Polishing pad with reduced defect and method of preparing a semiconductor device using the same

Abstract

In the polishing pad according to a specific example, the particle size of the debris obtained during conditioning and the zeta potential of the debris solution are adjusted to a specific range. As a result, the occurrence of defects and scratches during the CMP process can be minimized, while the debris size is reduced, thereby maintaining the excellent physical properties and performance of the polishing pad.

Description

Polishing Pad for Reducing Defects and Method for Preparing Semiconductor Device Using the Same Specific examples relate to a polishing pad having reduced defects and scratches in a chemical mechanical planarization (CMP) method and a method for preparing a semiconductor device using the same. Background of the Invention In a method for manufacturing a semiconductor, chemical mechanical planarization (CMP) is a step in which a semiconductor substrate such as a wafer is fixed to a head and brought into contact with the surface of a polishing pad mounted on a platform, and the surface of the semiconductor substrate is chemically treated by supplying a slurry while relatively moving the platform and the head, thereby mechanically planarizing the irregularities on the surface of the semiconductor substrate. In this CMP method, the polishing pad is a basic member playing an important role. Generally, the polishing pad is made of a polyurethane resin and has grooves for large slurry flow and holes for supporting its fine flow on its surface. For the preparation of this polishing pad, a diisocyanate is reacted with a polyol to obtain a prepolymer, which is mixed with a curing agent and a foaming agent and then cured to obtain a polyurethane foam board. Thereafter, the upper and lower surfaces of the polyurethane foam board are sliced to a desired thickness to obtain an upper pad, grooves of a specific shape are formed on the surface of the upper pad using a tip or the like, and then, it is bonded to a polyurethane lower pad to prepare a polishing pad. The CMP method can be performed several times in the method for manufacturing a semiconductor device. A semiconductor device includes a plurality of layers, and each layer includes a complex and fine circuit pattern. In addition, in recent years, the individual chip size of semiconductor devices has been reduced, and the pattern of each layer has evolved into more complex and finer ones. In addition, in the method for manufacturing a semiconductor device, the purpose of the CMP method has been expanded, which is not only used for the purpose of planarizing circuit wiring, but also for applications such as separating circuit wiring and improving the wiring surface, and similar purposes. As a result, more complex and reliable CMP performance is required. During the CMP method using this polishing pad, debris is formed due to the frictional force between the polishing surface and the semiconductor substrate or when the polishing surface is cut by a diamond disk for conditioning. Prior Art Document (Patent Document 1) Korean Early Publication Patent Announcement No. 2016 - 0027075 Technical Problem During the CMP method using a polishing pad, debris is formed due to the frictional force between the polishing surface and the semiconductor substrate or when the polishing surface is cut by a diamond disk for conditioning. This debris causes defects and scratches on the polishing surface during the CMP method. In addition, research results conducted by the inventors of this case have found that the debris size obtained from the polishing pad and its ζ-potential characteristics affect the occurrence of defects; and when the above characteristics are adjusted to a certain range, it can minimize the occurrence of defects and scratches during the CMP process while maintaining the excellent physical properties and performance of the polishing pad. In addition, research results conducted by the inventors of this case show that when UV light is irradiated during the CMP process, a polishing pad with a reduced debris particle size can be achieved; and by irradiating UV light during the CMP process and using these characteristics of the polishing pad, the occurrence of defects and scratches in the semiconductor device can be minimized. Therefore, the objective of this specific example is related to a polishing pad with reduced defects and a method for preparing a semiconductor device using the same. Solution to the problem According to a specific example, a polishing pad including a polishing layer is provided, where the polishing layer includes a urethane-based prepolymer, a foaming agent, and a curing agent; when the polishing layer is conditioned for 10 minutes under the conditions of a platform speed of 93 rpm, a conditioner load of 9 pounds, a conditioner speed of 64 rpm, and a sweep of 19 times per minute, while supplying deionized water at 300 cubic centimeters (cc) per minute, the D50 particle size of the obtained debris is 50 microns or less at pH 5.5; and the ζ-potential of an aqueous solution containing a debris concentration of 0.01% by weight is -20 millivolts to 30 millivolts at pH 5.5. According to another specific example, a polishing pad including a polishing layer containing a polyurethane resin is provided, where when the polishing layer is conditioned under the conditions of a platform speed of 93 rpm, a conditioner load of 9 pounds, a conditioner speed of 64 rpm, and a sweep of 19 times per minute, while supplying cerium oxide slurry at 250 milliliters per minute, and then irradiated with UV light having a wavelength of 100 nanometers to 380 nanometers at an intensity of 1 kilowatt from a distance of 5 centimeters, the obtained debris satisfies the following relationship (1). D50 [0 minutes] > D50 [4 minutes]…(1) Here, D50 [0 minutes] is the D50 particle size of the debris obtained during the conditioning before UV light irradiation, and D50 [4 minutes] is the D50 particle size of the debris obtained 4 minutes after UV light irradiation after the conditioning. According to still another specific example, a method for preparing a semiconductor device is provided, which includes using the polishing pad to polish the surface of a semiconductor substrate. According to still another specific example, a method for preparing a semiconductor device is provided, which includes irradiating UV light having a wavelength of 100 nanometers to 380 nanometers to condition the polishing layer of the polishing pad when chemically and mechanically polishing a semiconductor substrate using the polishing pad. Advantageous Effects of the Invention In the polishing pad according to a specific example, the debris size and the ζ-potential characteristics obtained therefrom are adjusted to a specific range. As a result, the occurrence of defects and scratches can be minimized during the CMP process while maintaining the excellent physical properties and performance of the polishing pad. The polishing pad according to a specific example has the characteristic of reducing the debris particle size when irradiated with UV light during the CMP process. Therefore, by irradiating UV light during the CMP process, these characteristics of the polishing pad can minimize the occurrence of defects and scratches in the semiconductor device. In addition, since the polishing pad according to a specific example has excellent characteristics such as a polishing rate, the CMP performance and productivity can be improved when using the polishing pad to fabricate a semiconductor device. Detailed