 204h disposed above a second polishing element 206h. In Figure 2H, the polishing pad 200h has four spiral first polishing elements 204h extending from the center of the polishing pad to the edge of the polishing pad. Even though four spiral polishing features are shown, fewer or more spiral first polishing elements 204h can be arranged in a similar manner. The spiral first polishing elements 204h define spiral grooves 218h. In one embodiment, each of the spiral first polishing elements 204h has a constant width. In one embodiment, the spiral groove 218h also has a constant width. During polishing, the polishing pad can rotate about a central axis in a direction opposite to that of the spiral first polishing elements 204h, thereby retaining the polishing slurry in the spiral grooves. For example, in Figure 2H, the spiral first polishing element 204h and the spiral grooves are formed in a counterclockwise direction, and therefore the polishing pad can rotate clockwise during polishing, thereby retaining the polishing slurry in the spiral grooves and on the polishing pad. In some configurations, each spiral groove is continuous from the center of the polishing pad to the edge of the polishing pad. This continuous spiral groove allows the polishing slurry, along with any polishing waste, to flow from the center of the polishing pad to the edge of the polishing pad. In one embodiment, the polishing pad can be cleaned by rotating the polishing pad in the same direction as the spiral first polishing element 204h (e.g., counterclockwise in Figure 2H).

[0097] Figure 2I is a schematic pixel diagram of a polishing pad design 200i having segmented first polishing elements 204i arranged in a spiral pattern on a second polishing element 206i. The advanced polishing pad illustrated in Figure 2I is similar to the polishing pad in Figure 2H, except that the first polishing elements 204i are segmented and the radial spacing of the first polishing elements 204i is different. In one embodiment, the radial spacing of the segmented first polishing elements 204i decreases from the center of the polishing pad to the edge region of the polishing pad, thereby adjusting and / or controlling the retention of slurry on different areas of the polishing pad surface during processing.

[0098] Figure 2J is a schematic pixel diagram of a polishing pad design 200j having a plurality of discrete first polishing elements 204j formed in a second polishing element 206j. In one embodiment, each of the plurality of first polishing elements 204j may be a cylindrical structure, similar to the configuration illustrated in Figure 2C. In one embodiment, the plurality of first polishing elements 204j may have the same size on the polishing surface plane. In one embodiment, the plurality of cylindrical first polishing elements 204j may be arranged concentrically. In one embodiment, the plurality of cylindrical first polishing elements 204j may be arranged in a regular 2D pattern relative to the polishing surface plane.

[0099] Figure 2K is a schematic pixel diagram of a polishing pad design 200k having a plurality of discrete first polishing elements 204k formed on a second polishing element 206k. The polishing pad in Figure 2K is similar to the polishing pad in Figure 2J, except that some of the first polishing elements 204k in Figure 2K can be connected to form one or more closed loops. One or more closed loops can create one or more dams to retain polishing slurry during polishing.

[0100] In the designs of Figures 2A to 2K, the first polishing elements 204a-204k can be formed from the same material or a composition of the same material. Alternatively, the material composition and / or material properties of the first polishing elements 204a-204k in the designs of Figures 2A to 2K can vary between polishing features. Individualized material composition and / or material properties allow for customization to meet specific needs. Examples of laminated manufacturing equipment and processes.

[0101] Figure 3A is a schematic cross-sectional view of a multilayer manufacturing system 350 that can be used to form advanced polishing pads using multilayer processes, according to one or more embodiments of this disclosure. Multilayer processes may include, but are not limited to, processes such as polymer jet deposition, inkjet printing, fused deposition modeling, adhesive jetting, powder bed fusion, selective laser sintering, stereolithography, photopolymerization curing, lamination, directional energy deposition, or other similar 3D deposition processes.

[0102] The lamination manufacturing system 350 generally includes a precursor delivery section 353, a precursor mixing section 354, and a deposition section 355. The deposition section 355 will generally include a lamination manufacturing apparatus or hereinafter referred to as a print station 300. An advanced polishing pad 200 can be printed on a carrier 302 within the print station 300. Typically, the advanced polishing pad 200 is formed layer by layer using one or more drop-jet printers 306, such as printers 306A and 306B illustrated in Figure 3A, by a computer-aided design (CAD) program. Printers 306A, 306B and the carrier 302 can move relative to each other during the printing process.

[0103] The droplet printer 306 may include one or more printheads 308 having one or more nozzles (e.g., nozzles 309-312) for dispensing liquid precursors. In the embodiment of Figure 3A, the droplet printer 306A includes a printhead 308A having nozzle 309 and a printhead 308B having nozzle 310. Nozzles 309 may be configured to dispense a first liquid precursor composition to form a first polymer material, such as a soft or low storage modulus E' polymer, while nozzles 310 may be used to dispense a second liquid precursor to form a second polymer material, such as a hard polymer or a polymer exhibiting a high storage modulus E'. The liquid precursor composition may be dispensed at selected locations or areas to form an advanced polishing pad with desired properties. These selected locations collectively form a target print pattern that can be stored as a CAD-compatible file, which is then read by an electronic controller 305 controlling the droplet delivery from the nozzles of the droplet printer 306.

[0104] Controller 305 is generally used to facilitate the control and automation of components within a multilayer manufacturing system 350, including a print station 300. Controller 305 may be, for example, a computer, a programmable logic controller, or an embedded controller. Controller 305 typically includes a central processing unit (CPU) (not shown), memory (not shown), and carrier circuitry (not shown) for input and output (I / O). The CPU may be one of any form of computer processor used to control various system functions, substrate movement, chamber methods, and control carrier hardware (e.g., sensors, motors, heaters, etc.) in an industrial device, and monitors the processes executed in the system. The memory is connected to the CPU and may be one or more readily available non-volatile memories, such as random access memory (RAM), flash memory, read-only memory (ROM), floppy disk, hard disk, or any other form of digital storage, local or remote. Software instructions and data may be encoded and stored in the memory for instructing the CPU. The carrier circuitry is also connected to the CPU, thereby supporting the processor in a conventional manner. The carrier circuitry may include cache memory, power supply, clock circuitry, input / output circuitry, subsystems, and the like. A program (or computer instruction) readable by the controller 305 determines which tasks the components in the multilayer manufacturing system 350 can perform. Preferably, the program is software readable by the controller 305, which includes code for performing and monitoring, implementing, and controlling the delivery and positioning of drops delivered by the printer 306, and tasks related to the movement, support, and / or positioning of components within the print station 300, as well as various process tasks and sequences executed within the controller 305.

[0105] After 3D printing, the advanced polishing pad 200 can be solidified using a curing device 320 disposed within the deposition section 355 of the stacking manufacturing system 350. The curing process performed by the curing device 320 can be performed by heating the printed polishing pad to a curing temperature or by exposing the pad to one or more forms of electromagnetic radiation or electron beam curing. In one example, the curing process can be performed by exposing the printed polishing pad to radiation 321 generated by an electromagnetic radiation source, such as a visible light source, an ultraviolet light source, and an X-ray source, or other types of electromagnetic wave sources disposed within the curing device 320.

[0106] The stacking process provides a convenient and highly controllable process for producing advanced polishing pads with discrete characteristics formed from different materials and / or different material compositions. In one embodiment, soft or low energy storage modulus E' characteristics and / or hard or high energy storage modulus E' characteristics can be formed using the stacking process. For example, the soft or low energy storage modulus E' characteristics of the polishing pad can be formed from a first composition containing polyurethane segments applied from the nozzle 312 of the printer 306B, and the hard or high energy storage modulus E' characteristics of the polishing pad can be formed from a second composition droplet applied from the nozzle 310 of the printer 306A.

[0107] In another embodiment, the first polishing element 204 and / or the second polishing element 206 may each be formed from a mixture of two or more components. In one example, the first component may be applied in droplet form by a first printhead such as printhead 308A, and the second component may be applied in droplet form by a second printhead such as printhead 308B of printer 306A. Forming the first polishing element 204 having a mixture of droplets delivered from multiple printheads requires / includes aligning pixels corresponding to the first polishing element 204 on predetermined pixels present in the deposition map in controller 305. Printhead 308A may then be aligned with the pixel corresponding to the location where the first polishing element 204 is to be formed, and then droplets may be applied to the predetermined pixels. The advanced polishing pad may thus be formed from a first material composition and a second material, the first material composition being formed by droplets depositing the first droplet composition, and the second material comprising a second material composition formed by droplets depositing the second droplet composition.

[0108] Figure 3B is an illustrated cross-sectional view of a portion of the print station 300 and the advanced polishing pad 200 during the pad fabrication process. As shown in Figure 3B, the print station 300 includes two printers 306A and 306B for continuously forming a portion of the advanced polishing pad 200. This portion of the advanced polishing pad 200 shown in Figure 3B may, for example, include portions of the first polishing element 204 or the second polishing element 206 in the ultimately formed advanced polishing pad 200. During processing, printers 306A and 306B are configured to deliver droplets "A" or "B" respectively onto a first surface of the carrier 302, and subsequently onto the surface of the grown polishing pad disposed on the carrier 302 in a layer-by-layer process. As shown in Figure 3B, a second layer 348 is deposited on the first layer 346 already formed on the carrier 302. In one embodiment, a second layer 348 is formed on a first layer 346 that has been treated by a curing apparatus 320 located downstream of printers 306A and 306B during the pad fabrication process. In some embodiments, portions of the second layer 348 may be treated simultaneously by the curing apparatus 320 while one or more printers 306A and 306B deposit droplets "A" and / or "B" onto the surface 346A of the previously formed layer 346. In this case, the currently formed layer may include a treated portion 348A and an untreated portion 348B disposed on either side of the cured region 349A. The untreated portion 348B generally includes a pattern (such as an array) of application droplets (such as application droplets 343 and 347) deposited on the surface 346A of the layer 346 previously formed using printers 306B and 306A, respectively.

[0109] Figure 3C is a close-up cross-sectional view of an application droplet 343 disposed on surface 346A of the previously formed layer 346. Based on the properties of the material within the application droplet 343 and attributable to the surface energy of surface 346A, the application droplet will diffuse on the surface by an amount greater than the original application droplet (e.g., droplet "A" or "B") due to surface tension. The amount of diffusion of the application droplet will vary with the instantaneous time since its deposition on surface 346A. However, after a very short time period (e.g., < 1 second), the diffusion of the droplet will reach an equilibrium size and have an equilibrium contact angle α. The diffusion of the application droplet on the surface affects the resolution of the droplet placement on the surface of the growth polishing pad, and thus affects the resolution of features and material composition present in various regions of the final polishing pad.

[0110] In some embodiments, it is necessary to expose one or both of droplets "A" and "B" to the substrate surface after a period of contact, so that each droplet can be cured or "fixed" to the desired size on the substrate surface before it has a chance to diffuse to its uncured equilibrium size. In this case, the energy supplied to the droplets by the curing apparatus 320 and the droplet material composition and the surface on which they are placed are adjusted to control the resolution of each droplet. Therefore, an important parameter to be controlled or tuned during the 3D printing process is to control the surface tension of the droplets relative to the surface on which they are placed. In some embodiments, it is necessary to add one or more curing enhancement components (e.g., photoinitiators) to the droplet formulation to control the kinetics of the curing process, prevent oxygen inhibition, and / or control the contact angle of the droplets on the surface on which they are deposited. It should be noted that the curing reinforcement component will generally include materials capable of adjusting: 1) the overall amount of curing present in the material of the application drop during initial exposure to the desired amount of electromagnetic radiation; 2) the amount of surface curing present in the material of the application drop during initial exposure to the desired amount of electromagnetic radiation; and 3) the amount of surface property modification (e.g., additives) of the surface-cured areas of the application drop. The amount of surface property modification of the surface-cured areas of the application drop generally includes adjusting the surface energy of the cured or partially cured polymer found on the surface of the application and at least partially cured drop.

[0111] It has been found that there is a need to partially cure each application droplet to "fix" its surface properties and spatial dimensions during the printing process. The ability to "fix" the droplet at the desired size can be achieved by adding at least one curing enhancement component in the required amount to the droplet material composition during the lamination process and by delivering sufficient electromagnetic energy to the curing device 320. In some embodiments, a curing device 320 is required to deliver ultraviolet (UV) light to the droplet at a concentration between about 1 mJ / cm² and 100 mJ / cm² (e.g., about 10-20 mJ / cm²) during the lamination process. The UV radiation can be provided by any UV source, such as a mercury microwave arc lamp (e.g., H-bulb, H+-bulb, D-bulb, Q-bulb, and V-bulb type lamp), a pulsed xenon flash lamp, a high-efficiency UV light emitting diode array, and a UV laser. The wavelength of the UV radiation can be between about 170 nm and about 500 nm.

[0112] In some embodiments, the size of the application drops "A" and "B" can be from about 10 micrometers to about 200 micrometers, such as from about 50 micrometers to about 70 micrometers. Depending on the surface energy (dynes) of the substrate or polymer layer on which the application drops are placed, the uncured drops can diffuse and spread across the surface in a size 343A between about 10 micrometers and about 500 micrometers (such as between about 50 micrometers and about 200 micrometers). In one example, the height of such drops can be from about 5 micrometers to about 100 micrometers, depending on factors such as surface energy, wetting, and / or the resin precursor composition, which may include other additives such as flow agents, thickeners, and surfactants. One source of the additives is BYK-Gardner GmbH in Gretzrid, Germany.

[0113] In some embodiments, it is generally necessary to select the amount of photoinitiator, the amount of photoinitiator in the droplet composition, and the amount of energy supplied by the curing device 320 to allow the application droplet to be "fixed" for less than about 1 second, such as less than about 0.5 seconds, after contact with the surface to which it is fixed. Due to exposure to the delivered curing energy, the actual time taken to partially cure the application droplet may be longer or shorter than the time the droplet remains on the surface before exposure to the delivered radiation, as the curing time of the application droplet will depend on the amount and wavelength of the radiation energy supplied from the curing source 320. In one example, for a radiation exposure level of about 10-15 mJ / cm² UV radiation, the exposure time for partially curing a 120-micrometer (μm) application droplet is about 0.4 microseconds (μs). To "fix" the droplet within this short timeframe, the application nozzle of the droplet printer 306 must be positioned at a short distance from the surface of the polishing pad, such as between 0.1 mm and 10 mm, or even 0.5 mm and 1 mm, while the surface 346A of the advanced polishing pad is exposed to radiation 321 delivered by the self-curing device 320. It has also been found that by controlling the droplet composition, the amount of curing of the previously formed layer (e.g., the surface energy of the previously formed layer), the amount of energy from the curing device 320, and the photoinitiation dose in the droplet composition, as well as the droplet contact angle α, can be controlled, thereby controlling the fixed droplet size and thus the resolution of the printing process. In one example, the lower layer curing may be a curing process with approximately 70% acrylate conversion. Droplets that have been fixed or at least partially cured are also referred to herein as cured droplets. In some embodiments, the fixed droplet size 343A is between approximately 10 micrometers and approximately 200 micrometers. In some embodiments, the contact angle of a "fixed" droplet, also referred to herein as the dynamic contact angle (e.g., the unbalanced contact angle), may be expected to be controlled to a value of at least 50°, such as greater than 55°, or even greater than 60°, or even greater than 70°.

[0114] The resolution of pixels within a pixel map formed by a layer or a portion thereof by a stacking process can be defined by the average "fixed" size of the application droplets. The material composition of the layer or a portion thereof can therefore be defined by the "application droplet composition," which is the percentage of the total number of pixels within the layer or a portion thereof that includes a droplet of a certain material composition. In one example, if the layer region forming the advanced polishing pad is defined as an application droplet composition having 60% of the first application droplet composition, then 60% of the pixels in this region will include fixed drops, which include the first material composition. In cases where a portion of the layer contains more than one material composition, the material composition of the region within the advanced polishing pad also needs to be defined as having a "material composition ratio." The material composition ratio is the ratio of the number of pixels having the first material composition disposed thereon to the number of pixels having the second material composition disposed thereon. In one example, if the region is defined as containing 1,000 pixels disposed on the surface area, and 600 pixels contain fixed drops of the first composition and 400 pixels contain fixed drops of the second composition, then the material composition ratio will be a 3:2 ratio of the first composition to the second composition. In a configuration where each pixel may contain more than one fixed drop (e.g., 1.2 drops / pixel), the material composition ratio will be defined by the ratio of the number of fixed drops of the first material to the number of fixed drops of the second material present within the defined region. In one example, if the region is defined as containing 1,000 pixels, and this region contains 800 fixed drops of the first composition and 400 fixed drops of the second composition, then the material composition ratio within this advanced polishing pad region will be 2:1.

[0115] The amount of curing on the surface of the application droplet forming the next layer is an important process parameter for polishing pad formation because the amount of curing in this "initial dose" affects the surface energy during the deposition process, to which subsequent layers of the application droplet will be exposed. The amount of the initial curing dose is also important because it will also affect the amount of curing that each deposited layer will ultimately achieve in the formation of the polishing pad, as each deposited layer is repeatedly exposed to additional transmitted curing radiation supplied by subsequent deposited layers during its growth. Over-curing of the forming layer is generally necessary to prevent, as it will affect the material properties of the over-cured material and / or the wettability of the cured layer surface to the application droplet deposited in subsequent steps. In one example, to achieve polymerization of 10-30 micrometer thick layers of application droplets, the droplets can be applied to the surface and then, after a period of approximately 0.1 seconds to approximately 1 second, exposed to UV radiation at a radiation exposure level between approximately 10 mJ / cm² and approximately 15 mJ / cm². However, in some embodiments, the level of radiation delivered during the initial curing dose can be different layer by layer. For example, due to the different droplet compositions in different layers, the UV radiation exposure in each initial dose can be adjusted to provide the desired curing level in the currently exposed layer and one or more underlying layers.

[0116] In some embodiments, it is necessary to control the amount of droplet composition and energy delivered by the self-curing device 320 during the initial curing step so that the layer is only partially cured to the required amount. This initial curing step is a step in which the deposited layer of the application droplet is directly exposed to the energy provided by the curing device 320. Generally, compared to bulk cure application droplets, the initial curing process requires significantly surface curing of the application droplet because controlling the surface energy of the formed layer is important for controlling the size of the application droplet. In one example, the amount of application droplet that is partially cured can be defined by the amount of chemical conversion of the material in the application droplet. In one example, the conversion rate of the acrylate present in the application droplet for forming a polyurethane-containing polyacrylate layer is defined as a percentage x, which is calculated by the following equation: where AC=C and AC=O are the C=C peak at 910 cm⁻¹ and the C=O peak at 1700 cm⁻¹, respectively, as found by FT-IR spectroscopy. During polymerization, the C=C bonds in the acrylate are converted to C=C bonds, while the C=O bonds in the acrylate are not converted. Therefore, the strength of C=C to C=O indicates the acrylate conversion rate. The AC=C / AC=O ratio refers to the relative ratio of C=C to C=O bonds within the cured droplet, and thus (AC=C / AC=O)0 represents the initial ratio of AC=C to AC=O in the droplet, while (AC=C / AC=O)x represents the ratio of AC=C to AC=O on the substrate surface after the droplet has cured. In some embodiments, the amount of the layer initially cured may be equal to or greater than about 70% of the application droplet. In some configurations, it may be necessary to partially cure the material in the application droplet during the initial exposure of the application droplet to a curing energy level of about 70% to about 80%, thus achieving a target contact angle for the application droplet. Uncured or partially cured acrylate material on the top surface copolymerizes with subsequent drops, thus creating cohesive forces between layers.

[0117] Partially curing the application droplets during the initial layer formation step can also be important to ensure some chemical bonding / adhesion between subsequent deposited layers due to the presence of residual unbonded groups (such as residual acrylic groups). Because the residual unbonded groups are not polymerized, they may be involved in forming chemical bonds with subsequent deposited layers. The formation of chemical bonds between layers can therefore increase the mechanical strength of the advanced polishing pad formed during the pad formation process in the layer-by-layer growth direction (e.g., the Z direction in Figure 3B). As noted above, the bonding between layers can therefore be formed by both physical and / or chemical forces.

[0118] The mixture of application drops or the positioning of the application drops can be adjusted layer by layer to form individual layers with tunable characteristics and polishing pads with desired pad characteristics, which are composite characteristics of the forming layer characteristics. In one example, as shown in Figure 3B, the mixture of application drops includes application drops 343 and 347 in a 50:50 ratio (or a material composition ratio of 1:1), wherein application drop 343 includes at least one material different from the material present in application drop 347. During the deposition process, the characteristics of portions of the polishing body 202 (such as the first polishing element 204 and / or the second polishing element 206) can be adjusted or tuned according to the ratio and / or distribution of the first and second components formed by the positioning of the application drops. For example, the weight percentage of the first component can be from about 1% by weight to about 100% by weight of the total components. Similarly, the second component can be from about 1% by weight to about 100% by weight of the total components. Depending on desired material properties such as hardness and / or storage modulus, components of two or more materials can be mixed in different proportions to achieve the desired effect. In one embodiment, the composition of the first polishing element 204 and / or the second polishing element 206 is controlled by selecting at least one component or a mixture of components and the size, position, and / or density of droplets applied by one or more printers. Thus, the controller 305 is generally adjusted to position nozzles 309-310, 311-312 to form a layer of intersecting droplets placed at the desired density and pattern on the surface of the formed polishing pad. In some configurations, the applied droplets can be deposited in such a manner to ensure that each droplet is placed in a position where it does not mix with other droplets, and therefore each droplet remains a discrete material "island" before curing. In some configurations, the application droplets may be placed on top of previously applied droplets within the same layer to increase build-up or blending properties. The placement of droplets relative to each other on the surface can also be adjusted to allow for partial mixing of the individual application droplets within the layer. In some cases, it may be necessary to place the droplets more compactly or more widely apart to provide more or less mixing of the components in adjacent droplets. It has been found that controlling the placement of droplets relative to other application droplets and the composition of each droplet can influence the mechanical and polishing properties of the resulting advanced polishing pad.

[0119] Although only two compositions for forming the first polishing element 204 and / or the second polishing element 206 are generally discussed herein, embodiments of this disclosure cover the formation of characteristic structures on a polishing pad using a plurality of materials interconnected via compositional gradients. In some configurations, the compositions of the first polishing element 204 and / or the second polishing element 206 in the polishing pad are adjusted in a plane parallel to the polishing surface and / or via the polishing pad thickness, as will be further discussed below.

[0120] The ability to form compositional gradients locally, within, and on the advanced polishing pad, and the ability to tune chemical content, are enabled by an "inkjetable" low-viscosity component or low-viscosity "ink" used in 3D printing technology to form droplets "A" and / or "B" as illustrated in Figure 3B. The low-viscosity ink is a "prepolymer" composition and a "precursor" present in the first polishing element 204 and the second polishing element 206 formed in the pad body 202. The low-viscosity ink enables the formation of controlled compositional transitions or gradients in different areas of the pad body 202 through the delivery of a wide variety of chemicals and discrete components that are not available through conventional techniques (e.g., molding and casting). This is achieved by adding and mixing a viscosity-reducing reactive diluent to a high-viscosity functional oligomer to achieve an appropriate viscosity formulation, followed by copolymerizing the diluent with the higher-viscosity functional oligomer upon exposure to curing energy delivered by the curing device 320. Reactive diluents can also act as solvents, thus eliminating the need for inert, non-reactive solvents or diluents that must be removed at each step.

