Polishing pad and manufacturing method of them

Abstract

To provide a polishing pad and a manufacturing method of them, capable of improving a polishing ratio and a polishing flatness level.SOLUTION: A polishing pad 100 according to an embodiment comprises: a top-pad that performs a polishing so as to be contacted to a wafer; and a sub-pad that is positioned to one surface of the top pad. In a CMP step polishing ratio against a silicon oxide film, by having a value of the polishing ratio at a point where a distance from a center of the wafer is 95 mm is larger than a point where a distance from a center of a wafer 600 is 85 m, the polishing ratio and the polishing flatness level can be improved, specifically, a polishing ratio profile characteristic of a polishing pad edge is excellent.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The realization example relates to a polishing pad used in a chemical mechanical polishing (CMP) process of a semiconductor element, and specifically, relates to a polishing pad and a method for manufacturing the same.

Background Art

[0002] Among semiconductor manufacturing processes, chemical mechanical polishing (CMP) is a process of flattening uneven portions on the surface of a semiconductor substrate by relatively moving the platen and the head in a state where a semiconductor substrate such as a wafer is attached to a head and brought into contact with the surface of a polishing pad fixed on the platen.

[0003] In such a CMP process, since the polishing pad greatly affects the surface processing quality of the semiconductor substrate, it is required to have stable physical properties. In particular, since the polishing rate of the CMP process can vary sensitively depending on the components contained in the polishing pad and their physical properties, it is necessary to optimize the components contained in the polishing pad and their physical properties.

[0004] On the other hand, the polishing pad may include a top-pad that contacts the wafer and performs polishing, and a sub-pad that is located below the top-pad and supports the top-pad. The sub-pad can be used to absorb and disperse the impact applied to the top-pad or to improve characteristics such as the polishing rate. However, there are limitations in improving characteristics such as the polishing rate by such a sub-pad. Therefore, research continues to further improve characteristics such as the polishing rate of the polishing pad by the sub-pad.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Therefore, an embodiment provides a polishing pad and a method for manufacturing the same that can improve the polishing rate and polishing flatness by including a specific sub-pad below the top pad without degrading the physical properties of the top pad and the like.

Means for Solving the Problems

[0007] A polishing pad according to an embodiment includes a top pad that contacts a wafer for polishing and a sub-pad located on one surface of the top pad, and satisfies the following formula (1). [Formula (1)] RR 85 <RR 95 In the formula (1), RR 85 is the polishing rate (Å / min) at a point where the distance from the center of the wafer is 85 mm in the CMP process polishing rate profile for a silicon oxide film, RR 95 is the polishing rate (Å / min) at a point where the distance from the center of the wafer is 95 mm in the CMP process polishing rate profile for a silicon oxide film.

[0008] A method for manufacturing a polishing pad according to another embodiment includes: (1) manufacturing a top pad using a composition for a top pad including a urethane prepolymer, a foaming agent, and a curing agent; (2) manufacturing a sub-pad including a nonwoven fabric layer and a suede layer; and (3) bonding the top pad and the sub-pad to manufacture a polishing pad, and the polishing pad satisfies the formula (1).

[0009] A method for manufacturing a semiconductor device according to still another embodiment includes polishing the surface of a semiconductor substrate using the polishing pad.

Advantages of the Invention

[0010] The polishing pad according to the implementation example includes a top pad that comes into contact with the wafer for polishing and a sub-pad located on one surface of the top pad. In the CMP process polishing rate profile for the silicon oxide film, the polishing rate at a point where the distance from the center of the wafer is 95 mm is greater than the polishing rate at a point where the distance from the center of the wafer is 85 mm, so that the polishing rate and the polishing flatness can be improved. In particular, the polishing rate profile characteristics of the edge of the polishing pad are excellent.

[0011] More specifically, the sub-pad has a double structure including a non-woven fabric layer and a suede layer. By controlling the physical properties such as the hardness, compression rate, and density of the sub-pad, in the CMP process polishing rate profile, unlike the conventional polishing pad where the gradient value at a distance of 85 mm to 95 mm from the center of the wafer is a negative number, it satisfies a positive number. Therefore, the polishing rate of the polishing pad can be improved. In particular, since the polishing rate profile characteristics of the edge of the polishing pad are excellent, it has excellent polishing flatness.

[0012] In addition, the polishing pad according to the implementation example can improve the polishing rate and the polishing flatness without degrading the physical properties and processability of the polishing pad. Therefore, when manufacturing a semiconductor device using this, the CMP performance and the yield can be improved.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

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Figure 8

Figure 9

Mode for Carrying Out the Invention

[0014] Hereinafter, the invention will be described in detail with reference to implementation examples. The implementation examples are not limited to the content disclosed below, and can be modified into various forms as long as the gist of the invention is not changed.

[0015] In this specification, the terms referring to each component are used to distinguish it from other components, and are not used with the intention of limiting the implementation examples. Also, in this specification, the singular expressions include plural expressions unless the context clearly has a different meaning.

[0016] In this specification, the description that a certain part "includes" a certain component means that, unless otherwise stated, it does not exclude other components, but may further include other components.

[0017] In this specification, the description that one component is formed above / below another component, or is connected or coupled to each other, includes all cases where they are directly formed, connected or coupled, or indirectly formed, connected or coupled via other components. Also, it should be understood that the criteria regarding above / below each component can vary depending on the direction of observing the object.

[0018] All numerical ranges indicating physical property values, dimensions, etc. of the components described in this specification should be understood to be modified by the term "about" in all cases, unless otherwise specified.

[0019] In a numerical range that limits the size, physical properties, etc. of the components described in this specification, when a numerical range limited only by the upper limit value and a numerical range limited only by the lower limit value are separately exemplified, it should be understood that the numerical range combined with these upper and lower limit values is also included in the exemplified range.

[0020] [Polishing pad] A polishing pad according to one embodiment includes a top pad that contacts a wafer to perform polishing, and a sub-pad located on one surface of the top pad, and satisfies the following formula 1. [Formula 1] RR 85 <RR 95 In the formula 1, RR 85 is the polishing rate (Å / min) at a point where the distance from the center of the wafer is 85 mm in the CMP process polishing rate profile for a silicon oxide film, RR 95 is the polishing rate (Å / min) at a point where the distance from the center of the wafer is 95 mm in the CMP process polishing rate profile for a silicon oxide film.

[0021] Specifically, a top pad generally made of a polyurethane material has viscoelasticity, but this causes a non-uniform pressure distribution during the CMP process, resulting in a problem that the pad deforms. In particular, in order to prevent the wafer from detaching, a strong pressure causes a rebounding shape, which may reduce the edge polishing rate profile characteristics in the CMP process polishing rate profile.

[0022] According to one implementation example, in order to improve such CMP process polishing rate profile characteristics, more specifically, the edge polishing rate profile characteristics, a sub-pad is provided on one surface of the top pad that contacts the wafer for polishing, and by controlling the type and characteristics of the sub-pad, the viscoelastic characteristics of the top pad can be effectively controlled. Therefore, the polishing pad according to one implementation example has a larger polishing rate at a point where the distance from the center of the wafer is 95 mm than at a point where the distance from the center of the wafer is 85 mm in the CMP process polishing rate profile for the silicon oxide film, thereby improving the polishing rate and polishing flatness, and in particular, having excellent polishing rate profile characteristics at the edge of the polishing pad.

[0023] According to one implementation example, in the CMP process polishing rate profile for the silicon oxide film, the average gradient value between 85 mm and 95 mm from the center of the wafer is a positive number for the polishing pad.

[0024] For example, in the CMP process polishing rate profile for a silicon oxide film, the average gradient value between 85 mm and 95 mm from the center of the wafer is 0.1 or more, 0.3 or more, 0.5 or more, 0.8 or more, 1.0 or more, 1.2 or more, 1.5 or more, 2 or more, 3 or more, 3.5 or more, 4 or more, 5.5 or more, 6 or more, 7 or more, 8 or more, 9.5 or more, 10.5 or more, 11 or more, 12 or more, 13.5 or more, or 15 or more, and can be 1.5 to 15, 2 to 11.5, 3 to 10.5, 4.5 to 9, or 5 to 8.5. By satisfying the above range for the average gradient value between 85 mm and 95 mm from the center of the wafer in the CMP process polishing rate profile for a silicon oxide film, the polishing rate and polishing flatness can be further improved.

