An apparatus and method of forming a polishing article that has a desired zeta potential

Abstract

Implementations described herein generally relate to polishing articles and methods of manufacturing polishing articles used in polishing processes and cleaning processes. More particularly, implementations disclosed herein relate to composite polishing articles having graded properties. In one implementation, a polishing article is provided. The polishing article comprises one or more exposed first regions formed from a first material and having a first zeta potential and one or more second exposed regions formed from a second material and having a second zeta potential, wherein the first zeta potential is different from the second zeta potential.

Description

[Technical Field]

[0001] The embodiments described herein generally relate to polished objects and methods for manufacturing polished objects used in polishing and cleaning processes. More specifically, the embodiments disclosed herein relate to composite polished objects with graded properties. [Previous Technology]

[0002] Chemical mechanical polishing (CMP) processes are commonly used for substrate planarization in semiconductor device manufacturing. During CMP, the substrate is held in place by a carrier head, and the surface of the device is placed against a rotating polishing pad. The carrier head provides a controlled load on the substrate to push the device surface toward the polishing pad. An abrasive fluid, such as a slurry containing abrasive particles (e.g., silicon dioxide (SiO2), aluminum oxide (Al2O3), or cerium dioxide (CeO2)), is typically supplied to the surface of the polishing pad.

[0003] As feature sizes decrease, front-layer and back-layer planarization via CMP processes becomes increasingly critical. Unfortunately, byproducts of CMP processes, such as abrasive particles and metal contaminants generated during the CMP process, can damage the substrate surface. In the case of abrasive slurries, these abrasive particles may originate from the slurry itself. In some cases, the abrasive particles may originate from the polishing pad itself. Additionally, abrasive particles may originate from the substrate's surface material being polished and the polishing equipment. Due to the mechanical pressure generated by the polishing pad, these particles may physically adhere to the substrate surface. Metal contaminants originate from the metal wires being polished, metal ions in the slurry, and the polishing equipment itself. These metal contaminants may embed in the substrate surface and are often difficult to remove using subsequent cleaning processes. Current polishing pad designs and post-polishing cleaning processes frequently produce polished substrates with defects caused by CMP process byproducts.

[0004] Therefore, there is a need for a polished object that provides an improved polishing process with reduced defects, and a method for manufacturing an improved polishing pad. [Summary of the Invention]

[0005] The embodiments described herein generally relate to polished objects and methods of manufacturing polished objects for use in polishing and cleaning processes. More specifically, the embodiments disclosed herein relate to composite polished objects having graded properties. In one embodiment, a polished object is provided. The polished object includes one or more exposed first regions and one or more second exposed regions, the first regions being formed of a first material and having a first threshold potential, the second exposed regions being formed of a second material and having a second threshold potential, wherein the first threshold potential is different from the second threshold potential.

[0006] In another embodiment, a polishing object is provided. The polishing object includes a composite polishing pad body having a first grooved surface, a second flat surface opposite the first grooved surface, and a gradient having a varying boundary potential toward the first grooved surface.

[0007] In yet another embodiment, a method for forming a polished object is provided. The method includes depositing a plurality of composite layers using a 3D printer to achieve a target thickness, wherein depositing the plurality of composite layers includes depositing a first material having an exposed first region and depositing a second material having an exposed second region, the exposed first region having a first threshold potential and the exposed second region having a second threshold potential. The plurality of composite layers are cured to form a composite pad body having one or more first features comprising the first material and one or more second features comprising the second material, wherein the one or more first features and the one or more second features form a single body.

[0008] In yet another embodiment, a method of forming a polished object may include depositing a plurality of composite layers using a 3D printer to achieve a target thickness. The method of depositing the plurality of composite layers may include depositing a first material and a second material, the first material comprising ethyl acrylate having exposed first regions having a first threshold potential, and the second material comprising ethyl acrylate having exposed second regions having a second threshold potential. The method may then include UV curing the plurality of composite layers to form a composite pad body having one or more first features comprising the first material and one or more second features comprising the second material, wherein the one or more first features and the one or more second features form a single body.

[0009] In yet another embodiment, a polishing object may include a composite polishing pad body having a first grooved surface, a second flat surface opposite the first grooved surface, and a material property gradient extending from the first grooved surface to the second flat surface, wherein the material property gradient includes a varying threshold potential. In some cases, the threshold potential of the material property gradient may become more positive toward the first grooved surface. In other cases, the threshold potential of the material property gradient may become more negative toward the first grooved surface. The varying threshold potential of the material property gradient, measured using a neutral solution, may vary between about -70 mV and about +50 mV.

Implementation Method

[0033] The embodiments described herein generally relate to polished objects and methods for manufacturing polished objects used in polishing and cleaning processes. More specifically, the embodiments disclosed herein relate to composite polished objects having graded properties (e.g., threshold potential). Threshold potential is the electromotive force of a solid surface relative to a liquid at a sliding plane. The electromotive force of a solid surface provides an indirect measurement of surface functionality. The addition or removal of protonated groups on a solid surface generates a charge on the surface. Static electricity between the solid and liquid interfaces has a significant effect on the charge of the interfacial bilayer.

[0034] Embodiments disclosed herein provide a polished object and a method for forming a polished object, the polished object having a varying threshold potential region across its entire surface. The varying threshold potential region of the polished object can be adjusted based on the slurry composition system used and the material to be polished. This varying threshold potential can be adjusted to deliver an active slurry to the interface between the polished object and the substrate, while simultaneously removing polishing byproducts and contaminants from the interface. For example, in some embodiments, the polished object has a more positive threshold potential near the polished surface of the polished object (i.e., the interface between the polished object and the liquid interface) and a more negative threshold potential near the bottom of the tank of the polished object. The more positive threshold potential repels unwanted positively charged ions (e.g., metal ions, dielectric material ions) from the liquid interface, while the more negative threshold potential attracts unwanted positive ions to the bottom of the tank, where the ions collected can be removed from the polished object.

[0035] In a polishing system in which the abrasive contained in the active slurry has a negative threshold potential (e.g., natural silica, such as pyrolytic silica), the abrasive can be attracted to a more positive threshold potential near the polishing surface and correspondingly repelled by a negative potential near the bottom of the tank. In some embodiments where the abrasive contained in the active slurry has a positive threshold potential (e.g., alumina), the polishing surface can be designed to have a more negative threshold potential relative to other areas of the workpiece surface to attract the abrasive to the interface between the workpiece and the liquid interface.

[0036] In some embodiments described herein, this adjustable threshold potential is achieved by adding a threshold potential modifier to a prepolymer containing a composition for forming a polished object. The prepolymer containing the composition may comprise one or more oligomers and one or more monomers, wherein at least one or two of the oligomers and monomers have an ionic charge (e.g., cationic, anionic, or nonionic), which adjusts the threshold potential of the polished object by copolymerizing with the prepolymer components.

[0037] In some embodiments described herein, the threshold potential gradient is formed in a direction perpendicular to the polished surface of the polished object or in a plane of the polished surface of the polished object. The threshold potential gradient may vary from high concentration to low concentration in one direction, or vice versa. In some embodiments described herein, one or more regions of the polished object may include more complex threshold potential gradients, such as high / low / high or low / high / low threshold potentials.

[0038] The average threshold potential of at least one exposed surface of a polished object, measured using a neutral solution, can be in the range of about -70 mV to about +50 mV. The average threshold potential of at least one exposed surface of a polished object, measured using a neutral solution, can be at least -70 mV, -65 mV, -60 mV, -55 mV, -50 mV, -45 mV, -40 mV, -35 mV, -30 mV, -25 mV, -20 mV, -15 mV, -10 mV, -5 mV, 0 mV, 5 mV, 10 mV, 15 mV, 20 mV, 25 mV, 30 mV, 35 mV, 40 mV, or 45 mV. The average threshold potential of at least one exposed surface of a polished object, measured using a neutral solution, can be up to -65 mV, -60 mV, -55 mV, -50 mV, -45 mV, -40 mV, -35 mV, -30 mV, -25 mV, -20 mV, -15 mV, -10 mV, -5 mV, 0 mV, 5 mV, 10 mV, 15 mV, 20 mV, 25 mV, 30 mV, 35 mV, 40 mV, 45 mV, or 50 mV. In another embodiment, the average threshold potential range of at least one exposed surface of the polished object, measured using a neutral solution, can be from about -70 mV to about 0 mV (e.g., from about -50 mV to about -5 mV; from about -40 mV to about -10 mV; or from about -30 mV to about -20 mV). In another embodiment, the average threshold potential range of at least one exposed surface of the polished object, measured using a neutral solution, can be from about 0 mV to about 50 mV (e.g., from about 5 mV to about 40 mV; from about 10 mV to about 30 mV; or from about 20 mV to about 30 mV).

[0039] The following disclosure describes a polished object and a method for manufacturing a polished object. Certain details are set forth in the following description and Figures 1 to 11 to provide a thorough understanding of the various embodiments of this disclosure. Other details of well-known structures and systems commonly associated with polished objects and methods of manufacturing polished objects are not set forth in the following disclosure to avoid unnecessarily obscuring the description of the various embodiments.

[0040] Many details, dimensions, angles, and other features shown in the figures are merely illustrative of specific embodiments. Therefore, other embodiments may have different details, elements, dimensions, angles, and features without departing from the spirit or scope of this disclosure. Furthermore, further embodiments of this disclosure may be implemented without some of the details described below.

[0041] It should be understood that although the polishing object described herein is a polishing pad, the embodiments described herein can also be applied to other polishing objects, including, for example, polishing pads. Furthermore, although the discussion of the polishing object herein relates to chemical mechanical polishing processes, the polishing object and the method of manufacturing the polishing object described herein can also be applied to other polishing processes, including polishing lenses and other processes involving abrasive and abrasive-free slurry systems. In addition, the polishing object described herein can be used in at least the following industries: aerospace, ceramics, hard disk drives (HDDs), MEMS and nanotechnology, metal processing, optical components and electro-optical components, and semiconductors, etc.

[0042] In one embodiment, a multilayer manufacturing process (e.g., a three-dimensional printing (or 3-D printing) process) can be used to produce (or manufacture) the polished object described herein. In one embodiment, a computer-aided design (CAD) model of the part is first created, followed by a slicing algorithm mapping information for each layer. In a non-limiting example of a 3-D printing process, the layers begin with a thin powder distribution dispersed on the surface of a powder bed. A selected binder material is then dispensed, selectively binding the particles at the location where the object will be formed. Subsequently, a piston supporting the powder bed and the part in use is lowered to form the next powder layer. After each layer, the same process is repeated, followed by a final heat treatment to form the object. In another example, the 3-D printing process may include, but is not limited to, a process in which droplets of liquid precursor constituent materials are dispensed onto a surface and subsequently cured to form a polished object in a layer-by-layer manner, as will be discussed further below. Because 3D printing allows for localized control over material composition, microstructure, and surface texture, it can be used to achieve a variety of (and previously unattainable) geometries.

[0043] In one embodiment, the polished object described herein may be represented by a data structure readable by a computer transpilation device or a computer display device. The computer-readable medium may contain a data structure representing the polished object. The data structure may be a computer file and may contain information about the structure, material, texture, physical properties, or other characteristics of one or more objects. The data structure may also contain code, such as computer-executable code or device control code that performs selected functions of the computer transpilation device or computer display device. The data structure may be stored on a computer-readable medium. The computer-readable medium may include physical storage media, such as magnetic memory, floppy disks, or any convenient physical storage media. The physical storage medium may be readable by a computer system for displaying the object represented by the data structure on a computer screen or physical transpilation device, which may be an additive manufacturing apparatus, such as a 3D printer.

[0044] Figure 1 is a schematic cross-sectional view of a polishing station 100, which may be located within a larger chemical mechanical polishing (CMP) system containing multiple polishing stations. The polishing station 100 includes a platform 102. The platform 102 is rotatable about a central axis 104. A polishing pad 106 may be placed on the platform 102. While not intended to limit the disclosure provided herein, typically the polishing pad 106 is the upper surface 103 covering the platform 102, which is at least one to two times larger than the dimensions (e.g., substrate diameter) of the substrates 110 to be processed in the polishing station 100. In one example, the diameters of the polishing pad 106 and the platform 102 are between approximately 6 inches (150 mm) and approximately 40 inches (1,016 mm). The polishing pad 106 includes a polishing surface 112 provided for contacting and processing one or more substrates 110. During polishing, the platform 102 supports and rotates the polishing pad 106. The support head 108 can hold the substrate 110, which is being processed against the polishing surface 112 of the polishing pad 106. A polishing interface 130 is formed between the polishing surface 112 and the substrate 110. The support head 108 typically includes a flexible partition 111 for pushing the substrate 110 against the polishing pad 106 and a support ring 109 for correcting inherent uneven pressure distribution that occurs at various points on the surface of the substrate during the polishing process. The support head 108 can rotate about a central axis 114 and / or move in a sweeping manner to generate relative movement between the substrate 110 and the polishing pad 106.