[0121] Referring to the precursor delivery section 353 and precursor mixing section 354 of Figure 3A, in one embodiment, a first precursor 356 is mixed with a second precursor 357 and a diluent 358 to form a first printable ink composition 359, which is delivered to the reservoir 304B of the printer 306B and used to form a portion of the polishing body 202. Similarly, a third precursor 366 may be mixed with a fourth precursor 367 and a diluent 368 to form a second new printable ink composition 369, which is delivered to the reservoir 304A of the printer 306A and used to form another portion of the polishing body 202. In some embodiments, the first precursor 356 and the third precursor 366 each comprise an oligomer, such as a multifunctional oligomer, the second precursor 357 and the fourth precursor 367 each comprise a multifunctional monomer, and the diluents 358 and 368 each comprise a reactive diluent (e.g., a monomer) and / or an initiator (e.g., a photoinitiator). One example of a first printable ink composition 359 may include a first precursor 356 comprising a reactive bifunctional oligomer containing aliphatic chain segments, having a viscosity at 25°C of about 1000 centipoise (cP) to about 12,000 cP, which is subsequently mixed with and thus diluted with a reactive diluent (e.g., diluent 358) having a viscosity of 10 cP at 25°C, such as a monoacrylate, to produce a new composition with a new viscosity. The resulting printable composition exhibits a viscosity of approximately 80 cP to approximately 110 cP at 25°C and a viscosity of approximately 15 cP to approximately 30 cP at 70°C, which can be effectively dispensed from the inkjet nozzles of a 3D printer.

[0122] Figures 4A to 4F provide an advanced polishing pad comprising a compositional gradient over one or more regions of the polishing body. In Figures 4A to 4D, white pixels are intended to schematically illustrate the locations where application drops of a first material are applied, while black pixels indicate the locations where unapplied material is used to form the polishing pad within one or more layers. By using these techniques, a compositional gradient of cured material or a material formed from a plurality of cured droplets can be formed in a printed layer used to form at least a portion of the complete polishing pad. Customized compositions of the printed layers within the polishing pad can be used to adjust and customize the overall mechanical properties of the polishing pad. The composition of the polishing feature structure can be any suitable pattern variation. Although the polishing pad described herein is illustrated as being formed from two materials, this configuration is not intended to limit the scope of the disclosure provided herein, as polishing pads comprising three or more materials are within the scope of this disclosure. It should be noted that the composition of the polishing feature structure in any polishing pad design (such as the polishing pads in Figures 2A to 2K) may differ from that in the polishing pads in Figures 4A to 4F.

[0123] Figures 4A and 4B are black and white bit images of the pixel map of a portion of the printed layer including the first polishing element 204 and the second polishing element 206 within the advanced polishing pad. In Figures 4A and 4B, white pixels mark the locations where drops of the first material are applied, while black pixels mark the locations where no material is applied or cured. Figure 4A is a pixel map 400a of the first portion of the inner layer of the advanced polishing pad 200, and Figure 4B is a pixel map 400b of the second portion of the same advanced polishing pad. The first portion can be applied by the first print head according to pixel map 400a, and the second portion can be applied by the second print head according to pixel map 400b. The two print heads superimpose pixel maps 400a and 400b to form one or more layers containing discrete polishing feature structures. The polishing feature structures near the edge region of the polishing pad contain more first material than second material. The polishing feature structures near the center region of the polishing pad contain more second material than first material. In this example, each polishing feature has a unique combination of a first material and a second material. In one example, the first polishing element 204 includes a first combination of the first material and the second material, and the second polishing element 206 includes a different second combination of the first material and the second material. Therefore, by using a pixel map, the polishing body can be formed continuously, thus achieving the desired gradient of the material composition in different parts of the polishing body, thereby achieving the desired polishing performance of the advanced polishing pad.

[0124] Figures 4C and 4D are schematic pixel images 400c and 400d of a polishing pad having a characteristic structure. In some embodiments, Figure 4C is a pixel image 400c of a first portion of the polishing pad, and Figure 4D is a pixel image 400d of a second portion of the same polishing pad. The polishing pads according to Figures 4C and 4D are similar to the polishing pads in Figures 4A and 4B, except that the gradient of the material composition of the polishing body changes from the left to the right side of the polishing pad.

[0125] Figure 4E is a schematic view based on a polishing pad 400e for the web, which is formed by using a lamination process to form a polishing surface 208 having a material composition gradient on the polishing surface 208 (e.g., in the Y direction). As shown in Figure 4E, polishing material can be placed above a platform 102 between a first roll 481 and a second roll 482. By constructing webs or even standard polishing pads with high and low energy moduli in different regions, the substrate can be moved at different locations on the polishing pad 400e during different portions of the polishing process, thereby providing the desired mechanical properties during each stage of the polishing process. One example may involve a substrate with an initial surface texture that has been rapidly removed, which uses a planarized portion of a polishing pad 400e with a high elastic modulus, and then moves the substrate to a second portion of a polishing pad 400e with a lower elastic modulus, thereby polishing the substrate surface and reducing scratch defects.

[0126] Figure 4F is a schematic side cross-sectional view of an advanced polishing pad 400f, which is formed by using a stacking process to form a polishing substrate layer 491 having a material composition gradient in the Z direction. The material composition and / or material property gradient of the stacked printed layers of the polishing substrate layer 491 may vary in one direction from high concentration to low concentration of a first material to a second material, or vice versa. In some cases, one or more regions within the polishing pad may include more complex concentration gradients, such as high / low / high or low / high / low concentration gradients of at least two materials with different material properties. In one example, at least two materials forming the concentration gradient have different storage moduli E', E'30 / E'90 ratio, tan δ, or other similar parameters. In some configurations, the advanced polishing pad 400f may include a polishing element region 494, which may include discrete regions including at least one first polishing element 204 and a second polishing element 206. In one example, the polishing element region 494 may include a portion of a polishing body 202 containing one or more of the structures shown in Figures 2A through 2K.

[0127] In one embodiment, the substrate layer 491 includes a homogeneous mixture of two or more different materials in the layers formed within the substrate layer 491. In one example, the homogeneous mixture may include a mixture of materials used to form the first polishing element 204 and the second polishing element 206 in the layers formed within the substrate layer 491. In some configurations, it is necessary to change the composition of the homogeneous mixture of materials layer by layer to form a material composition gradient in the layer growth direction (e.g., the Z direction in Figure 3B). The term homogeneous mixture is generally intended to describe a material formed by applying and curing print drops having at least two different compositions in the layers, and which may therefore contain a mixture of small regions of at least two different compositions sized at a desired resolution. The interface between the polishing substrate layer 491 and the polishing element region 494 may include a homogeneous blend of materials present on the upper surface of the polishing substrate layer 491 and the lower surface of the polishing element region 494, or may include a discrete transformation in which different material components in the first deposition layer of the polishing element region 494 are directly deposited on the surface of the polishing substrate layer 491.

[0128] In some embodiments of the polishing element region 494 or in any polishing body 202 more generally described above, a material composition gradient is required to form the first polishing element 204 and / or the second polishing element 206 in a direction perpendicular to the polishing surface of the polishing pad. In one example, a higher concentration material composition is required for forming soft or low energy storage modulus E' features in a printed layer near the polishing pad substrate (e.g., opposite the polishing surface), and a higher concentration material composition is required for forming hard or high energy storage modulus E' features in a printed layer near the polishing surface of the polishing pad. In another example, a higher concentration material composition is required for forming hard or high energy storage modulus E' features in a printed layer near the polishing pad substrate, and a higher concentration material composition is required for forming soft or low energy storage modulus E' features in a printed layer near the polishing surface of the polishing pad. Surface features with low energy storage modulus E' can be used for defect removal and scratch reduction, while high energy storage modulus E' features can be used to improve module and array-level planarization.

[0129] In one embodiment, a material composition gradient is required within the material used to form the first and / or second polishing elements in a direction perpendicular to the polishing surface of the polishing pad. In one example, a higher concentration material composition is required for forming the second polishing element 206 in a printing layer near the polishing pad substrate (e.g., opposite the polishing surface), and a higher concentration material composition is required for forming the first polishing element 204 in a printing layer near the polishing surface of the polishing pad. In another example, a higher concentration material composition is required for forming the first polishing element 204 in a printing layer near the polishing pad substrate, and a higher concentration material composition is required for forming the second polishing element 206 in a printing layer near the polishing surface of the polishing pad. For example, the first layer may have a 1:1 material composition ratio of the first printing composition to the second printing composition, the second layer may have a 2:1 material composition ratio of the first printing composition to the second printing composition, and the third layer may have a 3:1 material composition ratio of the first printing composition to the second printing composition. In one example, compared to the second printed composition, the first printed composition has a material with a higher energy storage modulus E', and the continuous growth directions of the first, second, and third layers are away from the support surface of the advanced polishing pad. Gradients can also be formed in different portions of a single layer by adjusting the position of the printed droplets within the plane of the deposited layer. Example of an advanced polishing pad formation process.

[0130] In some embodiments, the construction of the advanced polishing pad 200 begins with creating a CAD model of the polishing pad design. This can be achieved using existing CAD design software, such as Unigraphics or other similar software. The output file generated by the modeling software is then loaded into an analysis program to ensure that the advanced polishing pad design meets design requirements (e.g., watertightness, mass density). The output file is then presented, and the 3D model is subsequently "sliced" into a series of 2D data bitmaps or pixel maps. As noted above, the 2D bitmaps or pixel maps are used to define the locations on the X and Y planes where layers will be constructed in the advanced polishing pad. In some stacking process applications, these locations will define where the laser will pulse, and in other applications, they will define where the nozzle will eject material droplets.

[0131] Coordinates present in the pixel map are used, for example, with a polymer jet printhead to define the location where a specific droplet of uncured polymer will be placed. Each coordinate of the X and Y positions and the Z-stage position of a given pad support will be defined based on the pixel map. Each X, Y, and Z position will include droplet application or droplet non-application conditions. The printhead can be mounted in an array in the X and / or Y directions to increase build-up or deposit additional types of material. In the examples shown in Figures 4A through 4D, black pixels indicate locations where the nozzle will not deposit material, and white pixels indicate locations where the nozzle will deposit material. By combining the material map or pixel map, polishing pads with any desired shape or structural configuration can be printed in each forming layer by positioning discrete drops close to one discrete droplet.

[0132] A build-up fabrication apparatus, such as a 3D printer, can be used to form an advanced polishing pad by depositing a thermoplastic polymer, depositing and curing a photosensitive resin precursor composition, and / or laser pulsed sintering and melt-applied powder layer. In some embodiments, the advanced polishing pad formation process may include a polymer jet printing method for UV-sensitive materials. In this configuration, a precursor formulation (e.g., a first printable ink composition 359) is jetted from a nozzle of a drop jet printer 306, and the resin precursor composition is deposited onto a build-up stage. Because the material is deposited from the nozzle array, it can be leveled using rollers or other components to smoothly drop into a flat film layer or transfer transition material. During and / or immediately after the application drop, a UV lamp or LED radiation source passes through the deposited layer, thereby curing or partially curing the application drop into a solid polymer network structure. In some embodiments, a monochromatic light source (e.g., an LED light source) with a specifically tailored narrow emission wavelength range and / or narrow spot size is used to substantially or partially cure one or more application drops without negatively impacting other surrounding areas of the formed advanced polishing pad or previously formed layers. In some embodiments, the monochromatic light source is configured to deliver light wavelengths in the range of 100 nm to 500 nm (such as between about 170 nm and 400 nm). In one example, a UV LED source is configured to deliver UV light at a center wavelength of 240 nm, 254 nm, 365 nm, 385 nm, 395 nm, or 405 nm within a + / -10 nm band. This process builds one layer on top of another with sufficient cohesion within and between layers to ensure good mechanical performance of the final embodiment of the pad model.

[0133] To better control polymer stress during the construction process, heat can be added during the formation of one or more layers. The delivery of heat allows the polymer network structure formed in each cured or partially cured layer to relax, thus reducing stress and removing stress history from the film. Stress in the film can cause undesirable deformation of the polishing pad during or after the polishing pad formation process. Heating the partially formed polishing pad while it is located on the printer's construction tray ensures that the final pad properties are fixed through a layer-by-layer process, achieving predictable pad composition and polishing results. In addition to introducing heat into the polishing pad formation process, the area surrounding the grown polishing pad can be modified to reduce the exposure of uncured resin to oxygen. This can be achieved by using a vacuum or by filling the construction chamber with nitrogen (N2) or other inert gases. Reducing oxygen on the grown pad will reduce inhibition of free radical polymerization and ensure more complete surface curing of the application droplets. Pore formation by layering

[0134] In some embodiments, the formed advanced polishing pad 200 includes apertures formed in a desired distribution or pattern within a single pad body 202, such that the properties of the formed layers, for example, within a first polishing element or a second polishing element or the entire pad structure, will have desired thermal and / or mechanical properties. Therefore, by customizing the composition of various materials within different portions of the pad body and the formed apertures via a stacking process, the properties of one or more regions of the advanced polishing pad can be controlled. It is believed that forming apertures in at least the surface of the formed pad will help increase the interaction between the pad surface and the slurry and slurry nanoparticles (e.g., cerium oxide and silicon dioxide) loaded on the pad, thereby increasing the polishing removal rate and reducing the common inter-wafer removal rate deviation typically present in CMP processes.

[0135] Figure 5A illustrates a schematic planar view of a pixel chart. According to one or more embodiments of this disclosure, the pixel chart can be used to form a region 500 of layer 522 (Figure 5B) of a first or second polishing element of a polishing pad, the region 500 containing a pore-forming region. In this example, the pixel chart includes a rectangular pattern of pore-forming regions 502, which are formed by applying one or more drops of pore-forming agent 504 (Figure 5B) from a first printhead to a surface, and then by at least partially surrounding the pore-forming regions 502 with one or more structural material regions 501, the one or more structural material regions 501 including material formed by applying drops of one or more resin precursor compositions from at least a second printhead. The pore-forming agent 504 may subsequently be removed in a post-processing step or during a polishing process for forming pores in one or more layers of the polishing pad. In one example, the pore-forming material is removed from the formed advanced polishing pad 200 when the polishing pad is used in a CMP polishing process. In this example, the pore-forming material may be removed due to the interaction between the pore-forming material disposed on the surface 520 of the first or second polishing element in the advanced polishing pad and one or more components found in the slurry disposed between the first and / or second polishing elements and the substrate being polished. As shown in Figure 5A, the pore-forming region 502 is surrounded by a structured material region 501 formed by dropwise application of a resin-precursor formulation to the surface of the formed layer 522. By using the various techniques described herein, the compositional gradient in the cured structural material within the structured material region 501 and / or the size and density gradient of the pore-forming region 502 can be used to form at least a portion of a complete polishing pad having desired mechanical and thermal properties. The composition of the pore-forming material disposed within the pore-forming region 502 and the distribution and dimensions of the pore-forming region 502 throughout the polishing pad 200 (i.e., the XY plane) or through the thickness of the polishing element (i.e., the Z direction) can vary in any suitable pattern. Although the polishing pad described herein is illustrated as being formed of two materials, this configuration is not intended to limit the scope of the disclosure provided herein, as polishing pads comprising three or more materials are within the scope of this disclosure. It should be noted that the composition of the structural material found within the polishing pad (such as the polishing pad designs shown in Figures 2A to 2K) can vary in a similar manner as discussed above in conjunction with Figures 4A to 4F. Thus, in some embodiments, the material found within the formed structural material region 501 may include a mixture of two or more different materials varying throughout one or more directions of the formed layer (e.g., the X and / or Y directions) or through one or more directions of the formed layer (e.g., the Z direction).

[0136] Figure 5B is a side cross-sectional view of a portion of region 500 illustrated in Figure 5A according to one or more embodiments of this disclosure. The portion shown in Figure 5B includes a plurality of layers 522 formed on an optional substrate layer 521 by means of a lamination process described herein. For clarity of discussion, the layers illustrated in Figure 5B are positioned between two dashed lines; however, due to the process described herein, at least a portion of the structural material region 501 of adjacent layers can be formed, such that there is no clear solid distinction between the layers in the formed polishing pad 200. Each layer 522 includes a pore region 502 interposed between the regions containing the structural material region 501. As noted above, due to the interaction between the pore-forming agent in the pore-forming area 502 located on the surface 520 (i.e., the polishing surface 112) of the polishing pad 200 and the slurry (not shown) located in the polishing area 530, the pore-forming agent 504 can be easily removed, leaving unfilled voids in the pore-forming area 502, and thus forming a hole 503.

[0137] In one embodiment, the pixel map used to form each layer 522 includes a pattern comprising an array of pore-forming regions 502 containing pore-forming agent 504 formed throughout the surface of the formed layer with a desired pattern. As noted above, in some embodiments, the pattern of the pore-forming regions 502 containing pore-forming agent 504 may be formed as a rectangular array having a desired spacing in both the X and Y directions. However, the pattern of the pore-forming regions 502 containing pore-forming agent 504 may be formed as any desired pattern, including a hexagonal array of pore-forming regions 502, an orientation-varying pattern of pore-forming regions 502, a random pattern of pore-forming regions 502, or other available patterns of pore-forming regions 502. In some embodiments, the pixel maps used to form adjacent layers 522 are moved a desired distance 525 relative to each other in one or more directions (e.g., the X direction, the Y direction, or the X and Y directions), or are formed with different relative XY patterns, such that as the polishing pad grows, the pore-forming regions 502 are not located on top of each other in adjacent placement layers. In one embodiment, similar configuration patterns of the aperture regions 502 in adjacent layers may be staggered relative to each other by a required distance in one or more directions, such that the aperture regions 502 are not located on top of each other in adjacent placement layers.

[0138] Figure 5C illustrates a side cross-sectional view of a portion of region 500 shown in Figure 5A, according to another embodiment of this disclosure. In some embodiments, two or more deposited layers may be aligned with each other such that these layers are formed directly on top of each other. In one example, as shown in Figure 5C, two layers 522A and 522B are formed such that layer 522A is directly on top of layer 522B, such that one of the aperture regions 502 is on top of the other. The next or subsequent layer may then be moved a required distance 525 relative to layers 522A-B such that the aperture region 502 in the subsequent layer is not on top of layers 522A-B. This configuration, in which two or more layers within a larger layer stack are formed directly on top of each other, can be useful when the fixed droplet size resolution in the X and Y directions is greater than the thickness of the layer in the Z direction. In one example, the fixed droplet size in the X and Y directions is twice the thickness in the Z direction, thus allowing a regular pattern of printed material to be formed in the X, Y, and Z directions when the two layers are on top of each other.

[0139] Referring back to Figure 5A, the pixel map for forming the pore-forming region 502 within the layer and the surrounding structured material region 501 can be used to produce portions of polishing features having consistent or different porosities in one or more directions X, Y, or Z. In one example, the polishing feature near the edge region of the advanced polishing pad may contain more resin precursor formulation for forming the structured material within the structured material region 501 than the pore-forming region 502 containing pore-forming agent 504. The polishing feature near the center region of the polishing pad may also include a higher percentage of pore-forming region 502 per layer (e.g., higher density) than the polishing feature near the edge region. In this example, polishing features of the same type (e.g., the first polishing element 204) or different types (e.g., the first polishing element 204 and the second polishing element 206) have a unique combination of resin precursor formulation, pore-forming agent, and density of pore-forming region 502 per layer or per element. In one example, the first polishing element 204 includes a first combination of a resin precursor formulation and a pore-forming agent, and the second polishing element 206 includes a different second combination of a resin precursor formulation and a pore-forming agent. Therefore, by using a pixel map, a polishing body can be continuously formed, achieving the desired porosity gradient in different portions of the polishing body, thereby achieving the desired polishing performance of an advanced polishing pad.

[0140] A method for forming a layer of a porous advanced polishing pad according to embodiments described herein may include the following steps. First, one or more drops of a resin composition as described herein are applied in a desired X and Y pattern to form a structural material portion of the formed layer. In one embodiment, if one or more drops constitute a first layer, the one or more drops of resin composition are applied to a support. In some embodiments, the one or more drops of resin composition are applied to a previously deposited layer. Second, one or more drops of a pore-forming composition containing a pore-forming agent 504 are applied in a desired X and Y pattern to form a pore region 502 within the formed layer. In one embodiment, if one or more drops constitute a first layer, the one or more drops of pore-forming composition are applied to a support. In some embodiments, the one or more drops of pore-forming composition are applied to a previously deposited layer. The application processes of the first and second operations are typically performed separately in time and at different XY coordinates. Subsequently, or thirdly, at least partially, one or more of the applied drop-curable resin precursors and one or more of the applied drop-forming compositions are cured. Then, in a fourth step, the one or more applied drop-curable resin precursors and one or more applied drop-forming compositions are exposed to at least one or both of an annealing process and a cleaning process to remove the pore-forming agent. The cleaning process may include cleaning with water, another solvent such as an alcohol (e.g., isopropanol), or both. The annealing process may include heating the deposited pad structure to a lower temperature (e.g., about 100°C) under low pressure to evaporate the pore-forming agent. Subsequently, in a fifth step, an optional second curing process is performed on the forming layer or final pad to form the final pad structure. In some cases, the first, second, and third processing steps may also be repeated sequentially to form a large number of stacked layers before completing the fourth step.

[0141] In some embodiments, the pore-forming agent 504 may comprise materials having hydrophilic properties and / or hydrolyzable properties, such as hydrogels, poly(lactic-co-glycolic acid; PLGA), and polyethylene glycol (PEG), which exhibit degradation in aqueous solutions. In some configurations, during a CMP polishing process, the pore-forming agent 504 disposed within the formed polishing pad is configured to degrade, such as by dissolving into an aqueous slurry (e.g., the pore-forming agent is soluble in the slurry) or by decomposing in the presence of the slurry, leaving pores (e.g., openings or voids of 100 nm to 1 μm) in the exposed surface of the advanced polishing pad. The pore-forming agent 504 may comprise oligomeric and / or polymeric materials mixed with an inert soluble component. The inert soluble component may include ethylene glycol, polyethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, and glycerol. The inert, soluble component may also include corresponding monoalkyl or dialkyl ethers, and alkyl groups including methyl, ethyl, propyl, isopropyl, butyl, or isobutyl. In one embodiment, the pore-forming agent 504 includes PEG and about 5% to 15% of oligomeric and / or polymeric materials, such as acrylate materials. In some formulations, hydrogel materials based on polyethylene glycol acrylate or polyethylene glycol methacrylate may be used. These types of materials may be made from polar materials that are insoluble in most resin precursor formulations. The hydrogel material may be formed by crosslinking with diacrylate and dimethacrylate at a ratio of about 1% to 10%. The hydrogel material formed in this manner will still be soluble in water and can be washed away with water to form pores.

[0142] In some embodiments, the structural material region 501 may include a material formed from one or more of the resin precursor components disclosed herein. For example, the structural material region 501 may include a material formed using a resin precursor component selected from, but not limited to, at least one of the materials listed in Table 3 or the material family from which the materials listed in Table 3 originate. Other useful resin precursor components that may be used alone or in combination with one or more of the resin precursor components disclosed herein may also include thiol-ene and thiol-acetylene type components, epoxy group components, Michael addition type components, ring-opening polymerization (ROP) components, and cyclization polymerization or Diels-Alder polymerization (DAP) type components described herein.

[0143] In one embodiment, the pores formed together with the pad body 202 can be formed by a phase change in the porogen 504 during a subsequent advanced polishing pad formation process, such as by evaporation. In one example, the porosity within the formed pad can be generated by delivering electromagnetic radiation to a portion of the polishing pad to induce a phase change in the porogen material. In one embodiment, the advanced polishing pad prepolymer composition may contain a thermally unstable compound, polymer, or oligomer that may contain thermally unstable groups. These porogens and thermally unstable groups may be cyclic groups, such as unsaturated cyclic organic groups. The porogen may contain cyclic hydrocarbon compounds. Some exemplary porogens include, but are not limited to: norbornadiene (BCHD, bicyclo(2.2.1)hept-2,5-diene), alpha-terpinene (ATP), vinylcyclohexane (VCH), phenylacetate, butadiene, isoprene, and cyclohexadiene. In one embodiment, a prepolymer layer containing a radiation-curable oligomer with covalently bonded porogen groups is deposited. Upon exposure to UV radiation and heat, a porous polymer layer can be formed by the outflow of the porogen groups. In another embodiment, the advanced polishing pad prepolymer composition may contain a compound, polymer, or oligomer mixed with an aqueous compound. In this example, multiple porous layers can be formed by sequential layer deposition and subsequent removal of the aqueous compound to create pores. In other embodiments, pores can be created by the thermally induced decomposition of compounds that form gaseous byproducts, such as azo compounds, which decompose to form nitrogen bodies.