[0025] In addition, the polishing pad may have a polishing rate difference (ΔRR) according to the following formula 2 of 200 Å / min or less. [Formula 2] ΔRR = RR 95 - RR 85 In the above formula 2, RR 85 is the polishing rate (Å / min) at the point where the distance from the center of the wafer is 85 mm in the CMP process polishing rate profile for a silicon oxide film, RR 95 is the polishing rate (Å / min) at the point where the distance from the center of the wafer is 95 mm in the CMP process polishing rate profile for a silicon oxide film.

[0026] For example, the polishing rate difference (ΔRR) according to the above formula 2 can be 180 Å / min or less, 150 Å / min or less, 120 Å / min or less, 100 Å / min or less, 80 Å / min or less, or 50 Å / min or less. The polishing pad according to one implementation example is excellent in polishing uniformity by satisfying the above range for the polishing rate difference according to the above formula 2.

[0027] In addition, the above RR 85is 1950 Å / min to 3300 Å / min, 2000 Å / min to 3000 Å / min, 2100 Å / min to 2950 Å / min, 2250 Å / min to 2900 Å / min, or 2300 Å / min to 2650 Å / min, and the RR 95 can be 2000 Å / min to 3500 Å / min, 2150 Å / min to 3350 Å / min, 2200 Å / min to 3200 Å / min, or 2350 Å / min to 3000 Å / min.

[0028] Also, when polishing the silicon oxide layer of a silicon wafer with a ceria slurry using the polishing pad, the average polishing rate according to the following Mathematical Formula 1 can be 2100 Å / min to 3500 Å / min. [Equation 1] Average polishing rate (Å / min) = Film thickness change before and after polishing (Å) / Polishing time (min)

[0029] For example, when polishing the silicon oxide film of a silicon wafer with a ceria slurry using the polishing pad, the average polishing rate (removal rate) can be 2100 Å / min to 3300 Å / min, 2150 Å / min to 3100 Å / min, 2200 Å / min to 2950 Å / min, or 2250 Å / min to 2800 Å / min.

[0030] Specifically, the polishing rate can be the polishing rate for a 300 mm diameter silicon wafer on which silicon oxide is deposited. Also, the polishing rate can be measured while rotating the platen at 150 rpm for 60 seconds while injecting calcined ceria slurry at 250 mL / min under the conditions of a polishing load of 4.0 psi and a polishing pad rotation speed of 150 rpm. The temperature conditions during the polishing rate measurement are not particularly limited, but can be, for example, normal temperature conditions.

[0031] Also, the polishing pad can have a polishing flatness (WIWNU) of 10% or less with respect to the oxide. For example, the polishing flatness of the polishing pad with respect to the oxide can be 9% or less, 7% or less, 5% or less, 4% or less, or 3% or less.

[0032] The polishing flatness can be calculated by the following Mathematical Formula 2. [Number 2] Polishing flatness (%) = (standard deviation of polished thickness (Å) / average polishing thickness (Å)) × 100

[0033] <Sub-pad> The polishing pad according to one embodiment includes a sub-pad. Specifically, the sub-pad is located on one surface at the lower part of the top pad. More specifically, the sub-pad can minimize the occurrence of damage and defects to the object to be polished during the polishing process in which the polishing pad is applied by absorbing and dispersing the external impact applied to the polishing layer while supporting the top pad, that is, the polishing layer.

[0034] The sub-pad has a structure in which a plurality of pores are formed, and the pores can be, but are not limited to, an open cell structure. Also, the sub-pad may have a higher pore formation rate than the top pad and may be slightly softer because its hardness is lower than that of the top pad.

[0035] According to one embodiment, the sub-pad includes a non-woven fabric layer and a suede layer. Specifically, the sub-pad includes a suede layer on the non-woven fabric layer, and the suede layer may be located on one surface of the top pad. More specifically, the polishing pad has a structure in which the top pad is laminated on the sub-pad, and may have a structure in which a non-woven fabric layer / suede layer / top pad is laminated.

[0036] The non-woven fabric layer can be a resin-impregnated non-woven fabric layer. For example, the non-woven fabric layer can be a fiber non-woven fabric layer containing one or more fibers selected from the group consisting of polyester fibers, polyamide fibers, polypropylene fibers, and polyethylene fibers.

[0037] In addition, the resin impregnated in the non-woven fabric layer may contain one or more resins 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-based elastomer resin, and polyamide-based elastomer resin.

[0038] The suede layer may be bonded to the non-woven fabric layer to form a sub-pad. Specifically, the suede layer may be formed by casting a resin on the non-woven fabric layer.

[0039] The resin that can be used in the production of the suede layer may contain one or more resins 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-based elastomer resin, and polyamide-based elastomer resin.

[0040] The thickness ratio of the non-woven fabric layer to the suede layer may be 1:0.5 to 2. For example, the thickness ratio of the non-woven fabric layer to the suede layer may be 1:0.7 to 1.8, 1:0.9 to 1.5, 1:1 to 1.2, 1:0.7 to 0.9, or 1:1.5 to 1.8.

[0041] The sub-pad may have a thickness of 0.5 mm to 2.5 mm. For example, the total thickness of the sub-pad is 0.6 mm or more, 0.7 mm or more, 0.85 mm or more, 0.95 mm or more, 1 mm or more, 1.1 mm or more, 1.3 mm or more, or 1.5 mm or more, and may be 0.5 mm to 2.3 mm, 0.6 mm to 2.15 mm, 0.8 mm to 2 mm, 1 mm to 1.9 mm, 1.2 mm to 1.9 mm, or 1.3 mm to 1.85 mm.

[0042] Also, the sub-pad may have a hardness of 60 Shore D to 90 Shore D. For example, the hardness of the sub-pad may be 62 Shore D to 85 Shore D, 65 Shore D to 85 Shore D, or 65 Shore D to 83 Shore D.

[0043] The sub-pad may have a compression ratio of 5% to 15%. For example, the compression ratio of the sub-pad may be 5.5% to 13%, 6% to 11.5%, 6.5% to 10%, or 7% to 9%.

[0044] Specifically, the sub-pad was cut into a size of 5 cm in width and 5 cm in length, and using a Dial Thickness Gauge (129-E, manufactured by YASUDA), the thickness (A) measured after placing an 85 g weight for 30 seconds and the thickness (B) measured after additionally placing an 800 g weight (85 g weight + 800 g weight) for 3 minutes were measured, and the compression ratio was calculated by the following mathematical formula 3. [Equation 3] Compression ratio (%) = [(A - B) / A] × 100

[0045] Also, the sub-pad may have a density of 0.25 g / cm 3 ~0.7 g / cm 3 For example, the density of the sub-pad may be 0.25 g / cm 3 ~0.65 g / cm 3 0.3 g / cm 3 ~0.65 g / cm 3 or 0.3 g / cm 3 ~0.6 g / cm 3 For example, the compression elastic modulus of the sub-pad may be 70% to 90%. For example, the compression elastic modulus may be 72% to 88% or 75% to 85%.

[0046]

[0047] ​Specifically, the compression elastic modulus means the degree of recovery after crimping. The sub-pad was cut into 5 cm in length and 5 cm in width, and the thickness (A) measured after placing an 85 g weight for 30 seconds using a dial thickness gauge (129-E, manufactured by YASUDA) and the thickness (C) measured after placing an additional 800 g weight (85 g weight + 800 g weight) for 3 minutes, then removing the 800 g weight and leaving it for 1 minute were measured, and the compression elastic modulus was calculated by the following Mathematical Formula 4. [Equation 4] Compression elastic modulus (%) = [C / A] × 100

[0048] Compared with a sub-pad composed of a single layer of a non-woven fabric layer or a suede layer, the sub-pad has a low density despite its thick thickness, and the hardness, compression ratio, and compression elastic modulus are controlled within a preferable range, so that the polishing rate according to the distance from the center is uniformly distributed in the CMP process polishing rate profile, and the polishing flatness can be improved. In particular, the polishing rate profile characteristics at the edge of the polishing pad can be improved.