[0045] During the polishing process, an abrasive fluid 116 (e.g., an abrasive slurry or a non-abrasive slurry) can be supplied to the polishing surface 112 via a delivery arm 118. The abrasive fluid 116 may contain abrasive particles, pH adjusters, and / or chemically active ingredients to enable chemical mechanical polishing of the substrate. The slurry chemistry of 116 is designed to polish the substrate surface and / or features, which may include metals, metal oxides, and half-metal oxides. It will be noted that the delivery of the abrasive fluid 116 (e.g., slurry) interacting with the substrate 110 is controlled during the polishing process using the surface morphology of the polishing pad 106. For example, the surface morphology of the polishing pad 106 may include grooves, channels, and other protrusions that may be disposed above, on, and inside the polishing pad 106. The surface morphology of the polishing pad may be formed by techniques such as casting, molding, or machining.

[0046] In some embodiments, the polishing station 100 includes a pad adjustment assembly 120, which includes an adjustment arm 122 and actuators 124 and 126. Actuators 124 and 126 are configured to push and sweep a pad adjustment disc 128 (e.g., a diamond-set disc) toward and across the polishing surface 112 at different times during a polishing process cycle to grind and regenerate the polishing surface 112 of the polishing pad 106. During the process, the moving polishing pad 106 and the carrier head 108 apply mechanical energy to the substrate 110, which, combined with the chemicals and abrasive components in the polishing fluid 116, flattens the surface of the substrate.

[0047] Figure 2A is a schematic perspective view of a polishing pad 200 having a varying boundary potential region on its surface according to an embodiment of the present disclosure. Figure 2B is a schematic cross-sectional view of a portion of the polishing pad 200 in Figure 2A. Figure 2C is an enlarged schematic cross-sectional view of a portion of the polishing pad in Figure 2B. The polishing pad 200 can be used in a polishing station, such as polishing station 100, for polishing a substrate by chemical mechanical abrasion. The polishing pad 200 includes a pad body 202. The pad body 202 can be a homogeneous pad body. Alternatively, the pad body 202 can be a composite pad body. The pad body 202 can be formed by any suitable technique. Exemplary techniques for forming the pad body 202 include 3D printing, molding, casting, or sintering. The pad body 202 can include a plurality of exposed areas or surfaces.

[0048] In one embodiment, at least two exposed regions or surfaces have different surface properties, such as threshold potentials. In one embodiment, regions within each exposed surface are modified to have different threshold potentials. In one embodiment, the threshold potentials of regions or surfaces can be adjusted such that polishing byproducts, such as abrasive particles and metal contaminants, generated during the CMP process are easily removed from the polishing interface between the substrate and the polishing pad when an active slurry disposed on a polishing pad is delivered or attracted to the interface between the substrate and the polishing pad.

[0049] In one embodiment, the pad body 202 includes one or more exposed first regions or surfaces formed of a first material and having a first threshold potential. The pad body 202 also includes one or more second exposed regions formed of a second material and having a second threshold potential, wherein the first threshold potential differs from the second threshold potential. In one embodiment, the first threshold potential, measured using a neutral solution, is equal to or greater than -70 mV and less than 0 mV, and the second threshold potential, measured using a neutral solution, is equal to or greater than 0 mV and less than 50 mV. In another embodiment, the first threshold potential, measured using a neutral solution, is equal to or greater than 0 mV and less than 50 mV, and the second threshold potential, measured using a neutral solution, is equal to or greater than -70 mV and less than 0 mV.

[0050] The pad body 202 can be formed using any suitable material or combination of materials having the desired threshold potential properties. In one embodiment, the pad body can be formed from one or more thermoplastic polymers, thermosetting polymers, or both thermoplastic and thermosetting polymers. For example, the pad body 202 can be formed from thermoplastic polymers such as polyurethane, polypropylene, polystyrene, polyacrylonitrile, polymethyl methacrylate, polychlorotrifluoroethylene, polytetrafluoroethylene, polyoxymethylene, polyoxymethylene, polycarbonate, polyimide, polyetheretherketone, polyphenylene sulfide, polyethersulfone, acrylonitrile butadiene styrene (ABS), polyetherimide, polyamide, melamine, polyester, polyurethane, polyvinyl acetate, fluorinated hydrocarbons, etc., as well as acrylates, copolymers, grafts, and mixtures thereof. The liner body 202 may be formed of a thermoplastic polymer, including, for example, polyurethane, acrylate, epoxy resin, acrylonitrile butadiene styrene (ABS), polyetherimide, or polyamide. In one embodiment, different polymers with different arrival potentials are used to form each exposed surface. In another embodiment, the thermoplastic polymer is modified with various arrival potential modifiers to obtain exposed surfaces having different arrival potentials as described herein.

[0051] In one embodiment, the pad body 202 includes a plurality of layers that can be formed in a stacking direction. At least partially different layers of the plurality of layers can be formed using materials with different threshold potentials. At least two of the plurality of layers each have an exposed surface having a threshold potential different from the exposed surface of at least one other layer.

[0052] The pad body 202 includes a first polished surface 204 and a second flat surface 206 opposite to the first polished surface 204. The pad body 202 includes a lower portion 208, above which extends a plurality of grooves 210 or channels. The plurality of grooves 210 or channels are disposed in the polished surface 204 to form a groove surface of the polishing pad 200. The grooves 210 can have any suitable shape. The grooves 210 can be circular. In some embodiments where the grooves are circular, the grooves 210 can be concentric with each other.

[0053] The slots 210 are separated by a spacing P. The spacing P, most clearly illustrated in Figure 2B, is the radial distance between adjacent slots. Each slot is separated by a feature 212 or separator with a width Wp. The feature 212 can have any suitable shape. The feature 212 can be an annular feature. Each slot 210 includes a wall 214 terminating at a base 216. As shown in Figure 2B, the base 216 can have a rectangular profile. Alternatively, the base 216 can have a U-shaped profile. Each slot 210 can have a depth Dg and a width Wg. The wall 214 can be generally vertical and terminates at the base 216.

[0054] In one embodiment, the height 220 of feature 212 is higher than the base 216 of each groove 210, such that the upper surface 222 of feature 212 protrudes from the lower portion 208 of the pad body 202. Grooves 210 or channels are formed between feature 212 and base 216. During polishing, the upper surface 222 of feature 212 forms a polishing surface 204 that contacts the substrate, while the groove 210 retains the polishing fluid.

[0055] In one embodiment, the width Wp of feature 212 can be between about 250 micrometers and about 2 millimeters. The width Wg of groove 210 can be between about 250 micrometers and about 2 millimeters. The spacing "P" between features 212 can be between about 0.5 millimeters and about 5 millimeters. The width Wp of feature 212, the width Wg of groove 210, and / or the spacing P can vary across the radius of polishing pad 200 to areas with different hardness.

[0056] The pad body 202 may include a plurality of exposed surfaces. In one embodiment, at least a portion of two of the plurality of exposed surfaces have different surface properties, such as threshold potentials. In one embodiment, a region within each exposed surface is modified to have a different threshold potential. The exposed surfaces may be selected to form a gradient of increasing threshold potentials. In one embodiment, the exposed surface is selected from the upper surface 222 of feature 212, the surface 224 of wall 214, and the surface 226 of base 216. For example, in one embodiment, at least a portion of the upper surface 222 of feature 212 contains a first material having a first threshold potential, at least a portion of the surface 224 of wall 214 contains a material having a second threshold potential, and at least a portion of the surface 226 of base 216 of groove 210 contains a third material having a third threshold potential. In another embodiment, at least a portion of the upper surface 222 of feature 212 and a portion of the surface 224 of wall 214 have a first threshold potential, and at least a portion of the surface 226 of base 216 of groove 210 contains a second material having a second threshold potential different from the first threshold potential.

[0057] Referring to Figure 2C, the pad body 202 may include a plurality of material layers 2301-2309 (collectively referred to as 230). Materials with different surface properties (e.g., threshold potentials) may be used to form each of the different layers. At least two of the plurality of material layers 2301-2309 each have an exposed surface with a threshold potential different from the exposed surface of another layer. It should be understood that the polishing pad 200 comprising nine layers shown in Figure 2C is merely illustrative, and any number of material layers 230 may be used to form a desired threshold potential gradient.

[0058] In one embodiment, the potential of arrival is gradiented across the entire pad body 202. Grading the potential of arrival across the entire pad body 202 can be achieved using a material property gradient (240→250) from the polished surface 204 to the flat surface 206. In one embodiment, the potential of arrival varies between approximately -70 mV and approximately +50 mV, measured using a neutral solution, as a change in the material property gradient (240→250). In one embodiment, the potential of arrival gradient gradually increases from the polished surface 204 to the flat surface 206. For example, in one embodiment, one or more exposed first regions or surfaces and one or more second regions or surfaces are arranged to form a potential of arrival gradient, wherein the potential of arrival gradually increases from the polished surface 204 to the flat surface 206. In another embodiment, the potential of arrival gradually increases from the flat surface 206 to the polished surface 204. For example, in one embodiment, the upper surface 222 of feature 212 includes a first material layer 2301 having a first threshold potential, at least a portion of the surface 224 of wall 214 includes a second material layer (any combination of 2302-2308) having a second threshold potential, and the surface 226 of the base 216 of groove 210 includes a third material layer 2308 having a third threshold potential. In another embodiment, material layers 2301-2308 have a first threshold potential, and material layer 2309 has a second threshold potential.

[0059] Figure 3A is a schematic perspective view of a polishing pad 300 having a varying threshold potential on its surface, according to another embodiment of the present disclosure. Figure 3B is a schematic cross-sectional view of a portion of the polishing pad 300 in Figure 3A. The polishing pad 300 can be used in a polishing station, such as polishing station 100, for polishing a substrate by chemical mechanical polishing. This polishing pad is similar to polishing pad 200, except that polishing pad 300 includes a plurality of separated features having exposed areas or surfaces. In one embodiment, at least two of the plurality of exposed areas or surfaces have different surface properties, such as threshold potentials. In one embodiment, the threshold potential of the areas or surfaces can be adjusted such that polishing byproducts such as abrasive particles and metal contaminants generated during the CMP process are removed from the polishing interface between the substrate and the polishing pad, and an active slurry is delivered to the interface between the substrate and the polishing pad.

[0060] The polishing pad 300 includes a composite pad body 302. The composite pad body 302 includes a first polishing surface 305 and a second flat surface 307 opposite to the first polishing surface 305. The composite pad body 302 includes one or more first polishing features 304 and one or more second polishing features 306. Certain portions of at least two exposed surfaces of at least one of the one or more first polishing features 304 and one or more second polishing features 306 may be modified as described herein to have surfaces with different boundary potentials. The first polishing features 304 and the second polishing features 306 are separated features joined together at a boundary to form the composite pad body 302. In one embodiment, the first polishing feature 304 may be a hard feature with a Shore D hardness of about 40 to about 90. The second polishing feature 306 may be an elastic feature with a hardness value between about 26 and about 95 on the Shore A scale.

[0061] Exemplary techniques for forming the composite pad body 302 include 3D printing, molding, casting, or sintering. The composite pad body 302 may include a plurality of layers, wherein, depending on the design of the composite pad body 302 deposited by the 3D printer, each layer includes an area of ​​a second polished feature 306 and / or an area of ​​a first polished feature 304. The plurality of layers may then be cured, for example by UV light or by a heat source, to harden and achieve a target hardness. After deposition and curing, a single composite pad body 302 including the first polished feature 304 and the second polished feature 306 is formed, the first polished feature 304 and the second polished feature 306 being coupled or bonded together and having exposed surfaces with different arrival potentials.

[0062] Materials with different mechanical properties can be selected for the second polishing feature 306 and the first polishing feature 304 to achieve the target polishing process. The dynamic mechanical properties of the second polishing feature 306 and the first polishing feature 304 can be achieved by selecting different materials and / or selecting different curing processes used during the feature formation process. In one embodiment, the second polishing feature 306 may have a lower hardness value and a lower Young's modulus value, while the first polishing feature 304 may have a higher hardness value and a higher Young's modulus value. In one embodiment, the second polishing feature 306 may have a lower threshold potential value, while the first polishing feature 304 has a higher threshold potential value. In another embodiment, the second polishing feature 306 may have a higher threshold potential value, while the first polishing feature 304 has a lower threshold potential value. As described herein, surface properties, such as threshold potential, can be controlled within each feature and / or within or at various locations on the polishing surface of the polishing pad by the physical layout, pattern, or combination of the second polishing feature 306 and the first polishing feature 304.