[0144] Alternatively, in some embodiments, the resin precursor composition may include polymer spheres, such as polymer nanospheres or microspheres with a diameter of 100 nm to 1 μm disposed within a droplet for forming an advanced polishing pad. In some embodiments, the polymer sphere size is between 100 nm and 20 μm, such as between 100 nm and 5 μm. In some build-up manufacturing embodiments, it may be necessary to apply a droplet containing the resin precursor composition from a first nozzle and a droplet containing the polymer sphere formulation from a second nozzle, such that the two application droplets can be mixed to form a complete droplet that can subsequently be partially or completely cured to form a portion of the grown polishing pad. In some configurations, during the CMP polishing process, the polymer spheres are configured to degrade, such as by dissolving in an aqueous slurry or by decomposing in the presence of the slurry, leaving pores (e.g., pore features of 100 nm to 1 μm) in the exposed surface of the advanced polishing pad.

[0145] The polymer spheres may comprise one or more solid polymer materials having desired mechanical properties, thermal properties, abrasion properties, degradation properties, or other useful properties for use within the formed advanced polishing pad. Alternatively, the polymer spheres may comprise a solid polymer shell encapsulating a liquid (e.g., water) or gaseous material, such that the polymer spheres will provide desired mechanical properties, thermal properties, abrasion properties, or other useful properties for the formed advanced polishing pad. The polymer spheres may also be used to form pores within areas of a fixed droplet used to form one or more regions within portions of the formed polishing element (e.g., polishing element 204 and / or 206) to provide these portions of the formed advanced polishing pad with desired mechanical properties, thermal properties, abrasion properties, or other useful properties. The polymer spheres may comprise materials having hydrophilic behavior and / or hydro-degradable behavior, such as hydrogels and poly(lactic-co-glycolic acid), PLGA, which degrade in aqueous solutions. After a lamination process (e.g., 3D printing), the polymer spheres are typically uniformly dispersed in the drop formulation and curing material.

[0146] In some formulations, hydrogel particles based on polyethylene glycol acrylate or polyethylene glycol methacrylate may be used. These types of particles can be made from polar materials that are insoluble in most formulations. The hydrogel particles can be formed by crosslinking with diacrylate and dimethacrylate at a ratio of about 1% to 15%. The hydrogel particles formed in this way will still be water-soluble and can be washed away with water to form pores. Formulation and material examples

[0147] As discussed above, the materials used to form the pad body 202, such as portions of the first polishing element 204 and the second polishing element 206, may each be formed from at least one inkjetable prepolymer composition to achieve the desired properties of the advanced polishing pad. This composition may be a mixture of functional polymers, functional oligomers, reactive diluents, and curing agents. Generally, the prepolymer ink or composition, after deposition, may be processed using any number of components with or without a curing agent or chemical initiator, including exposure to or contact with radiation or heat. Generally, the deposited material may be exposed to electromagnetic radiation, which may include ultraviolet radiation (UV), gamma radiation, X-ray radiation, visible light radiation, IR radiation, and microwave radiation, as well as accelerating electron and ion beams that can be used to initiate the polymerization reaction. For the purposes of this disclosure, we do not limit the use of curing methods or additives that aid polymerization, such as sensitizers, initiators, and / or curing agents, such as full curing agents or oxygen inhibitors.

[0148] In one embodiment, two or more polishing elements within a single pad body 202, such as first and second polishing elements 204 and 206, may be formed by sequential deposition and post-deposition processing of at least one radiation-curable resin precursor composition, wherein the composition contains functional polymers, functional oligomers, monomers, and / or reactive diluents having unsaturated chemical portions or groups, including but not limited to: vinyl, acrylic, methacrylate, allyl, and ethynyl groups. During the polishing pad formation process, the unsaturated groups may undergo free radical polymerization upon exposure to radiation such as UV radiation in the presence of a curing agent such as a free radical photoinitiator (such as Irgacure® products manufactured by BASF in Ludwigshafen, Germany).

[0149] Two types of free radical photoinitiators can be used in one or more embodiments of the present disclosure provided herein. The first type of photoinitiator (also referred to herein as a bulk curing photoinitiator) is an initiator that decomposes upon exposure to UV radiation, immediately generating free radicals capable of initiating polymerization. The first type of photoinitiator can facilitate surface curing and complete or bulk curing of applied drops. The first type of photoinitiator can be selected from, but is not limited to, benzoyl ether, benzyl ketal, acetophenone, alkyl phenyl ketone, and phosphine oxide. The second type of photoinitiator (also referred to herein as a surface curing photoinitiator) is a photoinitiator activated by UV radiation, and it forms free radicals by hydrogen extraction from a second compound, which becomes the actual initiating free radical. This second compound is often referred to as a co-initiator or polymerization synergist and can be an amine synergist. Amine synergists are used to reduce oxygen inhibition, and therefore the second type of photoinitiator can facilitate rapid surface curing. The second type of photoinitiator can be selected from, but is not limited to, diphenyl ketone compounds and thioxanthone compounds. The amine synergist can be an amine containing active hydrogen, and in one embodiment, an amine synergist such as an amine-containing acrylate can be combined with a diphenyl ketone photoinitiator in the resin precursor composition formulation to: a) limit oxygen inhibition, b) rapidly cure the droplet or layer surface, thereby fixing the size of the droplet or layer surface, and c) increase layer stability during the curing process. In some cases, in order to prevent or inhibit free radical quenching caused by diatomic oxygen (which slows down or inhibits the free radical curing mechanism), we can choose an oxygen-limited or oxygen-free curing atmosphere or environment, such as an inert gas atmosphere, and dry, degassed, and virtually oxygen-free chemical reagents.

[0150] It has been found that controlling the amount of chemical initiator in the printing formulation is a crucial factor in controlling the properties of the advanced polishing pad, because repeated exposure of the underlying layers to curing energy during advanced polishing pad formation will affect the properties of these underlying layers. In other words, repeated exposure of the deposited layer to a certain amount of curing energy (e.g., UV light, heat, etc.) will affect the degree of curing within each forming layer or cause the surface of this layer to be over-cured. Therefore, in some embodiments, it is necessary to ensure that the surface curing kinetics are not faster than complete curing (overall curing), because the surface will cure first and block additional UV light from reaching the material below the surface-cured area; thus resulting in a partially cured structure that is "incompletely cured". In some embodiments, it is necessary to reduce the amount of photoinitiator to ensure proper chain elongation and crosslinking. Generally, higher molecular weight polymers will be formed by slower controlled polymerization. It is believed that if the reaction products contain too many free radicals, the reaction kinetics may proceed too quickly and the molecular weight will be lower, which will in turn reduce the mechanical properties of the cured material.

[0151] In some embodiments, the resin precursor composition includes a polymeric photoinitiator and / or an oligomer photoinitiator having a medium to high molecular weight selected such that it is relatively fixed within the entire area of ​​the applied droplet before, during, or after the curing process. Typically, medium to high molecular weight photoinitiators are selected such that they do not migrate or at least migrate minimally within the partially cured droplet. In one example, after UV curing or UV LED curing of a droplet having a medium to high molecular weight photoinitiator, the polymeric and oligomer photoinitiators tend to be fixed within the entire area of ​​the cured material and do not migrate to or evaporate from the surface or interface of the cured material, compared to conventional low molecular weight photoinitiators, due to the relatively high molecular weight of the photoinitiators. Because medium to high molecular weight photoinitiators are relatively fixed within the formed droplet, the overall curing, composition, and mechanical properties of the region, as well as the curing, composition, mechanical properties, and surface properties (e.g., hydrophilicity) of the applied droplet, will remain relatively uniform and stable. In one example, the medium to high molecular weight photoinitiator may be a material with a molecular weight greater than 600, such as greater than 1000. In another example, the medium to high molecular weight photoinitiator may be a material selected from the group consisting of Industries PL-150 and IGM Resins Omnipol 1001, 2702, 2712, 682, 910, 9210, 9220, BP, and TX. Compared to small molecule photoinitiators, the fixation characteristics of polymeric and oligomeric photoinitiators will also increase the health, safety, and environmental impacts of the build-up process used to form advanced polishing pads.

[0152] In some embodiments, a medium to high molecular weight photoinitiator can be selected for the droplet formulation such that it does not significantly alter the viscosity of the final formulation used to form droplets applied to the surface of a growth polishing pad. Conventionally, low molecular weight photoinitiators undesirably alter the viscosity of the formulation used to form droplets. Therefore, by selecting a desired medium to high molecular weight photoinitiator, the viscosity of the final droplet formulation can be adjusted or maintained at a level that allows for easy application and deposition by deposition hardware such as a printhead during a layering process (e.g., 3D printing). Some formulations are desired to have extremely low viscosity (10-12 cP at 70°C). However, in some cases, such as with the printing hardware of the Connex 500 printing tool, the viscosity is 13-17 cP at 70°C. To increase viscosity, the oligomer content in the formulation must be increased. Increasing the oligomer content will affect the mechanical properties of the formed layer. Therefore, the addition of a polymeric photoinitiator will automatically increase viscosity and have a minimal impact on the mechanical properties of the formed layer. Additionally, the migration of small-molecule photoinitiators is a concern because it affects the surface hydrophobicity of the formed layer, thereby influencing the printing resolution of the formed droplets and the contact angle of the formed layer. In one example, the photoinitiator is styrene-based, obtained from Synasia, IGM Resins, and PL Industries. Another example of a medium to high molecular weight photoinitiator of the desired type is shown in the following chemical structure (PI).

[0153] In some embodiments, the first polishing element 204 and the second polishing element 206 may contain at least one oligomeric and / or polymeric segment, compound or material selected from: polyamide, polycarbonate, polyester, polyetherketone, polyether, polyoxymethylene, polyether urethane, polyetherimide, polyamide, polyolefin, polysiloxane, polyurethane, polyphenylene, polyphenylene sulfide, polyurethane, polystyrene, polyacrylonitrile, polyacrylate, polymethyl methacrylate, polyurethane acrylate, polyester acrylate, polyether acrylate, epoxy acrylate, polycarbonate, polyester, melamine, polyurethane, polyethylene material, acrylonitrile butadiene styrene (ABS), copolymers derived from styrene, copolymers derived from butadiene, halogenated polymers, block copolymers and copolymers thereof. The composition used to form the first polishing element 204 and the second polishing element 206 can be generated and synthesized using at least one UV-curable functional and reactive oligomer having at least one of the aforementioned polymeric and / or molecular fragments, as shown in chemical structure (A):

[0154] The bifunctional oligomer represented by chemical structure A, namely bisphenol-A ethoxylated diacrylate, contains segments that contribute to the low, medium, and high storage moduli E' characteristics of the materials present in the first polishing element 204 and the second polishing element 206 in the pad body 202. For example, aromatic groups can impart increased rigidity to the pad body 202 due to some local stiffness imparted by the benzene ring. However, those skilled in the art will recognize that increasing the ether chain segment "n" will reduce the storage modulus E' and thus produce a softer material with increased flexibility. In one embodiment, a rubbery reactive oligomer, namely polybutadiene diacrylate, can be used to produce a softer and more elastic composition with some rubbery elastic elongation, as shown in chemical structure (B):

[0155] Polybutadiene diacrylate includes side-allyl functionalities (as shown) that can undergo crosslinking reactions with other unsaturated unreacted sites. In some embodiments, residual double bonds in the polybutadiene segment "m" react to produce crosslinks that facilitate reversible elastic properties. In one embodiment, an advanced polishing pad containing the crosslinked composition may have an elongation percentage of about 5% to about 40% and an E'30:E'90 ratio of about 6 to about 15. Examples of some crosslinking chemicals include sulfur vulcanization and peroxides such as tributyl perbenzoate, dicumyl peroxide, benzoyl peroxide, ditributyl peroxide, and the like. In one embodiment, 3% by weight of benzoyl peroxide reacts with polybutadiene diacrylate to form a crosslinked composition such that the crosslinking density is at least about 2%.

[0156] The chemical structure (C) represents another type of reactive oligomer, namely polyurethane acrylate, a material that can impart flexibility and elongation to advanced polishing pads. The acrylate containing polyurethane groups can be aliphatic or aromatic polyurethane acrylate, and the R or R' groups shown in this structure can be aliphatic, aromatic, or oligomeric, and can contain heteroatoms such as oxygen.

[0157] Reactive oligomers may contain at least one reactive site, such as an acrylic acid site, and may be monofunctional, difunctional, trifunctional, tetrafunctional, pentafunctional, and / or hexafunctional, thus acting as a focal point for crosslinking. Figures 7B can help generate stress-strain graphs for some cured reactive oligomers of 3D printable ink compositions. Oligomers may represent “soft” or low energy modulus E’ materials, “medium-soft” or medium energy modulus E’ materials, or “hard” or high energy modulus E’ materials (e.g., Table 1). As shown, the energy storage modulus E' (e.g., tilt or Δy / Δx) increases from soft and flexible and stretchable polyurethane acrylates to acrylates, then to polyester acrylates, and then to the hardest in the series (hard and high energy storage modulus E" epoxy acrylates). Figure 7B illustrates how one can select energy storage modulus E' materials, or ranges or mixtures of energy storage modulus E' materials, that can contribute to the production of advanced polishing pads. Functional oligomers are available from a variety of sources, including Sartomer USA in Exton, Pennsylvania, Dymax Corporation in Torrington, Connecticut, and Allnex Corporation in Alphalitta, Georgia.

[0158] In embodiments of this disclosure, multifunctional acrylates (including difunctional, trifunctional, tetrafunctional, and higher functional acrylates) can be used to create crosslinks within and / or between materials used to form the first polishing element 204 and the second polishing element 206, and thereby modulate polishing pad properties, including storage modulus E', viscous damping, resilience, compression, elasticity, elongation, and glass transition temperature. It has been found that desired pad properties can be achieved by controlling the degree of crosslinking within the various materials used to form the first polishing element 204 and the second polishing element 206. In some configurations, multifunctional acrylates can advantageously replace rigid aromatic groups in polishing pad formulations because the low viscosity of the materials provides a wider variety of molecular structures, such as linear, branched, and / or cyclic, and a broader range of molecular weights, which in turn broadens the formulation and process window. Some examples of multifunctional acrylates exhibited in chemical structures (D) (1,3,5-triacrylylhexahydro-1,3,5-triazine) and (E) (trimethylolpropane triacrylate) are as follows:

[0159] The type of crosslinking or the crosslinking agent, chemical structure, or mechanism of crosslinking is not limited to the embodiments disclosed herein. For example, an amine-containing oligomer may undergo a Michael addition reaction with the acrylic portion to form a covalent crosslink, or the amine group may react with an epoxy group to produce a covalent crosslink. In other embodiments, crosslinking may be formed by ionic bonds or hydrogen bonds. The crosslinking agent may contain linear, branched, or cyclic molecular segments and may further contain oligomeric and / or polymeric segments, and may contain heteroatoms such as nitrogen and oxygen. Crosslinking chemicals that can contribute to the composition of the polishing pad are available from a variety of sources, including: Sigma-Aldrich of St. Louis, Missouri, USA; Sartomer USA of Exton, Pennsylvania, USA; Dymax of Torrington, Connecticut, USA; and Allnex of Alphalitta, Georgia, USA.

[0160] As mentioned herein, reactive diluents can be used as viscosity-reducing solvents to blend with high-viscosity functional oligomers to achieve a suitable viscosity formulation, which is then copolymerized with the higher-viscosity functional oligomers upon exposure to curing energy. In one embodiment, when n is about 4, the viscosity of bisphenol A ethoxylated diacrylate at 25°C may be about 1350 centipoise (cP), which may be too high to achieve the application of such materials in 3D printing processes. Therefore, it may be necessary to blend bisphenol A ethoxylated diacrylate with a lower-viscosity reactive diluent, such as a low molecular weight acrylate, to reduce the viscosity to about 1 cP to about 100 cP at 25°C, such as about 1 cP to about 20 cP at 25°C. The amount of reactive diluent used depends on the viscosity of the formulation components and the diluent itself. For example, 1000 cP of reactive oligomer may require dilution by at least 40% of the formulation weight to achieve the target viscosity. Examples of reactive diluents are shown in the chemical structures (F) (isobornyl acrylate), (G) (decyl acrylate), and (H) (glycidyl methacrylate): F and G have viscosities of 9.5 cP, 2.5 cP, and 2.7 cP, respectively, at 25°C. Reactive diluents can also be multifunctional and therefore can undergo crosslinking reactions or other chemical reactions to produce polymeric network structures. In one embodiment, glycidyl methacrylate (H) acts as a reactive diluent and is mixed with a bifunctional aliphatic polyurethane acrylate, so the viscosity of the mixture is about 15 cP. The approximate dilution factor can be from about 2:1 to about 10:1, such as about 5:1. An amine acrylate, such as dimethylaminoethyl methacrylate, can be added to this mixture, so it is about 10% by weight of the formulation. Heating this mixture from about 25°C to about 75°C causes a reaction between the amine and the epoxide, forming an adduct of acrylated amine and acrylated epoxide. A suitable free radical photoinitiator (such as Irgacure® 651) can then be added at 2% by weight of the formulation, and the mixture can be applied using a 3D printer, thus forming a 20-micron thick layer on the substrate. Subsequently, the layer is cured by exposing the droplet or layer to UV light at an intensity of about 200 nm to about 400 nm for about 0.1 μs to about 10 seconds, such as about 0.5 seconds, using a scanning UV diode laser at an intensity of about 10 mJ / cm² to about 50 mJ / cm², thereby producing a thin polymer film. Reactive diluent chemicals that can facilitate the 3D printing polishing pad composition are available from various sources, including Sigma-Aldrich of St. Louis, Missouri, USA; Sartomer USA of Exton, Pennsylvania, USA; Dymax of Torrington, Connecticut, USA; and Allnex of Alphalitta, Georgia, USA.

[0161] Another radiation curing method that can facilitate the production of polishing pads is cationic curing initiated by UV or low-energy electron beams. The epoxy-containing material can be cationically curable, wherein ring-opening polymerization (ROP) of epoxy groups can be initiated by cationic groups such as protons and Lewis acids. The epoxy-containing material can be a monomer, oligomer, or polymer, and can have aliphatic, aromatic, cycloaliphatic, aryliphatic, or heterocyclic structures; and it can also include epoxy groups as side groups or groups forming alicyclic or heterocyclic systems.

[0162] Compared to free radical photopolymerization, UV-initiated cationic photopolymerization exhibits several advantages, including lower shrinkage, better transparency, better complete curing via living polymerization, and oxygen-free inhibition. UV cationic polymerization involves an acid catalyst that causes ring-opening of cyclic groups such as epoxy groups. Sometimes referred to as cationic ring-opening polymerization (CROP), this technique enables the polymerization of important classes of monomers that cannot be polymerized by free radical methods, such as epoxides, vinyl ethers, propylene ethers, siloxanes, oxetanes, cycloacetals and methylacetals, cyclosulfides, lactones, and lactamines. These cationic polymerizable monomers also include unsaturated monomers that can undergo free radical polymerization via carbon-carbon double bonds as described herein, such as glycidyl methacrylate (chemical structure H). Photoinitiators that generate photoacids when irradiated with UV light (approximately 225 nm to 300 nm) or an electron beam include, but are not limited to, arylium salts, such as iodonium and thionium salts, such as triarylthionium hexafluorophosphate, which are available from BASF (Irgacure® products) in Ludwigshafen, Germany.

[0163] In one embodiment, the material used to form the first polishing element 204 and the second polishing element 206, and thus the single pad body 202, is formed by continuous deposition and cationic curing of at least one radiation-curable resin precursor composition, wherein the composition contains a functional polymer having epoxy groups, a functional oligomer, a monomer, and / or a reactive diluent. A hybrid radical and cationic curing system can be used to save costs and balance physical properties. In one embodiment, the first polishing element 204 and the second polishing element 206 may be formed by continuous deposition and cationic and radical curing of at least one radiation-curable resin precursor composition, wherein the composition contains a functional polymer having acrylic and epoxy groups, a functional oligomer, a monomer, and a reactive diluent. In another embodiment, to obtain some of the transparency and light-absorbing advantages inherent in cationic curing systems, the observation window or CMP endpoint detection window, discussed further below, may be formed from a composition cured by a cationic method. In some embodiments, some layers forming in the advanced polishing pad may be formed using a cationic curing method, and some layers may be formed using a radical curing method. Examples of addition-type polymers

[0164] In addition to the aforementioned acrylic acid radical and cationic epoxy polymerization, other addition polymerization reactions and compounds can be used to prepare printed polished objects having a pad body 202, a first polishing element 204, and a second polishing element 206, such as CMP pads. In the process of printing polymer layers in polished objects, it is advantageous to use addition polymerization that does not produce solid, liquid, or gaseous byproducts. It is believed that the generation of one or more types of byproducts can cause material problems, structural problems, and environmental problems, such as byproduct trapping, void formation, foaming, and the release of potentially toxic substances. Compared to addition polymerization processes, condensation polymerization reactions can produce at least one byproduct, such as water or other compounds, and are therefore not a desirable synthetic route for forming printed polished objects. In addition to the aforementioned acrylic acid radical and cationic epoxy polymerizations, useful and alternative addition polymerizations include, but are not limited to, thiol-ene and thiol-alkyne types, epoxy reactions with amines and / or alcohols, Michael addition polymerization, ring-opening polymerization (ROP), and cyclization or Diels-Alder polymerization (DAP) types. Generally, and for the purposes of this disclosure, an "addition" polymerization reaction may involve the reaction of at least one compound with another compound and / or the use of electromagnetic radiation to form a polymer material with desired properties, but without the generation of byproducts. Furthermore, a compound undergoing an addition polymerization reaction with another compound may also be described herein as an "addition polymer precursor component," and may also be referred to as "part A" and / or "part B" in the process of forming a synthetic material involving at least one addition polymer precursor component.

[0165] Importantly, the aforementioned addition polymerizations, such as those of thiols-olefins and ROP types, can be tunable and manipulated to produce physical properties important in the production of printed polymer layers and polished objects, including but not limited to: storage modulus (E'), loss modulus (E''), viscous damping, resilience, compression, elasticity, elongation, and glass transition temperature. It should be noted that most of the basic synthetic formulations and / or material formation schemes and chemical bases previously described herein for acrylate materials remain applicable to the addition polymer reactions discussed below. For example, alternative addition polymers may contain portions that contribute to the low, medium, and high storage modulus E' characteristics of the materials seen in the first polishing element 204 and the second polishing element 206 in the pad body 202. In the example, the aromatic groups can impart increased rigidity to the pad body 202 due to some local stiffness imparted by the benzene ring. It is also believed that increasing the length of the alkyl and / or ether segments of the alternative addition polymers described herein will reduce the storage modulus E', and thus produce a softer material with increased flexibility. The alternative addition polymers may also contain aliphatic, aromatic, or oligomeric R groups, and may contain heteroatoms such as oxygen. The alternative addition polymers may also have monofunctional, difunctional, trifunctional, tetrafunctional, pentafunctional, and / or hexafunctional R groups, and thus act as the focus of crosslinking, the manipulation of which can produce "soft" or low storage modulus E' materials, "medium-soft" or medium storage modulus E' materials, or "hard" or high storage modulus E' materials.