Description of Preferred Embodiments Hereafter, a plurality of specific examples and embodiments will be described in detail with reference to the drawings. In the following description of these specific examples, when it is determined that the description may make the subject matter of these specific examples rather unclear, the detailed description of known functions and configurations incorporated herein will be omitted. In addition, for illustrative purposes, the dimensions of individual elements in the accompanying drawings may be exaggeratedly depicted or omitted, and they may be different from the actual dimensions. In this specification, when a member is described as being formed on / under another member or being directly or indirectly formed, connected, or coupled to each other, it encompasses the case where these members are formed, connected, or coupled through another member directly or indirectly. In addition, it should be understood that the terminology criteria for above and below each member may vary depending on the direction of observing the object. In this specification, the terminology indicating individual members is used to distinguish them from each other and is not intended to limit the scope of the specific examples. In addition, in this patent specification, a singular representation is interpreted to equally encompass a plural quantity unless otherwise specifically specified in the context. Throughout this specification, the terms "first", "second", and their like are used to describe different members. However, these members should not be limited by these terms. These terms are used for the purpose of distinguishing one element from another. In this specification, the term "comprising" is intended to specifically specify particular features, regions, steps, methods, elements, and / or members. It does not exclude the presence or addition of any other features, regions, steps, methods, elements, and / or members unless specifically described to the contrary. The molecular weight of the compound or polymer described in this specification, for example, the number average molecular weight or the weight average molecular weight, is the relative mass based on the well-known carbon-12. Although its unit is not described, if necessary, it can be understood as the molar mass (grams / mole) of the same value. In the numerical ranges limited to the dimensions, physical properties, and similar values of the components described in this specification, when numerical ranges limited only by the upper limit and numerical ranges limited only by the lower limit are respectively exemplified, it should be understood that the numerical ranges combining these upper and lower limits are also included within the exemplary ranges of the present invention. Chemical mechanical polishing Semiconductor devices are prepared by chemical and mechanical polishing using a polishing pad. A method for preparing a semiconductor device according to a specific example includes using a polishing pad to polish the surface of the semiconductor substrate. In particular, the method for preparing a semiconductor device may include providing a polishing pad according to a specific example; and when they are in contact with each other, relatively rotating the polishing surface of the polishing layer and the surface of the semiconductor substrate to polish the surface of the semiconductor substrate. FIG. 1 illustrates a method for preparing a semiconductor device using a polishing pad according to a specific example. Referring to FIG. 1, once a polishing pad (100) according to a specific example has been attached to a platform (200), a semiconductor substrate (600) to be polished is disposed on the polishing pad (100). In this case, the surface of the semiconductor substrate (600) to be polished is in direct contact with the polishing surface of the polishing pad (100). The polishing slurry (450) can be sprayed onto the polishing pad via a nozzle for polishing. The flow rate of the polishing slurry (450) supplied via the nozzle can be selected within a range of about 10 cubic centimeters per minute to about 1,000 cubic centimeters per minute according to the purpose. For example, it can be about 50 cubic centimeters per minute to about 500 cubic centimeters per minute, but it is not limited thereto. Thereafter, the semiconductor substrate (600) and the polishing pad (100) are rotated relative to each other to polish 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) can be the same direction or the opposite direction. The rotation speed of each of the semiconductor substrate (600) and the polishing pad (100) can be selected within a range of about 10 rpm to about 500 rpm according to the purpose. For example, it can be about 30 rpm to about 200 rpm, but it is not limited thereto. The semiconductor substrate (600) mounted on the polishing head (510) is pressed against the polishing surface of the polishing pad (100) to be in contact therewith with a predetermined load, and then its surface can be polished. The load applied by the polishing head (510) to the polishing surface of the polishing pad (100) and the surface of the semiconductor substrate (600) can be selected within a range of about 1 gram-force per square centimeter to about 1,000 gram-force per square centimeter according to the purpose. For example, it can be about 10 gram-force per square centimeter to about 800 gram-force per square centimeter, but it is not limited thereto. In a specific example, the semiconductor substrate (600) to be polished may include an oxide layer, a tungsten layer, or a composite layer thereof. In particular, the semiconductor substrate (600) may include an oxide layer, a tungsten layer, or a composite layer of an oxide layer and a tungsten layer. The composite layer of the oxide layer and the tungsten layer may be a multilayer film, where the tungsten layer is laminated on one side of the oxide layer; or may be a single-layer film, where an oxide region and a tungsten region are mixed in the single layer. When the object to be polished has such a film material, and at the same time, the polishing pad has the characteristics according to the specific example, the semiconductor device manufactured according to the method of manufacturing a semiconductor device may have the minimum defects. In a specific example, the method of manufacturing a semiconductor device may further include supplying any one of a slurry for polishing an oxide layer and a slurry for polishing a tungsten layer in the step of polishing the object to be polished; or, subsequently, supplying the slurry for polishing the oxide layer and the slurry for polishing the tungsten layer to the polishing surface. For example, if the semiconductor substrate as the object to be polished includes an oxide layer, the method of manufacturing a semiconductor device may include supplying a slurry for polishing the oxide layer. If the semiconductor substrate includes a tungsten layer, the method of manufacturing a semiconductor device may include supplying a slurry for polishing the tungsten layer. If the semiconductor substrate includes a composite layer of an oxide layer and a tungsten layer, the method of manufacturing a semiconductor device may include successively supplying a slurry for polishing the oxide layer and a slurry for polishing the tungsten layer to the polishing surface. Here, depending on the method, first the slurry for polishing the oxide layer may be supplied, and then the slurry for polishing the tungsten layer may be supplied; or first the slurry for polishing the tungsten