[0063] The first polishing feature 304 may be formed from one or more polymeric materials. The first polishing feature 304 may be formed from a single polymeric material or from a mixture of two or more polymers combined with various threshold potential modifiers to achieve exposed surfaces having different threshold potentials as described herein. In one embodiment, the first polishing feature 304 may be formed from one or more thermoplastic polymers. The first polishing feature 304 may be formed from thermoplastic polymers such as polyurethane, polypropylene, polystyrene, polyacrylonitrile, polymethyl methacrylate, polychlorotrifluoroethylene, polytetrafluoroethylene, polyoxymethylene, polyoxymethylene, polycarbonate, polyimide, polyetheretherketone, polyphenylene sulfide, polyethersulfone, acrylonitrile butadiene styrene (ABS), polyetherimide, polyamide, melamine, polyester, polysulfone, polyvinyl acetate, fluorinated hydrocarbons, etc., as well as acrylates, copolymers, grafts, and mixtures thereof. In another embodiment, the thermoplastic polymer used to form the first polishing feature 304 is modified with various threshold potential modifiers to obtain exposed regions having different threshold potentials as described herein. In one embodiment, the first polishing feature 304 may be formed from an acrylate. For example, the first polishing feature 304 may be a polyurethane acrylate, a polyether acrylate, or a polyester acrylate. In another embodiment, the first polishing feature 304 may comprise one or more thermosetting polymers, such as epoxy resins, phenolic resins, amines, polyesters, ethyl carbamate, silicone, and the aforementioned acrylates, mixtures, copolymers, and grafts.

[0064] In one embodiment, the first polishing feature 304 may be formed of a simulated plastic 3D printing material. In one embodiment, abrasive particles may be embedded in the first polishing feature 304 to enhance the polishing process. The material containing the abrasive particles may be a metal oxide, such as cerium oxide, aluminum oxide, silicon dioxide, or a combination thereof, a polymer, a dielectric metal, or a ceramic.

[0065] The second polishing feature 306 may be formed from one or more polymer materials. The second polishing feature 306 may be formed from a single polymer material or a mixture of two or more polymers to achieve the target properties. In one embodiment, the second polishing feature 306 may be formed from one or more thermoplastic polymers with a storage modulus. For example, the second polishing feature 306 may be formed from thermoplastic polymers such as polyurethane, polypropylene, polystyrene, polyacrylonitrile, polymethyl methacrylate, polychlorotrifluoroethylene, polytetrafluoroethylene, polyoxymethylene, polyoxymethylene, polycarbonate, polyimide, polyetheretherketone, polyphenylene sulfide, polyethersulfone, acrylonitrile butadiene styrene (ABS), polyetherimide, polyamide, melamine, polyester, polysulfone, polyvinyl acetate, fluorinated hydrocarbons, etc., as well as the above-mentioned acrylates, copolymers, grafts, and mixtures. In another embodiment, the thermoplastic polymer used to form the second polishing feature 306 is modified with various threshold potential modifiers to obtain exposed regions having different threshold potentials as described herein. In one embodiment, the second polishing feature 306 may be formed of an acrylate. For example, the second polishing feature 306 may be a polyurethane acrylate, a polyether acrylate, or a polyester acrylate. In another embodiment, the second polishing feature 306 may be formed of a thermoplastic elastomer. In one embodiment, the second polishing feature 306 may be formed of a rubber-like 3D printing material.

[0066] In some embodiments, the first polishing feature 304 is typically harder and more rigid than the second polishing feature 306, while the second polishing feature 306 is softer and more flexible than the first polishing feature 304. The materials and patterns of the first polishing feature 304 and the second polishing feature 306 can be selected to obtain a "tuned" block material for the polishing pad 300 having a region of varying threshold potential. Using such a "tuned" block material and a polishing pad 300 formed with varying threshold potentials offers various advantages, such as improved polishing results (e.g., reduced defects), lower manufacturing costs, and extended pad life. In one embodiment, the "tuned" block material or the polishing pad as a whole can have a hardness between about 65 on Shore A and about 75 on Shore D. The tensile strength of the polishing pad can be between 5 MPa and about 75 MPa. The polishing pad 300 can have an elongation at break of about 5% to about 350%. The polishing pad can have a shear strength greater than about 10 mPa. The polishing pad 300 can have a storage modulus between about 5 MPa and about 2000 MPa. The polishing pad can have a stable storage modulus in a temperature range of 25 degrees Celsius to 90 degrees Celsius, such that the storage modulus ratio of E'30 / E'90 falls in the range of about 6 to about 30, where E'30 is the storage modulus at 30 degrees Celsius and E'90 is the storage modulus at 90 degrees Celsius.

[0067] In one embodiment, the materials of the first polishing feature 304 and the second polishing feature 306 are chemically resistant to erosion from the abrasive slurry. In another embodiment, the materials of the first polishing feature 304 and the second polishing feature 306 are hydrophilic.

[0068] The composite pad body 302 includes a plurality of grooves 310 or channels extending above the lower portion 308 of the second polishing feature 306 of the composite pad body 302. The plurality of grooves 310 or channels are configured in the polishing surface 305 of the polishing pad 300. The grooves 310 can have any suitable shape. The grooves 310 can be circular. In some embodiments where the grooves are circular, the grooves 310 can be concentric with each other.

[0069] The grooves 310 are separated by a spacing P. The spacing P, most clearly illustrated in Figure 3B, is the radial distance between adjacent grooves. Between each groove is a first polishing feature 304 or separator with a width Wp. The first polishing feature 304 can have any suitable shape. The first polishing feature 304 can be an annular feature. Each groove 310 includes a wall 314 terminating at a base 316. As shown in Figure 3B, the base 316 can have a rectangular profile. Alternatively, the base 316 can have a U-shaped profile. Each groove 310 can have a depth Dg and a width Wg. The wall 314 can be generally vertical and terminate at the base 316.

[0070] In one embodiment, the first polishing feature 304 and the second polishing feature 306 may be alternating concentric rings to form a circular composite pad body 302. In one embodiment, the height of the first polishing feature 304 is greater than the height of the second polishing feature 306, such that the upper surface 322 of the first polishing feature 304 protrudes from the second polishing feature 306. A groove 310 or channel is formed between the first polishing feature 304 and the second polishing feature 306. During polishing, the upper surface 322 of the first polishing feature 304 forms a polished surface 305 that contacts the substrate, while the groove 310 retains the polishing fluid. In one embodiment, the first polishing feature 304 is thicker than the second polishing feature 306 in a direction perpendicular to a plane parallel to the composite pad body 302, such that the groove 310 and / or channel are formed on the top surface of the composite pad body 302.

[0071] In one embodiment, the width Wp of the first polishing feature 304 can be between about 250 micrometers and about 2 millimeters. The spacing "P" between the first polishing features 304 can be between about 0.5 millimeters and about 5 millimeters. Each first polishing feature 304 can have a width in the range of about 250 micrometers to about 2 millimeters. The width Wp and / or the spacing "P" can vary across the radius of the polishing pad 300 to areas with different hardness.

[0072] The composite gasket body 302 may include a plurality of exposed surfaces. In one embodiment, at least a portion of two of the exposed surfaces have different surface properties, such as threshold potentials. The exposed surfaces may be selected to form a gradient of increasing threshold potentials. In one embodiment, the exposed surfaces are selected from the upper surface 322 of the first polishing feature 304, the surface 324 of the wall 314, and the surface 326 of the base 316. For example, in one embodiment, at least a portion of the upper surface 322 of the first polishing feature 304 contains a first material having a first threshold potential, at least a portion of the surface 324 of the wall 314 contains a material having a second threshold potential, and at least a portion of the surface 326 of the base 316 of the groove 310 contains a third material having a third threshold potential. In another embodiment, at least a portion of the upper surface 322 of the first polishing feature 304 and a portion of the surface 324 of the wall 314 of the first polishing feature 304 have a first threshold potential, and at least a portion of the surface 326 of the base 316 of the groove 210 contains a second material having a second threshold potential different from the first threshold potential.

[0073] In one embodiment, the composite liner body 302 may include a plurality of material layers as shown in Figure 2C. Materials with different surface properties (e.g., threshold potentials) may be used to form each of the different layers. At least two of the plurality of layers each have an exposed surface with a threshold potential different from the exposed surface of another layer.

[0074] In one embodiment, the potential of arrival of the entire composite gasket body 302 is gradiented. Gradienting the potential of arrival of the entire composite gasket body 302 can be achieved using a material property gradient (340→350) from the polished surface 305 to the flat surface 307. In one embodiment, the potential of arrival gradient increases from the polished surface 305 to the flat surface 307. In another embodiment, the potential of arrival increases from the flat surface 307 to the polished surface 305. For example, in one embodiment, the upper surface 322 of the first polished feature 304 includes a first material layer having a first potential of arrival, at least a portion of the surface 324 of the wall 314 includes a second material layer having a second potential of arrival, and the surface 326 of the base 316 of the groove 310 includes a third material layer having a third potential of arrival.

[0075] Figure 3C is a schematic partial top view of a polishing pad 300c having a boundary potential change region on its surface according to an embodiment of the present disclosure. The polishing pad 300c is similar to the polishing pad 300 of Figure 3A, except that the polishing pad 300c includes interlocking first polishing features 304c and second polishing features 306c. The first polishing features 304c and second polishing features 306c may form a plurality of concentric rings. In one embodiment, the first polishing feature 304c may include a protruding vertical ridge 360, and the second polishing feature 306c may include a vertical recess 370 for receiving the vertical ridge 360. Alternatively, the second polishing feature 306c may include a protruding ridge, while the first polishing feature 304c includes a recess. Interlocking the second polishing feature 306c with the first polishing feature 304c increases the mechanical strength of the polishing pad 300c relative to shear forces that may be applied during CMP processes and / or material handling. The first polishing feature 304c and the second polishing feature 306c may each have a boundary potential change region.

[0076] Figure 3D is a schematic perspective cross-sectional view of a polishing pad 300d having a region of varying arrival potential on its surface according to an embodiment of the present disclosure. The polishing pad 300d includes a plurality of first polishing features 304d extending from a substrate layer such as a second polishing feature 306d. The upper surface 372 of the first polishing feature 304d forms a polishing surface for contacting the substrate during polishing. The first polishing features 304d and the second polishing features 306d have different material and structural properties. For example, the first polishing feature 304d may be formed of a material having a first arrival potential, such as the material used for the first polishing feature 304 of the polishing pad 300, while the second polishing feature 306d may be formed of a material having a second arrival potential. In addition, the first polishing feature 304d may be formed of a hard material, such as the material used for the hard features of the polishing pad 300, while the second polishing feature 306d may be formed of a soft or low storage modulus E' material, such as the material used for the second polishing features of the polishing pad 300. Polishing pad 300d can be formed by 3D printing, similar to polishing pad 300.

[0077] In one embodiment, the first polishing feature 304d may have substantially the same size. Alternatively, the first polishing feature 304d may vary in size to create varying mechanical and surface properties (e.g., varying threshold potential), varying storage modulus E', and / or varying loss modulus E'' across the polishing pad 300d. In one embodiment, the first polishing feature 304d may be uniformly distributed throughout the polishing pad 300d. Alternatively, the first polishing feature 304d may be arranged in a non-uniform pattern to achieve the desired properties within the polishing pad 300d.

[0078] In the 3D figure, the first polishing feature 304d is illustrated as a cylinder protruding from the second polishing feature 306d. Alternatively, the first polishing feature 304d can have any suitable shape, such as a cylinder with an elliptical, square, rectangular, triangular, polygonal, or irregular cross-section. In one embodiment, the first polishing feature 304d can have different cross-sectional shapes to adjust the hardness, mechanical strength, threshold potential, or other desired properties of the polishing pad.

[0079] Figure 3E is a schematic partial cross-sectional view of a polishing pad 300e having a boundary potential change region on its surface according to an embodiment of the present disclosure. The polishing pad 300e is similar to the polishing pads 300, 300c, or 300d in Figures 3A to 3D, except that the polishing pad 300e includes an interlocking first polishing feature 304e and a second polishing feature 306e. The first polishing feature 304e and the second polishing feature 306e may include a plurality of concentric rings and / or separating elements forming part of the composite pad body 302. In one embodiment, the first polishing feature 304e may include a protruding sidewall 374, while the second polishing feature 306e may include a recessed sidewall 375 to receive the first polishing feature 304e. Alternatively, the second polishing feature 306e may include a protruding sidewall, while the first polishing feature 304e includes a recessed sidewall. By interlocking the second polishing feature 306e and the first polishing feature 304e with their protruding sidewalls, the polishing pad 300e gains increased tensile, compressive, and / or shear strength. Additionally, the interlocking sidewalls prevent the polishing pad 300e from being pulled apart.

[0080] In one embodiment, the boundary between the first polished feature 304e and the second polished feature 306e 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 polished feature 304e to a second composition used to form the second polished feature 306e. Thus, the cohesiveness of the material formed by the compositions used to form certain portions of the composite liner body 302 is a direct result of the layer-by-layer fabrication process described herein, which enables micron-level control and fine mixing of one or more chemical components in a structure formed by layer-by-layer stacking.