[0166] In addition, the addition polymer and the R group may have water-soluble groups that may contain negative and / or positive charges, and may be uncharged, including but not limited to: amide, imidazole, ethylene and propylene glycol derivatives, carboxylic acid esters, sulfonates, sulfates, phosphates, hydroxyl groups and quaternary ammonium compounds. Some water-soluble compounds that can be polymerized include, but are not limited to: 1-vinyl-2-pyrrolidone, vinylimidazole, polyethylene glycol diacrylate, acrylic acid, sodium styrene sulfonate, Hitenol BC10®, Maxemul 6106®, hydroxyethyl acrylate, and [2-(methacryloxy)ethyltrimethylammonium chloride, sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, sodium 4-vinylbenzenesulfonate, [2-(methacryloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide, 2-acrylamino-2-methyl-1-propanesulfonic acid, vinylphosphonic acid, allyltriphenylphosphonium chloride, (vinylbenzenemethyl)trimethylammonium chloride, allyltriphenylphosphonium chloride, (vinylbenzenemethyl)trimethylammonium chloride, E-SPERSE RS-1618, E-SPERSE RS-1596, methoxy polyethylene glycol monoacrylate, methoxy polyethylene glycol diacrylate, methoxy polyethylene glycol triacrylate.

[0167] In some embodiments, the addition polymer may include one or more linear polymers. Examples of such polymers may include, but are not limited to, poly(methyl methacrylate), poly(styrene-co-methyl methacrylate), poly(styrene-co-methacrylic acid), poly(styrene-co-acrylonitrile), poly(methyl methacrylate-co-ethyl acrylate), and poly(phenyl methacrylate).

[0168] In some embodiments, thiol-ene type addition reactions can be used to produce printed polymer layers and polished objects such as CMP pads. Thiol-ene / thiol-alkyne reactions involve the addition of SH bonds to double or triple bonds via radical or ionic mechanisms. Thiol-ene reactions can be considered a sulfur version of silane hydroaddition reactions and can also be used to produce sulfur-centered radical substances that undergo polymerization with compounds containing unsaturated carbon-carbon bonds. The advantages of thiol-ene addition polymerization include: no oxygen inhibition, near 100% polymerization efficiency, reactivity with allyl groups (except acrylic acid), and a high degree of macromolecular structure control. Compared to polished object materials formed by conventional acrylic acid radical polymerization, this high degree of macromolecular structure control also provides the ability to tune the storage modulus or loss modulus and tanδ characteristics of the resulting polished object. Additionally, co-polymerization involving mixtures of at least one compound having acrylic and allyl groups can be performed to broaden the tan δ of the material and modulate its mechanical properties, such as flexibility, elongation, and hardness, while saving costs and balancing physical properties such as storage modulus. For example, in one embodiment, an aliphatic allyl ether can be mixed with an acrylate in a single reservoir at a 25:75 molar ratio prior to deposition. In certain areas of the polished object, the acrylic compound can be used to increase the modulus and crosslinking after curing, achieving a low-cost / molar monomer.

[0169] Figure 3D is a schematic view of a nozzle assembly according to one embodiment of the present disclosure, which can be used to mix and dispense one or more resin precursor components, such as portions A and B for thiol-olefin polymerization. As shown, the droplet printer 306A may include a nozzle 314 and reservoirs 315 and 316, each delivering at least one resin precursor component to a mixing zone 318. The resin precursor components delivered to the mixing zone 318 are mixed when used by a turbulence-inducing element 318a to form one or more drops 319 containing a mixture of the mixed resin precursor components. The turbulence-inducing element 318a may also include a helical path for mixing the resin precursor components. In another embodiment, the mixture may be premixed and contained in a single reservoir. After mixing, droplet 319 is delivered to the surface of a substrate, such as the polished object shown in Figures 3A to 3B and Figure 3D. The droplet is cured after the mixed resin precursor components are applied. It should be noted that the volume, mixing, and application scheme shown in Figure 3D may be suitable for any of the following chemicals described herein, such as thiol-olefin polymerization for printing polished objects.

[0170] Thiol-olefin addition polymerization typically requires UV irradiation to cure the application droplets. UV irradiation includes wavelengths between about 150 nm and 350 nm (e.g., 254 nm) with or without a photoinitiator (e.g., Irgacure TPO-L®, diphenyl ketone, or dimethoxyphenylacetophenone). Examples of thiols that can be used to produce 3D-printed polymer layers from thiool-olefin chemicals include: (I.) 1,3-propanedithiol, (J.) 2,2'-(ethylenedioxy)diethylthiol, and (K.) trimethylolpropanetriol (3-mercaptopropionate). Examples of unsaturated compounds that can be used to generate printed polymer layers by using thiol-olefin chemicals include: (L.) 1,4-butanediol divinyl ether, (M.) 1,4-cyclohexanediethanol divinyl ether, and (N.) 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione.

[0171] The chemical compounds described prior to the thiol-olefin polymerization reaction are intended as non-limiting illustrative examples and are not intended to limit the nature of this disclosure or the methods used herein for preparing thiol-olefin addition polymers. Chemical compounds used in the thiol-olefin polymerization reaction are available from suppliers such as BASF in Ludwigshafen, Germany; Sigma-Aldrich in St. Louis, Missouri, USA; and Sartomer USA in Exton, Pennsylvania, USA.

[0172] The reaction of amines and alcohols (nucleophiles) with electron-deficient carbon centers (such as those found in epoxy groups) is another type of addition polymerization (e.g., thermosetting) that can be used to produce printed polymer layers and polished objects such as CMP pads. Control of crosslinking and intrachain bond properties provides many desirable characteristics to cured epoxy groups. These characteristics include excellent adhesion to many substrates, high strength (tensile, compressive, and flexural), chemical resistance, fatigue resistance, and corrosion resistance. The properties of uncured epoxy resins (such as tackiness) and the final properties of cured epoxy resins (such as strength or chemical resistance) can be optimized by appropriately selecting epoxy monomers and curing agents or catalysts. The chemical structure of amine and alcohol curing agents and epoxides can be modified to obtain desired physical properties such as storage modulus (E'), hardness, tackiness, flexibility, and elongation. As previously mentioned, different levels of functionality can be selected to achieve the desired crosslinking density, thereby tuning the physical properties of the formed material, such as the energy storage modulus (E').

[0173] In one embodiment, an amine-epoxy type addition polymerization reaction can be used to produce a printed polymer layer and a polished object by co-blending part A (e.g., a diamine curing agent) and part B (e.g., a diepoxy compound). This is achieved as previously described and illustrated in Figure 3D. In one embodiment, after mixing and dispensing one or more mixed drops, one or more amine-epoxy addition polymer layers (approximately 1-200 μm thick) can then be formed by rapidly curing the dispensed drops to a solid state using a heat source such as a flash xenon lamp or an IR laser. Various thermosetting accelerators can also be used to cure epoxy thermosetting polymer layers to form printed polished objects, and these thermosetting accelerators include, but are not limited to: phenylurea, boron trichloride, amine complexes, imidazole, aliphatic diurea, phenol, and resorcinol. In an alternative embodiment, a one-component thermosetting formulation can be used to produce a printed polymer layer and a CMP pad, which is dispensed from a single reservoir. In this document, at least one diepoxide or multifunctional epoxy compound may be contained at a certain temperature (such as 25°C) in a single reservoir having a thermally latent initiator such as dicyandiamide (DICY) and with or without an accelerator such as 4,4'-methylenebis(phenyldimethylurea). Such mixtures may be stable for a period of time, such as several hours (depending on the reactivity of the components), until heat is applied. As noted above, heat may be applied using a flash xenon lamp or an IR laser, which promotes the activation of the DICY compound and solidifies it to a solid state.

[0174] The epoxy compound or resin may include bisphenol-F glycidyl ether, bisphenol-A glycidyl ether, epoxidized phenolic varnish resin, epoxidized cresol phenolic varnish resin, epoxidized rubber, epoxidized oil, epoxidized urethane, epoxy ether, polycyclic aliphatic epoxy resin, polycyclic aromatic epoxy resin, and combinations thereof. The epoxy resin may be a monomer, oligomer, or polymer. By wisely selecting the epoxy resin and considering the chemical structure and the degree of epoxidation or epoxy functionalization, printed and polished objects containing polymer layers with modulus adjustable within a desired range can be constructed. In one embodiment, the epoxy-modified polyurethane or rubber may be mixed with a low-viscosity aromatic epoxy compound and resorcinol glycidyl ether to achieve the modulus required for amine curing at temperatures from about 25°C to about 200°C (such as 75°C). Other examples that can be used to generate printing polymer layer epoxides are: (O.) resorcinol glycidyl ether, (P.) poly(propylene glycol) glycidyl ether and (Q.) 4,4'-methylenebis(N,N-diglycidylaniline).

[0175] Similarly, a wide range of amine compounds can be used to produce printed polymer layers and CMP pads. Amines can be in monomeric, oligomeric, and polymeric forms, and each molecule contains at least one amino group with at least one active amine hydrogen. Suitable amines include, but are not limited to: aliphatic amines, cyclic aliphatic amines, polyether amines, polyethyleneimine, dendritic amines, and aromatic amines. Some examples of amines that can be used to produce printed polymer layers are: (R.) 1,3-cyclohexanediamine, (S.) m-dimethyldiamine, and (T.) Jeffamine D®.

[0176] The aforementioned epoxy and amine chemical compounds capable of undergoing epoxy addition polymerization are provided as non-limiting illustrative examples and do not limit any form of the disclosure or the methods used herein for preparing polymer layers or polishing objects via printing processes. Chemical compounds capable of undergoing epoxy addition polymerization are available from suppliers such as BASF in Ludwigshafen, Germany; Sigma-Aldrich in St. Louis, Missouri, USA; Emerald Performance Materials in Mourston, New Jersey, USA, for its CVC thermosetting specialty products; and Huntsman Advanced Materials in Woodland, Texas, USA.

[0177] Polyfunctional amines, such as diamines, can be used in other addition polymerization reactions. One such reaction is called Michael addition (1,4-conjugated addition), in which a primary or secondary amine reacts with an electron-deficient double bond. Specifically, Michael addition is a reaction between a nucleophile and an activated olefin or alkyne functional group, wherein the nucleophile is added to a carbon-carbon multi-bond close to an electron-withdrawing and resonance-stabilizing activated group (such as a carbonyl group). The Michael addition nucleophile is called a "Michael donor," the activated electrophilic olefin is called a "Michael acceptor," and the reaction product of the two components is called a "Michael adduct." Examples of Michael donors include, but are not limited to, amines, thiols, phosphines, carbanions, and alkoxides. Examples of Michael acceptors include, but are not limited to: acrylates, alkyl methacrylates, acrylonitrile, acrylamide, maleic anhydride, cyanoacrylates, vinylene, ketene, nitrosylene, α,β-unsaturated aldehydes, vinyl phosphonates, acrylonitrile, vinylpyridine, azo compounds, β-ketoacetylene, and acetylene esters. It should be further noted that any number of different Michael acceptors and / or mixtures can be used to obtain or tune desired physical properties, such as flexibility, elongation, hardness, toughness, modulus, and hydrophobicity or hydrophilicity of the object. For example, Michael acceptors can be monofunctional, bifunctional, trifunctional, and tetrafunctional, and each group R can have different molecular weights, chain lengths, and molecular structures. Similarly, Michael donors can be selected or identified based on the foregoing characteristics. In one embodiment, printed polished objects can be produced using diacrylates, 1,4-butanediol diacrylate (10.1 mmol), and diamine piperazine (10 mmol) as shown in Reaction Example 1. As shown in Figure 3D, in one embodiment, the diacrylate and diamine can reside in two separate reservoirs 315 and 316, and can then be mixed and applied as droplets in the mixing zone 318 of the curved path application nozzle 314, and subsequently thermo-cured by a xenon flash lamp to form a polymer layer.

[0178] Numerous useful acrylates exist that can be used to generate Michael addition polymers, including but not limited to the previously described acrylate AH. Similarly, amines containing at least two primary or secondary amine groups may include, but are not limited to, the previously described amine RT. Sources of these compounds include Sigma-Aldrich of St. Louis, Missouri, USA; Sartomer USA of Exton, Pennsylvania, USA; Dymax of Torrington, Connecticut, USA; Allnex of Alphalitta, Georgia, USA; BASF of Ludwigshafen, Germany; and Huntsman Advanced Materials of Woodland, Texas, USA.

[0179] In another embodiment, the printed polished parts can be produced using ring-opening polymerization (ROP). ROP involves opening the ring of a cyclic monomer to produce linear, branched, and network polymer materials. Cyclic monomers that can be used in ROP include, but are not limited to, olefins, ethers, thioethers, amines (e.g., aziridine and oxazoline), thiolactones, disulfides, sulfides, acid anhydrides, carbonates, polysiloxanes, phosphazenes and phosphonite epoxides, acetals and methyl acetals, lactones and lactams. The starting material or initiator of the cyclic ROP can be multifunctional, monomeric, oligomeric, polymeric, and branched, and can be ring-opened by any number of mechanisms, including: radical ROP (RROP), cationic ROP (CROP), anionic ROP (AROP), and ring-opening metathesis polymerization (ROMP).

[0180] In most cases, ROP polymerization does not produce undesirable byproducts such as water and can provide a "dry" pathway to polymers that normally produce water byproducts, such as the condensation polymerization known to produce polycarbonates. For example, ROP of ketene acetal can produce useful polyesters without water byproducts. As mentioned above, another example is a ROP involving positively charged or cationic intermediates (cationic ROPs or CROPs), which can produce polymers including polyacetals, copolymers of 1,3,5-trioxane and oxirane or 1,3,5-trioxane and 1,3-dioxolane, polytetrahydrofuran, copolymers of tetrahydrofuran and oxirane, poly(3,3-bis(chloro-methyl)oxetane), polysiloxanes, ethyleneimine, and polyphosphazene. Useful polymers produced by ROPs include, but are not limited to: polycyclooctene, polycarbonate, polynorbornene, polyethylene oxide, polysiloxane, polyethyleneimine, polyglycolic acid, and polylactic acid.

[0181] By intelligently selecting the chemical structure of cyclic ROP precursors, such as ring size, side group substituents, and the degree of functionalization, the physical properties of printed and polished objects, such as flexibility, elongation, hardness and toughness, storage modulus (E'), and the hydrophobicity or hydrophilicity of the formed object, can be tuned. Examples of ROP cyclic monomers that can be used to generate printed and polished objects include: (U.) δ-valerolactone for generating polyesters, (V.) ε-caprolactam for generating polyamides, and (W.) 2-ethyl-2-oxazoline for generating polyoxazoline.

[0182] In another embodiment of this disclosure, the Diels-Alder (DA) reaction can be used to produce a printed polishing article. The classic DA reaction is a [4+2] cycloaddition reaction between a conjugated diene and a second component ("dienophile") to yield a stable cyclohexene derivative ("adduct"). The diene and dienophile can be selected from rings, heterocycles, and highly substituted materials containing complex functional groups and / or protected or potential functional groups. The diene can be understood as any conjugated diene in which two double bonds are separated by a single bond, and the dienophile can be a compound having double bonds with a preferred proximity to an electron-withdrawing group. The diene precursor can consist of any 5- to 8-membered ring containing a conjugated diene, where all ring members are carbon atoms in the conjugated diene system or mixtures of carbon atoms and heteroatoms selected from nitrogen, oxygen, sulfur, and mixtures thereof. The ring atoms may be unsubstituted or contain electron-donating substituents (e.g., alkyl, aryl, arylalkyl, alkoxy, aryloxy, alkylthio, arylthio, amino, alkyl-substituted amino, aryl-substituted amino, alkoxy-substituted amino, and similar groups). The dienophile may consist of any unsaturated group capable of undergoing a DA reaction. As mentioned, the dienophile may be unsubstituted or substituted with electron-withdrawing groups, such as cyano, amide, carboxyl, carboxyl ester, nitro, or an aromatic ring containing electron-withdrawing groups. Alternatively, the dienophile may be a double bond within a ring structure conjugated with one or more electron-withdrawing groups. DA reactions may also exhibit thermal reversibility, allowing the adduct to decouple by increasing the temperature. For the purposes of this disclosure, suitable dienes and dienophiles may be any such material capable of participating in a DA reaction that would not undergo a reverse or "retro" DA reaction at temperatures likely encountered in typical user environments (such as those seen during polishing processes). In one embodiment, the polished object can be recycled back to monomer at temperatures far above those visible during the polishing process.

[0183] In one embodiment, the Diels-Aldrich reaction can be used to produce printed polymer layers and polished objects such as CMP pads. As illustrated in Reaction Example 2, a dicis-butene diimidimide compound can react with a difuran compound to form a polymer: For polymerization in Reaction Example 2, the requirement is that the diene and dienophile molecules each contain at least two diene or dienophile reactive sites separated by one or more linking groups. Furthermore, the DA polymerization products can encompass linear copolymers, branched polymers or copolymers, block copolymers, star-shaped or dendritic polymers. One source of the diene and dienophile compound is Sigma-Aldrich in St. Louis, Missouri, USA.

[0184] In one embodiment of this disclosure, aromatic compounds containing photoresponsive groups can be used to generate polymer layers and print polished objects. When exposed to UV light, the photoresponsive groups can participate in polymerization and / or the bonding of part and / or a larger polymer network structure. This type of reaction can be carried out by a reversible [4π + 4π] or [2π + 2π] cycloaddition mechanism after the application of light of an appropriate wavelength (if desired). In the case of [4π + 4π] or [2π + 2π] cycloaddition reactions, photodimerization can occur between two olefins to form a cyclobutane dimer. Useful photoresponsive monomers, oligomers, and polymers may contain photoresponsive groups, including but not limited to: anthracene, cinnamic acid, coumarin, thymine, and stilbene groups, which can be reacted by [4π + 4π] or [2π + 2π] cycloaddition mechanisms. An illustrative example is reaction example 3, in which cinnamic acid undergoes a [2π + 2π] cycloaddition reaction to produce a cyclobutyl group. It should be noted that multifunctional monomers and oligomers undergoing [4π + 4π] or [2π + 2π] cycloaddition reactions can be used to produce polymeric materials when exposed to UV light or other forms of radiation at suitable wavelengths. One example of a [4π + 4π] or [2π + 2π] cycloaddition reaction may include reaction example 3: Reaction Example 3

[0185] Generally, [4π + 4π] or [2π + 2π] cycloaddition reactions or polymerizations will begin at a radiation exposure level between approximately 0.1 J / cm² and approximately 500 J / cm² at UV radiation wavelengths, lasting for periods of approximately 0.1 seconds and approximately 100 seconds, respectively. The amount and intensity of UV radiation can be adjusted to achieve the desired conversion level, depending on film thickness and other factors. UV radiation can be provided by any UV source, such as mercury microwave arc lamps (e.g., H-bulb, H+-bulb, D-bulb, Q-bulb, and V-bulb type lamps), pulsed xenon flash lamps, high-efficiency UV light-emitting diode arrays, and UV lasers. If necessary, suitable optics can be used to facilitate radiation or limit exposure to only the desired area. UV radiation can have wavelengths between approximately 170 nm and approximately 500 nm. The useful temperature range for photoreaction is approximately -25°C to approximately 25°C. These compounds are sourced from Sigma-Aldrich in St. Louis, Missouri, USA.

[0186] In another embodiment of this disclosure, benzocyclobutene (BCB) compounds can be used to produce printed polished objects, such as CMP pads. The benzocyclobutene compound is a thermally polymerizable monomer containing at least one BCB group per molecule. As shown in Reaction Example 4, the first equilibrium step involves the thermal activation and ring-opening of the four-membered ring of BCB to obtain highly reactive ortho- and posterior-joint groups (k1 / k2). This reactive intermediate then readily undergoes a [2π+4π]DA reaction (k3) to form a polymer. Depending on its functionality, BCB can be polymerized to produce thermosetting or thermoplastic materials and can be cured using any suitable method, such as a xenon flash lamp or IR laser, after droplet application. The polymer typically exhibits excellent thermal stability and retention of mechanical properties at the temperatures seen in polishing processes. Those skilled in the art will understand that the chemical structure of BCB can be altered to obtain desired physical properties, such as the storage modulus (E'), hardness, adhesion, flexibility, and elongation optimal for polishing the object. BCB compounds are sourced from Sigma-Aldrich in St. Louis, Missouri, USA, and Dow Chemical (Cyclotene®) in Midland, Michigan, USA.

[0187] Typically, when loads are applied during normal use of an advanced polishing pad, formulations used to form a more rigid material within the pad often result in a material that does not have the elongation required at the desired level. In some embodiments, to address this issue, it may be necessary to introduce an elastomeric material into the formulation and thus into the cured material, thereby increasing the elongation of the formed material while maintaining the desired tensile strength. In some cases, these modified materials can be achieved by using a combination of a polyurethane oligomer-based methacrylate material and an acrylic monomer. To prevent any degradation in the ability to cure the new formulation, exothermic materials can be used. Interpenetrating polymer network structure

[0188] As discussed above, the deposition process described herein enables the specific placement of material compositions with desired properties in specific pad regions of an advanced polishing pad, allowing the properties of the deposited compositions to be combined to produce polishing pads with average properties of individual materials or "composite" properties. In another embodiment of this disclosure, it has been found that average properties or "composite" properties can be uniquely tuned or modulated within and / or layer by layer by generating or fabricating an "interpenetrating polymer network" of the material by intelligently selecting resin precursor components selected from, but not limited to, those materials in Table 3 or other relevant resin precursor components described herein.

[0189] An interpenetrating polymer network (IPN) can be defined as a blend of two or more polymers in a network structure and at least one of polymers synthesized in the presence of another polymer. This can produce a "physically crosslinked" network structure, in which the polymer chains of one polymer are entangled with and / or penetrate the network structure formed by the other polymer. Each individual network structure retains its individual properties, allowing for synergistic improvements in properties including E'30, E'90, E'30 / E'90, strength, toughness, compression, and elongation. IPNs can be distinguished from polymer blends in that they are expandable but insoluble in solvents, and material creep and flow are suppressed. In some cases, due to the close polymer entanglement and / or network structure, IPNs can be called "polymer alloys," by which polymer blends can be made chemically compatible and / or highly miscible to achieve the desired phase morphology and related properties. IPNs can be distinguished from many other systems or network structures by their multi-continuous structure, which is ideally formed by at least two polymers that are solidly entangled or interlaced in close contact but can be chemically bonded or not chemically bonded to each other.

[0190] In embodiments of this disclosure, the IPN is used to tune and adjust the properties of the polishing pad to produce desired composite properties, such as E'30, E'90, E'30 / E'90, strength, toughness, compression, and elongation. In some embodiments, the polymer may be added to the formulation mixture or the mixture of resin precursor components from about 1% to about 50% by weight, from about 5% to about 25% by weight, and from about 10% by weight. Importantly, the molecular weight, chain length, and branching of the polymer may play a role in the weight percentage of the polymer due to factors including polymer miscibility and mixture viscosity. For example, linear polymers may produce a more viscous mixture than branched polymers. In some embodiments, the polymer in the pre-cured mixture may be inert to UV light and may not participate in the polymerization of other functional resin precursor components, such as monomers or oligomers. In other embodiments, the added polymer may contain chemically functional groups, such as acrylic and epoxy groups, which may participate in the polymerization of resin precursor components, such as monomers or oligomers. In this disclosure, we do not limit the methods of IPN synthesis, nor do we limit the types of resin precursor components or polymers used to generate IPN.

