Polishing pad with adjusted chlorine content and method for manufacturing semiconductor device using the same

Abstract

To provide a polishing pad which reduces the size of debris while maintaining various physical properties and performance of the polishing pad in excellent states by adjusting a chlorine content to be within a specific range, and can minimize generation of defects and scratches in a CMP process.SOLUTION: A polishing pad includes a polishing layer and a support layer, wherein the polishing layer contains a urethane-based prepolymer, a foaming agent and a curing agent, and a chlorine (Cl) content obtained by analyzing the polishing layer on the basis of IEC 62321-3-2 standard is 10,000 ppm or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An example of implementation relates to a polishing pad with an adjustable chlorine content that can reduce the occurrence of defects and scratches during the chemical mechanical planarization (CMP) process, and to a method for manufacturing semiconductor devices using the same. [Background technology]

[0002] In the semiconductor manufacturing process, the chemical mechanical planarization (CMP) process involves attaching a semiconductor substrate, such as a wafer, to a head and bringing it into contact with the surface of a polishing pad formed on a platen. A slurry is then supplied, causing a chemical reaction on the surface of the semiconductor substrate, while the platen and the head move relative to each other, thereby mechanically flattening the uneven surface of the semiconductor substrate.

[0003] Polishing pads, as essential components playing a crucial role in such CMP processes, are typically made of polyurethane resin and have grooves on their surface that facilitate large-scale slurry flow and pores that support fine-scale flow.

[0004] To manufacture the polishing pad, a prepolymer is obtained by reacting diisocyanate and polyol. Then, a curing agent and a foaming agent are mixed with the prepolymer and cured to obtain a polyurethane foam sheet. Subsequently, the polyurethane foam sheet is sliced ​​into upper and lower sections to the desired thickness to obtain an upper pad. Grooves are formed on the surface of the upper pad by carving grooves of a specific shape using a tip or the like, and then the upper pad is bonded to the polyurethane lower pad to complete the polishing pad.

[0005] The CMP (Chemical Polishing) process can be applied in multiple ways during the manufacturing process of semiconductor devices. In the case of semiconductor devices, multiple layers are included, and each layer contains a complex and fine circuit pattern. Furthermore, in recent years, semiconductor devices have evolved in the direction of decreasing individual chip sizes and making the patterns of each layer more complex and finer. As a result, the purpose of the CMP process in the manufacturing process of semiconductor devices has expanded beyond just planarizing circuit wiring to include applications such as circuit wiring separation and wiring surface improvement, and consequently, there is a demand for more sophisticated and reliable CMP performance.

[0006] During the CMP process for such polishing pads, debris is generated due to friction between the polishing surface and the semiconductor substrate, or when the polishing surface is cut by the diamond disc used for conditioning. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Korean Patent Publication No. 2016-0027075 [Overview of the project] [Problems that the invention aims to solve]

[0008] During the CMP (Chemical Polishing) process of polishing pads, debris is generated during the friction process between the polishing surface and the semiconductor substrate, or when the polishing surface is cut by the diamond disc used for conditioning. Such debris can induce defects and scratches on the polishing surface during the CMP process.

[0009] Therefore, as a result of research conducted by the inventors, it was found that the chlorine (Cl) content in the polishing pad affects the size and surface properties of the debris generated during the conditioning of the polishing pad. By adjusting the chlorine content to a specific range, it was possible to reduce the size of the debris while maintaining excellent physical properties and performance of the polishing pad, thereby minimizing the occurrence of defects and scratches during the CMP process.

[0010] Therefore, the problem of the implementation example relates to a polishing pad in which the chlorine content is adjusted to a certain range and a method for manufacturing a semiconductor device using the same.

Means for Solving the Problem

[0011] According to one implementation example, there is provided a polishing pad including a polishing layer and a support layer, wherein the polishing layer includes a urethane prepolymer, a foaming agent, and a curing agent, and the chlorine (Cl) content analyzed based on the IEC 62321-3-2 standard is 10,000 ppm or less.

[0012] According to another implementation example, there is provided a method for manufacturing a polishing pad, including: preparing a polishing pad composition including a urethane prepolymer, a foaming agent, and a curing agent; injecting and curing the polishing pad composition into a mold to manufacture a polishing layer; and bonding the polishing layer to a support layer, wherein the foaming agent includes a solid-phase foaming agent, the solid-phase foaming agent includes one or more selected from the group consisting of acrylonitrile copolymers, methyl methacrylate copolymers, methacrylonitrile copolymers, and acrylic copolymers, and the curing agent includes one or more selected from the group consisting of diethyl toluene diamine (DETDA), 3,5-dimethylthio-2,6-diaminotoluene (DMTDA), 1,3-propanediol bis(4-aminobenzoate) (PDPAB), N,N'-bis(sec-butylamino)diphenylmethane, 2,6-bis(methylthio)-4-methyl-1,3-benzenediamine, 4-(4-aminobenzoyl)oxyphenyl 4-aminobenzoate, 4-(4-aminobenzoyl)oxybutyl 4-aminobenzoate, 4-[4-(4-aminobenzoyl)oxy-3-methylbutoxy]butyl 4-aminobenzoate, and methylene bis-methyl anthranilate (MBNA).

[0013] According to still another implementation example, there is provided a method for manufacturing a semiconductor device, including polishing the surface of a semiconductor substrate using the polishing pad.

Advantages of the Invention

[0014] By adjusting the chlorine content of the polishing pad according to the above realization example, while maintaining excellent physical properties and performance of the polishing pad, the size of debris can be reduced, and the occurrence of defects and scratches during the CMP process can be minimized.

[0015] Furthermore, the polishing pad according to the above realization example does not use or minimizes chlorine-based components such as bis(4-amino-3-chlorophenyl)methane (MOCA) and vinylidene chloride (VDC) that are commonly used as raw materials conventionally, and there are no problems harmful to the human body and the environment.

Brief Description of the Drawings

[0016] [Figure 1] FIG. 1 is a semiconductor device manufacturing process using a polishing pad according to one realization example. [Figure 2] FIG. 2 is a diagram showing the occurrence of defects due to debris during the semiconductor device manufacturing process. [Figure 3] FIG. 3 is a device for measuring the chlorine content of a polishing pad according to one realization example. [Figure 4] FIG. 4 is a diagram showing a solid-phase foaming agent used in a polishing pad according to one realization example.

Modes for Carrying Out the Invention

[0017] Hereinafter, various realization examples and examples will be specifically described with reference to the drawings.

[0018] In describing the realization examples, if a specific description of a related known configuration or function is determined to obscure the gist of the realization examples, the detailed description thereof will be omitted. Also, the size of each component in the drawings may be exaggerated or omitted for the purpose of explanation and may be different from the actual size applied.

[0019] In this specification, any description of one component being formed above / below another, or being connected or joined to one another, includes all instances of direct or indirect formation, connection, or joining between these components. Furthermore, the criteria for above / below each component should be understood to vary depending on the direction from which the object is observed.

[0020] In this specification, terms used to refer to each component are used to distinguish them from other components and are not intended to limit the examples of implementation. Furthermore, in this specification, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0021] In this specification, terms such as "first," "second," etc., are used to describe various components, and such components should not be limited by these terms. These terms are used for the purpose of distinguishing one component from another.

[0022] In this specification, the word "includes" is used to specify particular characteristics, areas, stages, processes, elements, and / or components, and does not exclude the presence or addition of other characteristics, areas, stages, processes, elements, and / or components unless otherwise stated.

[0023] The molecular weights of compounds and polymers described herein, such as number-average molecular weight or weight-average molecular weight, are, as is well known, relative masses based on carbon-12 and do not have units listed. However, if necessary, they may be understood to represent the same numerical molar mass (g / mol).

[0024] In the numerical ranges that limit the size, physical properties, etc., of the components described herein, if numerical ranges limited only by upper limits and numerical ranges limited only by lower limits are given as separate examples, it should be understood that the numerical ranges that combine these upper and lower limits are also included in the exemplary ranges.

[0025] [Polishing pad] An example of a polishing pad includes a polishing layer and a support layer. Furthermore, an adhesive layer may be inserted between the polishing layer and the support layer.

[0026] In one example of an abrasive pad, the chlorine (Cl) content of the abrasive layer, as analyzed according to the IEC62321-3-2 standard, is 10,000 ppm or less.

[0027] Specifically, the chlorine content can be obtained by measuring the chlorine content in a sample according to IEC62321-3-2, an international standard for measuring specific substances in polymers by combustion-ion chromatography (C-IC). In this case, the sample from which the chlorine content is measured may be a circular sample with a diameter of 3 cm and a height of 0.3 cm taken from the polishing layer of the polishing pad.