[0081] Figure 3F is a schematic partial cross-sectional view of a polishing pad 300f having a boundary potential change region on its surface according to an embodiment of the present disclosure. Figure 3F is a schematic partial cross-sectional view of a polishing pad according to an embodiment of the present disclosure. The polishing pad 300f is similar to the polishing pad 300e of Figure 3E, except that the polishing pad 300f includes interlocking features arranged in a different manner. The polishing pad 300f may include a first polishing feature 304f and a second polishing feature 306f. The first polishing feature 304f and the second polishing feature 306f may include a plurality of concentric rings and / or separating elements. In one embodiment, the first polishing feature 304f may include a horizontal ridge 376, and the second polishing feature 306f may include a horizontal recess 377 to receive the horizontal ridge 376 of the first polishing feature 304f. Alternatively, the second polishing feature 306f may include a horizontal ridge, and the first polishing feature 304f includes a horizontal recess. In one implementation, vertical interlocking features (e.g., the interlocking features in Figure 3C) and horizontal interlocking features (e.g., the interlocking features in Figures 3E and 3F) can be combined to form a polishing pad.

[0082] Figures 3G to 3L are top views of a polishing pad design with a boundary potential change region on the surface according to the embodiments disclosed herein. Each of Figures 3G to 3L includes a pixel map with white areas (areas of white pixels) and black areas (areas of black pixels), where the white areas represent first polishing features 304g-304l for contacting and polishing the substrate, and the black areas represent second polishing features 306g-306l. The first polishing features 304g-304l may be similar to the first polishing feature 304 discussed herein. The second polishing features 306g-306l may be similar to the second polishing feature 306 of the polishing pad. As discussed similarly herein, the white areas typically protrude above the black areas, such that channels are formed in the black areas between the white areas. During polishing, the abrasive slurry can flow through the channels and can be retained in the channels. The polishing pad illustrated in Figures 3G-3L can be formed using a multilayer fabrication process to deposit multiple material layers. Each of the plurality of layers may comprise two or more materials to form the first polishing features 304g-304f and the second polishing features 306g-306f. In one embodiment, the first polishing features 304g-304f may be thicker than the second polishing features 306g-306f in a direction perpendicular to a plane parallel to the plurality of material layers, such that grooves and / or channels are formed on the top surface of the polishing pad.

[0083] Figure 3G is a schematic pixel diagram of a polishing pad design 300g having a plurality of first polishing features 304g as concentric polishing features. The first polishing features 304g can be concentric circles of the same width. In one embodiment, the second polishing features 306g can also have the same width, such that the spacing between the first polishing features 304g in the radial direction is fixed. During polishing, the channels between the first polishing features 304g retain the polishing slurry and prevent the polishing slurry from being rapidly lost 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).

[0084] Figure 3H is a schematic pixel diagram of a polishing pad design 300h having a plurality of segmented first polishing features 304h arranged in concentric circles. In one embodiment, the segmented first polishing features 304h may have approximately the same length. The segmented first polishing features 304h may form a plurality of concentric circles. In each circle, the segmented first polishing features 304h may be evenly distributed within each concentric circle. In one embodiment, the segmented first polishing features 304h may have the same width in the radial direction. In some embodiments, regardless of the radius of the concentric circles, each segmented first polishing feature 304h has approximately the same length (e.g., equal arc lengths, except for the central region of the polishing pad). In one embodiment, second polishing features 306h are arranged between the plurality of concentric circles and have the same width, such that the spacing between the concentric circles is fixed. In one embodiment, the gaps between the segmented first polishing features 304h may be staggered between the circles to prevent the abrasive 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.

[0085] Figure 3I is a schematic pixel diagram of a polishing pad design 300i having a spiral first polishing feature 304i on a second polishing feature 306i. In Figure 3I, the polishing pad design 300i has four spiral first polishing features 304i extending from the center of the polishing pad to the edge of the polishing pad. Although four spiral polishing features are shown, fewer or more spiral first polishing features 304i can be arranged in a similar manner. The spiral first polishing features 304i define a spiral channel. In one embodiment, each spiral first polishing feature 304i has a fixed width. In one embodiment, the spiral channel also has a fixed width. During polishing, the polishing pad can rotate about a central axis in a direction opposite to the direction of the spiral first polishing features 304i to retain the abrasive slurry in the spiral channel. For example, in Figure 3I, the spiral first polishing features 304i and the spiral channel are formed in a counterclockwise direction, so during polishing, the polishing pad can be rotated clockwise to retain the abrasive slurry in the spiral channel and on the polishing pad. In some embodiments, each spiral channel is continuous from the center to the edge of the polishing pad. This continuous spiral channel allows the abrasive slurry, along with any polishing waste, to flow from the center to the edge of the polishing pad. In one embodiment, the polishing pad can be cleaned by rotating it in the same direction as the spiral first polishing feature 304i (e.g., counterclockwise in Figure 3I).

[0086] Figure 3J is a schematic pixel diagram of a polishing pad design 300j having a first polishing feature 304j, which is a segmented polishing feature arranged in a spiral pattern on a second polishing feature 306j. The polishing pad illustrated in Figure 3J is similar to the polishing pad in Figure 3I, except that the first polishing feature 304j is segmented and the radial spacing of the first polishing feature 304j is changed. In one embodiment, the radial spacing of the first polishing feature 304j decreases from the center of the polishing pad to the edge region of the polishing pad.

[0087] Figure 3K is a schematic pixel diagram of a polishing pad design 300k, which has a plurality of separate first polishing features 304k formed in a second polishing feature 306k. In one embodiment, each of the plurality of first polishing features 304k may be a cylindrical structure similar to the structure illustrated in Figure 3D. In one embodiment, the plurality of first polishing features 304k may have the same dimensions on a plane of the polishing surface. In one embodiment, the plurality of first polishing features 304k may be arranged as concentric circles. In one embodiment, the plurality of first polishing features 304k may be arranged in a regular 2D pattern relative to the plane of the polishing surface.

[0088] Figure 3L is a schematic pixel diagram of a polishing pad design 300f, which has a plurality of separate first polishing features 304f formed on a second polishing feature 306f. The polishing pad in Figure 3L is similar to the polishing pad in Figure 3K, except that some of the first polishing features 304f in Figure 3L can be connected to form one or more closed circles. These one or more closed circles can form one or more barriers to retain the abrasive slurry during the polishing process.

[0089] The first polishing features 304a-304f in the design of Figures 3A to 3L can be formed of the same material or the same material composition. Alternatively, the material composition and / or material properties of the first polishing features 304a-304f in the design of Figures 3A to 3L can be varied depending on the polishing feature. Individualized material composition and / or material properties allow for the customization of polishing pads for specific needs.

[0090] Figure 4A is a schematic cross-sectional view of a multilayer manufacturing system 450, which can be used to form polishing pads with regions of boundary potential change on the surface using a multilayer manufacturing process according to one or more embodiments of the present disclosure. The multilayer manufacturing process may include, but is not limited to, processes such as multi-jet deposition, inkjet printing, fused deposition modeling, binder jetting, powder bed melting, selective laser sintering, stereolithography, photopolymerization curing, lamination, directional energy deposition, or other similar 3D deposition processes (e.g., 3D printing). Multilayer manufacturing processes (e.g., 3D printing) have been found to be particularly useful in forming polishing pads with regions of boundary potential change.

[0091] The lamination manufacturing system 450 typically includes a precursor delivery section 453, a precursor preparation section 454, and a deposition section 455. The deposition section 455 typically includes lamination manufacturing apparatus for forming polishing pads 200, 300-300l, or hereinafter referred to as a printing station 400. During processing, the polishing pads 200, 300-300l can be printed onto a support 402 within the printing station 400. In some embodiments, the polishing pads 200, 300-300l are formed layer by layer from a CAD (computer-aided design) program using one or more droplet jet printers 406 (e.g., printers 406A and 406B illustrated in Figure 4A). During the printing process, the printers 406A, 406B and the support 402 can move relative to each other.

[0092] The droplet jet printer 406 may include one or more print heads 408 having one or more nozzles (e.g., nozzles 409-412) for dispensing liquid precursors. In the embodiment of Figure 4A, the printer 406A includes a print head 408A with nozzle 409 and a print head 408B with nozzle 410. Nozzles 409 may be configured to dispense a first liquid precursor composition to form a first polymer material, such as a polymer material having a first threshold potential, while nozzles 410 may be used to dispense a second liquid precursor to form a second polymer material having a second threshold potential. The liquid precursor composition may be dispensed at selected locations or areas to form a polishing pad with a region of varying threshold potential. These selected locations collectively form a target print pattern, which may be stored as a CAD-compatible file, subsequently read by an electronic controller 405, which controls droplet delivery from the nozzles of the droplet jet printer 406.

[0093] An electronic controller 405 is typically used to facilitate the control and automation of components within a multilayer manufacturing system 450 (including a printing station 400). The electronic controller 405 can be, for example, a computer, a programmable logic controller, or an embedded controller. The electronic controller 405 typically includes a central processing unit (CPU), memory (e.g., computer-readable media), and support circuitry for input and output (I / O) (not shown). The CPU can be any form of computer processor used in an industrial environment to control various system functions, substrate movement, chamber processes, and control supporting hardware (e.g., sensors, motors, heaters, etc.), and to monitor processes occurring within the system. Memory or computer-readable media is connected to the CPU and can 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 local or remote digital storage. Software instructions and data can be decoded and stored in the memory to instruct the CPU. Support circuitry is also connected to the CPU to support the processor in a conventional manner. Supporting circuitry may include buffers, power supplies, clock circuits, input / output circuits, subsystems, and the like. A program (or computer instructions) readable by the electronic controller 405 determines what tasks the elements in the additive manufacturing system 450 can perform. In one embodiment, the program is software readable by the electronic controller 405 and includes decoding for tasks related to monitoring, executing, and controlling the delivery and positioning of droplets delivered by the droplet jet printer 406. The program may also include tasks related to the movement, support, and / or positioning of elements within the print station 400, as well as various process tasks and procedures performed in the electronic controller 405.

[0094] After 3D printing, the polishing pads 200, 300-300l can be cured using a curing apparatus 420 located within the deposition section 455 of the laminated manufacturing system 450. The curing process performed by the curing apparatus 420 can be carried out by heating the printed polishing pad to a curing temperature or by exposing the pad to one or more forms of electromagnetic radiation. In one example, the curing process can be carried out by exposing the printed polishing pad to ultraviolet radiation 421 generated by an ultraviolet light source within the curing apparatus 420.

[0095] The multilayer manufacturing process provides a convenient and highly controllable process for producing polishing pads with separation features formed from different materials and / or compositions of different materials. In one embodiment, the multilayer manufacturing process can be used to form features having a first threshold potential and / or features having a second threshold potential. For example, a polishing pad feature having a first threshold potential can be formed from a first composition containing a polyurethane segment dispensed from nozzle 412 of printer 406B, and a polishing pad feature having a second threshold potential can be formed from droplets of a second composition dispensed from nozzle 410 of printer 406A. Additionally, droplets of the first composition can be used to form soft or low storage modulus E' features of the polishing pad, and droplets of the second composition can be used to form hard or high storage modulus E' features of the polishing pad.

[0096] In another embodiment, the first polishing feature 304 and / or the second polishing feature 306 may each be formed from a mixture of two or more components. In one example, the first component may be dispensed in droplet form by a first printhead (e.g., printhead 408A), while the second component may be dispensed in droplet form by a second printhead (e.g., printhead 408B of printr 406A). Forming the first polishing feature 304 using a mixture of droplets delivered from multiple printheads will typically include aligning pixels corresponding to the first polishing feature 304 on predetermined pixels within a deposition map found in the electronic controller 405. The deposition map typically represents the locations of various droplets of each component to be disposed throughout a surface (e.g., an XY plane) to form layers (e.g., layers stacked in the Z direction) within a stack of deposition layers. Subsequently, printhead 408A may align with pixels corresponding to the locations where the first polishing feature 304 will be formed, and then dispense droplets on the predetermined pixels. Therefore, the polishing pad can be formed of a first material composition and a second material, the first material composition being formed by depositing droplets of the first droplet composition, and the second material comprising a second material composition formed by depositing droplets of the second droplet composition.

[0097] Figure 4B is a schematic enlarged cross-sectional view of a portion of a print station 400 and a polishing pad 300 during the polishing pad manufacturing process. In one example shown in Figure 4B, the print station 400 includes two printers 406A and 406B for sequentially forming a portion of the polishing pad 300 by a layer-by-layer deposition process. The portion of the polishing pad 300 shown in Figure 4B may include, for example, a portion of a first polishing feature 304 or a second polishing feature 306 in the ultimately formed polishing pad 300. During the process, printers 406A and 406B are configured to deliver droplets "A" or "B" respectively to a first surface of a support 402, subsequently reaching the surface of the grown polishing pad located on the support 402 in a layer-by-layer process. As shown in Figure 4B, a second layer 448 is deposited on top of a first layer 446 already formed on the support 402. In one embodiment, a second layer 448 is formed over a first layer 446, which has been processed by a curing device 420 located downstream of printers 406A and 406B in the pad manufacturing process.