[0191] In other embodiments of this disclosure, an IPN can be produced, wherein a linear polymer can be trapped in a growing cross-linked network structure that may be produced from a resin precursor component such as a monomer or oligomer through UV photopolymerization. In one case, the properties of the linear polymer (e.g., elongation) can be maintained within an IPN that also contains a hard cross-linked material that may have low elongation, thereby producing a "composite" or average property of the overall properties. Depending on the soft, medium-hard, or hard phase in the IPN, or the continuity, distribution, and weight or molar percentage of the material, the IPN can exhibit a wide range of properties, such as enhanced rubber-like properties to hard, high-impact plastic properties. In some embodiments of this disclosure, polishing pads containing IPNs can be produced that have high flexibility, elongation (e.g., 100% to 400%), and toughness (≥2 MPa). In some embodiments, an IPN containing a polymer such as poly(butyl methacrylate-co-methyl methacrylate) (A3 in Table 3) is produced. This polymer can be used to increase the elongation of the polishing pad while maintaining adequate tensile strength. Table 8 presents some experiments illustrating these embodiments. Item 1 in Table 8 serves as an experimental control (non-IPN) without the A3 polymer, and items 2-3 represent IPNs produced under different conditions involving increasing the weight percentage of A3 in the IPN. The results demonstrate the effectiveness of using an IPN in polishing pads. The tensile-elongation results shown in this table are based on the ASTM D638 tensile test method. Table 8 Project Number Material composition (see Table 3 for reference names) Formula composition (wt%) Viscosity (cP) 70℃ Tensile strength (MPa) Elongation (%) Flexible response 1 O8:A3:M2:P5 10:0:90:2 4.5 0.60 ~100 yes 2 O8:A3:M2:P5 10:5:85:2 9.4 1.5 - 1.9 162-211 yes 3 O8:A3:M2:P5 10:10:80:2 25.5 1.5-2.0 283-350 yes

[0192] In other embodiments of this disclosure, the IPN may be formed using two or more polymeric materials forming various portions of the forming pad body 202, such as blends including urethane, esters, thiols, and epoxy polymers. A mixture of urethane polyurethane acrylate and an epoxy polymer containing less than 5% epoxy groups will produce a material in which the epoxy polymer acts as a plasticizer for the polyurethane acrylate network structure. However, urethane polyurethane acrylate and an epoxy polymer containing more than 5% epoxy groups will produce a material in which the epoxy polymer is interwoven with the polyurethane acrylate network structure that affects the mechanical properties (such as elongation, hardness, and ultimate tensile strength) of the formed material. Other examples of materials that can be used to form IPN include poly(methyl methacrylate), poly(butyl methacrylate), poly(isobutyl methacrylate), poly(butyl methacrylate-co-methyl methacrylate), polystyrene, poly(styrene-co-α-methylstyrene), poly(tert-butyl acrylate-co-ethyl acrylate-co-methacrylic acid), and poly(phenyl methacrylate).

[0193] In some embodiments, the formulation mixture or the mixture of resin precursor components may contain between about 5% and about 50% of a thermoplastic polymer completely dissolved in the formulation applied by a deposition hardware (such as a printhead) during a lamination process (e.g., a 3D printing process). It is believed that formulations containing thermoplastic polymers will readily form polymers that interpenetrate with thermoplastic polymers to form an interpenetrating polymer network structure after UV curing. In one example, the thermoplastic polymers used to form an IPN include linear polymers such as polyurethane, polyester, polyether, polystyrene, polyacrylate, polymethacrylate, polyethylene, polypropylene, PEEK, and PEKK. Adding thermoplastic polymers to form an IPN will readily improve the mechanical properties of the cured material, including storage modulus, loss modulus, tensile strength, elongation, and flexibility. Since the incorporation of methacrylate polymer chains and methacrylate monomers during UV curing is extremely difficult, prepolymerized methacrylate monomers can be readily introduced into the formulation by dissolving the linear polymer.

[0194] In some embodiments, the lamination process may alternatively or may also include the use of a sprayable resin precursor composition comprising 20-70% photocurable oligomers / monomers and 30-80% post-printing heat-curable (e.g., annealed) oligomers / monomers. The photocurable portion is primarily based on an acrylate (polyester / polyether) formulation, and the heat-curable portion comprises a blocked isocyanate having a diol, which allows the groups to deblock at elevated annealing temperatures resulting from the reaction of the isocyanate with the diol to form ethyl carbamate, as in the following reaction examples: Examples of deblocking groups include phenols, oximes, and caprolactams having deblocking temperatures of 170°C, 140°C, and 170°C, respectively. Other examples of blocked isocyanates include ethyl isocyanate of (meth)acrylate blocked with phenol or diacetime, prepared by the addition of ethyl isocyanate of (meth)acrylate to phenol or diacetime. It is believed that these types of resin precursor compositions will allow for the formation of highly selective network structures, unlike most current photocurable inks that rely on the energy budget provided by electromagnetic radiation (e.g., UV light) delivery. Therefore, by controlling the desired formulation composition, the mechanical properties of the materials formed using these resin precursor compositions can be better controlled or customized to meet the requirements of advanced polishing pad components.

[0195] In one embodiment, the 3D-printed polymer layer may contain inorganic and / or organic particles for enhancing the properties of one or more selected material layers present in the formation of the advanced polishing pad 200. Since the 3D printing process involves the sequential deposition of at least one component per layer, it may also be necessary to additionally deposit inorganic or organic particles disposed on or within the pad layer to obtain a particular pad property and / or perform a particular function. The size of the inorganic or organic particles may range from 1 nanometer (nm) to 100 micrometer (μm) and may be added to the precursor material or to the uncured printed layer at a ratio between 1% and about 50% by weight prior to application by a drop-jet printer 306. The inorganic or organic particles may be added during the advanced polishing pad formation process to improve ultimate tensile strength, improve yield strength, improve the stability of the storage modulus over a certain temperature range, improve heat transfer, modulate the surface zeta potential, and / or modulate the surface energy. The type, chemical composition, or size of the particles, and the particles added, can vary depending on the application or desired effect. In some embodiments, particles may include intermetallic compounds, ceramics, metals, polymers, and / or metal oxides, such as cerium dioxide, alumina, silicon dioxide, zirconium oxide, nitrides, carbides, or combinations thereof. In one example, inorganic or organic particles disposed on, above, or within the pad may include particles of high-performance polymers, such as PEEK, PEK, PPS, and other similar materials that improve the mechanical properties and / or thermal conductivity of advanced polishing pads. Particles integrated in 3D printing polishing pads can also act as crosslinking focal points, which, depending on the loading weight percentage, can produce a higher storage modulus E'. In another example, polymer compositions containing polar particles such as cerium dioxide can provide further affinity for polar materials and liquids (such as CMP slurries) on the pad surface. Advanced Polishing Pad Characteristics

[0196] An advantage of forming an advanced polishing pad 200 having a pad body 202 including at least one first polishing element 204 and a second polishing element 206 is that it is possible to form a structure with mechanical, structural, and dynamic characteristics not present in a pad body formed from a single material composition. In some embodiments, it is necessary to form a polishing body 202 including at least one region in which the first polishing element 204 is disposed above and supported by a portion of the second polishing element 206 (e.g., portion 212A in Figure 2A). In this configuration, the combination of the characteristics of the two material and structural configurations can be used to form an advanced polishing pad with the desired mechanical, structural, and dynamic characteristics, and improve the polishing performance of conventional polishing pad designs.

[0197] The materials and chemical structures of the first polishing element 204 and / or the second polishing element 206 can be selected to achieve "tuning" of the host material by using the aforementioned chemical substances. The advanced polishing pad 200 formed by thus "tuning" the host material has various advantages, such as improved polishing results, reduced manufacturing costs, and extended pad life. In one embodiment, when measured as a whole, the hardness of the advanced polishing pad 200 can be between about 25 Shore A and about 75 Shore D, the tensile strength between 5 MPa and about 75 MPa, the elongation at break between about 5% and about 350%, the shear strength higher than about 10 MPa, and the storage modulus E' modulus between about 5 MPa and about 3000 MPa.

[0198] As discussed above, materials with different mechanical properties can be selected for use in the first polishing element 204 and / or the second polishing element 206 to achieve improved polishing results on the polishing substrate. Mechanical properties, such as storage modulus E', of the materials present in the materials forming the first polishing element 204 and / or the second polishing element 206 can be generated by selecting different materials, material compositions, and / or choosing different post-deposition processing steps (e.g., curing processes) during the polishing element formation process. In one embodiment, the second polishing element 206 may have a lower hardness value and a lower storage modulus E' value, while the first polishing element 204 may have a higher hardness value and a higher storage modulus E' value. In another embodiment, the storage modulus E' can be adjusted at various locations within each polishing element 204, 206 and / or on the polished surface of the polishing pad. In one embodiment, the hardness of the first polishing element 204 may be from about 40 Shore D scale to about 90 Shore D scale. The hardness value of the second polishing element 206 may be between approximately 26 Shore A scale and approximately 95 Shore A scale. The first polishing element 204 and the second polishing element 206 may each include different chemical compositions that are co-mixed and chemically bonded together at multiple boundaries within a single pad body 202.

[0199] In some embodiments, the hardness, storage modulus E', and / or loss modulus E” of the materials used to form the first polishing element 204 and the second polishing element 206 are each configured to improve one or more polishing process parameters and / or lifetime of the polishing pad. In some configurations, the hardness, storage modulus E', and / or loss modulus E” of the materials used to form the first polishing element 204 and the second polishing element 206 within the advanced polishing pad are configured to provide improved polishing rate and polishing uniformity (e.g., WiW uniformity, WtW uniformity). It has been found that controlling the hardness of the second polishing element 206 is very helpful in improving the polishing uniformity and polishing rate of the formed advanced polishing pad, which is generally positioned as shown in Figures 1F to 1G, 2A, and 2C to support the first polishing element. Figures 6A to 6B generally illustrate the effect of different material hardness on the polishing elements within advanced polishing pads (i.e., samples 1, 2, and 3) with structures similar to the advanced polishing pad construction shown in Figure 2A. Figure 6A is a graph illustrating the effect of different material hardness on the polishing rate of a similarly configured second polishing element in the advanced polishing pads (samples 1, 2, and 3). It should be noted that the advanced polishing pad structures used to collect the data in each sample include a similarly configured first polishing element 204 (e.g., material and structural shape), while the material properties (e.g., hardness) of the second polishing element 206 are changed by adjusting the material composition ratio of hard material formulation drops to soft material formulation drops within the second polishing element 206. In these examples, the first polishing element 204 for each sample is formed such that its hardness is greater than that of the second polishing element 206, and it has a Shore D hardness of approximately 80 and a storage modulus between 1700 MPa and 2000 MPa. As shown in Figure 6A, it should be noted that Samples 2 and 3 (with Shore A hardness of 80 and 70 respectively, and storage modulus of 13 MPa and 5 MPa) have relatively higher average material removal rates compared to Sample 1, which has a Shore A hardness of 90 and a storage modulus of 43 MPa. However, as shown in Figure 6B, Sample 3 exhibits the highest polishing rate uniformity compared to Samples 1 and 2. Advanced polishing pads exhibiting high polishing rate non-uniformity, such as Samples 1 and 2 compared to Sample 3, will result in non-uniform final polishing results on the substrate. Therefore, in some embodiments, it is necessary to adjust the material composition ratio of one or more layers within the second polishing element 206 to achieve a hardness less than 90 Shore A. In some configurations, the material composition ratio of one or more layers within the second polishing element 206 is adjusted to achieve a hardness less than 80 Shore A, such as less than 70 Shore A, less than 60 Shore A, less than 50 Shore A, or even less than 40 Shore A.In some configurations, the material composition ratios of one or more layers within the second polishing element 206 are adjusted to achieve a hardness between 10 Shore A and 80 Shore A, such as between 10 Shore A and 70 Shore A, or even between 20 Shore A and 60 Shore A. In some alternative embodiments, it may be desirable to change the resin precursor composition of at least one of the formulations used to form the second polishing element 206 in order to adjust the hardness of the material forming the second polishing element 206.

[0200] For the purposes of this disclosure and not intended to limit the scope of this disclosure, Table 2 summarizes materials for use in the first polishing element 204 and the second polishing element 206 of the advanced polishing pad 200, which possess the desired low, medium, and / or high energy storage modulus E' characteristics (E'30) and (E'90) at 30°C and 90°C: Table 2 Low energy storage modulus components Medium energy storage module components High energy storage modulus components E'30 5 MPa - 100 MPa 100 MPa - 500 MPa 500 MPa - 3000 MPa E'90 <17 MPa <83 MPa <500 MPa

[0201] In one embodiment of the advanced polishing pad 200, a plurality of first polishing elements 204 are configured to protrude over one or more second polishing elements 206, so that the polishing surfaces 208 of the first polishing elements 204 are used to polish the surface of the substrate 110 during the polishing process. In one embodiment, to ensure the desired flatness, polishing efficiency, and reduced pitting during the body material polishing step, it is necessary to form a first polishing element 204 that brings a material having a high energy storage modulus E', such as that defined in Table 2, into contact with the substrate surface during the polishing process. However, in one embodiment, to ensure the desired flatness, polishing efficiency, and reduced pitting during the polishing or residual material cleaning step, it may be necessary to form a first polishing element 204 that brings a material having a low or medium energy storage modulus E' into contact with the substrate surface during the polishing process.

[0202] In some embodiments, the storage modulus of the first polishing element 204 is adjusted to minimize the effect of pad polishing, which reduces the polishing process removal rate over time without performing a polishing process on the smooth surface of the polishing pad used (i.e., pad adjustment). It is believed that pad polishing is caused by the plastic deformation of the material on the contact substrate surface, which is inversely proportional to the shear modulus (G'), because the shear force on the pad surface causes "cold flow" or plastic deformation of the contact material. For isotropic solids, the shear modulus is generally related to the storage modulus by the following equation: G' = E' / 2(1+ν), where ν is Passon's ratio. Therefore, the material used to form the first polishing element 204 with a low shear modulus and therefore a low storage modulus will have a faster rate of plastic deformation and therefore a faster rate of formation of the polished region. Therefore, it is also necessary to form the first polishing element 204 with a high storage modulus E' and / or hardness as defined above.

[0203] To ensure that the polished surface of the polishing pad can be renewed by using the pad conditioning process, the material used to form the first polishing element 204 also needs to have the required tensile strength and elongation at break. In some embodiments, the ultimate tensile strength (UTS) of the material used to form the first polishing element 204 is between about 250 psi and 9,000 psi. It is believed that the higher the UTS of the material used to form the first polishing element 204, the more durable the polishing pad material and the less prone to microparticle formation before, during, or after the pad conditioning process. In one example, the UTS of the material used to form the first polishing element 204 is between about 5,000 psi and 9,000 psi. In some embodiments, the elongation at break of the material used to form the first polishing element 204 is between about 5% and 200%. It is believed that the lower the elongation at break of the material used to form the first polishing element 204, the less the material will deform, and therefore the easier it is to maintain the surface microtexture or roughness that allows for abrasive trapping and slurry transport. In one embodiment, the elongation at break of the material used to form the first polishing element 204 configured to contact the polished surface of the substrate is adjusted between about 5% and about 40%.

[0204] It is also necessary to provide a polishing pad with the required damping characteristics to reduce the elastic rebound of the pad during polishing, which can cause dents and other negative properties related to the annular deformation of the pad during processing. Therefore, in order to compensate for the need for the high energy storage modulus E' material to contact the substrate surface during polishing, the second polishing element 206, which is placed to support the first polishing element 204, is formed of a material with a lower energy storage modulus E'.

[0205] In one example, the advanced polishing pad 200 may include the tan δ characteristics illustrated in Figure 7A. Figure 7A includes tan δ data (1 Hz, rate 5 °C / min) for a first polishing pad material (e.g., curve 791), a second polishing pad material (e.g., curve 792), and an advanced polishing pad configuration (e.g., curve 793), which contains either a first polishing pad material (e.g., a soft material) or a second polishing pad material (e.g., a hard material). As illustrated, the tan δ data contains independent and discrete tan δ peaks for the first and second materials, as shown by curves 791 and 792. In contrast, the tan δ peak of the advanced polishing pad material (curve 793) is broadened and merged, indicating molecular-level mixing, chain entanglement, chemical bonding, and / or compositional gradients, such as those present in the first polishing pad material in the second polishing element 206 and those present in the second polishing pad material in the first polishing element 204. It has been found that at temperatures between 30°C and 90°C, a maximum tan δ value between approximately 0.1 and approximately 3 helps to minimize indentation, planarization efficiency, and other related polishing non-uniformities.

[0206] To further control process repeatability, another controllable parameter in advanced polishing pads is the "recovery rate" of the pad material. Figure 7C illustrates the storage modulus E' curve as a function of temperature, obtained from numerous simulated polishing cycles of materials that can form a portion of the first polishing element 204 or the second polishing element 206. Graph 780 includes multiple curves that measure the decrease in storage modulus E' from the initial storage modulus 776 during each polishing cycle when the polishing pad is heated from an initial temperature of approximately 30°C to a final stable polishing temperature of approximately 90°C (e.g., storage modulus value 788) and when the pad is cooled from approximately 90°C to a final temperature of approximately 30°C. For illustrative purposes and clarity, the graphs in Figure 7C illustrate data for three polishing cycles: the first polishing cycle, including curves 782 and 783; the second polishing cycle, including curves 784 and 785; and the third polishing cycle, including curves 786 and 787. As shown in Figure 7C, at the end of each cycle 777-779, the measured storage modulus decreases due to relaxation in at least part of the reconfiguration of the bond structure present in the polishing pad material and / or the polymeric material, which may occur at higher polishing temperatures when higher loads are applied during the polishing process. The degree of material recovery after a large number of consecutive cycles is called the material's "recovery" capability. Recovery is typically measured as the percentage decrease in the value of a material property (e.g., storage modulus) from the starting point 776 to the stable equilibrium point 779, measured at the same point in the polishing cycle. The recovery rate can be calculated by multiplying the ratio of the measured end value 789 to the starting value 790 by one hundred. To ensure the stability of the polishing process, the material recovery rate in the polishing pad is generally required to be as high as possible, and therefore it is generally believed that the recovery rate should be at least greater than 50%, or even greater than or equal to about 70%, these values ​​are obtained using dynamic mechanical analysis (DMA) tests configured to simulate the CMP process. In one example, the DMA test duration is between approximately 5 and 10 minutes, such as approximately 8 minutes, with a maximum temperature change rate of approximately 5°C / min, intended to simulate a standard CMP process. The DMA test is used to simulate heating occurring on the polisher due to friction between the substrate, paste, retainer, and polishing pad. Heat tends to accumulate during polishing and is subsequently cooled rapidly between substrate processing steps due to normal fluid convection or heat conduction away from the pad. In some embodiments, to ensure the polishing pad has the desired recovery rate and thus ensure polishing process stability, it is necessary to adjust the composition of the precursor formulation and / or curing process parameters to control the stress and / or degree of crosslinking in the formed layer. In some embodiments, heat treatment, plasma treatment, chemical treatment of the surface of the advanced polishing pad, and / or exposure to electromagnetic radiation may also be required to improve surface and / or overall material properties before use in the polishing process.In some cases, heat treatment of a portion of the advanced polishing pad may be required, such as after the formation of individual curing layers or multiple curing layers, or even after the formation of the entire advanced polishing pad.

[0207] Referring to Figures 6E to 6F, it has been found that the structural configuration of the first polishing element 204 relative to the second polishing element 206 can also be used to control the repeatability of the polishing process and improve the polishing rate of the polishing process. One such structural configuration relates to the physical arrangement of the first polishing element 204 relative to the second polishing element 206 in the formed advanced polishing pad, and is referred to herein as the surface area to volume ratio (SAVR) of the first polishing element 204 within the formed advanced polishing pad. It is believed that by controlling the relative physical arrangement of the first polishing element 204 relative to the second polishing element 206 and the mechanical properties (e.g., thermal conductivity, hardness, loss modulus, polishing contact area, etc.) of the materials used to form the first polishing element 204 and / or the second polishing element 206, the surface area to volume ratio can be adjusted, which can greatly improve the repeatability of the polishing process, the substrate polishing rate, and other polishing parameters. In one example, the mechanical properties of the material within the first polishing element 204 include a thermal diffusivity (m² / s) of less than about 6.0 E-6 m² / s, such as between about 1.0 E-7 m² / s and 6.0 E-6 m² / s.

[0208] Figure 6E illustrates two first polishing elements 204A1 and 204A2 supported by a second polishing element 206, such that a portion of each of the first polishing elements 204A1 and 204A2 is embedded within a portion of the second polishing element 206. The second polishing element 206 has a bottom surface 2061 supported by components of a polishing tool (not shown). The embedded area of ​​the first polishing element is generally described herein as an unexposed portion 2041, and the portion of the first polishing element not embedded within the second polishing element 206 is referred to herein as an exposed portion 2040. Each of the first polishing elements 204A1 and 204A2 has a characteristic height 2021 extending from the surface 2060 of the second polishing element 206 to the top surface 2011 of each of the first polishing elements 204. The first polishing elements 204A1 and 204A2 formed within the first polishing element group have a spacing 2020, which may be constant or vary in the XY plane depending on the configuration of the advanced polishing pad. In some embodiments, as shown in Figures 2A and 2F-2K, the spacing 2020 between elements in the array can be oriented radially (e.g., in the XY plane) and arcuately (e.g., in the XY plane), and as discussed above, the spacing can be constant or vary in one or more of these directions.

[0209] Structurally, the first polishing elements 204A1 and 204A2 each have a portion including a side 2010 located above the surface 2060 of the second polishing element 206 and a top surface 2011 on which the substrate is placed during polishing. In one example, the first polishing element (which is similar to the first polishing element configuration shown in Figure 2A) has a total surface area that varies depending on the radial position of each first polishing element (e.g., concentric rings of different diameters). However, in another example, for a first polishing element configuration similar to that shown in Figure 2C, the total exposed surface area of ​​each first polishing element may not vary between the two first polishing elements. Generally, the total exposed surface area (TESA) of each first polishing element 204 includes the substrate contact area (SCA), which is the area of ​​the top surface 2011, and the total exposed sidewall area of ​​the first polishing element, which is the sum of the areas of the exposed portions of each side 2010. It should be noted that the total surface contact area (generally the area in contact when polishing the substrate) is the sum of the areas of all top surfaces 2011 of all first polishing elements 204 in the advanced polishing pad. However, the contact area percentage is the total contact area of ​​the first polishing elements 204 divided by the total pad surface area of ​​the polishing pad (e.g., πD² / 4, where D is the outer diameter of the pad). The volume (V) of the first polishing element is generally the total internal volume of the first polishing element 204, such as the volume of a cylinder of the first polishing element 204 shown in Figure 2C. However, the total exposed surface area to volume ratio (SAVR) (e.g., SAVR = TESA / V) of first polishing elements 204 having similar cross-sectional shapes (e.g., having the same radial width (e.g., width 214 in Figure 2A) or characteristic dimensions (e.g., length 208L in Figure 2C), embedding depth within the second polishing element 206, and polishing element height) will generally have the same total exposed surface area to volume ratio for each of the first polishing elements 204 used to form the array of advanced polishing pads.

[0210] Figure 6F illustrates two first polishing elements 204B1 and 204B2, each supported by an independent second polishing element 206 and having different characteristic heights 2021B1 and 2021B2. During the polishing process, friction between the top surface of each of the first polishing elements 204B1 and 204B2 and the corresponding substrate generates heat flux 2071 or heat flux 2072 that is conducted away from the top surface of each of the first polishing elements 204B1 and 204B2. Generally, if the surface characteristics of the top surface 2011 and the polishing parameters used to polish the substrate are kept the same for each of these configurations, the heat fluxes 2071 and 2072 will be similar. However, it has been found that the exposed surface area and volume of the first polishing elements 204B1 and 204B2 have an impact on the polishing process results, partly due to the temperature difference achieved in the first polishing elements 204B1 and 204B2 with different configurations during normal polishing. Increasing the process temperature generally leads to a decrease in the mechanical properties of the polymer-containing materials used to form each of the first polishing elements 204B1 and 204B2 with different configurations. Moreover, it should be noted that higher polishing temperatures generally increase the polishing rate of the polishing process, and variations in polishing process conditions between the two substrates are generally undesirable for most polishing processes.