layer may be supplied, and then the slurry for polishing the oxide layer may be supplied. In a specific example, in order to maintain the polishing surface of the polishing pad (100) in a state suitable for polishing, the method of manufacturing a semiconductor device may further include treating the polishing surface of the polishing pad (100) with a conditioner (300) and simultaneously polishing the semiconductor substrate (600). In the polishing pad according to the specific example, the size and ζ-potential characteristics of the debris obtained from its polishing layer are adjusted to a specific range. As a result, the occurrence of defects and scratches during the CMP method can be minimized, while maintaining the excellent physical properties and performance of the polishing pad. Therefore, using this polishing pad can efficiently manufacture semiconductor devices of excellent quality. Polishing Pad The polishing pad according to the specific example includes a polishing layer. In particular, the polishing pad includes a polishing layer containing a polyurethane resin. In particular, the polishing pad includes a polishing layer and a support layer. In addition, an adhesive layer may be inserted between the polishing layer and the support layer. Figure 2 shows the occurrence of defects caused by debris during the method of manufacturing a semiconductor device. Referring to Figure 2, a defect (650) or scratch is formed on the surface of the semiconductor device by debris (150) originating from the polishing layer. According to a specific example, the size and ζ potential of the debris originating from the polishing layer can be adjusted to a specific range, thereby minimizing the occurrence of the defect or scratch. In a polishing pad according to a specific example, the debris obtained therefrom has a particle size within a specific range. Figure 3 shows a method of measuring the particle size of debris obtained from a polishing pad according to a specific example. Referring to Figure 3, a polishing pad is attached to the platform of a CMP polishing machine, the polishing layer is conditioned while supplying deionized water, and the debris formed after conditioning the polishing layer for 10 minutes is collected in the form of a solution mixed with deionized water. An aqueous nitric acid solution or an aqueous potassium hydroxide solution is used to adjust the pH of the aqueous solution of the debris, and then, a particle size analyzer is used to measure the particle size of the debris. In particular, the debris can be obtained during conditioning of the polishing layer of the polishing pad under the conditions of a platform speed of 93 rpm, a conditioner load of 9 pounds, a conditioner speed of 64 rpm, and a scan of 19 times per minute while supplying 300 cubic centimeters (cc) per minute of deionized water. The particle size of the debris can be the average particle size, i.e., the D50 particle size. For a specific embodiment, a diamond disk (e.g., a CI45 type disk from Saesol) having a pad cutting rate (PCR) of 80 micrometers per hour to 90 micrometers per hour can be used in the conditioner. According to a specific example, the D50 particle size of the debris obtained during conditioning of the polishing layer for 10 minutes is 50 micrometers or less at pH 5.5. In particular, when the polishing layer is conditioned for 10 minutes under the above conditions, the D50 particle size of the debris obtained can be 40 micrometers or less, 30 micrometers or less, 25 micrometers or less, 22 micrometers or less, 20 micrometers or less, 19 micrometers or less, 18 micrometers or less, or 17 micrometers or less, and 5 micrometers or more, 10 micrometers or more, or 15 micrometers or more at pH 5.5. More particularly, when the polishing layer is conditioned for 10 minutes under the above conditions, the D50 particle size of the debris obtained can be 10 micrometers to 50 micrometers, 10 micrometers to 40 micrometers, 10 micrometers to 30 micrometers, 10 micrometers to 25 micrometers, 10 micrometers to 22 micrometers, 10 micrometers to 21 micrometers, 10 micrometers to 20 micrometers, 10 micrometers to 19 micrometers, 10 micrometers to 18 micrometers, or 10 micrometers to 17 micrometers at pH 5.5. According to another specific example, the D50 particle size of the debris obtained during conditioning of the polishing layer for 10 minutes is 35 micrometers or less at pH 10. In particular, when the polishing layer is conditioned for 10 minutes under the above conditions, the D50 particle size of the obtained debris at pH 10 can be 35 microns or less, 30 microns or less, 25 microns or less, 24 microns or less, 23 microns or less, 22.3 microns or less, 22 microns or less, or 21 microns or less, and 5 microns or greater, 10 microns or greater, 15 microns or greater, or 20 microns or greater. More particularly, when the polishing layer is conditioned for 10 minutes under the above conditions, the D50 particle size of the obtained debris at pH 10 can be 15 microns to 35 microns, 15 microns to 30 microns, 15 microns to 25 microns, 15 microns to 24 microns, 15 microns to 23 microns, 15 microns to 22.3 microns, 15 microns to 22 microns, or 15 microns to 21 microns. According to a specific embodiment, the D50 particle size of the debris obtained during conditioning of the polishing layer can be 25 microns or less at pH 5.5 and 22.3 microns or less at pH 10. Within the above preferred ranges, the occurrence of defects and scratches during the CMP process can be minimized while maintaining the excellent physical properties and performance of the polishing pad. In addition, in a polishing pad according to an embodiment, the aqueous solution of the debris obtained therefrom can have a ζ potential within a specific range. FIG. 4 shows a method for measuring the ζ potential of an aqueous solution of debris obtained from a polishing pad according to an embodiment. Referring to FIG. 4, a polishing pad is attached to the platform of a CMP polishing machine, the polishing layer is conditioned while supplying deionized water, and after 10 minutes of conditioning, the debris formed by the polishing layer is collected in the form of a solution mixed with deionized water. To ensure the particle stability in the aqueous solution of the debris, it is stored at room temperature for 24 hours to precipitate particles having a particle diameter of 20 microns or greater. Then, the upper layer liquid located within 10 mm from the top surface of the solution is taken as a sample. Thereafter, the pH of the sample is adjusted using an aqueous nitric acid solution or an aqueous potassium hydroxide solution, and then, the ζ potential of the sample is measured using a Zetasizer. The sample can contain 0.01 wt% of debris. As an example, when the polishing layer is conditioned for 10 minutes under the above conditions, the ζ potential of the obtained aqueous solution containing 0.01 wt% of debris can be -20 mV or greater, -15 mV or greater, -10 mV or greater, -5 mV or greater, 0 mV or greater, 5 mV or greater, or 10 mV or greater at pH 5.5, and 50 mV or less, 40 mV or less, 30 mV or less, 20 mV or less, 15 mV or less, or 10 mV or less. According to a specific example, when the polishing layer is conditioned for 10 minutes under the above conditions, the ζ potential of the obtained aqueous solution containing 0.01% by weight of debris is -20 mV to 30 mV at pH 5.5. In particular, when the polishing layer is conditioned for 10 minutes under the above conditions, the ζ potential of the obtained aqueous solution containing 0.01% by weight of debris can be -15 mV to 25 mV, -10 