[0028] The IEC 62321-3-2 standard is a halogen component screening test method developed in response to regulations on halogen use. This test method offers superior precision, accuracy, and reproducibility compared to conventional halogen analysis methods (e.g., oxygen bomb-IC, oxygen flask-IC), and its automated nature ensures high reliability of test results.

[0029] Figure 3 shows a method for measuring the chlorine content of a polishing pad according to one implementation example. Referring to Figure 3, a sample 110 containing organochlorine (C-Cl) components is placed in a combustion tube 730, combusted in an electric furnace 750, and the resulting material is sent to an adsorption tube 770 to absorb chloride ions (Cl - The amount of ) will be measured by ion chromatography.

[0030] In the polishing pad according to the above-described example, the chlorine content in the polishing layer is 10,000 ppm or less, and may be, for example, 5,000 ppm or less, 1,000 ppm or less, 500 ppm or less, 200 ppm or less, 100 ppm or less, 80 ppm or less, or 50 ppm or less. By adjusting the chlorine content within the above range, it is possible to reduce the size of debris and minimize the occurrence of defects and scratches during the CMP process while maintaining excellent physical properties and performance of the polishing pad.

[0031] Furthermore, the lower limit of the chlorine content range in the polishing layer according to the above-mentioned examples may be, for example, 0 ppm or more, greater than 0 ppm, 1 ppm or more, 5 ppm or more, 10 ppm or more, 20 ppm or more, 50 ppm or more, or 100 ppm or more. Within this preferred range, the debris will solidify to an appropriate size, the surface area and adsorption force will be adjusted, adsorption and desorption will be facilitated on the wafer and pad, and the electrical attractive / chuck force will be adjusted, resulting in more appropriate polishing performance.

[0032] As a specific example, the chlorine (Cl) content of the abrasive layer, as analyzed according to the IEC62321-3-2 standard, may be between 10 ppm and 1000 ppm. As another specific example, the chlorine (Cl) content of the abrasive layer, as analyzed according to the IEC62321-3-2 standard, may be between 10 ppm and 100 ppm, 20 ppm and 80 ppm, or 20 ppm and 50 ppm. As yet another specific example, the chlorine (Cl) content of the abrasive layer, as analyzed according to the IEC62321-3-2 standard, may be between 50 ppm and 10000 ppm, or 100 ppm and 10000 ppm.

[0033] Thus, the polishing pad according to the above-described example can reduce the size of debris and minimize the occurrence of defects and scratches during the CMP process by adjusting the chlorine content to a specific range.

[0034] Figure 2 illustrates how defects can occur due to debris during the semiconductor device manufacturing process. Referring to Figure 2, debris 150 generated from the polishing layer can cause defects 650 and scratches on the surface of the semiconductor device. However, according to the above implementation example, the size of the debris generated from the polishing layer can be adjusted to a specific range, thereby minimizing the occurrence of defects and scratches.

[0035] For example, the polishing pad according to the above-mentioned example has debris particles of 30 μm or less, 25 μm or less, 20 μm or less, 19 μm or less, 18 μm or less, or 17 μm or less, and may also be 5 μm or more, 10 μm or more, or 15 μm or more.

[0036] Specifically, the debris is obtained when conditioning the polishing pad under the conditions of a platen speed of 93 rpm, a conditioner load of 9 lb, a conditioner speed of 64 rpm, and a sweep of 19 times / minute while supplying 300 cc / minute of deionized water, and the particle size of the debris may be the average particle size, i.e., a D50 particle size.

[0037] As a specific example, when the polishing pad is conditioned under the conditions of a platen speed of 93 rpm, a conditioner load of 9 lb, a conditioner speed of 64 rpm, and a sweep of 19 times / min while supplying 300 cc / min of deionized water, the D50 particle size of the polishing pad debris obtained may be 30 μm or less.

[0038] As another specific example, when conditioning the polishing pad under the conditions of a platen speed of 93 rpm, a conditioner load of 9 lb, a conditioner speed of 64 rpm, and a sweep of 19 times / min while supplying 300 cc / min of deionized water, the D50 particle size of the polishing pad debris obtained may be 10 μm to 30 μm, 10 μm to 25 μm, or 10 μm to 18 μm.

[0039] Furthermore, the polishing pad according to the above-described example allows for the measurement of the zeta potential value of the debris within a specific numerical range.

[0040] For example, the zeta potential of a pH 5.5 aqueous solution containing 0.01% by weight of the debris obtained by conditioning the polishing layer may be -20mV or higher, -10mV or higher, -5mV or higher, 0mV or higher, 5mV or higher, 7mV or higher, or 10mV or higher, and may also be 40mV or lower, 30mV or lower, 20mV or lower, 15mV or lower, 10mV or lower, or 8mV or lower. Specifically, the zeta potential value of the aqueous solution of the debris may be a positive (+) value.

[0041] As a specific example, the zeta potential of a pH 5.5 aqueous solution containing 0.01% by weight of the debris obtained by conditioning the polishing layer may be -10mV to 30mV. As another specific example, the zeta potential of a pH 5.5 aqueous solution containing 0.01% by weight of the debris obtained by conditioning the polishing layer may be 7mV to 15mV. As yet another specific example, the zeta potential of a pH 5.5 aqueous solution containing 0.01% by weight of the debris obtained by conditioning the polishing layer may be -10mV to 8mV.

[0042] Within the aforementioned preferred range, the zeta potential of the debris is similar to that of the polishing particles (e.g., ceria particles) in the CMP polishing composition (slurry), which can further reduce the occurrence of defects. Specifically, the zeta potential quantitatively represents the magnitude of the repulsive and attractive forces between particles generated by the positive / anionic ions present in the particles in the suspension. When the zeta potentials of the debris and the polishing particles are similar, the repulsive force between particles increases, preventing aggregation. This allows for a reduction in particle size within the composition, thereby reducing the occurrence of defects and scratches.

[0043] Furthermore, the polishing pad according to the above-mentioned example can maintain excellent performance and physical properties even when the chlorine content is adjusted to a specific range.

[0044] For example, when polishing the silicon oxide layer of a silicon wafer in a ceria slurry using the polishing pad, the removal rate may be 2000 Å / min or more, 2200 Å / min or more, 2300 Å / min or more, or 2400 Å / min or more, and may also be 3000 Å / min or less, 2800 Å / min or less, 2600 Å / min or less, or 2500 Å / min or less.

[0045] As a specific example, when polishing the silicon oxide layer of a silicon wafer in a ceria slurry using the aforementioned polishing pad, the polishing rate according to the following mathematical formula 1 may be 2200 Å / min to 2600 Å / min. [Mathematics 1] Polishing rate (Å / min) = Polishing thickness of silicon wafer (Å) / Polishing time (minutes)

[0046] Specifically, the polishing rate may be the polishing rate on a silicon wafer with a diameter of 300 mm on which silicon oxide has been deposited. Furthermore, the polishing rate may be measured under conditions of a polishing load of 4.0 psi and a polishing pad rotation speed of 150 rpm, while adding a calcined ceria slurry at a rate of 250 mL / min and rotating the platen at 150 rpm for 60 seconds. The temperature conditions during the measurement of the polishing rate are not particularly limited, but may, for example, be room temperature.

[0047] Furthermore, the pad cut rate of the abrasive layer may be 30 μm / hr to 60 μm / hr, 30 μm / hr to 50 μm / hr, 40 μm / hr to 60 μm / hr, or 40 μm / hr to 50 μm / hr.

[0048] The thickness of the polishing pad may be 0.8mm to 5.0mm, 1.0mm to 4.0mm, 1.0mm to 3.0mm, 1.5mm to 2.5mm, 1.7mm to 2.3mm, or 2.0mm to 2.1mm. Within this range, the basic physical properties of the polishing pad can be fully exhibited while minimizing the particle size deviation between the upper and lower parts of the pores.

[0049] [Polishing layer] The polishing layer provides a polishing surface that contacts the semiconductor substrate during the CMP process and constitutes the top pad in the polishing pad.

[0050] The polishing layer contains a urethane prepolymer, a foaming agent, and a curing agent. Specifically, the polishing layer contains a polyurethane-based resin that is a reaction product of a urethane prepolymer, a foaming agent, and a curing agent, i.e., a cured product of a composition in which the above components are mixed. More specifically, it contains a porous polyurethane-based resin. Also, the polishing layer may contain a plurality of pores formed from the foaming agent.