[0049] Also, an adhesive layer may be inserted between the top pad and the sub-pad. The adhesive layer may contain a hot melt adhesive. The hot melt adhesive may be one or more selected from the group consisting of a polyurethane-based resin, a polyester-based resin, an ethylene-vinyl acetate-based resin, a polyamide-based resin, and a polyolefin-based resin. As a specific example, the hot melt adhesive may be one or more selected from the group consisting of a polyurethane-based resin and a polyester-based resin.

[0050] Also, a double-sided tape is bonded to the lower part of the support layer, and when applied to a CMP apparatus, the release paper of the double-sided tape is removed and it can be used by sticking it to a platen.

[0051] <Top pad> A polishing pad according to an implementation example includes a top pad. Specifically, the top pad is configured to contact a wafer for polishing and includes a polishing layer. More specifically, the top pad includes a polishing layer containing a polyurethane resin.

[0052] The polishing layer includes a urethane prepolymer, a foaming agent, and a curing agent. Specifically, the polyurethane resin is obtained from a composition containing a urethane prepolymer, a foaming agent, and a curing agent.

[0053] More specifically, the polishing layer includes a polyurethane-based resin that is a reaction product of a urethane prepolymer, a foaming agent, and a curing agent, that is, a cured product of a composition in which the above components are mixed, thereby including a porous polyurethane-based resin. Also, the polishing layer may include a large number of pores formed from the foaming agent.

[0054] 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.

[0055] 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 is 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.

[0056] 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 can 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 can be 30 Shore D to 80 Shore D or 50 Shore D to 65 Shore D.

[0057] The tensile strength of the polishing layer is, for example, 5 N / mm 2 or more, 10 N / mm 2 or more, or 15 N / mm 2 or more, and can be 30 N / mm 2 or less, 25 N / mm 2 or less, or 20 N / mm 2 or less. As a specific example, the tensile strength of the polishing layer can be 5 N / mm 2 to 30 N / mm 2 or 15 N / mm 2 to 25 N / mm 2 .

[0058] The elongation rate of the polishing layer is, for example, 50% or more, 70% or more, 90% or more, 106% or more, or 120% or more, and can be 300% or less, 250% or less, 200% or less, or 150% or less. As a specific example, the elongation rate of the polishing layer can be 50% to 300% or 90% to 130%. The elongation rate can be the elongation at break.

[0059] As a specific example, the polishing layer can have a hardness of 50 Shore D to 65 Shore D, a tensile strength of 15 N / mm 2 to 25 N / mm 2 , and an elongation rate of 90% to 130%.

[0060] The pores are dispersed and present in the polishing layer. The average diameter of the pores is, 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.

[0061] Further, the total area of the pores may be 30% - 60%, 35% - 50%, or 35% - 43% based on the total area of the polishing layer. Also, the total volume of the pores may be 30% - 70% or 40% - 60% based on the total volume of the polishing layer.

[0062] The polishing layer may have grooves on its surface for mechanical polishing. The grooves can have appropriate depths, widths, and intervals for mechanical polishing and are not particularly limited.

[0063] A polishing pad according to one embodiment includes a urethane prepolymer. A prepolymer generally refers to a polymer with a relatively low molecular weight whose degree of polymerization is terminated at an intermediate stage for easy molding in the production of certain final molded products. The prepolymer can be molded by itself or after reacting with other polymerizable compounds. For example, a prepolymer can be prepared by reacting an isocyanate compound with a polyol.

[0064] The isocyanate compound used in the preparation of the urethane prepolymer can be one selected from the group consisting of aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and combinations thereof.

[0065] 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 - phenylene diisocyanate, tolidine diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and combinations thereof.

[0066] The polyol is a compound containing at least two or more hydroxy 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.

[0067] 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.

[0068] The polyol may have a weight - average molecular weight (Mw) of 100 g / mol to 3000 g / mol. For example, the weight - average molecular weight of the polyol may be 100 g / mol to 3000 g / mol, 100 g / mol to 2000 g / mol, or 100 g / mol to 1800 g / mol.

[0069] According to one implementation example, the polyol may include a low - molecular - weight polyol with a weight - average molecular weight (Mw) of 100 g / mol to 300 g / mol and a high - molecular - weight polyol with a weight - average molecular weight (Mw) of 300 g / mol to 1800 g / mol.

[0070] Also, the urethane prepolymer may have a weight - average molecular weight of 500 g / mol to 3000 g / mol. For example, the weight - average molecular weight of the urethane prepolymer may be 500 g / mol to 2500 g / mol, 1000 g / mol to 2000 g / mol, or 1000 g / mol to 1500 g / mol.

[0071] According to one implementation example, the isocyanate compound for preparing the urethane prepolymer includes an aromatic diisocyanate compound, and the aromatic diisocyanate compound 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 prepolymer may include polytetramethylene ether glycol (PTMEG) and diethylene glycol (DEG).

[0072] According to another implementation example, the isocyanate compound for preparing the urethane prepolymer can include an aromatic diisocyanate compound and an alicyclic diisocyanate compound. For example, the aromatic diisocyanate compound includes 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 prepolymer may include polytetramethylene ether glycol (PTMEG) and diethylene glycol (DEG).

[0073] The urethane prepolymer may have an isocyanate terminal group content (NCO%) of 5 wt% or more, 8 wt% or more, or 10 wt% or more, and may also be 13 wt% or less, 12 wt% or less, or 11 wt% or less. As a specific example, the urethane prepolymer may have an isocyanate terminal group content (NCO%) of 8 wt% to 11 wt% or 9 wt% to 10 wt%.

[0074] The isocyanate terminal group content (NCO%) of the urethane prepolymer can be designed by comprehensively adjusting the types and contents of the isocyanate compound and the polyol compound for preparing the urethane prepolymer, the process conditions such as the temperature, pressure, and time in the process of preparing the urethane prepolymer, and the types and contents of the additives used in the preparation of the urethane prepolymer.

[0075] When the isocyanate terminal group content (NCO%) of the urethane prepolymer satisfies the above range, the reaction rate, reaction time, final cured structure, etc. when subsequently reacting the urethane prepolymer with a curing agent can be adjusted in a direction advantageous to the polishing performance according to the use and purpose of the final polishing pad.

[0076] According to one implementation example, the isocyanate terminal group content (NCO%) of the urethane prepolymer can be 8 wt% - 11 wt% or 9 wt% - 10 wt%.

[0077] When the NCO% is less than the above range, as the electrical properties based on the chemical cured structure in the polishing pad, it may be realized that the target polishing performance cannot be achieved in terms of polishing rate and flatness, and there may be a problem that the life of the polishing pad is reduced due to an excessive increase in the cutting rate. On the other hand, when the NCO% exceeds the above range, surface defects such as scratches and chatter marks on the semiconductor substrate may increase.

[0078] The blowing agent may include one selected from the group consisting of a solid-phase blowing agent, a gas-phase blowing agent, a liquid-phase blowing agent, and combinations thereof as a component for forming the pore structure in the polishing layer.

[0079] According to one implementation example, the foaming agent is a non-chlorine-based foaming agent that does not contain a chlorine component. In particular, it does not contain a chlorine-based foaming agent component commonly used in the production of polishing pads, such as vinylidene chloride (VDC), or the use thereof can be minimized. For example, the content of the non-chlorine-based foaming agent based on the total weight of the foaming agent is 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 is also 100% by weight or less or 99.5% by weight or less. As specific examples, it can be 80% to 100% by weight, 90% to 100% by weight, or 80% to 99.5% by weight. Also, the content of the chlorine-based foaming agent based on the total weight of the foaming 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, 0.3% by weight or less, and is also 0% by weight or more, 0.1% by weight or more, 0.5% by weight or more. As specific examples, it can be 0% to 20% by weight, 0% to 1% by weight, 0% to 0.5% by weight, or 0.5% to 20% by weight.