[0098] It will be noted that in some embodiments, while one or more printers 406A and 406B are depositing droplets "A" and / or "B" onto the surface 446A of a pre-formed first layer 446, certain portions of the second layer 448 may be simultaneously processed by the curing apparatus 420. In this case, the layer currently being formed may include a processed portion 448A and an unprocessed portion 448B located on either side of the curing zone 449A. The unprocessed portion 448B typically includes an array of dispensing droplets, such as dispensing droplets 443 and 447 deposited on the surface 446A of the previously formed first layer 446 using printers 406B and 406A, respectively.

[0099] Figure 4C is an enlarged cross-sectional view of a distributing droplet 443 located on surface 446A of the previously formed first layer 446, as illustrated in Figure 4B. Based on the properties of the material within the distributing droplet 443, and due to the surface energy of surface 446A, the distributing droplet will expand to a larger surface area than the original distributing droplet (e.g., droplet "A" or "B") due to surface tension. The amount of expansion of the distributing droplet will vary as a function of the time from the moment it is deposited on surface 446A. However, after a very short period of time (e.g., <1 second), the expansion of the droplet will reach an equilibrium size and have a contact angle α. The expansion of the distributing droplet across the surface affects the resolution of the droplet's configuration on the surface of the grown polishing pad, and thus affects the resolution of features and components found in the various regions of the final polishing pad.

[0100] In some embodiments, it is desirable to expose droplets "A" and "B" simultaneously during their dispensing to cure or "fix" them to a desired size before they have a chance to expand to their normal uncured equilibrium size on the substrate surface. In this case, the energy supplied by the curing apparatus 420 to the dispensed droplets, the surface on which the droplets are placed, and the material composition of the droplets are adjusted to control the resolution of each dispensed droplet. Therefore, one parameter controlled or adjusted during the 3D printing process is the surface tension of the dispensed droplets relative to the surface on which the droplets are placed. Meanwhile, as further discussed below, in some embodiments, it is desirable to add one or more initiators (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.

[0101] It has been found that it is ideal to partially cure each dispensed droplet to "fix" the surface properties and size of the droplet during the printing process. The ability to "fix" the droplet to the desired size can be achieved by adding a desired amount of one or more photoinitiators to the material composition of the droplet and delivering a sufficient amount of energy from the curing apparatus 420 during the printing process. In some embodiments, it is ideal to use a curing apparatus 420 capable of delivering ultraviolet (UV) light between approximately 1 millijoules / (mJ / cm²) and 100 mJ / cm², for example, approximately 10⁻¹⁵ mJ / cm², during the droplet dispensing and lamination processes. The UV radiation can be provided by any UV source, such as a mercury microwave arc lamp, a pulsed xenon flash lamp, a high-efficiency UV light-emitting diode array, and a UV laser. The UV radiation can have wavelengths between approximately 170 nm and approximately 400 nm.

[0102] In some embodiments, the sizes of the dispensed droplets "A" and "B" can range from about 10 to about 100 micrometers, for example, from 50 to about 70 micrometers. Depending on the surface energy (dynes) of the substrate or polymer layer on which the droplets are dispensed, the uncured droplets can expand across the surface to a fixed droplet size 443A between about 10 and about 500 micrometers, for example, between about 50 and about 200 micrometers. The height of such droplets can range from about 5 to about 100 micrometers, also depending on factors such as surface energy, wetting properties, and / or resin composition, which may include other additives such as flow agents, thickeners, and surfactants. One source of the aforementioned additives is BYK-Gardner GmbH of Geretsried, Germany.

[0103] Ideally, the amount of photoinitiator, the amount of photoinitiator in the droplet composition, and the amount of energy supplied by the curing device 420 are selected to allow the dispensed droplets to be "fixed" in a time shorter than about 1 second, for example, shorter than about 0.5 seconds. In studies of "fixing" droplets within this short time range, the dispensing nozzle of the droplet jet printer 406 is positioned at a small distance from the surface of the polishing pad, such a small distance being, for example, between 0.1 and 10 millimeters (mm), or even between 0.5 and 1 mm, while exposing the nozzle and the surface 446A of the polishing pad to ultraviolet radiation 421 delivered by the curing device 420. It has also been found that by controlling the composition of the droplets, 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 420, and the amount of photoinitiator in the droplet composition, the contact angle α of the droplets can be controlled, thereby controlling the size of the fixed droplets and thus the resolution of the printing process. Droplets that have been fixed or at least partially cured are also referred to herein as cured droplets. In some embodiments, the size of the fixed droplet 443A is between about 10 and about 200 micrometers. In some embodiments, the contact angle can be ideally controlled to a value of at least 50°, for example greater than 55°, or even greater than 60°.

[0104] The amount of surface curing required to form the next lower layer of the distribution droplets is a parameter of the polishing pad formation process. The amount of curing in this initial dose may affect the surface energy that subsequent distribution droplet layers will be exposed to during the printing process. When a deposited layer is grown on top of a deposited layer, the amount of initial curing dose may affect the amount of curing that each deposited layer will ultimately achieve in the formed polishing pad because each deposited layer is repeatedly exposed to additional transmitted curing radiation supplied through the subsequently deposited layer. It will be noted that it is generally ideal not to over-cur the formed layer, as over-curing will affect the material properties of the over-cured material. The UV radiation exposure time for achieving the polymerization of an exemplary 10-micron-thick distribution droplet layer can be constituted during an exposure period of about 0.1 seconds to about 1 second, and the intensity of the UV radiation can be from about 10 to about 15 mJ / cm2.

[0105] In some embodiments, it is desirable to control the composition of the droplets and the amount of energy delivered from the curing apparatus 420 during the initial curing process, or in processes where the deposited layer of the distributed droplets is directly exposed to the energy provided by the curing apparatus 420, so that the layer is only partially cured by the desired amount. Generally, the initial curing process ideally cures the distributed droplets primarily on the surface, rather than curing the distributed droplets entirely, because controlling the surface energy of the formed layer is relevant to controlling the size of the distributed droplets in the subsequently printed layers. In one example, the amount of distributed droplets that are partially cured can be defined by the amount of chemical conversion of the material in the distributed droplets. In one example, the acrylate conversion achieved in the distributed droplets used to form a layer containing ethyl acrylate is defined as a percentage x, which is calculated by the following formula: where AC=C and AC=O are the values ​​of the C=C peak at 910 cm⁻¹ and the C=O peak at 1700 cm⁻¹, respectively, determined using FT-IR spectroscopy. The AC=C / AC=O ratio refers to the relative ratio of C=C to C=O bonds within the cured droplet. Therefore, (AC=C / AC=O)0 represents the initial ratio of AC=C to AC=O bonds in the droplet, while (AC=C / AC=O)x represents the ratio of AC=C to AC=O bonds on the surface of the cured substrate after the droplet has cured. In some embodiments, the amount of material initially partially cured in the layer may be equal to or greater than about 70% of the material in the dispensed droplet. In some configurations, it may be desirable to partially cure the material in the dispensed droplet to a level between about 70-80% during the initial layer formation step.

[0106] As discussed further below, the mixture or positioning of the distribution droplets can be adjusted on a layer-by-layer basis to form layers with the same or different material, mechanical, or dynamic properties. In one example, as shown in Figure 4B, the mixture of distribution droplets comprises distribution droplets 443 and 447 in a 50:50 ratio, wherein distribution droplet 443 includes at least one material different from the material found in distribution droplet 447. The properties of certain portions of the composite liner body 302 (e.g., the first polishing feature 304 and / or the second polishing feature 306) can be adjusted or regulated according to the ratio and / or distribution of the first and second components formed from the positioning of the distribution droplets during the deposition process. For example, the weight percentage of the first component can range from about 1 wt% to about 100% based on the total weight of the components. Similarly, the second component can range from about 1 wt% to about 100% based on the total weight of the components. Depending on the desired material properties, such as threshold potential, hardness, and / or modulus, compositions 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 feature 304 and / or the second polishing feature 306 is controlled by selecting at least one component or a mixture of components, and by the size, position, velocity, and / or density of droplets dispensed by one or more printers. Therefore, the electronic controller 405 is typically adapted to position nozzles 409-410, 411-412 to form a layer with staggered droplets positioned at a desired density and pattern on the surface of the forming polishing pad.

[0107] Although only two compositions for forming the first polishing feature 304 and / or the second polishing feature 306 are generally discussed herein, embodiments disclosed herein still include forming features on a polishing pad using a plurality of materials interconnected by compositional gradients. In some configurations, the composition of the first polishing feature 304 and / or the second polishing feature 306 in the polishing pad is adjusted in a plane parallel to the polishing surface and / or through the thickness of the polishing pad, as further discussed below.

[0108] The ability to form an arrival potential gradient and to adjust the chemical content locally, internally, and throughout the polishing pad is enabled by using an "inkjetable" low-viscosity composition or low-viscosity "ink" used in the field of 3D printing technology to form droplets "A" and / or "B" as illustrated in Figure 4B. The low-viscosity ink is a "prepolymer" composition and a "precursor" to the first polishing feature 304 and the second polishing feature 306 already formed in the composite pad body 302. Therefore, the low-viscosity ink allows for the delivery of a variety of chemical substances and separated components that cannot be obtained by conventional techniques (such as molding and casting), and thus allows for the control of compositional changes or arrival potential gradients formed in different areas of the composite pad body 302. This is achieved by adding and mixing a viscosity-thinning reactive diluent to the high-viscosity functional oligomer and the potential modifier to achieve a suitable viscosity formulation. The diluent is then copolymerized with the higher-viscosity functional oligomer and the potential modifier upon exposure to the curing energy (e.g., UV radiation and / or heat) delivered by the curing apparatus 420. The reactive diluent can also act as a solvent, thus eliminating the need for inert, non-reactive solvents or diluents typically removed at each step.

[0109] Referring to the precursor delivery portion 453 and precursor formulation portion 454 of Figure 4A, in one embodiment, a first potentiometer precursor 452, a first precursor 456, and an optional second precursor 457 are mixed with a diluent 458 to form a first printable ink composition 459, which is delivered to a reservoir 404B of a printer 406B and used to form certain portions of the pad body 202. Similarly, a second potentiometer precursor 465, a third precursor 466, and an optional fourth precursor 467 can be mixed with a diluent 468 to form a second printable ink composition 469, which is delivered to a reservoir 404A of a printer 406A and used to form another portion of the pad body 202. In some embodiments, the first precursor 456 and the third precursor 466 each comprise an oligomer, such as a multifunctional oligomer, the second precursor 457 and the fourth precursor 467 each comprise a multifunctional monomer, the diluent 458 and the diluent 468 each comprise a reactive diluent (e.g., a monomer) and / or an initiator (e.g., a photoinitiator), and the first potential-modifying precursor 452 and the second potential-modifying precursor 465 comprise a class of monomers / oligomers copolymerized with other monomers and oligomers to modify the potential of arrival.

[0110] Figures 5A to 5D provide examples of pixel diagrams 500a-500d of a polishing pad formed within a printing station 400, each including a boundary potential gradient. In Figures 5A to 5D, white pixels are intended to schematically illustrate the locations where distribution droplets of a first material are dispensed, while black pixels indicate locations where no material is dispensed within the one or more layers used to form the polishing pad. By using these techniques, a compositional gradient of cured material or material formed by a plurality of cured droplets can be formed in one or more printing layers used to form at least a portion of a complete polishing pad. The overall properties of the polishing pad can be adjusted and customized using the custom composition of one or more printing layers within the polishing pad. It should be noted that the composition of the polishing features 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 also within the scope of this disclosure. It should be noted that the composition of the polishing features in any design of polishing pad (e.g., the polishing pads in Figures 3A to 3L) can be changed in a manner similar to that of the polishing pads in Figures 5A to 5F.

[0111] Figures 5A and 5B are black-and-white raster images showing pixel maps of a printed layer within a polishing pad, which includes portions of a first polishing feature 304 and one or more second polishing features 306. In Figures 5A and 5B, white pixels mark locations where droplets of the first material are dispensed, while black pixels mark locations where no material is dispensed or cured. Figure 5A is a pixel map 500a of a first portion of a layer within the polishing pad 300, and Figure 5B is a pixel map 500b of a second portion of the same polishing pad. The first portion can be dispensed by a first printhead according to pixel map 500a, and the second portion can be dispensed by a second printhead according to pixel map 500b. The two printheads stack pixel maps 500a and 500b together to form one or more layers containing separate polishing features. Polishing features near the edge region of the polishing pad include more first material than second material. Polishing features near the center region of the polishing pad include more second material than first material. In this example, each polishing feature has a unique combination of a first material and a second material. Therefore, by using a pixel map, polishing bodies can be formed sequentially, enabling the desired boundary potential gradient in the material composition within the polishing body to achieve the desired polishing pad performance.