[0051] The thickness of the polishing layer is, for example, 0.8 mm or more, 1 mm or more, 1.2 mm or more, or 1.5 mm or more, and may be 5 mm or less, 3 mm or less, 2.5 mm or less, or 2 mm or less. As a specific example, the thickness of the polishing layer may be 0.8 mm to 5 mm, or 1.5 mm to 3 mm.

[0052] The specific gravity of the polishing layer is, for example, 0.6 g / cm 3 or more, 0.7 g / cm 3 or more, or 0.75 g / cm 3 or more, and may be 0.9 g / cm 3 or less, 0.85 g / cm 3 or less, or 0.8 g / cm 3 or less. As a specific example, the specific gravity of the polishing layer may be 0.6 g / cm 3 to 0.9 g / cm 3 or 0.7 g / cm 3 to 0.9 g / cm 3 and may be.

[0053] The hardness of the polishing layer is, for example, 30 Shore D or more, 40 Shore D or more, or 50 Shore D or more, and may be 80 Shore D or less, 70 Shore D or less, 65 Shore D or less, or 60 Shore D or less. As a specific example, the hardness of the polishing layer may be 30 Shore D to 80 Shore D, or 50 Shore D to 65 Shore D.

[0054] The tensile strength of the polished layer is, for example, 5 N / mm². 2 More than 10N / mm 2 15 N / mm² or more 2 That's all, and also 30 N / mm 2 Below, 25N / mm 2 The following, or 20 N / mm² 2 The following is possible. As a specific example, the tensile strength of the polished layer is 5 N / mm². 2 ~30N / mm 2 or 15 N / mm 2 ~25N / mm 2 It is possible.

[0055] The elongation rate of the abrasive layer may be, for example, 50% or more, 70% or more, 90% or more, 106% or more, or 120% or more, and may also be 300% or less, 250% or less, 200% or less, or 150% or less. As a specific example, the elongation rate of the abrasive layer may be 50% to 300% or 90% to 130%. The elongation rate may be the elongation at break.

[0056] As a specific example, the polishing layer has a hardness of 50 Shore D to 65 Shore D and a density of 15 N / mm². 2 ~25N / mm 2 It can have a tensile strength and an elongation rate of 90% to 130%.

[0057] The aforementioned pores are dispersed within the polished layer. The average diameter of the pores may be, for example, 10 μm to 60 μm, 10 μm to 50 μm, 20 μm to 50 μm, 20 μm to 40 μm, 10 μm to 30 μm, 20 μm to 25 μm, or 30 μm to 50 μm.

[0058] Furthermore, the total surface area of ​​the pores may be 30% to 60%, 35% to 50%, or 35% to 43% of the total surface area of ​​the polished layer. Also, the total volume of the pores may be 30% to 70% or 40% to 60% of the total volume of the polished layer.

[0059] The abrasive layer may have grooves on its surface for mechanical polishing. The grooves may have, and are not particularly limited, an appropriate depth, width, and spacing for mechanical polishing.

[0060] [Urethane-based prepolymer] One example of a polishing pad contains a urethane-based prepolymer. A prepolymer is a polymer with a relatively low molecular weight whose degree of polymerization has been stopped at an intermediate stage in the production of cured products, making it easier to mold. Prepolymers can be molded into the final cured product either on their own or after reacting with other polymerizable compounds.

[0061] In one example, the urethane-based prepolymer can be prepared by reacting an isocyanate compound with a polyol.

[0062] The isocyanate compound used in the preparation of the urethane-based prepolymer may be one selected from the group consisting of aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and combinations thereof.

[0063] The isocyanate compound may include, for example, one selected from the group consisting of toluene 2,4-diisocyanate (2,4-TDI), toluene 2,6-diisocyanate (2,6-TDI), naphthalene-1,5-diisocyanate, para-phenylenediisocyanate, tolidine diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and combinations thereof.

[0064] The polyol is a compound containing at least two hydroxyl groups (-OH) per molecule, and may include, for example, one selected from the group consisting of polyether polyols, polyester polyols, polycarbonate polyols, polycaprolactone polyols, and combinations thereof.

[0065] The polyol may include, for example, one selected from the group consisting of polytetramethylene ether glycol, polypropylene ether glycol, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, tripropylene glycol, and combinations thereof.

[0066] The polyol may have a weight-average molecular weight (Mw) of 100 to 3000. The polyol may have a weight-average molecular weight (Mw) of, for example, 100 to 3000, for example, 100 to 2000, or for example, 100 to 1800.

[0067] In one implementation example, the polyol may include a low molecular weight polyol with a weight-average molecular weight (Mw) of 100 to 300 and a high molecular weight polyol with a weight-average molecular weight (Mw) of 300 to 1800.

[0068] The urethane-based prepolymer may have a weight-average molecular weight of 500 to 3000. The urethane-based prepolymer may have a weight-average molecular weight (Mw) of, for example, 1000 to 2000, or for example, 1000 to 1500.

[0069] In one example, the isocyanate compound for preparing the urethane-based prepolymer includes an aromatic diisocyanate compound, which may include, for example, 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI). The polyol compound for preparing the urethane-based prepolymer may include polytetramethylene ether glycol (PTMEG) and diethylene glycol (DEG).

[0070] In other realizations, the isocyanate compound for preparing the urethane-based prepolymer may include aromatic diisocyanate compounds and alicyclic diisocyanate compounds. For example, the aromatic diisocyanate compound may include 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI), and the alicyclic diisocyanate compound may include dicyclohexylmethane diisocyanate (H12MDI). The polyol compound for preparing the urethane-based prepolymer may include polytetramethylene ether glycol (PTMEG) and diethylene glycol (DEG).

[0071] The urethane-based prepolymer has an isocyanate end group content (NCO%) of 5% by weight or more, 8% by weight or more, or 10% by weight or more, and may also be 13% by weight or less, 12% by weight or less, or 11% by weight or less. As a specific example, the urethane-based prepolymer may have an isocyanate end group content (NCO%) of 10% by weight to 11% by weight.

[0072] The isocyanate end group content (NCO%) of the urethane-based prepolymer can be designed by comprehensively adjusting the type and content of the isocyanate compound and polyol compound used to prepare the urethane-based prepolymer, the process conditions such as temperature, pressure, and time for the preparation of the urethane-based prepolymer, and the type and content of the additives used in the preparation of the urethane-based prepolymer.

[0073] When the isocyanate end group content (NCO%) of the urethane-based prepolymer satisfies the above range, the reaction rate, reaction time, and final cured structure during the subsequent reaction between the urethane-based prepolymer and the curing agent can be adjusted in a direction advantageous to the polishing performance of the final polishing pad according to its application and intended use.

[0074] In one implementation example, the isocyanate end group content (NCO%) of the urethane-based prepolymer may be 8% to 10% by weight, for example, 8% to 9.4% by weight. If the NCO% is below this range, the desired polishing performance may not be achieved in terms of polishing rate and flatness, and there may be problems such as a reduction in the lifespan of the polishing pad due to an excessive increase in the cutting rate. On the other hand, if the NCO% exceeds this range, surface defects such as scratches and chatter marks on the semiconductor substrate may increase.

[0075] [Foaming agent] The foaming agent may include one selected from the group consisting of solid-phase foaming agents, gas-phase foaming agents, liquid-phase foaming agents, and combinations thereof, as a component for forming a porous structure within the polished layer.

[0076] According to one example, the foaming agent is a non-chlorine foaming agent that does not contain chlorine components, and in particular, does not contain chlorine foaming agent components commonly used in the manufacture of polishing pads, such as vinylidene chloride (VDC), or its use can be minimized. For example, the content of the non-chlorine foaming agent based on the total weight of the foaming agent may be 50% by weight or more, 80% by weight or more, 90% by weight or more, 95% by weight or more, 97% by weight or more, 99% by weight or more, or 99.5% by weight or more, and may also be 100% by weight or less, or 99.5% by weight or less. Specific examples include 80% to 100% by weight, 90% to 100% by weight, or 80% to 99.5% by weight. Furthermore, the content of the chlorine-based blowing agent relative to the total weight of the blowing agent is 20% by weight or less, 10% by weight or less, 5% by weight or less, 1% by weight or less, or 0.5% by weight or less, or 0.3% by weight or less, and also 0% by weight or more, 0.1% by weight or more, or 0.5% by weight or more. Specific examples include 0% to 20% by weight, 0% to 1% by weight, 0% to 0.5% by weight, or 0.5% to 20% by weight.

[0077] The blowing agent may be one or more selected from a solid-phase blowing agent containing hollow-structured particles, a liquid-phase blowing agent using a volatile liquid, and an inert gas.