[0080] The foaming agent can be one or more selected from a solid-phase foaming agent containing particles with a hollow structure, a liquid-phase foaming agent using a volatile liquid, and an inert gas.

[0081] As an example, the solid-phase foaming agent can contain particles with a hollow structure that expand by heat and have their size adjusted. Such a solid-phase foaming agent has the advantage that it can be uniformly adjusted in the pore size by being put into the raw material in an already expanded form and having a uniform particle size.

[0082] Also, the solid-phase foaming agent can contain expandable particles. The expandable particles are particles having the property of being expandable by heat, pressure, etc., and the size in the final polishing layer can be determined by the heat, pressure, etc. applied during the process of manufacturing the polishing layer. The expandable particles are put into the raw material in a non-expanded particle state and are expanded by the heat or pressure applied during the manufacturing process of the polishing layer, and the final size can be determined.

[0083] The average particle size of the solid 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 foaming agent means the average particle size of the expanded particles themselves when the solid foaming agent is particles introduced into the raw material in an expanded state as described later, and may mean the average particle size of the particles after expansion by heat or pressure in the manufacturing process when the solid foaming agent is particles introduced into the raw material in an unexpanded state as described later.

[0084] The expandable particle type solid foaming agent may include a resinous outer skin and an expansion-inducing component present inside the outer skin. Such expandable particles can be formed into a hollow structure by vaporization of the internal expansion-inducing component by heat during the manufacturing process.

[0085] For example, the outer skin may include a thermoplastic resin. The thermoplastic resin may be one or more selected from the group consisting of acrylonitrile copolymers, methacrylonitrile copolymers, and acrylic copolymers.

[0086] The thickness of the outer skin 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 is also 15 μm or less, 12 μm or less, or 10 μm or less, and may specifically be 2 μm to 15 μm as an example.

[0087] The expansion-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, neopentane, 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.

[0088] The solid foaming agent may include particles treated with an inorganic component. In one implementation example, the solid foaming agent may be one whose surface is treated with silica (SiO 2 ) particles. The treatment of the inorganic component of the solid foaming agent may prevent aggregation between multiple particles. The solid foaming agent treated with the inorganic component may have different chemical, electrical, and / or physical properties on the surface of the foaming agent from those of the solid foaming agent not treated with the inorganic component.

[0089] Examples of commercially available products of the solid foaming agent include 920DE20d70, 051DET40d25, 051DET40d42, etc. of Nouryon, and F-65DE, F-80DE, FN-80SDE, etc. of Matsumoto.

[0090] As a specific example, the foaming agent used in the polishing pad according to the implementation example includes a solid foaming agent, and the solid foaming agent may include one or more selected from the group consisting of acrylonitrile copolymers, methyl methacrylate copolymers, methacrylonitrile copolymers, and acrylic copolymers.

[0091] The content of the solid foaming agent is 0.1 part by weight or more, 0.5 part by weight or more, or 1 part by weight or more based on 100 parts by weight of the urethane prepolymer, and can 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 foaming agent can 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 prepolymer.

[0092] The type and content of the solid foaming agent can be designed according to the intended pore structure and physical properties of the polishing layer.

[0093] On the other hand, the liquid foaming agent can be introduced during the process of mixing and reacting the prepolymer and the curing agent to form pores, and does not participate in the reaction between the prepolymer and the curing agent. Further, the liquid foaming agent physically vaporizes due to the heat generated during the process of mixing and reacting the prepolymer and the curing agent to form pores.

[0094] The volatile liquid foaming agent does not react with isocyanate groups, amide groups, and alcohol groups and can be in a liquid phase at 25°C. Specifically, the volatile liquid foaming agent can be selected from the group consisting of perfluorinated compounds such as cyclopentane, n-pentane, cyclohexane, n-butyl acetate, bis(nonafluorobutyl)(trifluoromethyl)amine, and perfluorotributylamine, perfluoro-N-methylmorpholine, perfluorotripentylamine, perfluorohexane. Commercially available products of the perfluorinated compounds include FC-40, FC-43, FC-70, FC-72, FC-770, FC-3283, FC-3284 of 3M.

[0095] 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.

[0096] The gas-phase blowing agent may include an inert gas. The gas-phase blowing agent is introduced during the reaction process of the urethane prepolymer and the curing agent and can be used as a pore-forming element.

[0097] The type of the inert gas is not particularly limited as long as it is a gas that does not participate in the reaction between the urethane prepolymer and the curing agent. For example, the inert gas is nitrogen gas (N 2 ), carbon dioxide gas (CO 2 ), argon gas (Ar), helium gas (He), or one selected from the group consisting of combinations thereof.

[0098] The type and content of the gas-phase blowing agent can be designed according to the target pore structure and physical properties of the polishing layer.

[0099] The inert gas can be introduced in a volume corresponding to 10% - 30% of the total volume of the composition. Specifically, the inert gas can be introduced in a volume corresponding to 15% - 30% of the total volume of the composition. Specifically, the gas-phase blowing agent can be injected through a predetermined injection line during the mixing process of the urethane prepolymer, the solid-phase blowing agent, and the curing agent. For example, the injection rate of the gas-phase blowing agent can be about 0.8 L / min to about 2.0 L / min, about 0.8 L / min to about 1.8 L / min, about 0.8 L / min to about 1.7 L / min, about 1.0 L / min to about 2.0 L / min, about 1.0 L / min to about 1.8 L / min, or about 1.0 L / min to about 1.7 L / min.

[0100] The hardener is a compound that chemically reacts with the urethane prepolymer to form the final cured structure within the polishing layer, and may include, for example, an amine compound or an alcohol compound. Specifically, the hardener may include one selected from the group consisting of aromatic amines, aliphatic amines, aromatic alcohols, aliphatic alcohols, and combinations thereof.

[0101] According to one implementation example, the hardener may include a non-chlorine-based hardener that does not contain a chlorine component. For example, the content of the non-chlorine-based hardener based on the total weight of the hardener is 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 is also 100% by weight or less or 99.5% by weight or less. As a specific example, it may be 80% by weight to 100% by weight, 90% by weight to 100% by weight, or 80% by weight to 99.5% by weight. Also, the content of the chlorine-based hardener based on the total weight of the hardener 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, 0.3% by weight or less, and is also 0% by weight or more, 0.1% by weight or more, 0.5% by weight or more. As a specific example, it may be 0% by weight to 20% by weight, 0% by weight to 1% by weight, 0% by weight to 0.5% by weight, or 0.5% by weight to 20% by weight.

[0102] The hardener may be at least one selected from a solid-phase hardener and a liquid-phase hardener.

[0103] The solid-phase hardener may contain an active hydrogen group. The solid-phase hardener may include an amine group (-NH 2 ) as the active hydrogen group.

[0104] Also, the solid-phase hardener may be an ester compound having two or more benzene rings. Specifically, the solid-phase hardener may contain two or more of the ester groups within the molecule.

[0105] The solid-phase curing agent may have a weight-average molecular weight of, for example, 150 g / mol to 400 g / mol, 150 g / mol to 350 g / mol, 200 g / mol to 350 g / mol, 250 g / mol to 350 g / mol, or 300 g / mol to 350 g / mol. Further, the solid-phase curing agent may have a melting point (m.p) of 100°C to 150°C, 100°C to 140°C, or 110°C to 130°C.

[0106] In one implementation 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-methyl anthranilate (MBNA).

[0107] The liquid-phase curing agent may contain an active hydrogen group. As the active hydrogen group, the liquid-phase curing agent includes one or more selected from the group consisting of an amine group (-NH 2 ), a hydroxyl group (-OH), a carboxylic acid group (-COOH), an epoxy group, and combinations thereof. Specifically, it may include an amine group (-NH 2 ).