mV to 25 mV, -10 mV to 20 mV, -10 mV to 15 mV, -5 mV to 30 mV, or 0 mV to 30 mV at pH 5.5. More particularly, the ζ potential of the aqueous solution of the debris can be positive (+). Within the above preferred range, the ζ potential of the debris is similar to that of the polishing particles (e.g., cerium dioxide particles) in the CMP polishing composition (slurry). Therefore, the occurrence of defects can be further reduced. In particular, the ζ potential is a quantitative representation of the size of the repulsion and attraction between particles caused by positive and negative ion particles in the suspension. If the ζ potentials of the debris and the polishing particles are similar, the repulsion between the particles increases, which prevents their aggregation. Therefore, the occurrence of defects and scratches can be reduced by reducing the particle size in the composition. Regarding another embodiment, when the polishing layer is conditioned for 10 minutes under the above conditions, the ζ potential of the obtained aqueous solution containing 0.01% by weight of debris can be -50 mV or greater, -45 mV or greater, -40 mV or greater, -35 mV or greater, or -30 mV or greater, and 30 mV or less, 20 mV or less, 10 mV or less, 0 mV or less, -10 mV or less, or -20 mV or less at pH 10. In particular, when the polishing layer is conditioned for 10 minutes under the above conditions, the ζ potential of the obtained aqueous solution containing 0.01% by weight of debris can be -50 mV to -10 mV at pH 10. More particularly, when the polishing layer is conditioned for 10 minutes under the above conditions, the ζ potential of the obtained aqueous solution containing 0.01% by weight of debris can be -50 mV to -15 mV, -50 mV to -20 mV, -50 mV to -25 mV, -40 mV to -10 mV, or -30 mV to -10 mV at pH 10. In addition, because the polishing pad has a certain relationship between the particle size of the debris and the ζ potential according to the pH conditions, the above effect can be further enhanced. According to specific examples, the value of the following equation (1) can be from -20 μm / mV to 30 μm / mV. In a specific example, it can be from -10 μm / mV to 20 μm / mV. D50 [5.5] / Zp[5.5]…(1) Herein, D50 [5.5] is the D50 particle size (μm) of the debris obtained during the conditioning of the polishing layer at pH 5.5, and Zp[5.5] is the ζ potential (mV) of an aqueous solution containing 0.01 wt% of the debris obtained during the conditioning of the polishing layer at pH 5.5. For example, the value of the equation (1) can be -20 μm / mV or greater, -10 μm / mV or greater, -5 μm / mV or greater, or 0 μm / mV or greater, and 30 μm / mV or less, 20 μm / mV or less, 15 μm / mV or less, 10 μm / mV or less, or 5 μm / mV or less. In particular, the value of the equation (1) can be from -10 μm / mV to 15 μm / mV, from -5 μm / mV to 20 μm / mV, from -5 μm / mV to 15 μm / mV, from 0 μm / mV to 15 μm / mV, from -5 μm / mV to 10 μm / mV, from 0 μm / mV to 10 μm / mV, from -5 μm / mV to 5 μm / mV, or from 0 μm / mV to 5 μm / mV. According to another specific example, the value of the following equation (2) can be from 60% to 120%. In a specific example, it can be from 70% to 110%. (D50 [5.5] / D50

[10] )×100…(2) Herein, D50 [5.5] is the D50 particle size (μm) of the debris obtained during the conditioning of the polishing layer at pH 5.5, and D50

[10] is the D50 particle size (μm) of the debris obtained during the conditioning of the polishing layer at pH 10. For example, the value of the equation (2) can be 60% or more, 70% or more, or 75% or more, and 120% or less, 110% or less, 105% or less, 100% or less, 95% or less, 90% or less, 85% or less, or 80% or less. In particular, the value of the equation (2) can be from 70% to 105%, from 70% to 100%, from 70% to 95%, from 70% to 90%, from 70% to 85%, or from 75% to 85%. According to another specific example, the value of the following equation (3) can be from 25 mV to 65 mV. In a specific example, it can be from 35.5 mV to 60 mV. Zp[5.5]-Zp

[10] …(3) Here, Zp[5.5] is the ζ potential (millivolts) of an aqueous solution containing 0.01 wt% debris obtained during the conditioning of the polishing layer at pH 5.5, and Zp

[10] is the ζ potential (millivolts) of an aqueous solution containing 0.01 wt% debris obtained during the conditioning of the polishing layer at pH 10. For example, the value of Equation (3) can be 25 millivolts or greater, 35.5 millivolts or greater, or 36 millivolts or greater, and 65 millivolts or less, 60 millivolts or less, 55 millivolts or less, 50 millivolts or less, or 45 millivolts or less. In particular, the value of Equation (3) can be from 35.5 millivolts to 55 millivolts, from 35.5 millivolts to 50 millivolts, from 35.5 millivolts to 45 millivolts, from 35.5 millivolts to 40 millivolts, from 36 millivolts to 60 millivolts, from 36 millivolts to 50 millivolts, from 36 millivolts to 45 millivolts, or from 36 millivolts to 40 millivolts. In addition, the polishing pad according to the specific examples has excellent performance and overall physical properties. For example, when the silicon oxide layer of a silicon wafer is polished using the polishing pad with cerium dioxide slurry, the polishing rate (removal rate) can be 2,000 Å / min or more, 2,200 Å / min or more, 2,300 Å / min or more, or 2,400 Å / min or more, and 3,000 Å / min or less, 2,800 Å / min or less, 2,600 Å / min or less, or 2,500 Å / min or less. Regarding a specific embodiment, when the silicon oxide layer of a silicon wafer is polished using the polishing pad with cerium dioxide slurry, the polishing rate according to the following Mathematical Equation 1 can be from 2,200 Å / min to 2,600 Å / min. [Mathematical Equation 1] Polishing rate (Å / min) = Thickness difference before and after polishing (Å) / Polishing time (minutes) In particular, the polishing rate can be the polishing rate of a silicon wafer with a diameter of 300 mm on which silicon oxide has been deposited. In addition, the polishing rate can be measured under a polishing load of 4.0 psi (pounds per square inch), while the polishing pad is rotating at a speed of 150 rpm, the calcined cerium dioxide slurry is supplied to the polishing pad at a rate of 250 ml / min, and the platform is rotating at a speed of 150 rpm for 60 seconds. The temperature conditions when measuring the polishing rate are not particularly limited, however, it can be, for example, room temperature conditions. In addition, the pad cutting rate of the polishing layer can be from 30 μm / hour to 60 μm / hour, from 30 μm / hour to 50 μm / hour, from 40 μm / hour to 60 μm / hour, or from 40 μm / hour to 50 μm / hour. The thickness of the polishing pad can be 0.8 mm to 5.0 mm, 1.0 mm to 4.0 mm, 1.0 mm to 3.0 mm, 1.5 mm to 2.5 mm, 1.7 mm to 2.3 mm, or 2.0 mm to 2.1 mm. Within the above ranges, the basic physical properties of the polishing pad can be fully exhibited while minimizing the change in particle size between the upper and lower parts. When irradiated with UV light, the characteristics of the polishing pad According to a specific example, the polishing pad has the characteristic of a reduced debris particle size when irradiated with UV light during the CMP process. Therefore, by irradiating with UV light during the CMP process and using these characteristics of the polishing pad, the occurrence of defects and scratches in the semiconductor device can be minimized. FIGS. 5 and 6 each show the change in the debris particle size obtained from the polishing pads according to the examples and comparative examples with respect to the UV irradiation time. Referring to