[0078] As an example, the solid-phase foaming agent may contain hollow-structured particles whose size is adjusted by thermal expansion. Such a solid-phase foaming agent has the advantage of uniformly adjusting the particle size of the pores because it is added to the raw material in an already expanded form and has a uniform particle size.

[0079] Furthermore, the solid-phase foaming agent may contain expandable particles. These expandable particles are particles that have the property of being able to expand by heat or pressure, and their size in the final polished layer may be determined by the heat or pressure applied during the manufacturing process of the polished layer. The expandable particles may be added to the raw material in an unexpanded particle state beforehand, and then expanded by the heat or pressure applied during the manufacturing process of the polished layer, thereby determining their final size.

[0080] The average particle size of the solid-phase foaming agent is, for example, 5 μm to 100 μm, and specifically may be 5 μm to 50 μm or 20 μm to 50 μm. The average particle size of the solid-phase foaming agent refers to the average particle size of the expanded particles themselves when the solid-phase foaming agent is introduced into the raw materials in an expanded state as described later, and may refer to the average particle size of the particles after they have expanded due to heat or pressure during the manufacturing process when the solid-phase foaming agent is introduced into the raw materials in an unexpanded state as described later.

[0081] Figure 4 shows an example of an expandable particle type solid-phase foaming agent used in a polishing pad. Referring to Figure 4, the expandable particle type solid-phase foaming agent 130 may include a resin material outer shell 131 and an expansion-inducing component 132 present inside the outer shell 131. Such expandable particles can be formed into a hollow structure by the vaporization of the internal expansion-inducing component due to heat during the manufacturing process.

[0082] For example, the outer shell may contain a thermoplastic resin. The thermoplastic resin may be one or more selected from the group consisting of acrylonitrile copolymers, methacrylonitrile copolymers, and acrylic copolymers.

[0083] The thickness of the outer layer is, for example, 0.1 μm or more, 0.5 μm or more, 1 μm or more, 2 μm or more, or 3 μm or more, and also 15 μm or less, 12 μm or less, or 10 μm or less, and as a specific example, it may be 2 μm to 15 μm.

[0084] The swelling-inducing component may include one selected from the group consisting of hydrocarbon compounds, tetraalkylsilane compounds, and combinations thereof. Specifically, the hydrocarbon compound may include one selected from the group consisting of ethane, ethylene, propane, propene, n-butane, isobutene, n-butene, isobutene, n-pentane, isopentane, n-hexane, heptane, petroleum ether, and combinations thereof. The tetraalkylsilane compound may include one selected from the group consisting of tetramethylsilane, trimethylethylsilane, trimethylisopropylsilane, trimethyl-n-propylsilane, and combinations thereof.

[0085] The solid-phase foaming agent may contain particles treated with inorganic components. In one embodiment, the solid-phase foaming agent may have a surface treated with silica (SiO2) particles. The inorganic component treatment of the solid-phase foaming agent can prevent aggregation between multiple particles. The inorganic-component-treated solid-phase foaming agent may have different chemical, electrical, and / or physical properties of the foaming agent surface compared to an inorganic-component-treated solid-phase foaming agent.

[0086] Examples of commercially available solid-phase foaming agents include Nouryon's 920DE20d70, 051DET40d25, 051DET40d42, etc., and Matsumoto's F-65DE, F-80DE, FN-80SDE, etc.

[0087] As a specific example, the foaming agent used in the polishing pad according to the above-mentioned embodiment includes a solid-phase foaming agent, and the solid-phase foaming agent may include one or more selected from the group consisting of acrylonitrile copolymers, methyl methacrylate copolymers, methacrylonitrile copolymers, and acrylic copolymers.

[0088] The content of the solid-phase foaming agent is 0.1 parts by weight or more, 0.5 parts by weight or more, or 1 part by weight or more, based on 100 parts by weight of the urethane-based prepolymer, and may also be 5 parts by weight or less, 3 parts by weight or less, or 2 parts by weight or less. As a specific example, the content of the solid-phase foaming agent may be 0.1 to 5 parts by weight or 0.5 to 2 parts by weight, based on 100 parts by weight of the urethane-based prepolymer.

[0089] The type and content of the solid-phase foaming agent can be designed according to the desired porosity structure and physical properties of the polished layer.

[0090] On the other hand, the liquid-phase foaming agent is introduced into the process of mixing and reacting the prepolymer and curing agent, and can form pores without participating in the reaction between the prepolymer and the curing agent. Furthermore, the liquid-phase foaming agent physically vaporizes due to the heat generated during the mixing and reaction process of the prepolymer and curing agent, thereby forming pores.

[0091] The volatile liquid-phase foaming agent does not react with isocyanate groups, amide groups, and alcohol groups, and may be in the liquid phase at 25°C. Specifically, the volatile liquid-phase foaming agent can be selected from the group consisting of perfluoro compounds such as cyclopentane, n-pentane, cyclohexane, n-butyl acetate, bis(nonafluorobutyl)(trifluoromethyl)amine, and perfluorotributylamine, perfluoro-N-methylmorpholine, perfluorotripentylamine, and perfluorohexane. Examples of commercially available perfluoro compounds include 3M's FC-40, FC-43, FC-70, FC-72, FC-770, FC-3283, and FC-3284.

[0092] In addition, the blowing agent may include a gas-phase blowing agent. For example, the blowing agent may include a solid-phase blowing agent and a gas-phase blowing agent.

[0093] The gas-phase blowing agent may contain an inert gas. The gas-phase blowing agent may be added during the reaction between the urethane-based prepolymer and the curing agent and used as a pore-forming element.

[0094] The type of inert gas is not particularly limited, as long as it is a gas that does not participate in the reaction between the urethane-based prepolymer and the curing agent. For example, the inert gas may include one selected from the group consisting of nitrogen gas (N2), carbon dioxide gas (CO2), argon gas (Ar), helium gas (He), and combinations thereof.

[0095] The type and content of the gas-phase foaming agent can be designed according to the desired porosity structure and physical properties of the polished layer.

[0096] The inert gas may be introduced in a volume corresponding to 10% to 30% of the total volume of the composition. Specifically, the inert gas may be introduced in a volume corresponding to 15% to 30% of the total volume of the composition. Specifically, the gas-phase blowing agent may be injected through a predetermined injection line during the mixing process of the urethane-based prepolymer, the solid-phase blowing agent, and the curing agent. The injection rate of the gas-phase blowing agent may be about 0.8 L / min to about 2.0 L / min, for example about 0.8 L / min to about 1.8 L / min, for example about 0.8 L / min to about 1.7 L / min, for example about 1.0 L / min to about 2.0 L / min, for example about 1.0 L / min to about 1.8 L / min, for example about 1.0 L / min to about 1.7 L / min.

[0097] [Hardening agent] The curing agent is a compound for chemically reacting with the urethane-based prepolymer to form the final cured structure in the polished layer, and may include, for example, an amine compound or an alcohol compound. Specifically, the curing agent may include one selected from the group consisting of aromatic amines, aliphatic amines, aromatic alcohols, aliphatic alcohols, and combinations thereof.

[0098] According to one example, the curing agent may include a non-chlorine curing agent that does not contain chlorine components. For example, the content of the non-chlorine curing agent based on the total weight of the curing agent may be 50% by weight or more, 80% by weight or more, 90% by weight or more, 95% by weight or more, 97% by weight or more, 99% by weight or more, or 99.5% by weight or more, and may also be 100% by weight or less, or 99.5% by weight or less. Specific examples include 80% to 100% by weight, 90% to 100% by weight, or 80% to 99.5% by weight. Furthermore, the content of the chlorine-based curing agent based on the total weight of the curing agent is 20% by weight or less, 10% by weight or less, 5% by weight or less, 1% by weight or less, or 0.5% by weight or less, or 0.3% by weight or less, and also 0% by weight or more, 0.1% by weight or more, or 0.5% by weight or more. Specific examples include 0% to 20% by weight, 0% to 1% by weight, 0% to 0.5% by weight, or 0.5% to 20% by weight.

[0099] The curing agent may be at least one selected from solid-phase curing agents and liquid-phase curing agents.

[0100] The solid-phase curing agent may contain an active hydrogen group. The solid-phase curing agent may contain an amine group (-NH2) as the active hydrogen group.

[0101] Furthermore, the solid-phase curing agent may be an ester compound having two or more benzene rings. Specifically, the solid-phase curing agent may contain two or more of the ester groups in its molecule.