[0108] Further, the liquid-phase curing agent may contain sulfur in the molecule, specifically, it may contain two or more sulfur elements in the molecule.

[0109] 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, for example, 200 to 250.

[0110] Further, the liquid-phase curing agent may be in a liquid phase at room temperature. Alternatively, the liquid-phase curing agent may have a boiling point (b.p) of 160°C to 240°C, specifically 170°C to 240°C, more specifically 170°C to 220°C.

[0111] Examples of the liquid-phase hardener may 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.

[0112] In addition to the liquid-phase hardener and the solid-phase hardener, the hardener may further include other hardeners. The other hardeners may be, for example, one or more of an amine compound and an alcohol compound. Specifically, the other hardeners may include one or more compounds selected from the group consisting of aromatic amines, aliphatic amines, aromatic alcohols, and aliphatic alcohols.

[0113] For example, the other hardeners may be one or more selected from the group consisting of diaminodiphenyl methane, diaminodiphenyl sulphone, m-xylylene diamine, isophoronediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, polypropylenediamine, polypropylenetriamine, ethylene glycol, diethyleneglycol, dipropyleneglycol, butanediol, hexanediol, glycerine, and trimethylolpropane.

[0114] As a specific example, the curing agent may include one or more selected from the group consisting of 4,4'-methylenebis(2-chloroaniline) (MOCA), 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 methylene bis-methyl anthranilate (MBNA).

[0115] 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 prepolymer, and may 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 parts by weight to 40 parts by weight based on 100 parts by weight of the urethane prepolymer, and more specifically, may be 15 parts by weight to 35 parts by weight or 15 parts by weight to 25 parts by weight.

[0116] Also, the equivalent ratio of the urethane prepolymer to the curing agent may be 1:0.5 to 2. For example, the equivalent ratio of the urethane prepolymer to the curing agent may be 1:0.5 to 1.5, 1:0.5 to 1.0, or 1:0.6 to 1.2.

[0117] The composition for producing the polishing layer may further include other additives such as a surfactant and a reaction rate regulator. The names such as "surfactant" and "reaction rate regulator" are arbitrary names based on the main role of the substance, and each corresponding substance does not necessarily perform only the functions limited by the name.

[0118] The surfactant is not particularly limited as long as it plays a role in preventing phenomena such as aggregation or overlap of pores. For example, the surfactant may include a silicone-based surfactant.

[0119] The surfactant can be used in a content of 0.2 parts by weight to 2 parts by weight based on 100 parts by weight of the urethane prepolymer. Specifically, the surfactant can be included in a content of 0.2 parts by weight to 1.9 parts by weight, 0.2 parts by weight to 1.8 parts by weight, 0.2 parts by weight to 1.7 parts by weight, 0.2 parts by weight to 1.6 parts by weight, 0.2 parts by weight to 1.5 parts by weight, or 0.5 parts by weight to 1.5 parts by weight based on 100 parts by weight of the urethane prepolymer. When the surfactant is included in the content within the above range, pores derived from the gas-phase foaming agent can be stably formed and maintained in the mold.

[0120] The reaction rate regulator plays a role in promoting or delaying the reaction, and a reaction accelerator, a reaction retarder, or both can be used according to the purpose. 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-based compounds and organometallic-based compounds.

[0121] Specifically, the reaction rate regulator 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-azanorborene, dibutyltin dilaurate, stannous octoate, dibutyltin diacetate, dioctyltin diacetate, dibutyltin maleate, dibutyltin di-2-ethylhexanoate, and dibutyltin dimercaptide. Specifically, the reaction rate regulator may include one or more selected from the group consisting of benzyldimethylamine, N,N-dimethylcyclohexylamine, and triethylamine.

[0122] The reaction rate regulator may be used in an amount of 0.05 parts by weight to 2 parts by weight based on 100 parts by weight of the urethane prepolymer. Specifically, the reaction rate regulator may be used in an amount of 0.05 parts by weight to 1.8 parts by weight, 0.05 parts by weight to 1.7 parts by weight, 0.05 parts by weight to 1.6 parts by weight, 0.1 parts by weight to 1.5 parts by weight, 0.1 parts by weight to 0.3 parts by weight, 0.2 parts by weight to 1.8 parts by weight, 0.2 parts by weight to 1.7 parts by weight, 0.2 parts by weight to 1.6 parts by weight, 0.2 parts by weight to 1.5 parts by weight, or 0.5 parts by weight to 1 part by weight based on 100 parts by weight of the urethane prepolymer. When the reaction rate regulator is used within the above content range, the curing reaction rate of the prepolymer composition can be appropriately adjusted to form a polishing layer having pores and hardness of a desired size.

[0123] [Method for manufacturing polishing pad] The manufacturing method of the polishing pad according to another embodiment includes: (1) a step of manufacturing a top pad using a composition for the top pad containing a urethane prepolymer, a foaming agent, and a curing agent; (2) a step of manufacturing a sub-pad including a nonwoven fabric layer and a suede layer; and (3) a step of manufacturing a polishing pad by bonding the top pad and the sub-pad together, and the polishing pad satisfies the above formula 1.

[0124] <Step (1) of manufacturing a top pad using a composition for the top pad containing a urethane prepolymer, a foaming agent, and a curing agent> The manufacturing method of the polishing pad according to another embodiment includes step (1) of manufacturing a top pad using a composition for the top pad containing a urethane prepolymer, a foaming agent, and a curing agent.

[0125] The specific types and contents of the urethane prepolymer, the curing agent, and the foaming agent are as exemplified above.

[0126] As a specific example, the foaming agent includes a solid-phase foaming agent, and 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. 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 methylene bis-methyl anthranilate (MBNA).

[0127] The composition for the top pad can be prepared by sequentially or simultaneously mixing a urethane prepolymer, a foaming agent, and a curing agent.

[0128] As an example, the step of preparing the composition for the top pad can be carried out by further mixing the foaming agent after mixing the urethane prepolymer with the curing agent, or by further mixing the curing agent after mixing the urethane prepolymer with the foaming agent.

[0129] As another example, the urethane prepolymer, the curing agent, and the foaming agent may be substantially simultaneously introduced into the mixing process. When further adding a foaming agent, a surfactant, and an inert gas, they may also be substantially simultaneously introduced into the mixing process.

[0130] As still another example, the urethane prepolymer, the foaming agent, and the surfactant may be premixed, and then the curing agent may be added, or the curing agent and the inert gas may be added together.

[0131] In the mixing, the urethane prepolymer and the curing agent are mixed to initiate the reaction, and the foaming agent and the inert gas can be uniformly dispersed in the raw material. At this time, the reaction rate regulator can intervene in the reaction between the urethane prepolymer and the curing agent from the initial stage 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. When within the speed range, it may be more advantageous for the inert gas and the foaming agent to be uniformly dispersed in the raw material.

[0132] Also, the step of preparing the composition for the top pad is carried out under the conditions of 50°C to 150°C and can be carried out under vacuum degassing conditions as required.

[0133] When the foaming agent contains a solid-phase foaming agent, the step of preparing the composition for the top pad may include a step of mixing the urethane prepolymer and the solid-phase foaming agent to prepare a first preliminary composition, and a step of mixing the first preliminary composition and the curing agent to prepare a second preliminary composition.

[0134] The viscosity of the first preliminary composition may be about 1000 cps to about 2000 cps, about 1000 cps to about 1800 cps, about 1000 cps to about 1600 cps, or about 1000 cps to about 1500 cps at about 80°C.

[0135] When the foaming agent includes a gas-phase foaming agent, the step of preparing the composition for the top pad may include the step of preparing a third preliminary composition including the urethane prepolymer and the curing agent, and the step of injecting the gas-phase foaming agent into the third preliminary composition to prepare a fourth preliminary composition. In one implementation example, the third preliminary composition may further include a solid-phase foaming agent.