[0211] Referring to Figure 6F, convective heat transfer generated by the movement of the polishing slurry relative to the exposed surfaces of the first polishing elements 204B1 and 204B2 removes at least a portion of the heat generated during the polishing process. During polishing, the temperature of the polishing slurry is typically lower than the normal temperature of the top surfaces (e.g., contact surfaces) of the first polishing elements 204B1 and 204B2. Therefore, the polishing process results of the first polishing elements 204B1 and 204B2 will differ at least due to: 1) the difference in exposed surface area, which affects the ability of the first polishing elements with different configurations to exchange heat with the slurry; 2) the difference in the insulation effect of the second polishing material 206 due to the difference in feature height; and 3) the difference in the mass (e.g., volume) of the first polishing elements. Figure 6C illustrates the effect of the feature height 2021 of the first polishing element on the removal rate during a standard polishing process. As shown in Figure 6F, the material removal rate will increase as the feature height decreases. Figure 6D illustrates the effect of the feature height 2021 on the ratio of total exposed surface area to volume. It is believed that the structural and thermal effects resulting from the ratio of the total exposed surface area to the volume of the formed first polishing element cause differences in the polishing process results of the different configurations of the first polishing elements (e.g., different feature heights 2021) shown in Figure 6C.

[0212] It should be noted that, due to the need for "pad condition" in polymer polishing pads, the action of polishing the top surface 2011 of the first polishing element will reduce the feature height 2021 throughout the lifespan of the polishing pad. However, when the advanced polishing pad is polished by the pad condition process, the change in feature height 2021 will cause a change in the total exposed surface area to volume ratio, and thus a change in the polishing process result. Therefore, it has been found that it is necessary to configure the first polishing element 204 in the advanced polishing pad so that the total exposed surface area to volume ratio remains stable throughout the lifespan of the polishing pad. In some embodiments, the total exposed surface area to volume ratio of the first polishing element 204, which is partially embedded in the second polishing element 206, is designed to have a total exposed surface area to volume ratio of less than 20 / mm (mm-1). In another example, the total exposed surface area to volume ratio is less than 15 mm-1, such as less than 10 mm-1, or even less than 8 mm-1.

[0213] In some embodiments, the first polishing element 204 in the advanced polishing pad is designed such that the total exposed surface area to volume ratio is within a stable range, for example, SAVR is less than 20 mm⁻¹, and the porosity of the first polishing element 204 is increased and / or controlled so that the slurry retention at the top surface 2011 is maintained in a desired manner. It has been found that adding porous features to the surface of the first polishing element 204 can also be used to stabilize temperature variations between wafers in the formed first polishing element 204, as similar to what has been found by adjusting the total exposed surface area to volume ratio. In one example, the porosity of the formed first polishing element is formed such that the thermal diffusivity (m² / s) of the material is between about 1.0E-7 m² / s and 6.0E-6 m² / s. The average pore size of the pores within the first polishing element 204 can be about 50 nm or more, such as about 1 μm to about 150 μm, and its void volume fraction is about 1% to about 50%.

[0214] Another advanced polishing pad structure configuration that can be used to control the repeatability of the polishing process and improve the polishing rate of the polishing process includes the substrate contact area (SCA) of the first polishing element 204 in the formed advanced polishing pad. Generally, the substrate contact area (the area in contact when polishing the substrate) is the sum of the areas of all top surfaces 2011 of all the first polishing elements 204 in the advanced polishing pad. However, the contact area percentage is the total surface contact area of ​​the first polishing elements 204 divided by the total pad surface area of ​​the polishing pad (e.g., πD² / 4, where D is the outer diameter of the pad). Figure 6G illustrates a graph of the polishing material removal rate of the first polishing elements (samples 4 and 5) formed in the advanced polishing pad as a percentage of the contact area. Figure 6H illustrates a graph of the average polishing process temperature of the first polishing elements (samples 4 and 5) formed in the advanced polishing pad as a percentage of the contact area. As shown in Figure 6G, by changing the contact area percentage of the advanced polishing pad from 50% to 40%, the medium material removal rate can be increased from approximately 3000 angstroms / min to approximately 3300 angstroms / min, or the material removal rate can be increased by 10%. As shown in Figure 6H, by changing the contact area percentage of the advanced polishing pad from 50% to 40%, the medium processing temperature can be increased from approximately 53°C to approximately 56°C, or the process temperature can be increased by 6%. Therefore, in some configurations, the contact area percentage of the first polishing element 204 is adjusted to achieve a contact area percentage of less than 40%, such as less than 35%, or less than 30%, or less than 25%, or even less than 20%. In some configurations, the contact area percentage of the first polishing element 204 is adjusted to be between 1% and 40%, such as between 10% and 40%, or between 10% and 30%, or between 10% and 20%.

[0215] It is also believed that, in order to maintain optimal polishing uniformity and polishing performance on the substrate, the E'30:E'90 ratio of the pad material should be controlled and adjusted as needed. To this end, in one embodiment, the E'30:E'90 ratio of one or more forming pad materials (e.g., the material used to form the first polishing element 204) and / or the overall advanced polishing pad 200 may be greater than or equal to 6, such as being between about 6 and about 15. The polishing pad may have a stable energy storage modulus E' in a temperature range of about 25°C to about 90°C, such that the E'30 / E'90 energy storage modulus E' ratio falls within the range of about 6 and about 30, where E'30 is the energy storage modulus E' at 30°C and E'90 is the energy storage modulus E' at 90°C. Polishing pads with an E'30:E'90 ratio of 6 or higher help reduce scratch-like defects that often occur when using materials with high energy storage modulus E' at steady-state processing temperatures below those visible during normal processing. In other words, as the temperature of the materials in contact with the substrate increases during processing, these materials will soften more readily than materials with a lower E'30:E'90 ratio, thus reducing the likelihood of scratching the substrate surface. Material softening during the polishing process can adversely affect the substrate and substrate stability of the process. However, materials with a high E'30:E'90 ratio may be useful in the initial portion of the polishing process (e.g., 10-40 seconds) where a high energy storage modulus polishing surface material is required, and subsequently, as the temperature continues to increase to the point where the polishing surface material becomes flexible, the polishing surface material completes the polishing process in a mode that reduces abrasion or scratching.

[0216] In some embodiments, it is necessary to control the thermal conductivity of individual sections of the advanced polishing pad to allow control of one or more polishing processes. In one embodiment, it is necessary to increase the overall thermal conductivity of the advanced polishing pad in the direction of the polishing surface (such as the Z direction in Figures 1A to 2K). In this example, the increased thermal conductivity in the Z direction compared to conventional polishing pad formulations allows the polishing pad surface temperature to be maintained at a low temperature because it is easier to conduct the heat generated on the polishing pad surface during processing to the large thermal mass and / or the frequently cooled polishing platform on which the advanced polishing pad is placed. The reduced polishing process temperature will reduce the polishing process variability often seen when polishing the first substrate of a batch of substrates and the last substrate of the batch (e.g., the 25th substrate), and mitigate the degradation of material properties (e.g., storage modulus E', E' ratio, etc.) often present in the polymeric materials in this batch of substrates. Alternatively, in some embodiments, it is necessary to reduce the overall thermal conductivity of the advanced polishing pad in the direction perpendicular to the polishing surface (such as the Z direction in Figure 1A). In this context, the reduced thermal conductivity in the Z-direction compared to conventional polishing pad formulations allows the polishing pad surface temperature to rise rapidly to the equilibrium processing temperature during polishing, as the polishing pad's ability to conduct heat generated on its surface during processing to the polishing platform on which the advanced polishing pad is placed is reduced. The often higher but more stable polishing process temperature can also be used to reduce the polishing process variability frequently observed when polishing the first substrate in a batch versus the last substrate in that batch (e.g., the 25th substrate).

[0217] Therefore, in some embodiments, one or more fillers, particles, or other materials need to be added to the first polishing element 204 and / or the second polishing element 206 during the forming process, thereby adjusting the thermal conductivity of the advanced polishing pad 200 in any direction (e.g., X, Y, or Z direction) within the polishing pad by using one or more stacking processes described herein. The thermal conductivity of polymers has been conventionally enhanced by adding thermally conductive fillers including graphite, carbon black, carbon fibers, and nitrides; therefore, polishing pad formulations and compositions may contain thermally conductive particles and compounds such as metal nitride materials, such as boron nitride (BN) or aluminum nitride (AlN), thereby increasing the thermal conductivity of the polishing pad. For example, the thermal conductivity of a conventional polishing pad without thermally conductive fillers can be from about 0.1 W / m•K to about 0.5 W / m•K at 25°C. In one embodiment, boron nitride with a thermal conductivity of about 250 W / m•K is added to the polishing pad at about 10 wt% of the formulation. The boron nitride layer may be deposited on and / or near the pad surface that is in contact with the polished substrate and is likely to experience the most heating due to the frictional polishing forces generated during polishing. In one embodiment, the additional boron nitride particles increase the thermal conductivity of the polishing pad from about 10% to about 25%, and thus increase the polishing pad lifetime by about two times. In another embodiment, a polymer layer on or near the polishing surface, such as the first polishing element 204, may contain particles that facilitate the removal of substrate metal and / or metal oxides.

[0218] In one embodiment, the weight percentage of silicon dioxide particles in the surface layer may be from about 0.1% by weight to about 30% by weight of the formulation, such as 10% by weight, and may increase the Shore hardness and modulus of such coatings by about 10% to about 50%. In one embodiment, the particle surface may be chemically modified so that the particles can be well mixed and / or suspended in the 3D polishing pad ink, and thus easier to apply without phase separation. Chemical modification includes the chemical bonding of surfactant molecules to the polar surface of the particles by a "coupling agent" such as a silane coupling agent. Other coupling agents that may be useful include titanates and zirconates. The chemical bonding, coupling, or attachment of the coupling agent to the particles may be carried out by chemical reactions such as hydrolysis and condensation. The coupling agents and related chemical compounds described herein are available from a wide range of sources, including Gelest Inc. of Morrisville, Pennsylvania, USA, and Sigma-Aldrich Chemicals of St. Louis, Missouri, USA.

[0219] The process for controlling and / or tuning the mechanical properties (such as modulus, tensile strength, elongation, flexibility, and compressibility) of the resulting advanced polishing pad material will also depend on the control and manipulation of the photopolymerization kinetics of the lamination process, including the regulation of oligomer / monomer steric hindrance and oxygen concentration. The kinetics of photopolymerization are crucial for the lamination of advanced polishing pads. Polymerization kinetics can be significantly affected by: 1) molecular steric hindrance of ink oligomers and monomers and 2) oxygen inhibition activating free radical activity.

[0220] Regarding steric hindrance, strong steric hindrance weakens photocuring kinetics and thus weakens the curability of the material formed during the lamination process, thereby allowing for tuning of mechanical properties. In some cases, the resin precursor composition contains oligomers and monomers to increase steric hindrance and improve the mechanical properties of the formed material, such as by blending methacrylate-based oligomers and / or monomers with acrylate-based oligomers and / or monomers. In other words, the elongation of the material formed by the lamination process can be controlled by managing the ratio of methacrylate-based oligomers and / or monomers to acrylate-based oligomers and / or monomers. Examples of methacrylate-based oligomers are shown below, including bifunctional methacrylate oligomers (X1) and trifunctional methacrylate oligomers (X2). Examples of acrylate-based oligomers are shown below, including bifunctional acrylate oligomer (Y1) and trifunctional acrylate oligomer (Y2).

[0221] Furthermore, specific examples of acrylate-based oligomers and monomers, and methacrylate-based oligomers and monomers, may include methacrylate-based materials SR203 and SR423A, and acrylate-based materials SR285 and SR506A, available from Sartomer. Typical examples of methacrylate oligomers include CN1963 and CN1964, which are also available from Sartomer. Enhanced material mechanical properties provide benefits to the mechanical performance of advanced polishing pads during the polishing process. For example, enhanced elongation can improve the removal rate of advanced polishing pads, wafer-to-wafer polishing non-uniformity (WTWNU), within-wafer non-uniformity (WIWNU), and polarization efficiency.

[0222] Regarding the oxygen effect on the mechanical properties of the formed material, the manipulation of the concentration of reactive gases (e.g., oxygen) in the additive manufacturing environment can also help tune the surface properties (e.g., hydrophilicity, dynamic contact angle formed by droplets) and mechanical properties of the formed material. As noted above, by removing various atmospheric contaminants (e.g., air) to control the composition of the environment within the additive manufacturing tool, the processes performed within the additive manufacturing tool can be controlled to improve process repeatability, process yield, and the properties of the formed layer. In some embodiments, the gas composition of the environment surrounding the printheads 308A-B and the surface of the formed layer is controlled by allowing an inert gas to flow through. Examples of inert gases may include nitrogen (N2) and argon (Ar), provided at a flow rate that forms a substantially laminar flow through the process environment. By delivering an inert gas through the process environment, the oxygen concentration can be controlled to control the curability of the deposited material. In one instance, Fourier transform infrared spectroscopy (FT-IR) characterization based on an acrylate-based sample (see Table A below) revealed a surface cure percentage of approximately 44% under standard atmospheric conditions (i.e., environmental conditions) using a UV LED irradiation source, compared to approximately 88% under nitrogen purging in the same environment. In another instance, FT-IR characterization based on another acrylate-based sample revealed a surface cure percentage of approximately 52% under standard atmospheric conditions (i.e., environmental conditions) using a standard UV irradiation source, compared to approximately 96% under nitrogen purging in the same environment. The dynamic contact angle under UV and UV LED conditions changed from 30°–50° without nitrogen purging to 60°–80° under nitrogen purging. Table A sample source Layer thickness (µm) Radiant energy (mJ / cm 2 ) surface Curing% (environment) bottom Curing% (environment) Surface curing % (N2 blanket covering) Bottom curing % (N2 blanket covering) 1 UV 125 12 52 84 96 88 2 UV-LED 125 12 44 80 88 88 Advanced Polishing Formulation Examples

[0223] As described above, in some embodiments, one or more materials used to form at least one of two or more polishing elements (such as the first polishing element 204 and the second polishing element 206) are formed by continuous deposition and post-deposition processing of at least one curing resin precursor composition. Generally, the curing resin precursor composition mixed during the precursor formulation process performed in the precursor delivery section 353 of the build-up manufacturing system 350 will include a formulation of a resin precursor composition containing functional oligomers, reactive diluents, and curing components (such as initiators). Some examples of such components are listed in Table 3. Table 3 Reference Name Materials Information sensibility Tg (°C) UTS (psi) Elongation % O1 Aliphatic polyurethane acrylate oligomers 2 27 5378 79 O2 Aliphatic hexafunctional polyurethane acrylate 6 145 11,000 1 O3 Low viscosity diacrylate oligomers 2 26 1,600 10 O4 Aliphatic hexafunctional acrylates 6 120 O5 Multifunctional polyurethane acrylate oligomers 3.4 46 3045 2 O6 Aliphatic polyurethane diacrylate oligomer 1 2 not applicable not applicable not applicable O7 Aliphatic polyurethane acrylate oligomer 2 not applicable not applicable not applicable not applicable O8 A blend of aliphatic polyester polyurethane diacrylate and aliphatic diacrylate 2+2 not applicable not applicable not applicable O9 acrylic oligomers not applicable not applicable not applicable not applicable M1 Dipropylene glycol diacrylate 2 104 2938 5 M2 2-Acrylic acid, 2-phenoxyethyl ester 1 5 19 236 M3 Tertiary-butyl cyclohexanol acrylate (TBCHA) 1 41 M4 Polyether-modified polydimethylsiloxane M5 CTFA 2 ether 1 32 - - M6 EOEO-EA 1 -54 - - M7 2-(((butylamino)carbonyl)oxy)ethyl ester 1 -3 M8 Tetrahydrofuran acrylate 1 -12 M9 Tetrafunctional polyether acrylate 4 not applicable not applicable not applicable M10 Isoborneol acrylate 1 not applicable not applicable not applicable M11 2-[[(butylamino)carbonyl]oxy]ethyl acrylate 1 not applicable not applicable not applicable P1 2-Hydroxy-2-methyl-1-phenyl-prop-1-one not applicable not applicable not applicable not applicable P2 4-Phenylbenzophenone not applicable not applicable not applicable not applicable P3 acetylglucosinolates not applicable not applicable not applicable not applicable P4 Bisphenylacetophosphine oxide not applicable not applicable not applicable not applicable P5 P1 and P3 mixture not applicable not applicable not applicable not applicable A1 Acrylated amine co-polymer <1 not applicable not applicable not applicable A2 Polyoxyethylene alkylphenyl ether ammonium sulfate non-migratory surfactant A3 Butyl methacrylate-co-methyl methacrylate copolymer 52 Examples of functional oligomers are shown in items O1-O9 of Table 3. Examples of functional reactive diluents and other additives are shown in items M1-M11 of Table 3. Examples of cured components are shown in items P1-P5 of Table 3. Items O1-O3, O7-O9, M1-M3, M5-M6, and M8-M10 in Table 3 were purchased from Sartomer USA; M11 was purchased from IGM Resins, USA; item O4 was purchased from Miwon Specialty Chemicals, Inc., South Korea; items O5-O6 were purchased from Allnex, Inc., Alphalitta, Georgia, USA; item M4 was purchased from BYK-Gardner GmbH, Germany; item M7 was purchased from Rahn USA, Inc.; and items P1-P5 and A1 were purchased from Ciba Specialty Chemicals, Inc. and Rahn USA, Inc. A2 was purchased from Montello, Inc., Tulsa, Oklahoma. Copolymer A3 was purchased from Sigma-Aldrich Chemical Company in St. Louis, Missouri, USA.

[0224] One advantage of the lamination process described herein includes the ability to form advanced polishing pads with properties that can be adjusted based on the material composition and structural configuration of the various materials used within the pad body structure. The following information provides some examples of material formulations and the effects of changing various components in these formulations and / or processing techniques on the desired properties of the advanced polishing pads, which will achieve improved polishing results superior to conventional polishing pad designs. The information provided in these examples can be used to form at least a portion of an advanced polishing pad 200, such as a first polishing element 204, a second polishing element 206, or a portion of both the first polishing element 204 and the second polishing element 206. The examples provided herein are not intended to limit the scope of the disclosure herein, as other similar chemical formulations and processing techniques can be used to adjust some of the properties described herein. The examples of the curing resin precursor composition components described above and below are intended as comparative examples, and those skilled in the art can find other suitable monomers / oligomers from various sources to achieve the desired properties. Some examples of reactive diluents are 2-ethylhexyl acrylate, octyl decyl acrylate, cyclic trimethylolpropane methyl acetal acrylate, caprolactone acrylate, isobornyl acrylate (IBOA), and alkoxylated dodecyl methacrylate. The aforementioned materials were purchased from Sigma-Aldrich and are also available from Sartomer USA and / or Rahn AG USA (SR series 203, 217, 238, 242, 306, 339, 355, 368, 420, 484, 502, 506A, 508, SR). 531, 550, 585, 495B, 256, 257, 285, 611, 506, 833S and 9003B; CD series 421A, 535, 545, 553, 590, 730 and 9075; Genomer series 1116, 1117, 1119, 1121, 1122, 5142, 5161, 5275, 6058, 7151 and 7210; Genocure series, BP, PBZ, PMP, DETX, ITX, LBC, LBP, TPO and TPO-L; and Miramer series, M120, M130, M140, M164, M166 and M170). Photomer 4184 is available from IGM Resins, USA. Some examples of bifunctional crosslinking agents are bisphenol A glyceryl dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, 1,6-hexanediol diacrylate and 1,4-butanediol diacrylate, which are available from Sigma-Aldrich.Some examples of oligomers may include aliphatic oligomers (CN series 131, 131B, 132, 152, 508, 549, 2910, 3100 and 3105, purchased from Sartomer USA); polyester acrylate oligomers (CN series 292, 293, 294E, 299, 704, 2200, 2203, 2207, 2261, 2261LV, 2262, 2264, 2267, 2270, 2271E, 2273, 2279, 2282, 2283, 2285 and 2303, purchased from Sartomer USA). USA); and aliphatic polyurethane oligomers (CN series 929, 959, 961H81, 962, 969, 964A85, 965, 968, 980, 986, 989, 991, 992, 996, 2921, 9001, 9007, 9013, 9178 and 9783, purchased from Sartomer USA). Reagents or additives are available from BYK, such as 3550, 3560, 307, 378, 1791, 1794, 9077, A515, A535, JET9510, JET9511, P9908, UV3500, UV3535, DISPERBYK168 and DISPERBYK2008. The first type of photoinitiators can be derived from BASF, such as the Irgacure series 184, 2022, 2100, 250, 270, 295, 369, 379, 500, 651, TPO, TPO-L, 754, 784, 819, 907, 1173 or 4265.Other functional oligomers and resin precursor components are available from Allnex, such as the Ebecryl series (EB): 40, 53, 80, 81, 83, 110, 114, 130, 140, 150, 152, 154, 168, 170, 180, 220, 230, 242, 246, 264, 265, 270, 271, 284, 303. 350, 411, 436, 438, 450, 452, 524, 571, 600, 605, 608, 657, 745, 809, 810, 811, 812, 830, 860, 870, 871, 885, 888, 889, 893, 1258, 1290, 1291, 1300, 1360, 1710, 3200, 3201, 3411, 3415, 3418, 35 00, 3600, 3700, 3701, 3720, 4265, 4827, 4833, 4849, 4858, 4883, 5129, 7100, 8100, 8296, 8301, 8311, 8402, 8405, 8411, 8412, 8413, 8414, 8465, 8501, 8602, 8701, 8702, 8804, 8807, 8808, and 8810. Non-migrating and non-polymerizable surfactants such as triethanolamine (TEA) and Hitenol and Maxemul trademarked materials are sourced from Sigma-Aldrich, Montello, Inc. of Tulsa, Oklahoma, USA, and Croda, Inc. of Newcastle, Delaware, USA. Example 1 - Energy storage module E' and E'30:E'90 comparison example.

[0225] The selection, formulation, and / or formation of materials with the desired energy storage modulus E' and E'30:E'90 ratio in the desired areas of the advanced polishing pad using a multilayer process are important factors in ensuring the uniformity of polishing results achieved by the advanced polishing pad on the substrate. It should be noted that the energy storage modulus E' is an inherent material property of the forming material, caused by the chemical bonds within the cured polymer material. The energy storage modulus can be measured at desired temperatures such as 30°C and 90°C using dynamic mechanical analysis (DMA) techniques. Examples of formulations containing different energy storage moduli are illustrated in Table 4 below. Table 4 Project Number Material composition (See Table 3 for reference names) Formulation components (wt%) E'30 (MPa) E'90 (MPa) E'30 / E'90 1 O1:M3 45:55 404 3.6 113.6 2 O1:M1 45:55 1595 169.5 9.4 3 O1:M3:M1:M2 45:22:22:11 680 10.4 65.3 4 O4:O1: M3:M1:M2 30:15:22:22:11 925 385.4 2.4 5 O4:O1:O3:M3:M1:M2:M4:P1 22.5:22.5:0.6:22:11:22:0.2:2 1536 8.9 6 O1:O3:M8:M7:M4:P1 42.5:0.6:34.5:23: 0.2:2 4.4 1.3 7 O1:O2:M1:M3:P3:P2:A1 11.65:5.826:8.544:12.816:0.776:0.098:0.292 1700- 2300 100-300 8 O6:M9:M10:O3:M4:P3:P2:A1 3.799:5.698:9.497:0.038:0.019:0.38:0.142:0.427 900- 1400 20-80 9 O1:M3:M1:O2:P4:P2:A1:A2:O3:M4 24.10:26.51:24.65:12.05:1.61:0.20:0.60:9.97:0.20:0.10

[0226] Referring to items 1 and 2 in Tables 3 and 4, resin precursor components containing higher functionality than other resin precursor components (e.g., monomers, oligomers, reactive diluents, and other materials containing chemically active functional groups or fragments) result in an increase in storage modulus at different temperatures, while simultaneously reducing the E'30:E'90 ratio of the formed material. In the formulation, changing the resin precursor component from type M3 (functionality 1) to type M1 (functionality 2) increases the storage modulus E' by nearly 400% at 30°C, while the E'30:E'90 ratio drops to approximately 8% of its original value. Similarly, comparing items 3 and 4 in Table 4, we will note that by adding multifunctional oligomers to formulations where the storage modulus can be moderately increased at different temperatures, the E'30:E'90 ratio of the formed material can be significantly reduced. Therefore, by adding the multifunctional oligomer O4 with a functionality of 6 to the formulation, the storage modulus E' at 30°C only increased by 136%, while the E'30:E'90 ratio dropped to about 4% of its original value. While not intended to be theoretically rigorous, it is believed that adding components to drop formulations with increased functionality significantly increases the degree of crosslinking within the polymer material at higher temperatures (e.g., 90°C) and thus significantly affects the E'30:E'90 ratio. Therefore, in some embodiments of this disclosure, precursor components with a functionality of 2 or greater are used in formulations for forming harder material regions (e.g., the first polishing element 204) in the advanced polishing pad 200. Similarly, softer regions of the advanced polishing pad 200 can be formed using formulations with a functionality lower than that of the harder regions in the polishing pad. Therefore, in some embodiments of this disclosure, precursor components with a functionality of 2 or less are used in formulations for forming softer material regions (e.g., second polishing elements 206) in the advanced polishing pad 200.