FIG. 5, for the polishing pad according to a specific example, as the time of irradiation with UV light elapses, the particle size of the debris decreases, and it is measured to be the smallest at 2 to 4 minutes. After that, when the irradiation time of UV light further elapses to 6 to 8 minutes, it shows a tendency to increase slightly. Overall, as the time of irradiation with UV light elapses, the particle size of the debris tends to decrease. On the other hand, the polishing pad according to the comparative example shows that as the time of irradiation with UV light elapses, the tendency of the debris particle size generally increases. When 10 minutes have elapsed, it has been measured to increase almost twofold compared to the initial stage. When irradiated with UV, molecular bonds are broken and at the same time particle aggregation occurs. It has been hypothesized that the particle size of the debris tends to increase or decrease depending on which of these dominates. This tendency can be revealed depending on the composition and characteristics of the polishing pad. To measure the particle size of the debris, a polishing pad is attached to the platform of a CMP polishing machine, the polishing layer is conditioned while supplying CMP slurry, and after conditioning for 10 minutes, the debris formed by the polishing layer is collected in the form of a solution mixed with the CMP slurry. After that, the debris solution is irradiated with UV light having a wavelength of 100 nm to 380 nm at an intensity of 1 kW from an appropriate distance, and then, a particle size analyzer is used to measure the particle size of the debris. In particular, the debris can be obtained during conditioning of the polishing layer of the polishing pad under the conditions of a platform speed of 93 rpm, a conditioner load of 9 pounds, a conditioner speed of 64 rpm, and 19 scans per minute, while supplying cerium dioxide slurry at 250 ml / min. The particle size of the debris can be the average particle size, i.e., the D50 particle size. For a specific embodiment, a diamond disk having a pad wear rate (PWR) of 80 to 90 microns per hour (e.g., a CI45 type disk from Saesol) can be used in the conditioner. In a polishing pad according to a specific example, when the polishing layer is conditioned under the conditions of a platform speed of 93 rpm, a conditioner load of 9 pounds, a conditioner speed of 64 rpm, and 19 scans per minute, while supplying cerium dioxide slurry at 250 ml / min, and then irradiated with UV light having a wavelength of 100 nm to 380 nm at an intensity of 1 kW from a distance of 5 cm, the debris obtained satisfies the following relationship (1). D50 [0 minutes] > D50 [4 minutes] …(1) Here, D50 [0 minutes] is the D50 particle size of the debris obtained during the conditioning before UV light irradiation, and D50 [4 minutes] is the D50 particle size of the debris obtained when irradiated with UV light for 4 minutes after the conditioning. In particular, in relationship (1), the difference between D50 [0 minutes] and D50 [4 minutes] can be a certain degree or more. For example, when ΔD50 [0 - 4 minutes] calculated according to the following equation is 5 microns or more, it is more excellent in terms of the effect of reducing debris due to UV irradiation. ΔD50 [0 - 4 minutes] = D50 [0 minutes] - D50 [4 minutes] Here, D50 [0 minutes] is the D50 particle size of the debris obtained during the conditioning before UV light irradiation, and D50 [4 minutes] is the D50 particle size of the debris obtained when irradiated with UV light for 4 minutes after the conditioning. In particular, ΔD50 [0 - 4 minutes] can be 5 microns or more, 7 microns or more, 10 microns or more, or 13 microns or more, and 35 microns or less, 30 microns or less, 25 microns or less, or 20 microns or less. More particularly, ΔD50 [0 - 4 minutes] can be 5 microns to 30 microns, 5 microns to 25 microns, 10 microns to 30 microns, or 10 microns to 25 microns. For example, D50 [4 minutes] can be 40 microns or less, 35 microns or less, 30 microns or less, 27 microns or less, or 25 microns or less, and 5 microns or more, 10 microns or more, 15 microns or more, or 20 microns or more. For a specific embodiment, D50 [4 minutes] can be 30 microns or less. For a more specific embodiment, D50 [4 minutes] can be from 5 microns to 30 microns. Within the above preferred range, the occurrence of defects due to debris in the semiconductor device can be further minimized. D50 [0 minutes] can be, for example, 20 microns or more, 25 microns or more, 30 microns or more, or 35 microns or more, and 65 microns or less, 60 microns or less, 55 microns or less, or 45 microns or less. In particular, D50 [0 minutes] can be from 20 microns to 60 microns, or from 30 microns to 50 microns. More particularly, D50 [0 minutes] can be 35 microns or more, and D50 [4 minutes] can be 30 microns or less. According to another specific example, the polishing pad can satisfy the following relationship 2: D50 [4 minutes] < D50 [8 minutes] …(2) Here, D50 [4 minutes] is the D50 particle size of the debris obtained after conditioning after irradiating with UV light for 4 minutes, and D50 [8 minutes] is the D50 particle size of the debris obtained after conditioning after irradiating with UV light for 8 minutes. Here, in relationship (2), the difference between D50 [8 minutes] and D50 [4 minutes] can be a certain degree or less. For example, when ΔD50 [8 - 4 minutes] calculated according to the following equation is 20 microns or less, it is more excellent for maintaining the trend of reducing the debris particle size due to UV irradiation. ΔD50 [8 - 4 minutes] = D50 [8 minutes] - D50 [4 minutes] Here, D50 [4 minutes] is the D50 particle size of the debris obtained after conditioning after irradiating with UV light for 4 minutes, and D50 [8 minutes] is the D50 particle size of the debris obtained after conditioning after irradiating with UV light for 8 minutes. In particular, ΔD50 [8 - 4 minutes] can be 20 microns or less, 15 microns or less, or 10 microns or less, and 3 microns or more, or 5 microns or more. More particularly, ΔD50 [8 - 4 minutes] can be from 3 microns to 20 microns, from 3 microns to 15 microns, from 3 microns to 10 microns, or from 5 microns to 15 microns. D50 [8 minutes] can be, for example, 55 microns or less, 50 microns or less, 45 microns or less, or 40 microns or less, and 15 microns or more, 20 microns or more, 25 microns or more, or 30 microns or more. In particular, D50 [8 minutes] can be 20 microns to 50 microns, or 25 microns to 40 microns. More particularly, D50 [8 minutes] can be 30 microns to 40 microns, and D50 [4 minutes] can be 20 microns to 30 microns. According to another specific example, the polishing pad can satisfy the following relationship 3: (D90 [0 minute] - D10 [0 minute]) > (D90 [4 minutes] - D10 [4 minutes])…(3) Here, D10 [0 minute] and D90 [0 minute] are the D10 and D90 particle sizes of the debris obtained before conditioning by UV light irradiation, and D10 [4 minutes] and D90 [4 minutes] are the D10 and D90 particle sizes of the debris obtained after the conditioning after 4 minutes of UV light irradiation. In relationship (3), the difference between (D90 [0 minute] - D10 [0 minute]) and (D90 [4 minutes] - D10 [4 minutes]) can be a certain degree or more. For example, when ΔD90-10 [4 minutes] calculated according to the following equation is 50 microns or more, in terms of the effect of reducing the debris particle size due to UV irradiation, this is better. ΔD90-10 [4 minutes] = (D90 [0 minute] - D10 [0 minute]) - (D90 [4 minutes] - D10 [4 minutes]) Here, D10 [0 minute] and D90 [0 minute] are the D10 and D90 particle sizes of the debris obtained before conditioning by UV light irradiation, and D10 [4 minutes] and D90 [4 minutes] are the D10 and D90 particle sizes of the debris obtained after the conditioning after 4 minutes of UV light irradiation. In particular, ΔD90-10 [4 minutes] can be 50 microns or more, 70 microns or more, 100 microns or more, or 120 microns or more, and 300 microns or less, 250 microns or less, 200 microns or less, or 150 microns or less. More particularly, ΔD90-10 [4 minutes] can be 50 microns to 300 microns, 100 microns to 200 microns, or 100 microns to 150 microns. In relation (3), (D90 [0 minutes] - D10 [0 minutes]) can be 80 microns or greater, 100 microns or greater, 120 microns or greater, or 140 microns or greater, and 220 microns or less, 200 microns or less, or 180 microns or less. In particular, (D90 [0 minutes] - D10 [0 minutes]) can be 100 microns to 200 microns, or 140 microns to 180 microns. In relation (3), (D90 [4 minutes] - D10 [4 minutes]) can be 10 microns or greater, 20 microns or greater, or 30 microns or greater, and 80 microns or less, 70 microns or less, 60 microns or less, or 50 microns or less. In particular, (D90 [4 minutes] - D10 [4 minutes]) can be 20 microns to 60 microns, or 30 microns to 50 microns. Furthermore, the polishing pad according to the specific example is excellent in overall physical properties. For example, when the silicon dioxide layer of a silicon wafer is polished using a polishing pad with cerium dioxide slurry, and at the same time irradiated with UV light having a wavelength of 100 nm to 380 nm at an intensity of 1 kW from a distance of 5 cm, the polishing rate (removal rate) can be 1,700 Å / minute or more, 1,800 Å / minute or more, 1,900 Å / minute or more, or 2,000 Å / minute or more, and 2,600 Å / minute or less, 2,400 Å / minute or less, 2,300 Å / minute or less, 2,200 Å / minute or less, or 2,100 Å / minute or less. Regarding a specific embodiment, when the silicon dioxide layer of a silicon wafer is polished using a polishing pad with cerium dioxide slurry, and at the same time irradiated with UV light having a wavelength of 100 nm to 380 nm at an intensity of 1 kW from a distance of 5 cm, the polishing rate according to the following mathematical equation 1 can be 1,800 Å / minute to 2,200 Å / minute. [Mathematical equation 1] Polishing rate (Å / minute) = Thickness difference before and after polishing (Å) / Polishing time (minutes) In particular, the polishing rate can be the polishing rate of a silicon wafer having a diameter of 300 mm on which silicon dioxide has been deposited. Furthermore, the polishing rate can be measured under a polishing load of 4.0 psi, while the polishing pad is rotating at a speed of 150 rpm, the calcined cerium dioxide slurry is supplied to the polishing pad at a rate of 250 ml / minute, and the platform is rotating at a speed of 150 rpm for 60 seconds. The temperature conditions when measuring the polishing rate are not particularly limited, however, it can be, for example, room temperature conditions. In addition, when the polishing pad is tested at a conditioning pressure of 6 pounds force and a rotational speed of 100 to 110 rpm, the pad wear rate (PWR) can be 15 to 40 microns per hour. In particular, the pad wear rate of the polishing layer can be 15 to 35 microns per hour, 15 to 30 microns per hour, 20 to 40 microns per hour, or 15 to 22 microns per hour. The thickness of the polishing pad can be 0.8 mm to 5.0 mm, 1.0 mm to 4.0 mm, 1.0 mm to 3.0 mm, 1.5 mm to 2.5 mm, 1.7 mm to 2.3 mm, or 2.0 mm to 2.1 mm. Within the above ranges, the basic physical properties of the polishing pad can be fully exhibited while the particle size variation between the upper and lower parts is minimized. Polishing layer The polishing layer provides a polishing surface that contacts a semiconductor substrate in a CMP process and forms the top pad in the polishing pad. The polishing layer according to a specific example includes a polyurethane resin. The polishing layer includes a urethane-based prepolymer, a foaming agent, and a curing agent. In particular, the polyurethane resin can be formed from a composition including a urethane-based prepolymer, a foaming agent, and a curing agent. In particular, the polishing layer includes a polyurethane-based resin, which is a reaction product of a urethane-based prepolymer, a foaming agent, and a curing agent, that is, a cured product of a composition mixing these components. More particularly, it includes a porous polyurethane-based resin. In addition, the polishing layer can include a plurality of holes formed from the foaming agent. The polishing layer can have a thickness such as 0.8 mm or thicker, 1 mm or thicker, 1.2 mm or thicker, or 1.5 mm or thicker, and 5 mm or thinner, 3 mm or thinner, 2.5 mm or thinner, or 2 mm or thinner. For specific embodiments, the thickness of the polishing layer can be 0.8 mm to 5 mm, or 1.5 mm to 3 mm. The polishing layer can have a specific gravity such as 0.6 g / cm³ or greater, 0.7 g / cm³ or greater, or 0.75 g / cm³ or greater, and 0.9 g / cm³ or smaller, 0.85 g / cm³ or smaller, or 0.8 g / cm³ or smaller. For specific embodiments, the specific gravity of the polishing layer can be 0.6 g / cm³ to 0.9 g / cm³, or 0.7 g / cm³ to 0.9 g / cm³. The polishing layer may have a hardness of, for example, 30 Shore D or greater, 40 Shore D or greater, or 50 Shore D or greater, and 80 Shore D or less, 70 Shore D or less, 65 Shore D or less, or 60 Shore D or less. For specific embodiments, the hardness of the polishing layer may be 30 Shore D to 80 Shore D, or 50 Shore D to 65 Shore D. The polishing layer may have a tensile strength of, for example, 5 N / mm² or greater, 10 N / mm² or greater, or 15 N / mm² or greater, and 30 N / mm² or less, 25 N / mm² or less, or 20 N / mm² or less. For specific embodiments, the tensile strength of the polishing layer may be 5 N / mm² to 30 N / mm², or 15 N / mm² to 25 N / mm². The polishing layer may have an elongation of, for example, 50% or more, 70% or more, 90% or more, 106% or more, or 120% or more, and 300% or less, 250% or less, 200% or less, or 150% or less. For specific embodiments, the elongation of the polishing layer may be 50% to 300%, or 90% to 130%. The elongation may be the elongation at break. For specific embodiments, the polishing layer may have a hardness of 50 Shore D to 65 Shore D, a tensile strength of 15 N / mm² to 25 N / mm², and an elongation of 90% to 130%. The holes are present as being dispersed in the polishing layer. The average diameter of the holes 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. In addition, the total area of the holes may be 30% to 60%, 35% to 50%, or 35% to 43%, based on the total area of the polishing layer. In addition, the total volume of the holes may be 30 to 70%, or 40 to 60%, based on the total volume of the polishing layer. The polishing layer may have grooves on its surface for mechanical polishing. The grooves may have a depth, a width, and a spacing as desired for mechanical polishing, which are not particularly limited. In a polishing pad according to a specific example, the polishing layer has a chlorine (Cl) content of 10,000 ppm or less when analyzed according to the IEC 62321-3-2 standard. In particular, the chlorine content can be obtained by measuring the chlorine content in the sample according to IEC 62321-3-2, where IEC 62321-3-2 is an international standard for measuring specific substances in polymers by combustion ion chromatography (C-IC). In this case, the sample for measuring the chlorine