[0136] In one implementation example, the step of manufacturing the polishing layer may include the step of preparing a mold preheated to a first temperature, the step of injecting the composition for the top pad into the preheated mold and curing it, and the step of post-curing the cured composition for the top pad under a second temperature condition higher than the preheating temperature.

[0137] According to one implementation example, the temperature difference between the first temperature and the second temperature may be about 10°C to about 40°C, for example about 10°C to about 35°C, or about 15°C to about 35°C. In one implementation example, the first temperature may be about 60°C to about 100°C, about 65°C to about 95°C, or about 70°C to about 90°C. In one implementation example, the second temperature may be about 100°C to about 130°C, for example about 100°C to about 125°C, or about 100°C to about 120°C.

[0138] The step of curing the composition for the top pad at the first temperature may be performed for about 5 minutes to about 60 minutes, about 5 minutes to about 40 minutes, about 5 minutes to about 30 minutes, or about 5 minutes to about 25 minutes.

[0139] The step of post-curing the composition for the top pad cured at the first temperature at the second temperature may be performed for about 5 hours to about 30 hours, about 5 hours to about 25 hours, about 10 hours to about 30 hours, about 10 hours to about 25 hours, about 12 hours to about 24 hours, or about 15 hours to about 24 hours.

[0140] Thereafter, the step of injecting the composition for the top pad into a mold and then curing it can be carried out under temperature conditions of 60°C to 120°C and pressure conditions of 50 kg / m 2 ~200 kg / m 2 .

[0141] In addition, the method for manufacturing the top pad may further include a step of cutting the surface of the obtained top pad, a step of processing grooves on the surface, and the like. Such steps can be carried out by a normal method for manufacturing a top pad.

[0142] As a specific example, the method for manufacturing the top 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 a step of forming grooves on at least one surface of the polishing layer, a step of turning at least one surface of the polishing layer, and a step of roughening at least one surface of the polishing layer.

[0143] The grooves may include at least one of concentric grooves formed at a predetermined interval 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 can be carried out by a method of shaving off a predetermined thickness of the polishing layer using a cutting tool. The roughening can be carried out by a method of processing the surface of the polishing layer with a sanding roller.

[0144] <Step (2) of manufacturing a sub-pad including a non-woven fabric layer and a suede layer> The method for manufacturing a polishing pad according to another embodiment includes a step (2) of manufacturing a sub-pad including a non-woven fabric layer and a suede layer.

[0145] Specifically, after manufacturing the non-woven fabric layer first, a sub-pad having a double structure of a non-woven fabric layer and a suede layer can be manufactured by forming a suede layer on the non-woven fabric layer.

[0146] More specifically, the step (2) includes a step of impregnating a non-woven fabric with a resin to produce a non-woven fabric layer, and a step of casting a resin on one surface of the non-woven fabric layer to form a suede layer.

[0147] First, the non-woven fabric layer can be produced by impregnating a non-woven fabric with a resin. The non-woven fabric can be a fibrous non-woven fabric containing one or more fibers selected from the group consisting of polyester fibers, polyamide fibers, polypropylene fibers, and polyethylene fibers. Further, the impregnating resin can contain one or more resins selected from the group consisting of polyurethane resins, polybutadiene resins, styrene-butadiene copolymer resins, styrene-butadiene-styrene copolymer resins, acrylonitrile-butadiene copolymer resins, styrene-ethylene-butadiene-styrene copolymer resins, silicone rubber resins, polyester-based elastomer resins, and polyamide-based elastomer resins.

[0148] Specifically, the non-woven fabric layer can be formed by impregnating the fibrous non-woven fabric with the impregnating resin. As a specific example, the non-woven fabric layer is performed after impregnating polyester fibers with a polyurethane resin and drying, and the drying step can be performed at 120°C to 150°C or 125°C to 145°C for 5 minutes to 60 minutes or 5 minutes to 30 minutes.

[0149] The suede layer can be formed by casting a resin on the non-woven fabric layer. For example, the suede layer can be formed by casting one or more resins selected from the group consisting of polyurethane resins, polybutadiene resins, styrene-butadiene copolymer resins, styrene-butadiene-styrene copolymer resins, acrylonitrile-butadiene copolymer resins, styrene-ethylene-butadiene-styrene copolymer resins, silicone rubber resins, polyester-based elastomer resins, and polyamide-based elastomer resins on the produced non-woven fabric layer. As a specific example, the suede layer is performed by casting a polyurethane resin on the non-woven fabric layer and drying, and the drying step can be performed at 120°C to 150°C or 125°C to 145°C for 5 minutes to 60 minutes or 5 minutes to 30 minutes.

[0150] Also, after the suede layer is formed on the non-woven fabric layer, both sides of the surf pad, that is, the outer surfaces of the non-woven fabric layer and the suede layer, can be sanded. As a specific example, it can be performed by a method of processing the outer surfaces of the non-woven fabric layer and the suede layer with a sanding roller.

[0151] <Step (3) of manufacturing a polishing pad by bonding the top pad and the sub-pad> The method for manufacturing a polishing pad according to another embodiment includes step (3) of manufacturing a polishing pad by bonding the top pad and the sub-pad.

[0152] For example, the bonding of the top pad and the sub-pad can be performed using an adhesive layer. As a specific example, the sub-pad can be disposed below the top pad, and the top pad and the sub-pad can be bonded using a hot melt adhesive to manufacture a polishing pad.

[0153] The hot melt adhesive can be one or more selected from the group consisting of polyurethane-based resins, polyester-based resins, ethylene-vinyl acetate-based resins, polyamide-based resins, and polyolefin-based resins. As a specific example, the hot melt adhesive can be one or more selected from the group consisting of polyurethane-based resins and polyester-based resins.

[0154] Also, a double-sided tape is bonded to the lower part of the support layer, and when applied to a CMP apparatus, the release paper of the double-sided tape can be removed and attached to the platen for use.

[0155] [Method for manufacturing a semiconductor device] The method for manufacturing a semiconductor device according to another embodiment includes the step of polishing the surface of a semiconductor substrate using the polishing pad.

[0156] Specifically, the method for manufacturing the semiconductor device may include providing the polishing pad according to the above-described implementation example, and relatively rotating the polishing surface of the polishing layer and the surface of the semiconductor substrate in contact with each other to polish the surface of the semiconductor substrate.

[0157] FIG. 9 shows a semiconductor device manufacturing process using a polishing pad according to an implementation example. Referring to FIG. 9, after mounting the polishing pad 100 according to the implementation example on the platen 200, a semiconductor substrate 600 to be polished is disposed on the polishing pad 100. At this time, the surface to be polished of the semiconductor substrate 600 is in direct contact with the polishing surface of the polishing pad 100. For polishing, polishing slurry 400 may be sprayed onto the polishing pad via a nozzle. The flow rate of the polishing slurry 400 supplied via the nozzle is selected according to the purpose within the range of about 10 cm 3 / min to about 1000 cm 3 / min, and for example, may be about 50 cm 3 / min to about 500 cm 3 / min, but is not limited thereto.

[0158] Thereafter, the semiconductor substrate 600 and the polishing pad 100 may rotate relative to each other, and the surface of the semiconductor substrate 600 may be polished. At this time, the rotation direction of the semiconductor substrate 600 and the rotation direction of the polishing pad 100 may be the same direction or the opposite direction. The rotation speeds of the semiconductor substrate 600 and the polishing pad 100 are each selected according to the purpose within the range of about 10 rpm to about 500 rpm, and for example, may be about 30 rpm to about 200 rpm, but are not limited thereto.

[0159] The semiconductor substrate 600 may be pressed against the polishing surface of the polishing pad 100 with a predetermined load while being mounted on the polishing head 510, and then its surface may be polished. The load applied to the surface of the semiconductor substrate 600 and the polishing surface of the polishing pad 100 by the polishing head 510 is selected according to the purpose within the range of about 1 gf / cm 2 to about 1000 gf / cm 2 and for example, may be about 10 gf / cm 2~about 800 gf / cm 2 It may be, but is not limited thereto.