[0227] In other embodiments of this disclosure, high-modulus formulations with larger 40 kg batches can be produced, such as those exemplified in items 7 and 8 of Table 4. In these and other embodiments, the amount of the multifunctional resin precursor component can be increased to achieve a high degree of crosslinking while ensuring that the formulation has the viscousity (e.g., 5 cP to 30 cP at 70°C) that allows for application using a lamination process as described herein. For example, the material derived from item 7 contains a hexafunctional polyurethane acrylate O1 and exhibits a high modulus and a stable E'30:E'90 modulus ratio. A similar rigid high-modulus polishing pad material can be produced from the formulation of item 8, which contains a tetrafunctional acrylate diluent (item M9). Notably, polishing pads produced using the formulation of item 8 exhibit advantageous high oxide removal rates between approximately 2500 Å / min and approximately 3500 Å / min (using cerium-based polishing slurries), with a median removal rate of approximately 3000 Å / min. The formulation in Project 8 also showed a range of "thermal stability" during multiple polishing experiments, with the pad temperature only changing from about 27°C to about 31°C, and the median temperature being about 30°C.

[0228] In other embodiments of this disclosure, formulations that can be tunable or modified, including but not limited to item 7 of Table 4, have been found to produce new hydrophilic or "water-loving" polishing pad materials and / or pad surfaces with enhanced pad polishing properties, such as high substrate removal rates at typical polishing process temperatures. Specifically, new hydrophilic polishing pads with high removal rates can be produced by adding a polymerizable surfactant to the formulation, such as the formulation shown in item 9 of Table 4. In this example, an appropriate amount of polymerizable surfactant can be added to the formulation to produce new hydrophilic rather than hydrophobic polishing pad materials by using the lamination process described herein. In some cases, polymerizable surfactants may also be referred to as non-migratory surfactants (NMS) or "surfamers." NMS materials do not migrate into or out of or diffuse or diffuse out of the material because they are covalently bonded to, or copolymerized with, other polymeric resin precursor components in the formulation, such as oligomers and monomers. The functionality and / or copolymerization mechanism of NMS are not limited to those disclosed herein, and therefore NMS may contain any suitable functional groups that could induce such copolymerization, such as double bonds or another unsaturated site, which can copolymerize via radical mechanisms, such as by radical reactions with acrylates and / or any suitable resin precursor components such as those disclosed herein. In general, NMS may contain chemical functionalities that can participate in any chemical reaction, transformation, or interaction, including but not limited to: synthesis, decomposition, single substitution, double substitution, oxidation / reduction, acid / base, nucleophilic substitution, electrophilic substitution, and free substitution and addition / elimination reactions.

[0229] NMS materials and surfactants are generally beneficial for producing active surface coatings and material dispersions or gels because they can form stable micelles, in which the hydrophilic portion of the surfactant interacts with the aqueous solvent or medium, while the hydrophobic portion of the molecule stabilizes the particles or gel within the micelles. Conventional surfactants and NMS surfactants may include, but are not limited to, anionic and / or nonionic compounds or portions thereof, such as alkali metal or alkyl, aryl or alkylaryl ammonium salts, sulfates, sulfonates, phosphates or phosphate esters, alkyl sulfonic acids, sulfosuccinates, fatty acids and ethoxylated alcohols or ethoxylated phenols. The amount of NMS or surfactant typically used in a typical process can be between about 0.1% by weight and 6% by weight, based on the weight of the particles, fluids, monomers and / or resin precursor components.

[0230] Polishing slurries also typically use surfactants to stabilize and suspend abrasive particles and other components. It is understood that some aqueous slurry emulsions will not interact with conventional polishing pad surfaces because the pad surfaces have repulsive or hydrophobic characteristics. Advantageously, the embodiments of this disclosure provided herein utilize NMS materials to form hydrophilic polishing pad formulations, thereby producing polishing pads with a surface having surface energy that will allow them to interact with most conventional polishing slurries, such as water-based polishing slurries. Specifically, novel polishing pads and / or novel polishing pad surfaces containing covalently bonded NMS materials provide surfactant-like pad surfaces (e.g., dynamic contact angle less than 60°) that chemically react with the polishing slurry at the polishing pad-slurry-substrate interface and thus stabilize the polishing slurry. It is understood that because the slurry is smoothly maintained between the pad surface and the substrate by exposing the hydrophilicity of the pad surface, using a pad surface formed with an NMS-containing formulation provides an increased substrate material removal rate. Useful non-migrating surfactants include Hitenol, Maxemul, and E-Sperse trademarked materials, which were purchased from Montello, Inc. of Tulsa, Oklahoma, USA; Croda, Inc. of Newcastle, Delaware, USA; and Ethox Chemicals, LLC of Greenville County, South Carolina, USA, respectively.

[0231] Polishing pads modified with NMS material are expected to exhibit increased surface wettability and a reduced contact angle when in contact with aqueous polishing slurries. This is because the hydrophilic pad surface energy (measured in dynes) more closely matches the hydrophilic pad surface energy of the slurry or slurry droplets, causing the droplets to interact with the pad surface and diffuse out a hydrophobic surface. In some embodiments, the hydrophilic pad material may exhibit increased slurry interaction and slurry transport on the pad surface, believed to be due to the interaction between the NMS-modified surface and the slurry. Such materials may exhibit a dynamic contact angle of approximately 60 degrees on the water pad surface, such as between approximately 10 degrees and approximately 60 degrees, between approximately 20 degrees and approximately 60 degrees, between approximately 30 degrees and approximately 60 degrees, between approximately 40 degrees and approximately 60 degrees, and between approximately 50 degrees and approximately 60 degrees.

[0232] In one embodiment, item 7, which is a hydrophobic formulation, can be modified by adding a polymerizable interfacial activator and other suitable materials to produce a new hydrophilic formulation represented by item 9 in Table 4. Compared to the hydrophobic control sample formed using the formulation of item 7, the hydrophilic polishing pad formed using the formulation of item 9 showed an increased silicon oxide removal rate during polishing. In one embodiment, the pad derived from the hydrophilic formulation of item 9 exhibited a removal rate approximately 1.5 times higher than that of the hydrophobic pad material of item 7. For example, the pad material formed using the formulation of item 9 exhibited a removal rate between approximately 2200 Å / min and approximately 2400 Å / min, with a median rate of approximately 2350 Å / min. In contrast, the polishing pad derived from the hydrophobic formulation of item 7 exhibited a removal rate between approximately 1470 Å / min and approximately 1685 Å / min, with a median rate of approximately 1590 Å / min.

[0233] Due to friction generated during substrate surface polishing, the material removal rate generally tends to increase with increasing polishing process temperature. This is reflected in one embodiment of the polishing process, where the hydrophilic pad of item 9 exhibits a process temperature between about 26°C and about 29°C, with a median temperature of about 28°C. In contrast, the hydrophobic pad derived from the hydrophobic item 7 formulation exhibits a significantly lower process temperature between about 20°C and about 23°C, with a median temperature of about 22°C. In another embodiment of this disclosure, similar heating behavior was observed during the polishing process, where the hydrophilic pad of item 9 exhibits a process temperature between about 44°C and about 49°C, with a median temperature of about 48°C. In contrast, the hydrophobic pad derived from the hydrophobic item 7 formulation exhibits a significantly lower process temperature between about 37°C and about 42°C, with a median temperature of about 40°C. Example 2 – Energy Storage Modulus E' and Recovery Rate Comparison Example

[0234] Table 5 below illustrates examples of different formulations that can be used to adjust the energy storage modulus E' and recovery rate (%) of materials used in advanced polishing pads. Table 5 Project Number Material composition (see Table 3 for reference names) Formulation composition (wt%) E'30 (MPa) UTS (MPa) E'30 / E'90 Elongation at break % Response rate % 1 O1:O2:M3:M1:M2 40:5:10:10:35 347 9.8 19 38.5 40 2 O1:O2:M3:M1:M2 25:5:10:50:10 1930 19.5 11 1.9 86

[0235] Referring to items 1 and 2 in Table 5, we will note that by adjusting the amounts of various components in the formulation, an increase in storage modulus E', an increase in recovery rate (%), and a decrease in elongation at break can be achieved at lower temperatures (e.g., 30°C). It is believed that the significant changes in storage modulus E', recovery rate (%), and elongation at break at 30°C are mainly attributed to the increased percentage of chemical components with high glass transition temperatures (Tg). We will note that materials with low glass transition temperatures (e.g., Tg = 5°C), such as resin precursor component M2, tend to be softer at room temperature, while materials with high glass transition temperatures (e.g., Tg = 104°C), such as resin precursor component M1, tend to be harder and more brittle at temperatures close to room temperature. In this example, we will note that although the percentage of the multifunctional oligomer O1 with a functionality of 2 decreases slightly, and the percentage of the resin precursor component M1 with a functionality of 2 increases significantly, the change in the E'30:E'90 ratio is only modest. Therefore, it is believed that the crosslinking density of the polymer materials formed from the compositions of items 1 and 2 in Table 5 is likely to be similar, supported by a very modest change in the E'30:E'90 ratio of the two materials. Therefore, in some embodiments, a precursor component with a high glass transition temperature can be added to the formulation to form a material with a higher storage modulus E', greater hardness, a greater recovery percentage during treatment, and lower elongation at break. Similarly, in some embodiments, a precursor component with a low glass transition temperature can be added to the formulation to form a material with a lower storage modulus E', lower hardness, and greater elongation at break.

[0236] In some embodiments, it is necessary to adjust various components in the droplet formulation for forming a low energy storage modulus E' material such that the amount of the component with a glass transition temperature (Tg) less than or equal to 40°C is greater than the amount of the component with a glass transition temperature (Tg) greater than 40°C. Similarly, in some embodiments, it is necessary to adjust various components in the droplet formulation for forming a high energy storage modulus E' material such that the amount of the component with a glass transition temperature (Tg) greater than 40°C is greater than the amount of the component with a glass transition temperature (Tg) less than or equal to about 40°C. In some embodiments, the glass transition temperature (Tg) of one or more resin precursor components in the droplet formulation for forming a low energy storage modulus E' material in an advanced polishing pad is less than or equal to 40°C, and the glass transition temperature (Tg) of one or more resin precursor components in the droplet formulation for forming a higher energy storage modulus E' material of the same advanced polishing pad is greater than or equal to 40°C.

[0237] In some embodiments, the low energy storage modulus E' material formed in the advanced polishing pad has a glass transition temperature (Tg) such that the tan δ of the formed material is greater than 0.25 in a temperature range between 25°C and 90°C. In some embodiments, one or more resin precursor components in the drop formulation are used to form the low energy storage modulus E' material in the advanced polishing pad.

[0238] Example 3 – Contact Angle Comparison Example

[0239] As discussed above in conjunction with Figure 3C, Table 6 below illustrates examples of different formulations that can be used to adjust the contact angle of the droplet deposited on the surface. As noted above, it has been found that the contact angle α of the droplet can be controlled to improve the resolution of the features formed by the lamination process described herein by controlling at least the following: 1) the composition of the components in the droplet during the lamination process, 2) the amount of curing of the previously formed layer, 3) the amount of energy from the curing device, 4) the composition on the surface on which the droplet is placed, and 5) the amount of curing agent (e.g., photoinitiator) in the droplet composition. Table 6 Project Number Material composition (see Table 3 for reference names) Formulation components (wt%) E'30 (MPa) Contact angle (°) E'30 / E'90 Response rate (%) 1 O1:O2:M1:M2:P1 22:18:30:30:<1 2078 30 9.4 85 2 O1:O2:M1:M2: O3:M4:P1:P2: A1 22.5:22.5:30:25:0.06:0.02:<1:<1:<1 1353 60 4 82 3 O1:O2:M1:M2: O3:M4:P1:P2: A1 27.5:17.5:30:25:0.06:0.02:<1:<1:<1 2632 90 4.4 79

[0240] Referring to items 1, 2 and 3 in Table 6, we will note that by adjusting the amounts of various components in the formulation, the contact angle of the cured drop or "fixed" drop on a surface formed from the same or similar drop formulation can be adjusted. It is believed that significant changes in the contact angle can be achieved by adjusting the type and amount of functional monomers (e.g., items M1-M2 and M4) and photoinitiator components (e.g., items P1, P2 and Al) in the formulation of the applied drop.

[0241] The contact angle of the drop formulation can be improved by: 1) ensuring a fully or completely cured photoinitiator (e.g., a first-class photoinitiator) that achieves at least partial curing of the mechanical properties of the drop; 2) using a second-class photoinitiator, such as diphenyl ketone, and an amine synergist, which achieves rapid surface curing by reducing the ability of O2 to quench free radicals generated by UV exposure in the environment (e.g., a second-class photoinitiator); and 3) a surface modifier that readily imparts more or less polarity to the surface of the application drop. For example, a surface modifier can be used to alter the surface energy of the application drop when a hydrophilic uncured resin drop is deposited on a hydrophobic surface. This will result in a larger contact angle and thus ensure that the drop does not "wet" the surface. Preventing surface wetting will allow subsequent deposited drops to accumulate vertically (e.g., in the Z direction). As the drops approach each other horizontally, horizontal wetting of the surface needs to be prevented; therefore, sidewalls with vertically formed features will be formed vertically relative to the ramp shape. This improved contact angle ensures that the sidewalls of the printed feature are vertical or have a gentle slope when one is deposited on top of another. This resolution is important in advanced polishing pads because the substrate contact area of ​​the polishing feature throughout each polishing process needs to be maintained under a consistent contact area, and / or because the pad polishing material throughout the pad's lifespan needs to be removed by polishing or pad conditioning.

[0242] Example 4 – Tuning Example of Low Energy Storage Modulus E'

[0243] When combined with a higher energy storage modulus E', the selection, formulation, and / or formation of materials with the desired low energy storage modulus E' and desired E'30:E'90 ratio in various regions of the advanced polishing pad are important factors in ensuring the adjustable static and dynamic mechanical properties of the advanced polishing pad to achieve the desired polishing results. Table 7 below illustrates examples of formulations containing different energy storage moduli E'. Table 7 Project Number Material composition (see Table 3 for reference names) Formulation components (wt%) E'30 (MPa) E'90 (MPa) E'30 / E'90 1 O1:O5:M3:M5:M6:P1 25:25:21.4:14.3:14.3:<1 88 20 4.4 2 O8:M8:O9:O3:M4:P5 27:40:33:0.3:0.1:2 25.2 5.2 4.8 3 O1: M3:M2 45:27.5:27.5:<1 17.9 3.1 5.9

[0244] Referring to items 1 and 3 in Table 7, as similarly noted in Example 1 above, we will observe that by producing formulations containing multifunctional oligomers with a functionality of 2 or greater and different glass transition temperatures (Tg), the storage modulus E' at different temperatures can be adjusted, while the E'30:E'90 ratio of the formed material remains constant. For example, by adding the multifunctional oligomer O5 with a functionality of 3.4 to the formulation, the storage modulus E' at 30°C can increase by nearly 500%, while the E'30:E'90 ratio only drops to about 75% of its original value. Although not intending to be bound by theory, it is believed that when used in combination with resin precursor components with relatively low glass transition temperatures (Tg), the increased degree of crosslinking within the formed polymer material due to the addition of the multifunctional oligomer O5 component to the formulation has a significant effect on the storage modulus E' at lower temperatures (e.g., 30°C). Therefore, in some embodiments of this disclosure, resin precursor components with a functionality of 2 or greater may be used in combination with resin precursor components having a relatively low glass transition temperature Tg to form softer material regions (e.g., the second polishing element 206) in the advanced polishing pad 200. Furthermore, in some embodiments of this disclosure, precursor components with a functionality of 2 or less and functional oligomers are used in formulations for forming softer material regions (e.g., the second polishing element 206) in the advanced polishing pad 200. We further note that ratio adjustment and resin precursor component identification can advantageously produce high elongation materials exhibiting a desired E'30:E'90 ratio, as illustrated in item 2 of Table 7, wherein the material exhibits an elongation of approximately 82% to approximately 114% and an E'30:E'90 of approximately 4.8. In another embodiment of this disclosure, a high elongation material exhibiting an elongation of about 80% to about 195% is produced, wherein the weight percentage of the resin precursor components O7:M10:M11:P5 can be about 15:10:75:2. Similarly, a stable E'30:E'90 material can be produced by combining the resin precursor components in the following ratio: O1:M7:M8:O3:M4:P1, wherein a 40 kg batch can be produced when the relative weight percentage (kg) is about 16.537:8.949:13.424:0.233:0.078:0.778. According to the above embodiments and examples, by wisely selecting the resin precursor components and their proportions, while ensuring that the formulation has a viscosity (e.g., 15 cP to 30 cP at 70°C) that allows it to be applied using the lamination process described herein, a balance between hardness and elongation can be achieved.

[0245] In some embodiments, it is desirable to control the amount of crosslinking in the cured material formed from the resin precursor composition by controlling the relative amount of oligomer to monomer in the resin precursor composition (or also referred to herein as controlling the oligomer-monomer ratio) to control the characteristics of one or more polishing elements 204, 206 in the advanced polishing pad. By controlling the oligomer-monomer ratio in the resin precursor composition, the characteristics of the formed material (e.g., mechanical performance, dynamic performance, polishing performance, etc.) can be further controlled. In some configurations, the molecular weight of the monomer is less than 600. In some configurations, the molecular weight of the oligomer is 600 or more, such as a molecular weight greater than 1000. In some configurations, the oligomer-monomer ratio is defined as the weight ratio of the oligomer component to the monomer component, and this oligomer-monomer ratio is typically chosen to achieve the desired strength and modulus. In some embodiments, the oligomer-monomer ratio is from about 3:1 to about 1:19. In some embodiments, the oligomer-to-monomer ratio is in the range of about 3:1 to about 1:3 (e.g., a ratio of 2:1 to 1:2; a ratio of 1:1 to 1:3; a ratio of 3:1 to 1:1). In one example, a 1:1 oligomer-to-monomer ratio can be used to achieve desired toughness properties, such as elongation and storage modulus E', while maintaining the printability of the formed formulation. In some embodiments, it is desirable to select an oligomer-to-monomer ratio greater than 1:1, and therefore contain a larger weight ratio of oligomer to monomer. Resin precursor compositions with an oligomer-to-monomer ratio greater than 1:1 can be used to form more tough or more resilient material regions (e.g., the first polishing element 204) in the advanced polishing pad 200. In some embodiments, it is desirable to select an oligomer-to-monomer ratio less than 1:1, and therefore contain a larger weight ratio of oligomer to monomer. Resin precursor compositions with an oligomer-to-monomer ratio of less than 1:1 can be used to form more resilient and elastic material regions (e.g., second polishing element 206) in advanced polishing pad 200.

[0246] Example 5 – Example of Advanced Polishing Pad Features

[0247] As discussed above, the stacking process described herein enables the specific placement of material compositions with desired characteristics in specific pad regions of an advanced polishing pad, allowing the properties of the deposited compositions to be combined to produce polishing pads with average properties of individual materials or "composite" properties. In one example, an advanced polishing pad can be formed to thus possess the desired average loss tangent (tan δ) characteristics within a desired temperature range. Curves 821-823, 831-833, and 841 in Figure 8A illustrate the average tan δ characteristics of different configurations and / or loaded advanced polishing pads as a function of temperature.

[0248] Figures 8B and 8C are side cross-sectional views of two basic configurations of advanced polishing pads used to generate the tan δ and temperature data shown in Figure 8A. The tan δ to temperature data in curves 821-823 of Figure 8A was collected using DMA technology, which circulates the advanced polishing pad sample of the type shown in Figure 8B in a test apparatus with cantilevered samples loaded in the Z direction. The tan δ to temperature data in curves 831-833 of Figure 8A was collected using DMA technology, which circulates the advanced polishing pad sample of the type shown in Figure 8B in a test apparatus with cantilevered samples loaded in the X direction (e.g., parallel to the forming layer). The tan δ to temperature data in curve 841 of Figure 8A was collected using DMA technology, which circulates the advanced polishing pad sample of the type shown in Figure 8C in a test apparatus with cantilevered test samples loaded in the Z direction. During all tests, the advanced polishing pad samples were heated from -81°C to 95°C at a rate of 5°C / min.

[0249] Figure 8B illustrates a portion of an advanced polishing pad 200, which contains discrete layers of a first polishing pad material 801 and a second polishing pad material 802 formed using the stacking process described herein, such that the layers are aligned parallel to the XY plane and stacked in the Z direction. The first polishing pad material 801 comprises a low-energy-dissipating-modulus polyurethane acrylate material having a low glass transition temperature (Tg), and the second polishing pad material 802 comprises a high-energy-dissipating-modulus polyurethane acrylate material having a high glass transition temperature (Tg). The layers of the first polishing pad material 801 and the second polishing pad material 802 each have thicknesses of 810 and 811 in the Z direction, respectively.

[0250] Referring again to Figure 8A, the plotted data contains independent and discrete tan δ peaks for the first polishing pad material 801 and the second polishing pad material 802, as shown by curves 801C and 802C. Curves 821-823 and 831-833 illustrate the tan δ data of the DMA test performed on the advanced polishing pad configuration shown in Figure 8B, and curve 841 illustrates the tan δ data of the DMA test performed on the advanced polishing pad configuration shown in Figure 8C.

[0251] Curves 821, 822, and 823 illustrate the effect of changing the thickness and relative spacing of the layers shown in Figure 8B when loaded in the Z direction during testing. Curve 821 illustrates the tan δ as a function of temperature for the advanced polishing pad structure shown in Figure 8B, which has a 50:50 composition of a first polishing pad material 801 and a second polishing pad material 802, and therefore has equal thicknesses 810 and 811 for each layer in the Z direction. The thicknesses 810 and 811 in the first sample are both 0.16 mm (0.006 inches). Curve 822 illustrates the tan δ as a function of temperature for the same general advanced polishing pad structure used to generate curve 821, except that the thicknesses 810 and 811 of the layers of the first material 801 and the second material 802 are both twice as large. Similarly, curve 823 illustrates the tan δ as a function of temperature for the same general-purpose advanced polishing pad structure used to generate curve 821, with the exception that the thicknesses 810 and 811 of the first polishing pad material 801 and the second polishing pad material 802 are three times greater. We will note that curves 821, 822, and 823 all demonstrate the mixing or averaging characteristics present in the individual materials 801 and 802, as can be seen from the two distinct peaks (e.g., peaks 825 and 826) and the decreasing peak values ​​in the tan δ data. The two peaks seen in curves 821, 822, and 823 may indicate molecular-level mixing, chain entanglement, and / or chemical bonding formed between the first and second polishing pad materials. Therefore, in some embodiments, molecular-level mixing, chain entanglement, and / or chemical bonding may be formed as needed within the advanced polishing pad between the first material composition in the first polishing element and the second material composition in the second polishing element, which may help improve the properties of the formed advanced polishing pad (e.g., tan δ, E'30:E'90 ratio, E'30, etc.).