[0102] The solid-phase hardening agent may have a weight-average molecular weight of 150 to 400, for example, 150 to 350, for example, 200 to 350, for example, 250 to 350, or for example, 300 to 350. The solid-phase hardening agent has a melting point (mp) of 100°C to 150°C, for example, 100°C to 140°C, or for example, 110°C to 130°C.

[0103] In one example, the solid-phase curing agent may include one or more selected from the group consisting of 1,3-propanediol bis(4-aminobenzoate) (PDPAB), 4-(4-aminobenzoyl)oxyphenyl 4-aminobenzoate, 4-(4-aminobenzoyl)oxybutyl 4-aminobenzoate, 4-[4-(4-aminobenzoyl)oxy-3-methylbutoxy]butyl 4-aminobenzoate, and methylene bis-methylanthranilate (MBNA).

[0104] The liquid-phase curing agent may contain an active hydrogen group. The liquid-phase curing agent may contain one or more active hydrogen groups selected from the group consisting of an amine group (-NH2), a hydroxide group (-OH), a carboxylic acid group (-COOH), an epoxy group, and combinations thereof, and specifically may contain an amine group (-NH2).

[0105] Furthermore, the liquid-phase curing agent may contain sulfur within its molecule, specifically two or more intramolecular sulfur elements.

[0106] The liquid-phase curing agent has a weight-average molecular weight of 50 to 300, for example, 100 to 250, for example, 150 to 250, or for example, 200 to 250.

[0107] Furthermore, the liquid-phase curing agent may be in the liquid phase at room temperature. Alternatively, the liquid-phase curing agent may have a boiling point (bp) of 160°C to 240°C, specifically 170°C to 240°C, or more specifically 170°C to 220°C.

[0108] Examples of the liquid-phase curing agent include one or more selected from the group consisting of 3,5-dimethylthio-2,6-diaminotoluene (DMTDA), 2,6-bis(methylthio)-4-methyl-1,3-benzenediamine, and N,N'-bis(sec-butylamino)diphenylmethane.

[0109] Furthermore, the curing agent may further contain other curing agents in addition to the liquid-phase curing agent and the solid-phase curing agent. The other curing agents may be, for example, one or more amine compounds and alcohol compounds. Specifically, the other curing agents may contain one or more compounds selected from the group consisting of aromatic amines, aliphatic amines, aromatic alcohols, and aliphatic alcohols.

[0110] For example, the other curing agent may be one or more selected from the group consisting of diaminodiphenyl methane, diaminodiphenyl sulfone, m-xylylene diamine, isophoronediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, polypropylenediamine, polypropylenetriamine, ethyleneglycol, diethyleneglycol, dipropyleneglycol, butanediol, hexanediol, glycerin, and trimethylolpropane.

[0111] As a specific example, the curing agent may include one or more selected from the group consisting of diethyltoluenediamine (DETDA), 3,5-dimethylthio-2,6-diaminotoluene (DMTDA), 1,3-propanediol bis(4-aminobenzoate) (PDPAB), N,N'-bis(sec-butylamino)diphenylmethane, 2,6-bis(methylthio)-4-methyl-1,3-benzenediamine, 4-(4-aminobenzoyl)oxyphenyl 4-aminobenzoate, 4-(4-aminobenzoyl)oxybutyl 4-aminobenzoate, 4-[4-(4-aminobenzoyl)oxy-3-methylbutoxy]butyl 4-aminobenzoate, and methylenebis-methylanthranilate (MBNA).

[0112] The content of the curing agent is 5 parts by weight or more, 10 parts by weight or more, 15 parts by weight or more, or 20 parts by weight or more, based on 100 parts by weight of the urethane-based prepolymer, and may also be 50 parts by weight or less, 45 parts by weight or less, 40 parts by weight or less, 35 parts by weight or less, 30 parts by weight or less, or 25 parts by weight or less. Specifically, the content of the curing agent is 10 to 40 parts by weight, based on 100 parts by weight of the urethane-based prepolymer, and more specifically, may be 15 to 35 parts by weight or 15 to 25 parts by weight.

[0113] [Additives] The composition for producing the abrasive layer may further include other additives such as surfactants and reaction rate modifiers. The names "surfactant," "reaction rate modifier," etc., are arbitrary names based on the main role of the substance in question, and each substance in question does not necessarily perform only the function limited to the role indicated by that name.

[0114] The surfactant is not particularly limited as long as it is a substance that plays a role in preventing phenomena such as pore aggregation or overlapping. For example, the surfactant may include a silicone-based surfactant.

[0115] The surfactant may be used in an amount of 0.2 to 2 parts by weight based on 100 parts by weight of the urethane-based prepolymer. Specifically, the surfactant may be included in an amount of 0.2 to 1.9 parts by weight, for example, 0.2 to 1.8 parts by weight, for example, 0.2 to 1.7 parts by weight, for example, 0.2 to 1.6 parts by weight, for example, 0.2 to 1.5 parts by weight, for example, 0.5 to 1.5 parts by weight, based on 100 parts by weight of the urethane-based prepolymer. Including the surfactant in an amount within the above range allows pores derived from the gas-phase blowing agent to be stably formed and maintained within the mold.

[0116] The reaction rate regulator plays a role in either accelerating or delaying the reaction, and depending on the purpose, a reaction accelerator, a reaction retarder, or both may be used. The reaction rate regulator may include a reaction accelerator. For example, the reaction accelerator may be one or more reaction accelerators selected from the group consisting of tertiary amine compounds and organometallic compounds.

[0117] Specifically, the reaction rate modifier may include one or more selected from the group consisting of triethylenediamine, dimethylethanolamine, tetramethylbutanediamine, 2-methyl-triethylenediamine, dimethylcyclohexylamine, triethylamine, triisopropanolamine, 1,4-diazabicyclo(2,2,2)octane, bis(2-methylaminoethyl) ether, trimethylaminoethylethanolamine, N,N,N,N,N''-pentamethyldiethylenetriamine, dimethylaminoethylamine, dimethylaminopropylamine, benzyldimethylamine, N-ethylmorpholine, N,N-dimethylaminoethylmorpholine, N,N-dimethylcyclohexylamine, 2-methyl-2-azanorbornene, dibutyltin dilaurate, stanas octoate, dibutyltin diacetate, dioctyltin diacetate, dibutyltin malate, dibutyltin di-2-ethylhexanoate, and dibutyltin dimercaptide. Specifically, the reaction rate modifier may include one or more selected from the group consisting of benzyldimethylamine, N,N-dimethylcyclohexylamine, and triethylamine.

[0118] The reaction rate modifier may be used in an amount of 0.05 to 2 parts by weight based on 100 parts by weight of the urethane-based prepolymer. Specifically, the reaction rate modifier may be used in an amount of 0.05 to 1.8 parts by weight, for example, 0.05 to 1.7 parts by weight, for example, 0.05 to 1.6 parts by weight, for example, 0.1 to 1.5 parts by weight, for example, 0.1 to 0.3 parts by weight, for example, 0.2 to 1.8 parts by weight, for example, 0.2 to 1.7 parts by weight, for example, 0.2 to 1.6 parts by weight, for example, 0.2 to 1.5 parts by weight, for example, 0.5 to 1 part by weight, based on 100 parts by weight of the urethane-based prepolymer. When the reaction rate modifier is used within the above content range, the curing reaction rate of the prepolymer composition can be appropriately adjusted to form an abrasive layer having pores of a desired size and hardness.

[0119] [Support layer] The support layer constitutes a sub-pad and supports the polishing layer while absorbing and dispersing external impacts applied to the polishing layer, thereby minimizing the occurrence of damage and defects to the object being polished during the polishing process in which the polishing pad is applied.

[0120] The support layer may include, but is not limited to, nonwoven fabric or suede. In one implementation example, the support layer may be a resin-impregnated nonwoven fabric. The nonwoven fabric may be a fibrous nonwoven fabric comprising one selected from the group consisting of polyester fibers, polyamide fibers, polypropylene fibers, polyethylene fibers, and combinations thereof.

[0121] The resin impregnated into the nonwoven fabric may include one selected from the group consisting of polyurethane resin, polybutadiene resin, styrene-butadiene copolymer resin, styrene-butadiene-styrene copolymer resin, acrylonitrile-butadiene copolymer resin, styrene-ethylene-butadiene-styrene copolymer resin, silicone rubber resin, polyester elastomer resin, polyamide elastomer resin, and combinations thereof.

[0122] The thickness of the support layer is, for example, 0.3 mm or more or 0.5 mm or more, and may also be 3 mm or less, 2 mm or less, or 1 mm or less. As a specific example, the thickness of the support layer may be 0.3 mm to 3 mm or 0.5 mm to 1 mm.