[0160] 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 may be a single-layer film in which an oxide region and a tungsten region are mixed in one layer. When the object to be polished has such film quality characteristics and at the same time the polishing pad has the characteristics according to the implementation example, the semiconductor element manufactured by the manufacturing method of the semiconductor element may minimize defects.

[0161] In one implementation example, the method for manufacturing a semiconductor element may further include supplying either one of the slurry for polishing an oxide film and the slurry for polishing a tungsten film, or sequentially supplying the slurry for polishing an oxide film and the slurry for polishing a tungsten film to the polishing surface in the step of polishing the object to be polished.

[0162] For example, when the semiconductor substrate to be polished includes an oxide film, the method for manufacturing a semiconductor element may include supplying the slurry for polishing an oxide film. When the semiconductor substrate includes a tungsten film, the method for manufacturing a semiconductor element may include supplying the slurry for polishing a tungsten film. When the semiconductor substrate includes a composite film of an oxide film and a tungsten film, the method for manufacturing a semiconductor element may include sequentially supplying the slurry for polishing an oxide film and the slurry for polishing a tungsten film to the polishing surface. At this time, the slurry for polishing an oxide film may be supplied first and then the slurry for polishing a tungsten film according to the process, or the slurry for polishing a tungsten film may be supplied first and then the slurry for polishing an oxide film may be supplied later.

[0163] In one implementation example, the method for manufacturing the semiconductor device may further include, in order to maintain the polishing surface of the polishing pad 100 in a state suitable for polishing, a step of processing the polishing surface of the polishing pad 100 by a conditioner 470 simultaneously with the polishing of the semiconductor substrate 600.

[0164] In the polishing pad according to the one implementation example, by adjusting the chlorine content of the polishing layer within a specific range, while maintaining excellent physical properties and performance of the polishing pad, the size of debris is reduced to minimize the occurrence of defects and scratches during the CMP process. Therefore, a semiconductor device of excellent quality can be efficiently manufactured using the polishing pad.

[0165] (Example) The above content will be further described in detail by the following examples. However, the following examples are only for illustrating the present invention, and the scope of the examples is not limited only to these.

[0166] [Manufacture of Polishing Pad] (Example 1) (1) Manufacture of Top Pad Toluene diisocyanate (TDI), dicyclohexylmethane diisocyanate (H12MDI), polytetramethylene ether glycol (PTMEG), and diethylene glycol (DEG) were charged into a four-necked flask and reacted at 80°C for 3 hours to prepare a urethane prepolymer with a terminal NCO group content (NCO%) of 8 wt% to 12 wt%.

[0167] A casting device equipped with tanks and input lines for respectively supplying raw materials such as the urethane prepolymer, curing agent, and inert gas was prepared. Specifically, the urethane prepolymer prepared in step (1), curing agent (4,4'-methylenebis(2-chloroaniline), MOCA), solid-phase foaming agent (average particle size: 20 μm), inert gas (N 2) and a silicone surfactant (Evonik) were filled into their respective tanks. At this time, 1.5 parts by weight of a solid foaming agent was added to 100 parts by weight of the urethane prepolymer, and the urethane prepolymer and the curing agent were added in an equivalent ratio of 1:1 and a total amount of 10 kg / min.

[0168] After that, while stirring, the raw materials were fed into the mixing head at a constant speed through each feeding line (rotation speed of the mixing head: about 5000 rpm). A mold (1000 mm × 1000 mm × 3 mm) was prepared and preheated at 80°C, and the stirred mixture was discharged into the mold for reaction to obtain a solidified cake-shaped molded body. Then, the upper and lower ends of the molded body were cut to manufacture a top pad. At this time, the top pad had a thickness of 2 mm, a hardness of 58.8 Shore D, a specific gravity of 0.79 g / cc, and an elongation rate of 111%.

[0169] (2) Manufacture of the sub-pad A polyester fiber non-woven fabric was impregnated with a polyurethane resin and dried at 140°C for 10 minutes to manufacture a non-woven fabric layer with a thickness of about 0.7 mm. A polyurethane resin was cast on the non-woven fabric layer and dried at 140°C for 10 minutes to form a suede layer with a thickness of about 0.8 mm, thereby manufacturing a sub-pad (total thickness: 1.53 mm) composed of a double structure of the non-woven fabric layer and the suede layer. Then, both sides of the sub-pad were sanded. Figure 1 shows an image of a scanning electron microscope (SEM) of the cross-section of the sub-pad of Example 1.

[0170] (3) Manufacture of the polishing pad After subjecting the top pad manufactured in the step (1) to surface milling and groove forming processes, the sub-pad manufactured in the step (2) was placed under the top pad, and the top pad and the sub-pad were bonded together using a hot melt adhesive to manufacture a polishing pad (total thickness: 3.55 mm). At this time, the pads were bonded so that the suede layer of the sub-pad was in contact with the top pad. Further, a double-sided tape (model name: 442JS, 3M) was attached to the lower part of the sub-pad so that it could adhere to the platen of the CMP apparatus.

[0171] (Comparative Example 1) (1) Manufacture of top pad A top pad was manufactured in the same manner as in Example 1.

[0172] (2) Manufacture of sub-pad A polyurethane resin was cast on a polyethylene terephthalate (PET) film and dried at 140 °C for 10 minutes to form a suede layer having a thickness of about 0.63 mm, thereby manufacturing a sub-pad having a suede single-layer structure. Then, the surface of the suede layer was sanded. Fig. 2 shows a scanning electron microscope (SEM) image of the cross-section of the sub-pad in Comparative Example 1.

[0173] (3) Manufacture of polishing pad A polishing pad (total thickness: 2.65 mm) was manufactured in the same manner as in Example 1.

[0174] (Comparative Example 2) (1) Manufacture of top pad A top pad was manufactured in the same manner as in Example 1.

[0175] (2) Manufacture of sub-pad A polyester fiber nonwoven fabric was impregnated with a polyurethane resin and dried at 140°C for 10 minutes to form a nonwoven fabric layer with a thickness of about 1.30 mm, thereby manufacturing a sub-pad having a single nonwoven fabric structure. Then, both surfaces of the nonwoven fabric layer were sanded. Figure 3 shows a scanning electron microscope (SEM) image of the cross-section of the sub-pad in Comparative Example 2.

[0176] (3) Manufacture of polishing pad A polishing pad (total thickness: 3.32 mm) was manufactured in the same manner as in Example 1.

[0177] <Physical properties of sub-pad> (Experimental Example 1: Hardness) The hardness of the sub-pads manufactured in Example 1, Comparative Example 1, and Comparative Example 2 was measured. Specifically, the sub-pads were cut into 5 cm in length and 5 cm in width, stored at 25°C for 12 hours, and then the Shore D hardness was measured using a hardness tester.

[0178] (Experimental Example 2: Compression ratio) The compression ratio of the sub-pads manufactured in Example 1, Comparative Example 1, and Comparative Example 2 was measured. Specifically, the sub-pads were cut into 5 cm in length and 5 cm in width, and using a Dial Thickness Gauge (129-E, manufactured by YASUDA), the thickness (A) measured after placing an 85 g weight for 30 seconds and the thickness (B) measured after additionally placing an 800 g weight (85 g weight + 800 g weight) for 3 minutes were measured, and the compression ratio was calculated according to the following Mathematical Formula 3. [Equation 3] Compression ratio (%) = [(A - B) / A] × 100

[0179] (Experimental Example 3: Density) The density of the sub-pads manufactured in Example 1, Comparative Example 1, and Comparative Example 2 was measured based on ASTM D1622.