content can 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. The IEC 62321-3-2 standard is a test method developed in response to halogen use regulations for screening halogen components. Compared with conventional halogen analysis methods (e.g., oxygen bomb-IC and oxygen flask-IC), this test method has excellent precision / accuracy, reproducibility, and automation. Therefore, the reliability of the test results is excellent. In the method for measuring the chlorine content in a polishing pad according to a specific example, a sample containing an organic chlorine (C-Cl) component is charged into a combustion tube and burned by an electric furnace. The resulting material is transferred to an adsorption tube to measure the amount of chloride ions (Cl - ) by ion chromatography. In the polishing pad according to a specific example, the chlorine content in the polishing layer can be 10,000 ppm or less, 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. When the chlorine content is adjusted to the above range, the debris size may be reduced while maintaining the excellent physical properties and performance of the polishing pad, thereby minimizing the occurrence of defects and scratches during the CMP process. In addition, the lower limit of the chlorine content range in the polishing layer according to a specific example can 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 the above preferred range, the surface area and adsorption force can be adjusted as the debris aggregates into an appropriate size to facilitate adsorption and desorption in the wafer and pad; and the electro-attraction / repulsion force can be adjusted to make the polishing performance more suitable. For specific embodiments, when analyzed according to the IEC 62321-3-2 standard, the polishing layer has a chlorine (Cl) content of 10 ppm to 1,000 ppm. For another specific embodiment, when analyzed according to the IEC 62321-3-2 standard, the polishing layer has a chlorine (Cl) content of 10 ppm to 100 ppm, 20 ppm to 80 ppm, or 20 ppm to 50 ppm. For another specific embodiment, when analyzed according to the IEC 62321-3-2 standard, the polishing layer has a chlorine (Cl) content of 50 ppm to 10,000 ppm or 100 ppm to 10,000 ppm. When the chlorine content of the polishing pad according to a specific example is adjusted to a certain range as described above, it can reduce the size of debris, thereby minimizing the occurrence of defects and scratches during the CMP process. Urethane-based prepolymer The polishing pad according to a specific example comprises a urethane-based prepolymer. A prepolymer generally refers to a polymer having a relatively low molecular weight, wherein the degree of polymerization is adjusted to an intermediate degree to facilitate molding a molded article during the process of manufacturing a cured product. The prepolymer can be molded into the final cured product by itself or after reacting with another polymerizable compound. In a specific example, the urethane-based prepolymer can be prepared by reacting an isocyanate compound with a polyol. The isocyanate compound used in the preparation of the urethane-based prepolymer can be a compound selected from the group consisting of: aromatic diisocyanates, aliphatic diisocyanates, cycloaliphatic diisocyanates or combinations thereof. The isocyanate compound can include, for example, a compound selected from the group consisting of: toluene-2,4-diisocyanate (2,4-TDI), toluene-2,6-diisocyanate (2,6-TDI), 1,5-naphthalene diisocyanate, p-phenylene diisocyanate, diisocyanate toluidine ester, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate and combinations thereof. The polyol is a compound containing at least two or more hydroxyl groups (-OH) per molecule. For example, it can include a compound selected from the group consisting of: polyether polyols, polyester polyols, polycarbonate polyols, polycaprolactone polyols and combinations thereof. The polyol may include, for example, compounds selected from the group consisting of: polytetramethylene ether glycol, polypropylene glycol, ethylene glycol, 1,2 - propylene glycol, 1,3 - propylene glycol, 1,2 - butylene glycol, 1,3 - butylene glycol, 2 - methyl - 1,3 - propylene glycol, 1,4 - butylene glycol, neopentyl glycol, 1,5 - pentanediol, 3 - methyl - 1,5 - pentanediol, 1,6 - hexanediol, diethylene glycol, dipropylene glycol, tripropylene glycol, and combinations thereof. The polyol may have a weight - average molecular weight (Mw) of 100 to 3,000. For example, the polyol may have a weight - average molecular weight (Mw) of 100 to 3,000, for example, 100 to 2,000, for example, 100 to 1,800. In a specific example, the polyol may include a low - molecular - weight polyol having a weight - average molecular weight (Mw) of 100 to 300 and a high - molecular - weight polyol having a weight - average molecular weight (Mw) of 300 to 1,800. The urethane - based prepolymer may have a weight - average molecular weight (Mw) of 500 to 3,000. For example, the urethane - based prepolymer may have a weight - average molecular weight (Mw) of 1,000 to 2,000, or for example, 1,000 to 1,500. In a specific example, the isocyanate compound used for the preparation of the urethane - based prepolymer may include an aromatic diisocyanate compound, and the aromatic diisocyanate compound may, for example, include 2,4 - tolylene diisocyanate (2,4 - TDI) and 2,6 - tolylene diisocyanate (2,6 - TDI). The polyol compound used for the preparation of the urethane - based prepolymer may include polytetramethylene ether glycol (PTMEG) and diethylene glycol (DEG). In another specific example, the isocyanate compound used for the preparation of the urethane - based prepolymer may include an aromatic diisocyanate compound and a cycloaliphatic diisocyanate compound. For example, the aromatic diisocyanate compound includes 2,4 - tolylene diisocyanate (2,4 - TDI) and 2,6 - tolylene diisocyanate (2,6 - TDI), and the cycloaliphatic diisocyanate compound includes dicyclohexylmethane diisocyanate (H12MDI). The polyol compound used for the preparation of the urethane - based prepolymer may include polytetramethylene ether glycol (PTMEG) and diethylene glycol (DEG). The urethane-based prepolymer may have an isocyanate terminal group content (NCO%) of 5 wt% or more, 8 wt% or more, or 10 wt% or more, and 13 wt% or less, 12 wt% or less, or 11 wt% or less. For a specific embodiment, the urethane-based prepolymer may have an isocyanate terminal group content (NCO%) of 10 wt% to 11 wt%. The isocyanate terminal group content (NCO%) of the urethane-based prepolymer can be designed by widely adjusting the following: the type and content of the isocyanate compound and polyol compound used for the preparation of the urethane-based prepolymer; the process conditions in the method for preparing the urethane-based prepolymer, such as temperature, pressure, and time; and the type and content of the additives used in the preparation of the urethane-based prepolymer. When the isocyanate terminal group content (NCO%) of the urethane-based prepolymer satisfies the above range, from the viewpoint of the use and purpose of the final polishing pad, the reaction rate, reaction time, and final cured structure in the subsequent reaction between the urethane-based prepolymer and the curing agent can all be adjusted in a manner suitable for the polishing performance. In a specific example, the urethane-based prepolymer may have an isocyanate terminal group content (NCO%) of 8 wt% to 10 wt%, for example, 8 wt% to 9.4 wt%. If the NCO% of the urethane-based prepolymer is less than the above range, it