[0123] The hardness of the support layer may be, for example, 50 Asker C or higher, 60 Asker C or higher, or 70 Asker C or higher, and may also be 100 Asker C or lower, 90 Asker C or lower, or 80 Asker C or lower. As a specific example, the hardness of the support layer may be 50 Asker C to 100 Asker C or 60 Asker C to 90 Asker C.

[0124] Furthermore, an adhesive layer may be inserted between the polishing layer (upper pad) and the support layer (lower pad).

[0125] The adhesive layer may include a hot-melt adhesive. The hot-melt adhesive may be one or more selected from the group consisting of polyurethane resins, polyester resins, ethylene-vinyl acetate resins, polyamide resins, and polyolefin resins. Specifically, the hot-melt adhesive may be one or more selected from the group consisting of polyurethane resins and polyester resins.

[0126] Furthermore, double-sided tape is attached to the lower part of the support layer, and when applying it to the CMP device, the release paper of the double-sided tape can be removed and it can be attached to the platen for use.

[0127] [Method for manufacturing polishing pads] A method for manufacturing a polishing pad according to one example includes the steps of: preparing a polishing pad composition containing a urethane-based prepolymer, a foaming agent, and a curing agent; injecting the polishing pad composition into a mold and curing it to produce a polishing layer; and bonding the polishing layer to a support layer.

[0128] The specific types and contents of the urethane-based prepolymer, curing agent, and blowing agent are as illustrated above.

[0129] As a specific example, the foaming agent includes a solid-phase foaming agent, the solid-phase foaming agent includes one or more selected from the group consisting of acrylonitrile copolymers, methyl methacrylate copolymers, methacrylonitrile copolymers, and acrylic copolymers, and the curing agent may include one or more selected from the group consisting of diethyltoluenediamine (DETDA), 3,5-dimethylthio-2,6-diaminotoluene (DMTDA), 1,3-propanediol bis(4-aminobenzoate) (PDPAB), N,N'-bis(sec-butylamino)diphenylmethane, 2,6-bis(methylthio)-4-methyl-1,3-benzenediamine, 4-(4-aminobenzoyl)oxyphenyl 4-aminobenzoate, 4-(4-aminobenzoyl)oxybutyl 4-aminobenzoate, 4-[4-(4-aminobenzoyl)oxy-3-methylbutoxy]butyl 4-aminobenzoate, and methylenebis-methylanthranilate (MBNA).

[0130] The polishing pad composition may be prepared by sequentially or simultaneously mixing a urethane-based prepolymer, a foaming agent, and a curing agent.

[0131] As an example, the step of preparing the polishing pad composition may be carried out by mixing a urethane-based prepolymer with a curing agent and then further mixing it with a foaming agent, or by mixing the urethane-based prepolymer with the foaming agent and then further mixing it with the curing agent.

[0132] As another example, urethane prepolymers, curing agents, and blowing agents are added to the mixing process substantially at almost the same time, and if blowing agents, surfactants, and inert gases are further added, they too may be added to the mixing process substantially at almost the same time.

[0133] Another example is to pre-mix a urethane-based prepolymer, a foaming agent, and a surfactant, and then add the curing agent, or to add the curing agent and an inert gas together.

[0134] In the aforementioned mixing process, the urethane-based prepolymer and the curing agent are mixed to initiate the reaction, and the blowing agent and inert gas can be uniformly dispersed within the raw materials. At this time, the reaction rate regulator can intervene in the reaction between the urethane-based prepolymer and the curing agent from the initial stages of the reaction to adjust the reaction rate. Specifically, the mixing can be carried out at a speed of 1000 rpm to 10000 rpm or 4000 rpm to 7000 rpm. This speed range may be more advantageous because it allows for uniform dispersion of the inert gas and blowing agent within the raw materials.

[0135] Furthermore, the step of preparing the polishing pad composition may be carried out under conditions of 50°C to 150°C, and may be carried out under vacuum degassing conditions if necessary.

[0136] If the foaming agent includes a solid-phase foaming agent, the steps of preparing the polishing pad composition may include the steps of mixing the urethane-based prepolymer and the solid-phase foaming agent to prepare a first preliminary composition, and mixing the first preliminary composition with a curing agent to prepare a second preliminary composition.

[0137] The viscosity of the first preliminary composition is approximately 1000 cps to approximately 2000 cps at approximately 80°C, and may be, for example, approximately 1000 cps to approximately 1800 cps, for example, approximately 1000 cps to approximately 1600 cps, or for example, approximately 1000 cps to approximately 1500 cps.

[0138] If the foaming agent includes a gas-phase foaming agent, the steps of preparing the polishing pad composition may include preparing a third preliminary composition containing the urethane-based prepolymer and the curing agent, and preparing a fourth preliminary composition by injecting the gas-phase foaming agent into the third preliminary composition. In one embodiment, the third preliminary composition may further include a solid-phase foaming agent.

[0139] In one embodiment, the process for manufacturing the polishing layer may include the steps of preparing a mold preheated to a first temperature, injecting the polishing pad composition into the preheated mold and curing it, and post-curing the cured polishing pad composition under a second temperature condition higher than the preheating temperature.

[0140] In one implementation example, the temperature difference between the first temperature and the second temperature is approximately 10°C to approximately 40°C, and could be, for example, approximately 10°C to approximately 35°C, or for example, approximately 15°C to approximately 35°C. In one implementation example, the first temperature is approximately 60°C to approximately 100°C, and could be, for example, approximately 65°C to approximately 95°C, or for example, approximately 70°C to approximately 90°C. In one implementation example, the second temperature is approximately 100°C to approximately 130°C, and could be, for example, approximately 100°C to approximately 125°C, or for example, approximately 100°C to approximately 120°C.

[0141] The step of curing the polishing pad composition at the first temperature may be carried out for about 5 minutes to about 60 minutes, for example, about 5 minutes to about 40 minutes, for example, about 5 minutes to about 30 minutes, for example, about 5 minutes to about 25 minutes.

[0142] The step of post-curing the polishing pad composition cured at the first temperature at the second temperature may be carried out for about 5 hours to about 30 hours, for example, about 5 hours to about 25 hours, for example, about 10 hours to about 30 hours, for example, about 10 hours to about 25 hours, for example, about 12 hours to about 24 hours, for example, about 15 hours to about 24 hours.

[0143] Subsequently, the step of injecting the polishing pad composition into the mold and then curing it is performed under temperature conditions of 60°C to 120°C and a curing rate of 50 kg / m². 2 ~200kg / m 2 This can be done under pressure conditions.

[0144] Furthermore, the manufacturing method may further include steps such as cutting the surface of the obtained polishing pad, processing grooves on the surface, bonding with the underlying layer, inspection, and packaging. These steps can be carried out using conventional polishing pad manufacturing methods.

[0145] As an example, the method for manufacturing the polishing pad may include a step of processing at least one surface of the polishing layer. The step of processing at least one surface of the polishing layer may include at least one of the following steps: forming grooves on at least one surface of the polishing layer; lathe turning at least one surface of the polishing layer; and roughening at least one surface of the polishing layer.

[0146] The groove may include at least one of the following: concentric grooves formed at predetermined intervals from the center of the polishing layer, and radial grooves continuously connected from the center of the polishing layer to the edge of the polishing layer. The turning may be performed by removing the polishing layer to a predetermined thickness using a cutting tool. The roughening may be performed by processing the surface of the polishing layer with a sanding roller.

[0147] [Manufacturing method for semiconductor element] A method for manufacturing a semiconductor device according to one embodiment includes the step of polishing the surface of a semiconductor substrate using the polishing pad according to the embodiment.

[0148] Specifically, the method for manufacturing the semiconductor element may include the steps of providing a polishing pad according to the embodiment, and polishing the surface of the semiconductor substrate by rotating the polishing surface of the polishing layer and the surface of the semiconductor substrate relative to each other so that they come into contact.

[0149] Figure 1 shows a semiconductor device manufacturing process using a polishing pad according to one implementation example. Referring to Figure 1, after mounting the polishing pad 100 according to one implementation example onto a platen 200, the semiconductor substrate 600 to be polished is placed on the polishing pad 100. At this time, the surface of the semiconductor substrate 600 to be polished is in direct contact with the polishing surface of the polishing pad 100. For polishing, polishing slurry 400 can be sprayed onto the polishing pad through a nozzle. The flow rate of the polishing slurry 400 supplied through the nozzle is approximately 10 cm³. 3 / min ~ approx. 1000cm 3 The range is selected according to the purpose within the minute range, for example, approximately 50 cm. 3 / min ~ approx. 500cm 3 It could be, but is not limited to, / minutes.