[0112] Figures 5C and 5D are pixel images 500c and 500d of a polishing pad with features. In some embodiments, Figure 5C is a pixel image 500c of a first portion of the polishing pad, and Figure 5D is a pixel image 500d of a second portion of the same polishing pad. The polishing pads according to Figures 5C and 5D are similar to the polishing pads in Figures 5A and 5B, except that the gradient in the material composition of the polishing body changes from left to right across the polishing pad.

[0113] Figure 5E is a schematic diagram of a roll-based polishing pad 500e formed by using a multilayer manufacturing process to form a polishing surface 508. The polishing surface 508 has a boundary potential gradient across the polishing surface 508 (e.g., in the Y direction). As shown in Figure 5E, polishing material can be disposed on a platform 102 between a first roller 581 and a second roller 582.

[0114] Figure 5F is a schematic side cross-sectional view of a polishing pad 500f formed by forming a polishing substrate 591 using a multilayer fabrication process. The polishing substrate 591 has a potential gradient in the Z direction. The potential gradient of the stacked printed layers of the polishing substrate 591 can vary from high concentration to low concentration in one direction, or vice versa. In one example, stacked printed layers are sequentially stacked in the Z direction using a multilayer fabrication process. In some cases, one or more regions of the polishing pad may include more complex concentration gradients, such as high / low / high or low / high / low concentration gradients in one or more directions (e.g., X, Y, and Z directions). In some configurations, the polishing pad 500f may include a polishing feature region 594, which may include a separation region forming at least a first polishing feature 304 and a second polishing feature 306. In one example, the polishing feature region 594 may include a portion of a pad body 202 containing one or more structures illustrated in Figures 3A to 3L.

[0115] In one embodiment, the polishing substrate 591 comprises a homogeneous mixture of two or more different materials in each layer formed within the polishing substrate 591. In one example, the homogeneous mixture may comprise a mixture of materials used to form the first polishing feature 304 and the second polishing feature 306 in each layer formed within the polishing substrate 591. In some configurations, it is desirable to change the composition of the homogeneous mixture of materials layer by layer to create a boundary potential gradient in the layer growth direction (e.g., the Z direction in Figure 4B). The term homogeneous mixture is intended to broadly describe the material of a mixed region formed by dispensing and curing print droplets having at least two different components within each layer, and thus potentially containing small areas of at least two different components, wherein each component is sized at the resolution of the droplet jet printer 406. The interface between the polishing substrate 591 and the polishing feature region 594 may include a homogeneous blend of materials found on the upper surface of the polishing substrate 591 and the lower surface of the polishing feature region 594, or a discontinuous transition of different material compositions in the first deposited layer of the polishing feature region 594 directly deposited on the surface of the polishing substrate 591.

[0116] In some embodiments of the polishing feature region 594, or more generally, any of the aforementioned pad bodies 302, it is desirable to form a threshold potential gradient in the first polishing feature 304 and / or the second polishing feature 306 in a direction perpendicular to the polishing surface of the polishing pad. In one example, it is desirable to have a higher concentration of a material composition for forming a high threshold potential region in the printed layer near the base of the polishing pad (e.g., opposite the polishing surface), and a higher concentration of a material composition for forming a low threshold potential region in the printed layer near the polishing surface of the polishing pad. In another example, it is desirable to have a higher concentration of a material composition for forming a low threshold potential region in the printed layer near the base of the polishing pad, and a higher concentration of a material composition for forming a high threshold potential region in the printed layer near the polishing surface of the polishing pad.

[0117] In one embodiment, it is desirable to form a gradient in the material composition within the material used to form the first and / or second polishing features in a direction perpendicular to the polishing surface of the polishing pad. In one example, it is desirable to have a higher concentration of the material composition for forming the second polishing feature 306 in the print layer near the base of the polishing pad (e.g., opposite the polishing surface), and a higher concentration of the material composition for forming the first polishing feature 304 in the print layer near the polishing surface of the polishing pad. In another example, it is desirable to have a higher concentration of the material composition for forming the first polishing feature 304 in the print layer near the base of the polishing pad, and a higher concentration of the material composition for forming the second polishing feature 306 in the print layer near the polishing surface of the polishing pad. For example, the first layer may have a 1:1 ratio of the first print composition to the second print composition, the second layer may have a 2:1 ratio of the first print composition to the second print composition, and the third layer may have a 3:1 ratio of the first print composition to the second print composition. Gradients can also be created in different parts of a single layer by adjusting the position of the printing droplets in the plane of the deposition layer.

[0118] Figure 6 is a schematic side cross-sectional view of a portion of a polishing pad 600 including a boundary potential gradient (340→350) according to an embodiment of the present disclosure. The polishing pad 600 includes a second polishing feature 602, which is a soft or low storage modulus E' material similar to a second polishing feature 306 of a 3D-printed polishing pad. Similar to the second polishing feature 306, the second polishing feature 602 may be formed of one or more elastic polymer compositions, which may include polyurethane and aliphatic segments. The polishing pad 600 includes a plurality of surface features 606 extending from the second polishing feature 602. The outer surface 608 of the surface features 606 may be formed of a soft or low storage modulus E' material or a composition of a soft or low storage modulus E' material.

[0119] In one embodiment, the outer surface 608 of surface feature 606 may be formed of the same material or the same material composition as the second polishing feature 602. Surface feature 606 may also include a hard or high storage modulus E' feature 604 embedded therein. The hard or high storage modulus E' feature 604 may be formed of a material or material composition that is harder than surface feature 606. The hard or high storage modulus E' feature 604 may be formed of one or more materials similar to the hard or high storage modulus E' feature 604 of a polishing pad, including cross-linked polymer compositions and compositions containing aromatic groups. The embedded hard or high storage modulus E' feature 604 alters the effective hardness of surface feature 606 and thus provides the desired target pad hardness for polishing. A soft or low storage modulus E' polymer layer on the outer surface 608 may be used to reduce defects and improve planarization on the polished substrate. Alternatively, a soft or low storage modulus E' polymer material may be printed on the surface of other polishing pads disclosed herein to provide the same benefits.

[0120] Figure 7 is a schematic perspective cross-sectional view of a polishing pad 700 having one or more viewing windows 710 and a boundary potential gradient (340→350) formed therein, according to an embodiment of the present disclosure. The polishing pad 700 may have a pad body 702. The pad body 702 may include one or more second polishing features 706 and a plurality of first polishing features 704 extending from the second polishing features 706 for polishing. The second polishing features 706 and the first polishing features 704 may be formed of a material similar to the material used for the second polishing features 306 and the first polishing features 304 of the polishing pad 300. According to the present disclosure, the first polishing features 704 may be arranged in any suitable pattern.

[0121] One or more viewing windows 710 may be formed of a transparent material or composition to allow observation of the polished substrate. One or more viewing windows 710 may be formed by and / or around certain portions of the second polishing feature 706 or the first polishing feature 704. In some embodiments, one or more viewing windows 710 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 high enough to provide at least about 25% (e.g., at least about 50%, at least about 80%, at least about 90%, at least about 95%) of light transmission across 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).

[0122] In one embodiment, one or more observation windows 710 are formed of a material with a transmittance >35% at wavelengths between 280-399 nm and a transmittance >70% at wavelengths between 400-800 nm. In some embodiments, one or more observation windows 710 are formed of a material having a low refractive index approximately the same as that of the polishing slurry, and having high optical transparency to reduce reflections from the air / window / water interface and improve light transmission through one or more observation windows 710 to the substrate and from the substrate through one or more observation windows 710.

[0123] In one embodiment, one or more viewing windows 710 may be formed from a transparent printing material comprising polymethyl methacrylate (PMMA). In another embodiment, the window is formed using a transparent polymeric composition containing epoxy groups, wherein the composition may be cured using cationic curing, and may provide additional transparency and less shrinkage. In a similar embodiment, the window may be formed from a mixture of compositions undergoing cationic and free radical curing. In another embodiment, the window may be produced by another process and may be mechanically inserted into a pre-formed aperture or region formed by a 3D process in a polishing pad.

[0124] Figure 8 is a schematic perspective cross-sectional view of a polishing pad 800 comprising a boundary potential gradient and a backing layer 806 according to an embodiment disclosed herein. The backing layer 806 may be a supporting foam layer. The polishing pad 800 includes a second polishing feature 804 and a plurality of first polishing features 802 protruding from the second polishing feature 804. The polishing pad 800 may be similar to any polishing pad described herein, except that the backing layer 806 is attached to the second polishing feature 804. The backing layer 806 may provide the polishing pad 800 with desired compressibility. The backing layer 806 may also be used to modify the overall mechanical performance of the polishing pad 800 to achieve desired hardness and / or have desired storage modulus E' and loss modulus E''. The backing layer 806 may have a Shore A hardness value less than 80.

[0125] In one embodiment, the backing layer 806 may be formed of open-cell or closed-cell foam (e.g., polyurethane or polysiloxane (polysiloxane)), such that under pressure, the cells collapse and the backing layer 806 is compressed. In another embodiment, the backing layer 806 may be formed of natural rubber, EPDM rubber (ethylene propylene diene monomer), nitrile, or cyclohexane (polychloroprene).

[0126] Figure 9 is a schematic cross-sectional view of a polishing pad 900 having multiple regions. The polishing pad 900 can be designed to have different properties in regions that contact the central region of the substrate and regions that contact the edge region of the substrate during polishing. Figure 9 schematically illustrates a carrier head 108 positioning the substrate 110 relative to the polishing pad 900. In one embodiment, the polishing pad 900 may include a composite pad body 902 located on a backing layer 904. The composite pad body 902 can be manufactured by 3D printing. As shown in Figure 9, the polishing pad 900 can be divided into an outer edge region 906, a central region 908, and an inner edge region 910 along the radius of the polishing pad. The outer edge region 906 and the inner edge region 910 contact the edge region of the substrate 110 during polishing, while the central region 908 contacts the central region of the substrate during polishing.

[0127] The polishing pad 900 has different surface properties, such as threshold potentials, on the edge regions 906, 910 along the surface from the central region 908 to improve the edge polishing quality. In one embodiment, the edge regions 906, 910 may have different threshold potentials than the central region 908.

[0128] Figure 10 is a partially enlarged cross-sectional view of the polishing pad 900, illustrating an exemplary design of the outer edge region 906 and the central region 908. The outer edge region 906 includes a substrate layer 1006 and a plurality of surface features 1002. Surface features 1004 may be formed of a material harder than the substrate layer 1006. The central region 908 includes a substrate layer 1008 and a plurality of surface features 1004. Surface features 1002 may be formed of a material with an arrival potential different from that of the substrate layer 1006. In one embodiment, the central region 908 may include a locking layer 1010 beneath the substrate layer 1008. The plurality of surface features 1004 may be printed on the locking layer 1010 to improve stability. As shown in Figure 10, the dimensions of the surface features 1002 in the central region 908 are larger than the dimensions of the surface features 1004 in the outer edge region 906. In one embodiment, the spacing of surface features 1004 in the outer edge region 906 may be smaller than the spacing of surface features 1002 in the central region 908. Example formulation:

[0129] The polished objects described herein may be formed from at least one prepolymer composition. The prepolymer composition may be an inkjet-compatible prepolymer composition. The inkjet-compatible prepolymer composition may contain at least one of the following: (1) one or more oligomeric components; (2) one or more monomeric components; (3) one or more boundary potential modifier components; (4) a photoinitiator component; (5) inorganic particles, organic particles, or both; and (6) additional additives. The prepolymer ink or composition may be processed after deposition using any number of means, including exposure to or contact with radiation or heat with or without a curing agent or chemical initiator. For example, ultraviolet radiation (UV), gamma rays, X-rays, accelerated electrons, and ion beams may be used to initiate the polymerization reaction. For the purposes of this disclosure, a curing method or the use of additives to aid polymerization may be employed, such as sensitizers, initiators, and / or curing agents, for example, by means of a curing agent or oxygen inhibitor.

[0130] The ink composition may contain one or more oligomeric components. Any suitable oligomeric component capable of achieving the desired performance in the final polished object may be used. One or more oligomeric components may contain at least one of acrylic oligomers, ethyl carbamate oligomers, polyester-based (meth)acrylate oligomers, polyether-based (meth)acrylate oligomers, polysiloxymethyl (acrylate), vinyl (meth)acrylate, or epoxy (meth)acrylate oligomers.

[0131] The oligomer component may have low viscosity, low volatility, high reactivity, and low glass transition temperature. The oligomer component may be a multifunctional component. The functionality of the oligomer component may be 3 or less. The functionality of the oligomer component may be 2 or less.

[0132] Examples of suitable acrylic oligomers include, but are not limited to, those from Sartomer® with the names CN820, CN152, and CN146. Examples of suitable ethyl (meth)acrylates include, but are not limited to, those from Sartomer® with the names CN929, CN966, CN978, CN981, CN991, CN992, CN994, CN997, CN1963, CN9006, CN9007, and those from Cytek® Surface Specialty with the names Ebecryl 8402 and Ebecryl 1290.