[0180] (Experimental Example 4: Compression elastic modulus) For the sub-pads manufactured in Example 1, Comparative Example 1, and Comparative Example 2, the compression elastic modulus was measured. Specifically, the sub-pad was cut into 5 cm in length and 5 cm in width, and after placing an 85 g weight for 30 seconds using a Dial Thickness Gauge (129-E, manufactured by YASUDA), the measured thickness (A) and, after placing an additional 800 g weight (85 g weight + 800 g weight) for 3 minutes and then removing the 800 g weight and leaving it for 1 minute, the measured thickness (C) were measured, and the compression elastic modulus was calculated by the following Mathematical Formula 4. [Equation 4] Compression elastic modulus = [C / A] × 100

[0181] <Physical properties of polishing pad> (Experimental Example 5: Polishing rate) For the polishing pads of Example 1, Comparative Example 1, and Comparative Example 2, the polishing pad was fixed on the platen of the CMP apparatus, a silicon oxide film of a silicon wafer (diameter: 300 mm) was set downward, and a CMP process was performed to measure the polishing rate.

[0182] Specifically, the polishing load was adjusted to 4.0 psi, and while introducing a calcined ceria slurry / silica slurry onto the polishing pad at a rate of 250 mL / min, the platen was rotated at 150 rpm for 60 seconds to polish the silicon oxide film. After polishing, the silicon wafer was removed from the carrier, attached to a spin dryer, washed with purified water, and then dried with nitrogen for 15 seconds. The thickness difference of the silicon oxide film before and after polishing of the dried silicon wafer was measured using a spectroscopic interference thickness measuring instrument (SI-F80R, manufactured by Kyence), and the polishing rate was calculated by the following Mathematical Formula 1. [Equation 1] Polishing rate (Å / min) = Change in film thickness before and after polishing (Å) / Polishing time (min)

[0183] Further, in the polishing rate profile obtained by the polishing rate measurement, the gradient value at a distance of 85 mm to 95 mm from the center of the wafer was calculated. (Experimental Example 6: Polishing flatness) Regarding the polishing pads of Example 1, Comparative Example 1, and Comparative Example 2, the polishing pad was fixed on the platen of the CMP apparatus, and a silicon oxide film of a silicon wafer (diameter: 300 mm) was set below, and a CMP process was performed to measure the polishing flatness.

[0184] Specifically, after polishing by the same method as in Experimental Example 5, the film thickness inside the wafer surface at 98 locations was measured, and the polishing flatness (within wafer non uniformity, WIWNU) on the wafer surface was measured by the following Mathematical Formula 2. [Equation 2] Polishing flatness (%) = (standard deviation of polished thickness (Å) / average polishing thickness (Å)) × 100

[0185]

Table 1

[0186] As can be seen from Table 1 above, the polishing pad of Example 1 had a higher polishing rate at a point where the distance from the center of the wafer was 95 mm than at a point where the distance from the center of the wafer was 85 mm in the CMP process polishing rate profile for the silicon oxide film, and thus both the polishing rate and the polishing flatness were excellent.

[0187] More specifically, in Comparative Example 1 and Comparative Example 2 including a sub-pad composed of a single layer of a suede layer or a non-woven fabric layer as in the prior art, in the CMP process polishing rate profile for the silicon oxide film, the average gradient value between 85 mm and 95 mm from the center of the wafer is a negative number, whereas the polishing pad of Example 1 includes a double-structured sub-pad composed of a non-woven fabric layer and a suede layer. As a result, in the CMP process polishing rate profile for the silicon oxide film, the average gradient value between 85 mm and 95 mm from the center of the wafer is a positive number, and the tendency of the polishing rate profile characteristics is completely different. In particular, in Comparative Example 1 and Comparative Example 2, the gradient values are negative values and as large as about -30.948 and -20.311, whereas in Example 1, the gradient value is a positive value and about 7.3989. Compared with Comparative Examples 1 and 2 in which the polishing rate rapidly decreases at the polishing pad edge, the change is small and the polishing uniformity is excellent (see FIGS. 4 to 8).

[0188] In addition, the sub-pad of Example 1 has a lower density with respect to the thickness than the sub-pads of Comparative Example 1 and Comparative Example 2. Therefore, in the CMP process polishing rate profile, the polishing rate according to the distance from the center of the wafer is uniformly distributed and the polishing flatness is excellent.

Description of Reference Numerals

[0189] 100: Polishing Pad 200: Platen 300: Conditioner 400: Polishing Slurry 510: Polishing Head 520: Carrier 600: Semiconductor Substrate (Wafer)

Claims

1. A top pad that comes into contact with the wafer to perform polishing; a sub-pad located on one surface of the top pad, A polishing pad that satisfies the following formula 1: [Formula 1] RR ８５ <RR ９５ In the above formula 1, R.R. ８５ is the polishing rate (Å / min) at a point 85 mm away from the center of the wafer in the polishing rate profile of the CMP process for the silicon oxide film; R.R. ９５ is the polishing rate (Å / min) at a point 95 mm away from the center of the wafer in the polishing rate profile of the CMP process for the silicon oxide film.

2. 2. The polishing pad according to claim 1, wherein in a CMP process polishing rate profile for a silicon oxide film, an average gradient value between a distance of 85 mm and 95 mm from the center of the wafer is a positive number.

3. 2. The polishing pad according to claim 1, wherein in a polishing rate profile of a CMP process for a silicon oxide film, an average gradient value between a distance of 85 mm and 95 mm from the center of a wafer is 0.5 or more.

4. The polishing pad has a polishing flatness (WIWNU) of 10% or less for oxide; 2. The polishing pad according to claim 1, wherein the polishing rate difference (ΔRR) according to the following formula 2 is 200 Å / min or less: [Formula 2] ΔRR=RR ９５ -RR ８５ In the formula 2, R.R. ８５ is the polishing rate (Å / min) at a point 85 mm away from the center of the wafer in the polishing rate profile of the CMP process for the silicon oxide film; R.R. ９５ is the polishing rate (Å / min) at a point 95 mm away from the center of the wafer in the polishing rate profile of the CMP process for the silicon oxide film.

5. 2. The polishing pad of claim 1, wherein when a silicon oxide layer of a silicon wafer is polished with a ceria slurry using the polishing pad, the average polishing rate is 2100 Å / min to 3500 Å / min according to the following mathematical formula 1: [Equation 1] Average polishing rate (Å / min) = change in film thickness before and after polishing (Å) / polishing time (min).

6. the subpad includes a nonwoven layer and a suede layer; the suede layer is located on one side of the top pad; 2. The polishing pad according to claim 1, wherein the thickness ratio of the nonwoven fabric layer to the suede layer is 1:0.5-2.

7. The subpad comprises: A thickness of 0.5 mm to 2.5 mm; Hardness of 60 Shore D to 90 Shore D; A compression ratio of 5% to 15%; 0.25 g / cm ３ ~0.7g / cm ３ and the density of and a compressive elastic modulus of 70% to 90%; The top pad is Hardness of 50 Shore D to 65 Shore D; 0.6 g / cm ３ ~0.9g / cm ３ The specific gravity of 15N / mm ２ ~25N / mm ２ and a tensile strength of 2. The polishing pad of claim 1, having an elongation of 90% to 130%.

8. (1) producing a top pad using a composition for a top pad including a urethane-based prepolymer, a foaming agent, and a curing agent; (2) preparing a subpad including a nonwoven layer and a suede layer; (3) bonding the top pad and the subpad together to produce a polishing pad; The polishing pad satisfies the following formula 1. [Formula 1] RR ８５ <RR ９５ In the above formula 1, R.R. ８５ is the polishing rate (Å / min) at a point 85 mm away from the center of the wafer in the polishing rate profile of the CMP process for the silicon oxide film; R.R. ９５ is the polishing rate (Å / min) at a point 95 mm away from the center of the wafer in the polishing rate profile of the CMP process for the silicon oxide film.

9. The step (2) comprises: impregnating a nonwoven fabric with a resin to produce a nonwoven fabric layer; and forming a suede layer on one surface of the nonwoven fabric layer by casting a resin on the one surface of the nonwoven fabric layer.

10. 10. A method for manufacturing a semiconductor device, comprising the step of polishing a surface of a semiconductor substrate with the polishing pad of claim 1.

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