[0150] Subsequently, the semiconductor substrate 600 and the polishing pad 100 rotate relative to each other, thereby polishing the surface of the semiconductor substrate 600. In this case, the rotation direction of the semiconductor substrate 600 and the rotation direction of the polishing pad 100 may be the same or opposite. The rotation speeds of the semiconductor substrate 600 and the polishing pad 100 are selected according to the purpose within a range of approximately 10 rpm to approximately 500 rpm, and may be, for example, approximately 30 rpm to approximately 200 rpm, but are not limited thereto.

[0151] The semiconductor substrate 600, while mounted on the polishing head 510, is pressed against the polishing surface of the polishing pad 100 with a predetermined load, and then its surface is polished. The load applied to the surface of the semiconductor substrate 600 by the polishing head 510 and the polishing surface of the polishing pad 100 is approximately 1 gf / cm². 2 ~About 1000gf / cm 2 The appropriate value is selected within the range depending on the purpose, for example, approximately 10 gf / cm³. 2 ~About 800gf / cm 2 These are possible, but not the only possibilities.

[0152] In one implementation example, the semiconductor substrate 600 to be polished may include an oxide film, a tungsten film, or a composite film thereof. Specifically, the semiconductor substrate 600 may include an oxide film, a tungsten film, or a composite film of an oxide film and a tungsten film. The composite film of the oxide film and the tungsten film may be a multilayer film in which the tungsten film is laminated on one surface of the oxide film, or a monolayer film in which oxide regions and tungsten regions are mixed within a single layer. As the object to be polished has such film properties, and the polishing pad has the properties according to the implementation example, defects can be minimized in the semiconductor device manufactured by the semiconductor device manufacturing method.

[0153] In one embodiment, the method for manufacturing the semiconductor device may further include, in the step of polishing the object to be polished, a step of supplying either the oxide film polishing slurry or the tungsten film polishing slurry, or a step of sequentially supplying the oxide film polishing slurry and the tungsten film polishing slurry to the polishing surface.

[0154] For example, if the semiconductor substrate to be polished contains an oxide film, the method for manufacturing the semiconductor device may include a step of supplying the slurry for polishing the oxide film. If the semiconductor substrate contains a tungsten film, the method for manufacturing the semiconductor device may include a step of supplying the slurry for polishing the tungsten film. If the semiconductor substrate contains a composite film of an oxide film and a tungsten film, the method for manufacturing the semiconductor device may include a step of sequentially supplying the slurry for polishing the oxide film and the slurry for polishing the tungsten film to the polishing surface. In this case, depending on the process, the slurry for polishing the oxide film may be supplied first and then the slurry for polishing the tungsten film may be supplied later, or the slurry for polishing the tungsten film may be supplied first and then the slurry for polishing the oxide film may be supplied later.

[0155] In one embodiment, the method for manufacturing the semiconductor device may further include a step of processing the polishing surface of the polishing pad 100 with a conditioner 300 at the same time as polishing the semiconductor substrate 600, in order to maintain the polishing surface of the polishing pad 100 in a state suitable for polishing.

[0156] The polishing pad according to the above-mentioned example has its polishing layer chlorine content adjusted to a specific range, thereby maintaining excellent physical properties and performance while reducing the size of debris and minimizing the occurrence of defects and scratches during the CMP process. As a result, high-quality semiconductor devices can be efficiently manufactured using this polishing pad.

[0157] (Examples) Examples are described below, but the feasible scope is not limited to these.

[0158] (Examples and comparative examples: Manufacturing of polishing pads) Step (1) Preparation of prepolymer Toluene diisocyanate (TDI), dicyclohexylmethane diisocyanate (H12MDI), polytetramethylene ether glycol (PTMEG), and diethylene glycol (DEG) were placed in a four-necked flask and reacted at 80°C for 3 hours to prepare a urethane-based prepolymer. The NCO% of the prepolymer was measured and is shown in Table 1 below.

[0159] Stage (2) Manufacturing of polishing pads A casting apparatus was prepared, equipped with tanks and input lines for supplying raw materials such as prepolymers, curing agents, inert gases, and foaming agents. The urethane-based prepolymer, foaming agent, curing agent, inert gas (N2), and silicone-based surfactant (Evonik) prepared above were filled into their respective tanks. The raw materials were introduced into the mixing head at a constant speed via each input line and stirred. The foaming agent and curing agent used were those listed in Table 1 below, and the prepolymer and curing agent were introduced in an equivalent ratio of 1:1 and at a total rate of 10 kg / min.

[0160] A mold (1000mm x 1000mm x 3mm) was prepared and preheated to 80°C. The stirred raw material was then extruded into the mold and reacted to obtain a solid-phase cake-like molded body. Subsequently, the upper and lower ends of the molded body were cut to obtain an abrasive layer for the upper pad.

[0161] Subsequently, the polishing layer underwent surface milling and groove formation processes, and was then bonded to the lower pad support layer using hot-melt adhesive to manufacture the polishing pad.

[0162] Double-sided tape (442JS, 3M) was attached to the lower part of the support layer so that it could be attached to the surface plate of the CMP device.

[0163] The curing agent and blowing agent used in the examples and comparative examples are as follows: - DMTDA: 3,5-dimethylthio-2,6-diaminotoluene, Covestro - MOCA:4,4'-methylenebis(2-chloroaniline), Ishihara Co., Ltd. - F-65DE: Acrylonitrile / methyl methacrylate / methacrylonitrile copolymer, extended cell type, Matsumoto Co., Ltd. - F-80DE: Acrylonitrile / methyl methacrylate / methacrylonitrile copolymer, extended cell type, Matsumoto Co., Ltd. - 051DET40d25: Acrylonitrile / methacrylonitrile copolymer, extended cell type, Nouryon - 051DET40d42: Acrylonitrile / methacrylonitrile copolymer, extended cell type, Nouryon - 461DET40d25: Acrylonitrile / Dichloroethane, Extended Cell Type, Nouryon

[0164] The configurations of the above-mentioned examples and comparative examples are summarized in Table 1 below.

[0165] JPEG0007851346000001.jpg153164

[0166] (Test Example 1) The polishing layer, support layer, and polishing pad formed by laminating them as described above were tested as follows.

[0167] (1)Hardness The samples were cut into 5cm x 5cm (thickness: 2mm) pieces and stored for 12 hours at room temperature, 30°C, 50°C, and 70°C. After storage, the Shore D hardness and Asker C hardness were measured using a hardness tester.

[0168] (2) Specific gravity The sample was cut into 2cm x 5cm (thickness: 2mm) pieces, stored at 25°C for 12 hours, and then its specific gravity was measured using a hydrometer.

[0169] (3) Tensile strength The sample was cut into 4cm x 1cm (thickness: 2mm) pieces, and the maximum strength value just before the abrasive pad broke was measured using a universal test meter (UTM) at a speed of 50mm / min.

[0170] (4) Growth rate The sample was cut into 4cm x 1cm (thickness: 2mm), and the maximum deformation of the polishing pad just before breakage was measured using a universal tester (UTM) at a speed of 50mm / min. The ratio of the maximum deformation to the initial length was then expressed as a percentage (%). The results are summarized in the table below.

[0171] JPEG0007851346000002.jpg127162

[0172] As can be seen from the table above, the polishing pads of Examples 1 to 7 were at or above the level of the polishing pads of Comparative Examples 1 and 2 in terms of hardness, specific gravity, tensile strength, and elongation.

[0173] (Test Example 2) The following tests were conducted on each of the polishing pads manufactured as described above.

[0174] (1)Removal rate A 300 mm diameter silicon wafer, on which silicon oxide had been deposited by the CVD process, was placed in the CMP polishing apparatus. The silicon wafer was then set with the silicon oxide film facing downwards on a surface plate to which the porous polyurethane polishing pad had been attached.

[0175] Subsequently, under conditions of a polishing load of 4.0 psi and a polishing pad rotation speed of 150 rpm, the silicon oxide film was polished by rotating the surface plate at 150 rpm for 60 seconds while adding a calcined ceria slurry onto the polishing pad at a rate of 250 mL / min.

[0176] After polishing, the silicon wafer was removed from the carrier, placed in a spin dryer, washed with deionized water (DIW), and then dried with nitrogen for 15 seconds. The film thickness change of the dried silicon wafer before and after polishing was measured using a spectroscopic interferometric wafer thickness gauge (model name: SI-F80R, Keyence Corporation).