[0133] Examples of suitable polyester or polyether-based (meth)acrylate oligomers include, but are not limited to, those from Sartamomer® USA, LLC, with names such as CN292, CN293, CN294E, CN299, CN704, CN2200, CN2203, CN2207, CN2261, CN2261LV, CN2262, CN2264, CN2267, CN2270, CN2271E, CN2273, CN2279, CN2282, CN2283, CN2303, CN3200, etc. Examples of suitable epoxy (meth)acrylate oligomers include, but are not limited to, those from Cytek® Surface Specialty with the names Ebecryl 3701, Ebecryl 3708, Ebecryl 3200, Ebecryl 3600, etc., and CN151 from Sartomer®.

[0134] Based on the total weight of the ink composition, one or more oligomeric components may comprise at least 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, or 55 wt%. Based on the total weight of the ink composition, one or more oligomeric components may comprise up to 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, or 60 wt%. Based on the total weight of the ink composition, the amount of oligomeric components in the ink composition may range from about 10 wt% to about 60 wt% (e.g., from about 20 wt% to about 50 wt%; from about 40 wt% to about 50 wt%; or from about 10 wt% to about 30 wt%).

[0135] The ink composition may further contain one or more monomeric components. The monomeric components typically provide good solubility for the oligomeric components in the ink formulation, thereby diluting the ink to a low viscosity. The monomeric components may also have a low glass transition temperature, which contributes to the flexibility of the ink after curing. The monomeric components may be multifunctional. The functionality of the monomeric components may be 3 or less. The functionality of the monomeric components may be 2 or less.

[0136] In one embodiment, the monomer component comprises both monofunctional and bifunctional monomers.

[0137] Examples of suitable monofunctional monomers include, but are not limited to, tetrahydrofurfuryl acrylate (e.g., SR285 from Sartamomer®), tetrahydrofurfuryl methacrylate, vinylcaprolactam, isocamphene acrylate, isocamphene methacrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, 2-(2-ethoxyethoxy)ethyl acrylate, isooctyl acrylate, isodecyl acrylate, isodecyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate, stearyl methacrylate, cyclic trimethylolpropane acetal acrylate, 2-[[(butylamino)carbonyl]oxy]ethyl acrylate (e.g., Genomer 1122 from RAHN USA), 3,3,5-trimethylcyclohexane acrylate, and monofunctional methoxylated PEG (350) acrylate, etc.

[0138] Examples of suitable bifunctional monomers include, but are not limited to, diacrylates or dimethacrylates of diols and polyether diols, such as propoxylated neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, alkoxylated aliphatic diacrylates (e.g., SR9209A from Sartomer®), diethylene glycol diacrylate, diethylene glycol dimethacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, triethylene glycol dimethacrylate, and alkoxylated hexanediol diacrylate, such as SR562, SR563, and SR564 from Sartomer®.

[0139] Based on the total weight of the ink composition, one or more monomeric components may comprise at least 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, or 55 wt%. Based on the total weight of the ink composition, one or more monomeric components may comprise up to 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, or 60 wt%. Relative to the total weight of the ink composition, the amount of monomeric components in the ink composition may range from about 10 wt% to about 60 wt% (e.g., from about 30 wt% to about 60 wt%; from about 20 wt% to about 50 wt%; from about 40 wt% to about 50 wt%; or from about 10 wt% to about 30 wt%).

[0140] The ink composition also includes one or more threshold potential modifier components. The threshold potential modifier component includes one or more oligomers, monomers, or both of which have an ionic charge (cationic, anionic, or nonionic) capable of modifying the threshold potential of the polished object surface. Any suitable threshold potential modifier that provides the desired charge on the target surface can be used.

[0141] Cationic monomers that can be used in ink compositions include, but are not limited to, diallyl dimethylammonium halides such as diallyl dimethylammonium chloride (DADMAC), methacryloyloxyethyl trimethylammonium halides such as methacryloyloxyethyl trimethylammonium chloride (MADQUAT), and the like. Furthermore, copolymers of cationic and nonionic monomers (e.g., alkyl acrylates, alkyl methacrylates, acrylamide, styrene, and the like), such as poly(acryloylamine-co-diallyl dimethylammonium) chloride, can also be used in ink compositions. Some other non-limiting examples of such cationic polymers include polyethyleneimine, ethoxylated polyethyleneimine, poly(diallyl dimethylammonium) halides, poly(aminoamine), poly(methacryloyloxyethyl dimethylammonium) chloride, polyvinylpyrrolidone, polyvinylimidazole, poly(vinylpyridine), and polyethyleneamine. As used herein, the term "cationic monomer" refers to a monomer having a positive charge. The term "cationic monomer" also includes monomers that become cationic from pH 1 to pH 12.

[0142] Anionic monomers that can be used in ink compositions include, for example, anionic monomers of homopolymers such as polyacrylic acid (“PAA”), polymethacrylic acid (“PMAA”), polymaleic acid (“PMA”), poly(2-acrylamide-2-methyl-1-propanesulfonic acid (polyAMPS)®, and the like, as well as copolymers of anionic and nonionic monomers such as poly(acrylic acid-co-methacrylic acid), poly(acrylic acid-co-2-acrylamide-2-methyl-propanesulfonic acid), and the like. Anionic monomers may be used in acidic form or as salts (e.g., sodium salts). The actual ionic properties of the anionic polymer (i.e., fully ionized or partially ionized) will depend on the pH of the CMP composition, as is well known in the art.

[0143] Nonionic monomers that can be used in ink compositions include, for example, monomers of the following homopolymers: polyacrylamide ("PAM") homopolymers, and copolymers of acrylamide with one or more other nonionic monomers, such as methacrylamide, N-vinylpyrrolidone ("NVP"), and the like.

[0144] In one embodiment, the boundary potential modifier is an acrylate monomer or oligomer. The acrylate monomer or oligomer may have one of the following functional groups: amino, ammonium, hydroxyl, ethyl, methyl, butyl, siloxane, or a combination of the above functional groups. The acrylate monomer or oligomer may be primary, secondary, tertiary, or quaternary branched. The acrylate monomer or oligomer may be monofunctional or polyfunctional (e.g., bifunctional, trifunctional, etc.).

[0145] Examples of (meth)acrylate monomers and / or oligomers include monofunctional monomers such as isoamyl acrylate, stearyl acrylate, lauryl acrylate, octyl acrylate, decyl acrylate, isomyristyl acrylate, isostearyl acrylate, 2-ethylhexyl-diethylene glycol acrylate, 2-hydroxybutyl acrylate, 2-acryloyloxyethyl hexahydrophthalate, 2-butoxyethyl acrylate, ethoxydiethylene glycol acrylate, methoxydiethylene glycol acrylate. Acrylates, methoxy polyethylene glycol acrylates, methoxypropylene glycol acrylates, phenoxyethyl acrylates, tetrahydrofurfuryl acrylates, isoborneol acrylates, 2-hydroxyethyl acrylates, 2-hydroxypropyl acrylates, 2-hydroxy-3-phenoxypropyl acrylates, 2-acryloyloxyethyl succinate, 2-acryloyloxyethyl phthalate, 2-acryloyloxyethyl-2-hydroxyethyl phthalate, lactone-modified flexible acrylates, and tert-butylcyclohexyl acrylate; bifunctional Monomers, such as triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, neopentyl glycol diacrylate, dimethyloltricyclodecane diacrylate, diacrylates of the PO adduct of bisphenol A, neopentyl glycol diacrylate of hydroxytrimethylacetic acid, and polytetramethyl glycol. Diacrylates; trifunctional or higher functional monomers, such as trimethylolpropane triacrylate (“TMPTA”), neopentyl tetraacrylate, neopentyl tetraacrylate, dinepentyl tetraacrylate, di(trimethylolpropane)tetraacrylate, glycerol propoxy triacrylate, caprolactone-modified trimethylolpropane triacrylate, neopentyl tetraacrylate, and caprolactam-modified dinepentyl tetraacrylate; and oligomers thereof.

[0146] Other examples of (meth)acrylate monomers and / or oligomers include 2-(dimethylamino)ethyl methacrylate, [2-(methacryloxy)ethyl]trimethylammonium methyl sulfate (“METAMS”), [2-(acryloxy)trimethylammonium chloride (“AETAC”), [2-(methacryloxy)ethyl]trimethylammonium sulfate, [2-(methacryloxy)ethyl]trimethylammonium chloride (“METAC”), N-acrylaminopropyl-N,N,N-trimethylammonium chloride (“APTMAC”), methacrylaminopropyltrimethylammonium chloride (“MPTMAC”), dimethyl methacrylate, diallyl dimethylammonium chloride (“DADMAC”), quaternized N-vinylpyridine, quaternized 2-vinylpyridine, quaternized 4-vinylpyridine, or combinations thereof.

[0147] Based on the total weight of the ink composition, the threshold potential modifier component in the ink composition may contain at least 0.1 wt%, 1 wt%, 2 wt%, 5 wt%, 10 wt%, 15 wt%, or 17 wt%. Based on the total weight of the ink composition, the threshold potential modifier component may contain up to 1 wt%, 2 wt%, 5 wt%, 10 wt%, 15 wt%, 17 wt%, or 20 wt%. Relative to the total weight of the ink composition, the amount of the threshold potential modifier component in the ink composition may range from about 0.1 wt% to about 20 wt% (e.g., from about 1 wt% to about 5 wt%; from about 5 wt% to about 10 wt%; from about 10 wt% to about 15 wt%; or from about 15 wt% to about 20 wt%).

[0148] The ink composition may also contain one or more photoinitiator components. During the radiation curing process, the photoinitiator component responds to the incident radiation and initiates curing. The type of photoinitiator component in the ink composition is typically chosen based on the wavelength of the curing radiation used in the curing of the ink composition. Typically, the peak absorption wavelength of the selected photoinitiator varies with the wavelength range of the curing radiation to effectively utilize the radiant energy, especially when ultraviolet light is used as the radiation.

[0149] Examples of suitable photoinitiators include, but are not limited to, 1-hydroxycyclohexylphenyl ketone, 4-isopropylphenyl-2-hydroxy-2-methylprop-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-prop-1-one, 2,2-dimethyl-2-hydroxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methylpropanone, diphenyl(2,4,6-trimethylbenzoyl) Phosphine oxides, bis(2,6-dimethoxy-benzoyl)-2,4,6-trimethylphenylphosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-prop-1-one, 3,6-bis(2-methyl-2-morpholinopropyl)-9-n-octylcarbazole, 2-benzyl-2-(dimethylamino)-1-[4-(4-morpholino)phenyl]1-butanone, benzophenone, 2,4,6-trimethylbenzophenone, and isopropylthioxanone. Suitable blends of commercially available photoinitiators include, but are not limited to, those from Ciba® Specialty Chemicals under the names Darocur 4265, Irgacure 1173, Irgacure 2022, and Irgacure 2100; and Esacure KT37, Esacure KT55, and Esacure KTO046 from Lamberti®.

[0150] Based on the total weight of the ink composition, the photoinitiator component in the ink composition may contain at least 0.1 wt%, 1 wt%, 2 wt%, 5 wt%, 10 wt%, 15 wt%, or 17 wt%. Based on the total weight of the ink composition, the photoinitiator component may contain up to 1 wt%, 2 wt%, 5 wt%, 10 wt%, 15 wt%, 17 wt%, or 20 wt%. Relative to the total weight of the ink composition, the amount of the photoinitiator component in the ink composition may range from about 0.1 wt% to about 20 wt% (e.g., from about 1 wt% to about 5 wt%; from about 5 wt% to about 10 wt%; from about 10 wt% to about 15 wt%; or from about 15 wt% to about 20 wt%).

[0151] The ink composition may further include inorganic particles, organic particles, or both. Because 3D printing processes involve the sequential deposition of at least one composition per layer, it may be desirable to additionally deposit inorganic or organic particles on or within the pad layer to obtain certain pad properties and / or perform certain functions. The inorganic or organic particles may have a size ranging from 50 nanometers (nm) to 100 micrometers (μm) and may be added to the precursor material before being dispensed by the droplet jet printer 406, or added to the uncured printed layer in a ratio between 1 and 50 weight percent (wt%). The inorganic or organic particles may be added during the polishing pad formation process to improve ultimate tensile strength, improve yield strength, improve the stability of storage modulus within a temperature range, improve thermal transfer, adjust the surface interface potential, and adjust the surface energy.

[0152] The type, chemical composition, or size of the particles, and the particles added, can vary depending on the application or the desired effect to be achieved. In some embodiments, the particles may include mesometals, ceramics, metals, polymers, and / or metal oxides, such as cerium oxide, alumina, silicon dioxide, zirconium oxide, nitrides, carbides, or combinations thereof. In one example, inorganic or organic particles located on or within the pad may include particles of high-performance polymers, such as PEEK, PEK, PPS, and other similar materials, to improve the thermal conductivity and / or other mechanical performance of the polishing pad.