[0252] Curves 831, 832, and 833 illustrate the effect of changing the thickness and relative spacing of the layers shown in Figure 8B when loaded in the X direction during testing. Curve 831 illustrates the tan δ as a function of temperature for the advanced polishing pad structure shown in Figure 8B, which has a 50:50 composition of a first polishing pad material 801 and a second polishing pad material 802, and therefore has equal thicknesses 810 and 811 for each layer in the Z direction. The thicknesses 810 and 811 in the first sample are both 0.16 mm (0.006 inches). Curve 832 illustrates the tan δ as a function of temperature for the same general advanced polishing pad structure used to generate curve 831, except that the thicknesses 810 and 811 of the layers of the first material 801 and the second material 802 are twice as large. Similarly, curve 833 illustrates the tan δ as a function of temperature for the same general-purpose advanced polishing pad structure used to generate curve 831, with the exception that the thicknesses 810 and 811 of the first polishing pad material 801 and the second polishing pad material 802 are both three times greater. We will note that curve 931 shows the blending or averaging characteristics present in the individual materials 801 and 802, as can be seen by the two distinct peaks (e.g., peaks 835 and 836) and the decrease in the peak values ​​in the tan δ data. Meanwhile, curves 932 and 833 only show a smaller blending or averaging of the characteristics present in the individual materials 801 and 802, as can be seen by the absence of two distinct peaks.

[0253] Figure 8C illustrates a portion of an advanced polishing pad 800 containing a first polishing pad feature 815 and a substrate layer 816, both formed using a multilayer process. The first polishing pad feature 815 is supported by the substrate layer 816 and aligned in the Z direction (e.g., item 204a in Figure 2A). In this configuration, the substrate layer 816 comprises a 50:50 "mixture" (i.e., a 1:1 material composition ratio) of fixed droplets of the first polishing pad material 801 and fixed droplets of the second polishing pad material 802. The thicknesses of the first polishing pad feature 815 and the substrate layer 816 each have widths 818 and 819 aligned in the X direction. Curve 841 illustrates the effect of forming the constituent "mixed" polishing pad elements on the average or "composite" characteristics of the advanced polishing pad 200. We will note that curve 841 illustrates the mixing or averaging of the properties present in the individual materials 801 and 802 of the substrate 816, as can be seen by the two distinct peaks (e.g., peaks 845 and 846) and the decrease in the peak values ​​in the tan δ data. The two peaks seen in curve 841 may indicate the molecular-level mixing, chain entanglement, and / or chemical bonding formed between the first and second polishing pad materials within the substrate 816.

[0254] The tan δ and temperature data shown in Figure 8A illustrate that the structural spacing or thickness of layers along the loading direction (e.g., curves 821 and 841) can have a significant impact on the average tan δ characteristics within an advanced polishing pad. Referring to curves 831, 832, and 833, we will note that as the spacing between harder and softer material layers increases, when loaded in an orientation parallel to the forming layer orientation (e.g., the X direction), the characteristics of the harder material tend to dominate the characteristics of the formed polishing pad. However, referring to curves 821, 822, and 823, we will note that the spacing between harder and softer material layers has almost no effect on the characteristics of an advanced polishing pad formed with polishing features aligned in an orientation perpendicular to the loading direction, because the measured tan δ does not change significantly with increasing feature thickness at temperature. Therefore, by controlling the structural orientation of one or more layers relative to the loading direction and the relative spacing between the "hard" and "soft" layers within an advanced polishing pad, one or more pad properties (e.g., tan δ) can be adjusted, thereby better controlling the polishing process performance of the advanced polishing pad. Alternative pad structure design.

[0255] Figure 9 is a schematic perspective cross-sectional view of a polishing pad 900 according to one embodiment of the present disclosure. The polishing pad 900 includes a second polishing element 902 of a soft or low energy storage modulus E' material similar to a second polishing element 206 of a printed polishing pad. Similar to the second polishing element 206, the second polishing element 902 may be formed of one or more elastic polymer compositions including polyurethane and aliphatic segments. The polishing pad 900 includes a plurality of surface features 906 extending from the second polishing element 902. Surfaces 908 outside the surface features 906 may be formed of a soft or low E' material, or a soft or low energy storage modulus E' material composition. In one embodiment, the surface 908 outside the surface features 906 may be formed of the same material or the same material composition as the second polishing element 902. Surface features 906 may also include hard features 904 embedded therein. Hard or high energy storage modulus E' features 904 may be formed of a material or material composition harder than the surface features 906. The hard or high energy modulus E' feature 904 can be formed of a material similar to the hard or high energy modulus E' feature 204 of an advanced polishing pad, including cross-linked polymer compositions and aromatic group-containing compositions. The embedded hard feature 904 alters the effective hardness of the surface feature 906, and thus provides the target pad hardness required for polishing. The soft or low energy modulus E' polymer layer on the outer surface 908 can be used to reduce defects on the polished substrate and improve flatness. Alternatively, the soft or low energy modulus E' polymer material can be printed onto the surface of other polishing pads that provide the same benefits as disclosed herein.

[0256] Figure 10 is a schematic perspective cross-sectional view of a polishing pad 1000 having one or more viewing windows 1010. The polishing pad 1000 may have a pad body 1002. The pad body 1002 may include one or more soft or low energy storage modulus E' features 1006 and a plurality of first polishing elements 1004 extending from the second polishing element 1006 for polishing. The second polishing element 1006 and the first polishing element 1004 may be formed of a material similar to the second polishing element 206 and the first polishing element 204 of the advanced polishing pad 200. The first polishing elements 1004 may be arranged in any suitable pattern according to this disclosure.

[0257] One or more viewing windows 1010 may be formed of a transparent material or composition to allow observation of the polished substrate. Viewing windows 1010 may be formed entirely and / or approximately partially by a second polishing element 1006 or a first polishing element 1004. In some embodiments, viewing windows 1010 may be formed of a substantially transparent material and thus be able to transmit light emitted from a laser and / or white light source used in a CMP optical endpoint detection system. The optical transparency should be sufficiently high to provide at least about 25% (e.g., at least about 50%, at least about 80%, at least about 90%, at least about 95%) light transmittance over the wavelength range of the light beam used by the optical detector of the endpoint detection system. Typical optical endpoint detection wavelength ranges include the visible spectrum (e.g., about 400 nm to about 800 nm), the ultraviolet (UV) spectrum (e.g., about 300 nm to about 400 nm), and / or the infrared spectrum (e.g., about 800 nm to about 1550 nm). In one embodiment, the observation window 1010 is formed of a material with a transmittance > 35% at wavelengths between 280 and 800 nm. In another embodiment, the observation window 1010 is formed of a material with a transmittance > 35% at wavelengths between 280 and 399 nm and a transmittance > 70% at wavelengths between 400 and 800 nm. In some embodiments, the observation window 1010 is formed of a material having a low refractive index approximately the same as the polishing slurry and high optical transparency, thereby reducing reflections from the air / window / water interface and improving the transmittance of light traveling to and from the substrate via the observation window 1010.

[0258] In one embodiment, the viewing window 1010 may be formed from a transparent printing material comprising polymethylmethacrylate (PMMA). In another embodiment, the window is formed using a transparent polymeric composition containing epoxy groups, wherein such compositions may be cured using cationic curing and provide additional transparency and less shrinkage. In similar embodiments, the window may be formed from a mixture of compositions undergoing cationic curing and free radical curing. In another embodiment, the window may be produced by another process and may be mechanically inserted into a pre-formed opening in a polishing pad formed by a 3D process.

[0259] Figure 11 is a schematic perspective cross-sectional view of a polishing pad 1100 including a backing layer 1106. The polishing pad 1100 includes a second polishing element 1104 and a plurality of first polishing elements 1102 protruding from the second polishing element 1104. The polishing pad 1100 may be similar to any of the polishing pads 200, 900, and 1000 described above, except that the backing layer 1106 is attached to the second polishing element 1104. The backing layer 1106 may provide the polishing pad 1100 with the required compressibility. The backing layer 1106 can also be used to modify the overall mechanical properties of the polishing pad 1100 to achieve the desired hardness and / or have the desired storage modulus E' and loss modulus E'. The hardness value of the backing layer 1106 can be less than 80 on the Shore A scale. In one embodiment, the backing layer 1106 can be formed from an open-cell or closed-cell foam such as polyurethane or polysiloxane (polysiloxane), so that these pores disintegrate and the backing layer 1106 is compressed under pressure. In another embodiment, the backing layer 1106 can be formed from natural rubber, EPDM rubber (ethylene propylene diene monomer), nitrile, or chloroprene rubber (polychloroprene).

[0260] In one embodiment, the materials of the first polishing element 204 and the second polishing element 206 are chemically resistant to attacks from the polishing slurry. In another embodiment, the materials of the first polishing element 204 and the second polishing element 206 are hydrophilic. The hydrophilicity and hydrophobicity of the polishing pad can be adjusted by those skilled in the art through the informed selection of formulation chemicals.

[0261] Although the polishing pad described herein is circular in shape, the polishing particles according to this disclosure may include any suitable shape, such as polishing webs configured to move linearly during polishing.

[0262] Compared to conventional polishing pads, the advanced polishing pads disclosed herein offer several manufacturing and cost-related advantages. For example, conventional polishing pads typically consist of a processed and textured polished surface supported by a sub-pad formed from a soft or low energy modulus E' material, such as foam, to achieve a target hardness and / or energy modulus E' for the polished substrate. However, by selecting materials with various mechanical properties and adjusting the size and arrangement of different features formed on the advanced polishing pad, the same properties can be achieved in the pad body of the advanced polishing pad without the need for a sub-pad. Therefore, advanced polishing pads reduce the user's ownership costs by eliminating the need for a sub-pad.

[0263] Polishing next-generation IC components significantly increases the complexity of the polishing pad design required, thus greatly increasing the manufacturing complexity of such polishing pads. Several types of non-additive manufacturing processes and / or subtractive processes exist for manufacturing these complex pad designs. These processes may include multi-material injection molding and / or continuous UV casting to form material layers from a single discrete material. Subsequently, these formation steps are typically followed by processing and post-processing using polishing, grinding, or laser ablation operations or other subtractive techniques.

[0264] Although the foregoing embodiments relating to this disclosure are described, other and further embodiments of this disclosure may be designed without departing from its basic scope, and the scope thereof is determined by the following claims. [Simplified Explanation of the Diagram]

[0024] Therefore, the above-described features of this disclosure can be understood in detail by referring to embodiments with a more specific description of the disclosure briefly described above, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only typical embodiments of this disclosure and are therefore not intended to limit its scope, as other equally effective embodiments are permissible.

[0025] Figure 1A is a schematic cross-sectional view of the polishing table.

[0026] Figures 1B to 1E are schematic cross-sectional views of a portion of the arrangement of the polishing head and polishing pad placed in the polishing table shown in Figure 1A.

[0027] Figures 1F to 1G are schematic cross-sectional views of a portion of the arrangement of a polishing head and polishing pad placed in the polishing table illustrated in Figure 1A, according to one embodiment of the present disclosure.

[0028] Figure 1H is a schematic cross-sectional view of a portion of the substrate being polished using the polishing table configuration shown in Figures 1B to 1C.

[0029] Figure 1I is a schematic cross-sectional view of a portion of the substrate being polished using the polishing table configuration shown in Figures 1D to 1E.

[0030] Figure 1J is a schematic cross-sectional view of a portion of a substrate being polished using a polishing table configuration shown in Figures 1F to 1G, according to one embodiment of the present disclosure.

[0031] Figure 2A is a schematic isometric and cross-sectional view of a polishing pad according to one embodiment of the present disclosure.

[0032] Figure 2B is a schematic partial top view of a polishing pad according to one embodiment of the present disclosure.

[0033] Figure 2C is a schematic isometric and cross-sectional view of a polishing pad according to one embodiment of the present disclosure.

[0034] Figure 2D is a schematic side cross-sectional view of a portion of a polishing pad according to one embodiment of the present disclosure.

[0035] Figure 2E is a schematic side cross-sectional view of a portion of a polishing pad according to one embodiment of the present disclosure.

[0036] Figures 2F to 2K are top views of a polishing pad design according to an embodiment of the present disclosure.

[0037] Figure 3A is a schematic view of a system for manufacturing an advanced polishing pad according to one embodiment of the present disclosure.

[0038] Figure 3B is a schematic view of a portion of the system illustrated in Figure 3A according to one embodiment of the present disclosure.

[0039] Figure 3C is a schematic view of an application droplet placed on the surface of the area of ​​the advanced polishing pad illustrated in Figure 3B, according to one embodiment of the present disclosure.

[0040] The 3D figure is a schematic view of a nozzle assembly for manufacturing an advanced polishing pad according to one embodiment of the present disclosure.

[0041] Figures 4A to 4D are top views of a pixel map for forming an advanced polishing pad according to at least one embodiment of the present disclosure.

[0042] Figure 4E is a schematic top view of a mesh or roll-to-roll polishing pad according to one embodiment of the present disclosure.

[0043] Figure 4F is a schematic side cross-sectional view of a portion of a polishing pad according to one embodiment of the present disclosure.

[0044] Figure 5A is a top view of a pixel map for forming an advanced polishing pad that may contain holes, according to at least one embodiment of the present disclosure.

[0045] Figure 5B is a schematic side cross-sectional view of a portion of an advanced polishing pad according to one embodiment of the present disclosure.

[0046] Figure 5C is a schematic side cross-sectional view of a portion of an advanced polishing pad according to one embodiment of the present disclosure.

[0047] Figure 6A illustrates a graph of polishing material removal rate versus material hardness for various pad materials used to form advanced polishing pads according to one embodiment of the present disclosure.

[0048] Figure 6B illustrates a graph of the polishing material removal rate versus radial position of a polishing substrate according to one embodiment of the present disclosure.

[0049] Figure 6C illustrates a graph of the polishing material removal rate versus feature height of a polishing pad according to one embodiment of the present disclosure.

[0050] Figure 6D illustrates a graph of the surface area versus volume ratio of a polishing pad according to one embodiment of the present disclosure, relative to the feature height.

[0051] Figure 6E is a schematic cross-sectional view of a polishing pad according to one embodiment of the present disclosure.

[0052] Figure 6F is a schematic cross-sectional view of a polishing pad according to one embodiment of the present disclosure.

[0053] Figure 6G illustrates a graph of the polishing material removal rate versus the percentage of contact area for a first polishing element formed in an advanced polishing pad according to one embodiment of the present disclosure.

[0054] Figure 6H illustrates a graph of the polishing pad temperature versus contact area percentage of a first polishing element formed in an advanced polishing pad according to one embodiment of the present disclosure.

[0055] Figure 7A illustrates a graph of tan δ versus temperature for various materials and advanced polishing pads according to one embodiment of the present disclosure.

[0056] Figure 7B illustrates a stress-strain curve for a material that can be used in an advanced polishing pad according to one embodiment of the present disclosure.

[0057] Figure 7C illustrates a graph of temperature as a function of the change in the energy storage modulus of a pad material undergoing cyclic processing in a polishing system, according to one embodiment of the present disclosure.

[0058] Figure 8A illustrates a graph of tan δ versus temperature for various materials and advanced polishing pads according to one embodiment of this disclosure.

[0059] Figures 8B and 8C are schematic side cross-sectional views of several portions of an advanced polishing pad according to one embodiment of the present disclosure.

[0060] Figure 9 is a schematic side cross-sectional view of a portion of a polishing pad according to one embodiment of the present disclosure.

[0061] Figure 10 is a schematic side cross-sectional view of a polishing pad in which a transparent area is formed in a polishing pad according to one embodiment of the present disclosure.

[0062] Figure 11 is a schematic perspective cross-sectional view of a polishing pad including a supporting foam layer according to one embodiment of the present disclosure.

[0063] To facilitate understanding, common terms are used to indicate the same elements in common throughout the drawings, where possible. It should be understood that elements disclosed in one embodiment may be advantageously used in other embodiments without being specifically described. [Biomaterial Storage]

[0266] Domestic storage information (please note in order of storage institution, date, and number): None. International storage information (please note in order of storage country, institution, date, and number): None.

Claims

1. A polished object having a polishing surface configured to polish one surface of a substrate during a polishing process, the polished object comprising: An array of a plurality of first polishing elements, the first polishing elements being distributed in a first pattern, wherein each of the first polishing elements is formed by a plurality of stacked first polymer layers, at least one surface of the plurality of first polymer layers forming the polishing surface, and each of the first polymer layers including a plurality of regions containing a first material and a plurality of regions containing a second material; and one or more second polishing elements, formed by a plurality of stacked second polymer layers, wherein each of the second polymer layers includes a plurality of the regions containing the first material.

2. The polished object as claimed in claim 1, wherein the regions containing the second material are formed by a resin precursor component comprising an aliphatic multifunctional polyurethane acrylate with a functionality greater than or equal to 2.

3. The polished object as claimed in claim 1, wherein at least a region of each of the one or more second polishing elements is disposed between a support surface of the polished object and at least one first polishing element in the array of the first polishing elements.

4. The polished object as claimed in claim 1, wherein the plurality of second polymer layers further includes a plurality of regions containing the second material.

5. The polished object as claimed in claim 4, wherein the ratio of the regions containing the first material to the regions containing the second material in each of the second polymer layers of each of the second polishing elements is different from the ratio of the regions containing the first material to the regions containing the second material in at least a portion of each of the first polishing elements.

6. The polished object as claimed in claim 1, wherein the ratio of the regions containing the first material to the regions containing the second material within at least a portion of each of the first polishing elements varies across a first plane parallel to the polishing surface.

7. The polished object as claimed in claim 6, wherein the ratio of the regions containing the first material to the regions containing the second material in one or more of the second polymer layers in each of the second polishing elements varies across a second plane parallel to the first surface.

8. The polished object as claimed in claim 6, wherein the first polymer layer further includes a second pattern of a plurality of regions containing a porosity-forming agent, wherein the second pattern is aligned in at least one direction parallel to the first plane.

9. The polished object as claimed in claim 8, wherein the second pattern of the regions containing the pore-forming agent includes a pore-forming agent material that degrades upon exposure to an aqueous solution.

10. The polished object as claimed in claim 9, wherein the pore-forming material further comprises an acrylate.

11. The polished object as claimed in claim 1, wherein each of the regions containing the first material and each of the regions containing the second material comprises a material comprising an acrylate.

12. The polished object as claimed in claim 1, wherein each of the regions containing the first material and each of the regions containing the second material comprises a material formed of a first amount of a first resin precursor component, a second amount of a second resin precursor component, and a first amount of a first curing agent.

13. The polished object as claimed in claim 1, wherein each of the regions containing the first material and each of the regions containing the second material comprises a material formed by partially curing an amount of a first precursor formulation, the first precursor formulation comprising a multifunctional polyurethane oligomer, a polyester acrylate oligomer, a polyether acrylate oligomer, an epoxy acrylate oligomer, a monofunctional acrylate monomer, or a multifunctional acrylate monomer.

14. The polished object as claimed in claim 1, wherein one or both of the regions containing a first material and the regions containing a second material comprise an interpenetrating polymer network structure, wherein the polymer chains of the second polymer are entangled and / or penetrate the network structure of the polymer chains of the second polymer.

15. The polished object as claimed in claim 1, wherein the regions containing the first material are formed by applying and curing one or more droplets, wherein the cured droplets have a contact angle relative to a surface of a previously formed first polymer layer, the contact angle being greater than or equal to 50 degrees, and the regions containing the second material are formed by applying and curing one or more droplets, wherein the cured droplets have a contact angle relative to the surface of the previously formed first polymer layer, the contact angle being greater than or equal to 50 degrees.

16. A polished object having a polishing surface configured to polish one surface of a substrate during a polishing process, the polished object comprising: An array of a plurality of first polishing elements, the first polishing elements being distributed in a first pattern, wherein each of the first polishing elements is formed of a plurality of stacked first polymer layers, at least one surface of the plurality of first polymer layers forming the polishing surface, each of the first polymer layers including a plurality of regions containing a first material and a plurality of regions containing a second material, and each of the regions containing the first material and the regions containing the second material each including a material formed of a first amount of an oligomer and a second amount of a monomer, wherein the first amount to the second amount is in a weight ratio of about 3:1 to about 1:3; and one or more second polishing elements formed of a plurality of stacked second polymer layers, wherein each of the second polymer layers includes a plurality of the regions containing the first material.

17. The polished object as claimed in claim 16, wherein the ratio of the regions containing the first material to the regions containing the second material within at least a portion of each of the first polishing elements varies across a first plane parallel to the polishing surface.

18. A method of forming a polished object, comprising sequentially forming a plurality of polymer layers, wherein forming the plurality of polymer layers includes: A first layer forming a plurality of first polishing elements of the polished object, wherein forming the first layer includes: forming a first pattern containing a plurality of first material regions on a surface on which the first layer is formed; and forming a second pattern containing a plurality of second material regions on the surface on which the first layer is formed, wherein the first layer includes a first ratio of the first material regions to the second material regions; and a second layer forming the plurality of first polishing elements, wherein the formed second layer is disposed on a surface of the first layer and includes: forming a third pattern containing a plurality of first material regions on the surface of the first layer; and forming a fourth pattern containing a plurality of second material regions on the surface of the first layer.

19. The method of claim 18, wherein each of the regions containing the first material and each of the regions containing the second material comprises a material formed from a first resin precursor component comprising an aliphatic multifunctional polyurethane acrylate with a functionality greater than or equal to 2.

20. The method as described in claim 19, wherein the second layer includes a second ratio of the regions containing the first material to the regions containing the second material, and the first ratio is different from the second ratio.

21. The method as described in claim 20, wherein the first ratio also varies in a first direction parallel to the surface on which the first layer is disposed, and the second ratio also varies in the first direction parallel to the surface on which the first layer is disposed.

22. The method as described in claim 18, wherein forming the regions containing the first material comprises: (a) Applying a first amount of a first precursor formulation to the surface on which the first layer is formed by using an additive manufacturing process; (b) exposing the applied first amount of the first precursor formulation to electromagnetic radiation for a first time period to partially cure the first amount of the first precursor formulation; and (c) repeating (a) and (b).

23. The method as described in claim 18, wherein forming the regions containing the first material comprises: A first amount of a first resin precursor component, a second amount of a second resin precursor component, and a first amount of a first curing agent are mixed to form a first precursor formulation having a first viscosity so that the first precursor formulation can be applied using a lamination manufacturing process.

24. The method as claimed in claim 18, wherein the regions containing the first material or the regions containing the second material have a gradient in material composition in at least one direction parallel to the surface of the first layer.

25. The method of claim 18, wherein forming the regions containing the first material includes applying and curing one or more drops, wherein each of the cured drops has a contact angle relative to the surface on which the first layer is formed, the contact angle being greater than or equal to 50 degrees, and forming the regions containing the second material includes applying and curing one or more drops, wherein each of the cured drops has a contact angle relative to the surface of the first layer, the contact angle being greater than or equal to 50 degrees.

26. The method of claim 18, wherein the regions containing the first material are formed by a first drop composition and the regions containing the second material are formed by a second drop composition, the first drop composition comprising a resin precursor composition with a glass transition temperature less than or equal to about 40 degrees Celsius, and the second drop composition comprising a resin precursor composition with a glass transition temperature greater than about 40 degrees Celsius.

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