[0177] Subsequently, the polishing rate was calculated using the following mathematical formula 1. [Mathematics 1] Polishing rate (Å / min) = Polishing thickness of silicon wafer (Å) / Polishing time (minutes)

[0178] (2) Defects Polishing was performed using a CMP polishing apparatus in the same manner as the polishing rate test described above. After polishing, the silicon wafer was moved to a cleaning unit and washed for 10 seconds each with 1% HF, deionized water (DIW), and 1% H2NO3, deionized water (DIW). Then, it was moved to a spin dryer and washed with deionized water (DIW), and then dried with nitrogen for 15 seconds. The dried silicon wafer was then used with a defect measurement device (model name: XP+, KLA-TENCOR) to measure the change in defects before and after polishing. Specifically, the total number of scratches, chatter marks, pits, and residues on the wafer was measured.

[0179] (3) Chlorine content A circular sample measuring 3 cm in diameter and 0.3 cm in height was prepared from the polishing layer of the polishing pad. The chlorine content in the sample was measured according to IEC62321-3-2, an international standard for measuring specific substances in polymers by combustion ion chromatography (C-IC) (see Figure 3).

[0180] (4) Debris size A porous polyurethane polishing pad was attached to the platen of the CMP polishing apparatus and set up. Subsequently, debris from the polishing layer was collected using only conditioner and deionized water (DIW), with the carrier operation excluded. The polishing layer was conditioned by setting the platen speed to 93 rpm, conditioner load to 9 lb, rotation speed to 64 rpm, and sweep speed to 19 times / min, and injecting deionized water at 300 cc / min. Debris from the polishing layer that came out with the deionized water during conditioning was collected. The D50 particle size of the collected debris was obtained using a particle size analyzer (Mastersize 3000, Malvern) and a medium-capacity automatic wet disperser (Hydro MV, Malvern). The analyzer settings were: refractive index of polyurethane 1.55, refractive index of deionized water 1.33, and stirring speed of 2500 rpm.

[0181] (5) Zeta potential A porous polyurethane polishing pad was attached to the platen of the CMP polishing apparatus and set up. Then, without operating the carrier, debris from the polishing layer was collected using only conditioner and deionized water (DIW).

[0182] The polishing layer was conditioned using a disc with a CI of 45, under the following conditions: platen speed 93 rpm, conditioner load 9 lb, rotation speed 64 rpm, and sweep speed 19 times / min. Deionized water was injected at a rate of 300 cc / min. Debris from the polishing layer generated during conditioning was collected in a solution mixed with deionized water and stored for 24 hours. The supernatant liquid located within 10 mm of the top surface of the solution was taken as a sample. The obtained sample was approximately pH 6.5, and the pH was adjusted to 5.5 using nitric acid and potassium hydroxide. The nitric acid aqueous solution concentration used was 35%, and the potassium hydroxide aqueous solution concentration was 10%. The debris concentration in the liquid phase sample was confirmed to be approximately 0.01% by weight. This concentration was measured using a heated moisture meter (MX-50, AND Corporation) after placing about 5 g of the liquid phase sample in an aluminum dish.

[0183] The zeta potential of the sample was measured using a zetasizer (Nano-ZS90, Malvern). Specifically, 1 mL of the sample was placed in the zetasizer cuvette, and the zeta potential was obtained by repeating the measurement three times. At this time, the instrument settings were set to RI 1.550 and Absorption 0.010 based on the polyurethane value. The results of the above tests are summarized in the table below.

[0184] JPEG0007851346000003.jpg100164

[0185] As can be seen from the table above, the polishing pads of Examples 1 to 7 had chlorine (Cl) content measured within a preferred range, and their performance, such as polishing efficiency, was at a level equivalent to or better than that of Comparative Examples 1 and 2. In particular, the debris size of the polishing pads of Examples 1 to 7 was measured to be smaller than that of Comparative Examples 1 and 2, and the number of defects / scratches was measured to be significantly lower. Furthermore, the zeta potential of the polishing pads of Examples 1 to 7 was also measured within a preferred range. [Explanation of Symbols]

[0186] 100: Polishing pad 110: Polished layer (sample) 130: Solid-phase foaming agent 131: Hull 132: Swelling-inducing component 150: Debris 200: Platen 300: Conditioner 400: Polishing slurry 510: Polishing head 520: Career 600: Semiconductor substrate (wafer) 650: Defect 700: Apparatus for measuring the chlorine content of polishing pads 710: Injection gas (Ar / O2) 730: Combustion tube 750: Electric furnace 770: Adsorption tube 790: Valve for transferring to ion chromatography

Claims

1. A polishing pad comprising a polishing layer and a support layer, The polishing layer comprises a urethane-based prepolymer, a foaming agent, and a curing agent. The abrasive layer was analyzed according to the IEC 62321-3-2 standard and its chlorine (Cl) content was 10,000 ppm or less. When the polishing pad is conditioned using a CI45 disc under the conditions of a platen speed of 93 rpm, a conditioner load of 9 lb, a conditioner speed of 64 rpm, and a sweep of 19 times / min, while supplying 300 cc / min of deionized water, the D50 particle size of the polishing pad debris obtained is 10 μm to 25 μm. A polishing pad in which, when polishing the silicon oxide layer of a silicon wafer with the aforementioned polishing pad under the conditions of a polishing load of 4.0 psi and a polishing pad rotation speed of 150 rpm, while introducing a calcined ceria slurry at a rate of 250 mL / min, the polishing rate according to the following mathematical formula 1 is 2200 Å / min to 2600 Å / min. [Mathematics 1] Polishing rate (Å / min) = Polishing thickness of silicon wafer (Å) / Polishing time (minutes).

2. The polishing pad according to claim 1, wherein the chlorine (Cl) content of the polishing layer, as analyzed according to the IEC 62321-3-2 standard, is 10 ppm to 1000 ppm.

3. The aforementioned foaming agent includes a solid-phase foaming agent. The polishing pad according to claim 1, wherein the solid-phase foaming agent comprises one or more selected from the group consisting of acrylonitrile copolymers, methyl methacrylate copolymers, methacrylonitrile copolymers, and acrylic copolymers.

4. The aforementioned hardening agent is The polishing pad according to claim 1, comprising one or more selected from the group consisting of diethyltoluenediamine (DETDA), 3,5-dimethylthio-2,6-diaminotoluene (DMTDA), 1,3-propanediol bis(4-aminobenzoate) (PDPAB), N,N'-bis(sec-butylamino)diphenylmethane, 2,6-bis(methylthio)-4-methyl-1,3-benzenediamine, 4-(4-aminobenzoyl)oxyphenyl 4-aminobenzoate, 4-(4-aminobenzoyl)oxybutyl 4-aminobenzoate, 4-[4-(4-aminobenzoyl)oxy-3-methylbutoxy]butyl 4-aminobenzoate, and methylenebis-methylanthranilate (MBNA).

5. The aforementioned polished layer is Hardness ranges from 50 Shore D to 65 Shore D, 15 N / mm ２ ~25 N / mm ２ The tensile strength and The polishing pad according to claim 1, having an elongation rate of 90% to 130%.

6. The polishing pad according to claim 1, wherein the zeta potential value of an aqueous solution with pH 5.5 containing 0.01% by weight of debris obtained by conditioning the polishing layer is -10 mV to 30 mV.

7. A step of preparing an abrasive pad composition comprising a urethane-based prepolymer, a foaming agent, and a curing agent, The steps include: injecting the polishing pad composition into a mold and curing it to produce a polishing layer; The step includes bonding the polished layer to the support layer, The foaming agent comprises a solid-phase foaming agent, the solid-phase foaming agent comprising one or more selected from the group consisting of acrylonitrile copolymers, methyl methacrylate copolymers, methacrylonitrile copolymers, and acrylic copolymers. The method for producing an abrasive pad according to claim 1, wherein the curing agent comprises one or more selected from the group consisting of diethyltoluenediamine (DETDA), 3,5-dimethylthio-2,6-diaminotoluene (DMTDA), 1,3-propanediol bis(4-aminobenzoate) (PDPAB), N,N'-bis(sec-butylamino)diphenylmethane, 2,6-bis(methylthio)-4-methyl-1,3-benzenediamine, 4-(4-aminobenzoyl)oxyphenyl 4-aminobenzoate, 4-(4-aminobenzoyl)oxybutyl 4-aminobenzoate, 4-[4-(4-aminobenzoyl)oxy-3-methylbutoxy]butyl 4-aminobenzoate, and methylenebis-methylanthranilate (MBNA).

8. A method for manufacturing a semiconductor device, comprising the step of polishing the surface of a semiconductor substrate using the polishing pad described in claim 1.

Images