[0153] Based on the total weight of the ink composition, the particulate component in the ink composition may contain at least 0.1 wt%, 1 wt%, 2 wt%, 5 wt%, 10 wt%, 15 wt%, or 17 wt%. Based on the total weight of the ink composition, the particulate component may contain up to 1 wt%, 2 wt%, 5 wt%, 10 wt%, 15 wt%, 17 wt%, or 20 wt%. Relative to the total weight of the ink composition, the amount of particulate component in the ink composition may range from about 0.1 wt% to about 20 wt% (e.g., from about 1 wt% to about 5 wt%; from about 5 wt% to about 10 wt%; from about 10 wt% to about 15 wt%; or from about 15 wt% to about 20 wt%).

[0154] The ink composition may further include one or more layering components. Layering additives include, but are not limited to, stabilizers, surfactants, leveling additives, and colorants. Example:

[0155] The following non-limiting examples are provided to further illustrate the embodiments described herein. However, these examples are not intended to be exhaustive, nor are they intended to limit the scope of the embodiments described herein. The specific materials and quantities, as well as other conditions and details stated in these examples, should not be used to limit the embodiments described herein.

[0156] As described above, in some embodiments, one or more materials used to form at least one of two or more polishing features (e.g., first and second polishing features 304 and 306) are formed by sequential deposition and post-deposition of at least one curable prepolymer composition. Generally, the curable resin precursor composition mixed during the precursor formulation process in the precursor delivery section 453 of the laminated manufacturing system 450 will include a formulation of a prepolymer composition containing functional oligomers, reactive diluents, and curing components, such as initiators. Examples of some of these components are listed in Table 1 below.

[0157] Examples of functional oligomers can be found in items O1-O2 of Table 1 below. Examples of functional reactive diluents and other additives can be found in item M1 of Table 1. DMA and AMEC are available from Sigma-Aldrich. Examples of curing components can be found in item P1 of Table 1 and are available from Ciba Specialty Chemicals and RAHN USA. Reference Name Materials Information sensibility Tg (°C) Viscosity (mPa·s) MW (Da) O1 Aliphatic polyester diacrylate ethyl carbamate 2 O2 Tetrahydrofurfuryl acrylate 1 -28 6 156 M1 2-[[(butylamino)carbonyl]oxy]ethyl acrylate <100 215 DMMA Dimethylaminoethyl methacrylate 18 1.34 143 AMEC [2-(Acryloyloxy)ethyl]trimethylammonium chloride 193 P1 2-Hydroxy-2-methyl-1-phenyl-prop-1-one N / A N / A 164 Table 1

[0158] Examples of the formulations are listed in Table 2. Formula number Material composition (See Table 1 for reference names) Formula ingredients (by weight %) 1 O1:O2:M1:AMEC:P1 41:33:22:1.9:1.9 2 O1:O2:M1:AMEC:P1 39.7:32:21.5:4.7:1.9 3 O1: DMMA: P1 49:49:2 4 O1:O2:M1:P1 42:34:23:2 Table 2

[0159] Figure 1100 depicts the measured threshold potential of polished objects from the formulations described in Table 2 relative to pH. The threshold potential of the polished surface of the polished objects was measured using a SurPASS™ electric analyzer available from Anton Parr, based on flow potential technology, with a 1 mM KCl solution used. Current polyurethane pads have a negative threshold potential. As depicted in Figure 11, the addition of a threshold potential modifier changes the polarity of the polished object from negative to positive, demonstrating the ability to modulate the threshold potential.

[0160] Although the foregoing content pertains to the embodiments disclosed herein, other and further embodiments disclosed herein may be designed without departing from the basic scope of the disclosure, and the scope of the disclosure is determined by the following claims. [Simplified Explanation of the Diagram]

[0010] To gain a more detailed understanding of the features of this disclosure, a more specific description of the above-briefly summarized embodiments can be made with reference to the embodiments (some of which are illustrated in the accompanying drawings). However, it should be noted that the accompanying drawings only illustrate typical embodiments of this disclosure and should not be considered as limiting the scope of this disclosure, as other equally effective embodiments are permissible under this disclosure.

[0011] Figure 1 is a schematic cross-sectional view of a polishing station that can benefit from the polishing pad design described herein;

[0012] Figure 2A is a schematic perspective view of a polishing pad having a boundary potential change region on the surface according to an embodiment of the present disclosure;

[0013] Figure 2B is a schematic cross-sectional view of a portion of the polishing pad in Figure 2A;

[0014] Figure 2C is an enlarged schematic cross-sectional view of a portion of the polishing pad in Figure 2B;

[0015] Figure 3A is a schematic perspective view of a polishing pad having a boundary potential change region on its surface according to another embodiment of this disclosure;

[0016] Figure 3B is a schematic cross-sectional view of a portion of the polishing pad in Figure 3A;

[0017] Figure 3C is a schematic partial top view of a polishing pad having a boundary potential change region on its surface according to another embodiment of the present disclosure;

[0018] Figure 3D is a schematic perspective cross-sectional view of a polishing pad having a boundary potential change region on its surface, according to another embodiment of this disclosure;

[0019] Figure 3E is a schematic partial cross-sectional view of a polishing pad having a boundary potential change region on its surface according to another embodiment of this disclosure;

[0020] Figure 3F is a schematic partial cross-sectional view of a polishing pad having a boundary potential change region on its surface according to another embodiment of this disclosure;

[0021] Figures 3G to 3L are top views of a polishing pad design with a boundary potential change region on the surface according to the embodiments disclosed herein;

[0022] Figure 4A is a schematic diagram of a system for manufacturing a polishing pad with a surface having a region of boundary potential change according to an embodiment of the present disclosure;

[0023] Figure 4B is a schematic diagram of the deposition zone of a system for manufacturing the polishing pad illustrated in Figure 4A according to an embodiment of the present disclosure;

[0024] Figure 4C is a magnified close-up schematic diagram of the dispensing droplets disposed on the surface of the polishing pad area illustrated in Figure 4B according to the embodiment of the present disclosure;

[0025] Figures 5A to 5F provide examples of polishing pads having varying potential surfaces that span one or more regions of a polishing body formed within the system of Figure 4A according to the embodiments disclosed herein;

[0026] Figure 6 is a schematic side cross-sectional view of a portion of a polishing pad having a region of boundary potential change on its surface according to an embodiment of the present disclosure;

[0027] Figure 7 is a schematic side cross-sectional view of a polishing pad having a transparent area and a surface in which a bounded potential change area is formed, according to an embodiment of the present disclosure;

[0028] Figure 8 is a schematic perspective cross-sectional view of a polishing pad with a surface having a defined potential change region and a supporting foam layer according to the embodiment disclosed herein;

[0029] Figure 9 is a schematic cross-sectional view of a polishing pad having multiple regions and a surface having a boundary potential change region according to the embodiment of this disclosure;

[0030] Figure 10 is a partially enlarged cross-sectional view of the polishing pad in Figure 9 according to the embodiment of this disclosure; and

[0031] Figure 11 is a graph depicting the measured threshold potential of a polished object formed using the formula disclosed herein, relative to pH.

[0032] For ease of understanding, the same element symbols have been used where possible to refer to the same elements in relation to the drawings. It is conceivable that elements and features of one embodiment can be beneficially incorporated into other embodiments without further detail. However, it should be noted that the drawings illustrate only exemplary embodiments of this disclosure and should not be construed as limiting the scope of this disclosure, as other equally effective embodiments are permissible under this disclosure. [Biomaterial Storage]

[0162] 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 polishing object comprising: a composite polishing pad body having: a first trench surface comprising: a plurality of polishing pad features formed of a first polymer material and having a first threshold potential, wherein the first polymer material comprises acrylonitrile butadiene styrene, polycarbonate, polypropylene, or any mixture thereof; and one or more base features formed of a second polymer material and having a second threshold potential, wherein the second polymer material comprises acrylonitrile butadiene styrene, polycarbonate, polypropylene, or any mixture thereof; and a second flat surface opposite the first trench surface, wherein the first threshold potential is different from the second threshold potential.

2. The polished object as claimed in claim 1, wherein the first threshold potential, measured using a neutral solution, is equal to or greater than -70 mV and less than 0 mV, and the second threshold potential, measured using a neutral solution, is equal to or greater than 0 mV and less than 50 mV.

3. The polished object as claimed in claim 1, wherein the first threshold potential, measured using a neutral solution, is equal to or greater than 0 mV and less than 50 mV, and the second threshold potential, measured using a neutral solution, is equal to or greater than -70 mV and less than 0 mV.

4. The polished object as claimed in claim 1, wherein the composite polishing pad body further comprises a third polymer material having a third threshold potential, wherein the third threshold potential is different from the first threshold potential and the second threshold potential.

5. The polished object as claimed in claim 1, wherein the first polymer material is formed of a first composition comprising a first threshold potential modifier selected from cationic monomers, anionic monomers, nonionic monomers, or combinations thereof.

6. The polished object as claimed in claim 5, wherein the second polymer material is formed of a second composition comprising a second threshold potential modifier selected from cationic monomers, anionic monomers, nonionic monomers, or combinations thereof.

7. The polished object as described in claim 1 further comprises abrasive particles.

8. The polished object as claimed in claim 1, wherein the plurality of polishing pad features are segmented polishing features arranged in a spiral pattern.

9. A polishing object comprising: a polishing pad body having: a polishing surface comprising: one or more first polishing features having an upper surface and a sidewall defining a plurality of grooves, wherein the upper surface comprises a first polymer material having a first threshold potential, and wherein the first polymer material comprises acrylonitrile butadiene styrene, polycarbonate, polypropylene, or any mixture thereof; and one or more second polishing features defining a bottom surface of the plurality of grooves, wherein the bottom surface comprises a second polymer material having a second threshold potential different from the first threshold potential, and wherein the second polymer material comprises acrylonitrile butadiene styrene, polycarbonate, polypropylene, or any mixture thereof.

10. The polished object as claimed in claim 9, wherein the sidewall comprises the first polymer material.

11. The polished object as claimed in claim 9, wherein the first threshold potential, measured using a neutral solution, is equal to or greater than -70 mV and less than 0 mV, and the second threshold potential, measured using a neutral solution, is equal to or greater than 0 mV and less than 50 mV.

12. The polished object as claimed in claim 9, wherein the first threshold potential, measured using a neutral solution, is equal to or greater than 0 mV and less than 50 mV, and the second threshold potential, measured using a neutral solution, is equal to or greater than -70 mV and less than 0 mV.

13. The polished object as claimed in claim 9, wherein the polishing pad body further comprises a third polymer material having a third threshold potential, wherein the third threshold potential is different from the first threshold potential and the second threshold potential.

14. The polished object as claimed in claim 9, wherein the sidewall comprises a third polymer material having a third threshold potential, wherein the third threshold potential is different from the first threshold potential and the second threshold potential.

15. The polished object as claimed in claim 9, wherein the first polymer material is formed of a first composition comprising a first threshold potential modifier selected from cationic monomers, anionic monomers, nonionic monomers, or combinations thereof.

16. The polished object as claimed in claim 15, wherein the second polymer material is formed of a second composition comprising a second threshold potential modifier selected from cationic monomers, anionic monomers, nonionic monomers, or combinations thereof.

17. The polished object as described in claim 9 further comprises abrasive particles.

18. The polished object as claimed in claim 9, wherein the plurality of grooves are segmented polishing grooves arranged in a spiral pattern.

19. A method of forming a polished object, comprising the steps of: depositing a plurality of composite layers using a 3D printer to achieve a target thickness, wherein the step of depositing the plurality of composite layers comprises the steps of: depositing a first material having an exposed first region having a first threshold potential, wherein the first material is formed from a first precursor comprising acrylate, methacrylate, thiol, epoxy resin, or any mixture thereof; and depositing a second material having an exposed second region having a second threshold potential, wherein the second material is formed from a second precursor comprising acrylate, methacrylate, thiol, epoxy resin, or any mixture thereof; and curing the plurality of composite layers to form a composite pad body having one or more first features comprising the first material and one or more second features comprising the second material, wherein the one or more first features and the one or more second features form a single body.

20. The method of claim 19, wherein the first material comprises a first material composition formed by depositing droplets of a third material and a fourth material, and wherein the third material or the fourth material comprises the first precursor.

21. The method of claim 19, wherein the second material comprises a second material composition formed by depositing droplets of a fifth material and a sixth material, and wherein the fifth material or the sixth material comprises the second precursor.

22. The method as described in claim 19, wherein the first material forms one or more discontinuous polished features, and the second material forms one or more base features, wherein the one or more base features collectively surround the plurality of polished features to form a single body.

23. The method as described in claim 19, wherein the one or more first features are segmented polishing grooves arranged in a spiral pattern.

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