may be possible to achieve the electrical properties based on the chemical cured structure in the polishing pad, making it impossible to achieve the desired polishing performance in terms of polishing rate and flatness, and there will be a problem that the service life of the polishing pad is reduced due to an excessive increase in the pad cutting rate or cutting wear rate. On the other hand, if the NCO% exceeds the above range, surface defects on the semiconductor substrate, such as scratches and chatter marks, can be increased. Blowing agent The blowing agent is a component used to form a pore structure in the polishing layer. It may include components selected from the group consisting of: solid blowing agents, gas blowing agents, liquid blowing agents, and combinations thereof. According to specific examples, the blowing agent can be a non-chlorine blowing agent that does not include a chlorine component. In particular, it may not include or minimize the use of chlorine-based blowing agent components commonly used in the preparation of polishing pads, such as vinylidene chloride (VDC). For example, the content of the non-chlorine blowing agent can 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 100% by weight or less, or 99.5% by weight or less; for specific embodiments, 80% by weight to 100% by weight, 90% by weight to 100% by weight, or 80% by weight to 99.5% by weight, based on the total weight of the blowing agent. In addition, the content of the chlorine-based blowing agent can be 20% by weight or less, 10% by weight or less, 5% by weight or less, 1% by weight or less, 0.5% by weight or less, or 0.3% by weight or less, and 0% by weight or more, 0.1% by weight or more, 0.5% by weight or more; for specific embodiments, 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, based on the total weight of the blowing agent. The blowing agent can be at least one selected from the following: a solid-phase blowing agent containing particles with a hollow structure, a liquid-phase blowing agent using a volatile liquid, and an inert gas. For embodiments, the solid-phase blowing agent can contain particles with a hollow structure, where the structure has been thermally expanded and the size has been adjusted. This solid-phase blowing agent has the advantage of having uniformly controlled pore sizes because it is used in the raw material in an expanded form and has a uniform particle size. In addition, the solid-phase blowing agent can contain expandable particles. The expandable particles are particles having the characteristic of being expandable by heat or pressure. Their size in the final polishing layer can be determined by the heat or pressure applied in the method for preparing the polishing layer. The expandable particles are used in the raw material in a non-expanded granular state. Their final size is determined by the thermal or pressure expansion applied during the method for preparing the polishing layer. The solid-phase blowing agent can have an average particle size of 5 microns to 100 microns, in particular, 5 microns to 50 microns, or 20 microns to 50 microns. The average particle size of the solid-phase blowing agent can refer to the average particle size of the expanded particles themselves when the solid-phase blowing agent is used in the raw material in the expanded state particles as described below. It can refer to the average particle diameter after the particles are expanded by heat or pressure in the preparation method when the solid-phase blowing agent is used in the raw material in the non-expanded state particles as described below. The solid-phase blowing agent in the form of expandable granules may comprise a resinous shell and a component encapsulated within the shell that initiates expansion. These expandable granules can form a hollow structure by heating during the preparation method to evaporate the encapsulated expansion-initiating component. For example, the shell may comprise a thermoplastic resin. The thermoplastic resin may be at least one selected from the group consisting of acrylonitrile copolymers, methacrylonitrile copolymers, and acrylic copolymers. The thickness of the shell may be, for example, 0.1 micrometers or thicker, 0.5 micrometers or thicker, 1 micrometer or thicker, 2 micrometers or thicker, or 3 micrometers or thicker, and 15 micrometers or thinner, 12 micrometers or thinner, or 10 micrometers or thinner, and in a specific embodiment, 2 micrometers to 15 micrometers. The expansion-initiating component may comprise a component selected from the group consisting of hydrocarbon compounds, tetraalkylsilane compounds, and combinations thereof. In particular, the hydrocarbon may comprise a compound selected from the group consisting of ethane, ethylene, propane, propylene, n-butane, isobutane, n-butene, isobutene, n-pentane, isopentane, neopentane, n-hexane, heptane, petroleum ether, and combinations thereof. The tetraalkylsilane compound may comprise a compound selected from the group consisting of tetramethylsilane, trimethylethylsilane, trimethylisopropylsilane, trimethyl-n-propylsilane, and combinations thereof. The solid-phase blowing agent may comprise granules treated with an inorganic component. In a specific example, the solid-phase blowing agent may be a reagent treated with silica (SiO 2 ) granules. Treating the solid-phase blowing agent with an inorganic component can prevent aggregation between plural granules. In terms of the chemical, electrical, and / or physical properties of the surface of the blowing agent, the solid-phase blowing agent treated with an inorganic component may be different from the solid-phase blowing agent not treated with an inorganic component. Commercial products of the solid-phase blowing agent include 920DE20d70, 051DET40d25, and 051DET40d42 of Nouryon; and F-65DE, F-80DE, and FN-80SDE of Matsumoto. In a specific embodiment, the blowing agent used in a polishing pad according to a specific example comprises a solid-phase blowing agent. The solid-phase blowing agent may comprise at least one selected from the group consisting of acrylonitrile copolymers, methyl methacrylate copolymers, methacrylonitrile copolymers, and acrylic copolymers. The content of the solid foaming agent may be 0.1 part by weight or more, 0.5 part by weight or more, or 1 part by weight or more, and 5 parts by weight or less, 3 parts by weight or less, or 2 parts by weight or less, relative to 100 parts by weight of the urethane-based prepolymer. For specific embodiments, the content of the solid foaming agent may be from 0.1 part by weight to 5 parts by weight, or from 0.5 part by weight to 2 parts by weight, relative to 100 parts by weight of the urethane-based prepolymer. The type and content of the solid foaming agent can be designed according to the desired pore structure and physical properties of the polishing layer. Meanwhile, the liquid foaming agent can be introduced during the mixing and reaction of the prepolymer and the curing agent to form pores. It does not participate in the reaction between the prepolymer and the curing agent. In addition, the liquid foaming agent is physically evaporated by the heat generated during the mixing and reaction of the prepolymer and the curing agent to form pores. The volatile liquid foaming agent can be a liquid at 25 °C, and it does not react with isocyanate groups, amide groups, and alcohol groups. In particular, the volatile liquid foaming agent can be selected from the group consisting of: cyclopentane, n-pentane, cyclohexane, n-butyl acetate, bis(nonafluorobutyl)(trifluoromethyl)amine; and perfluorinated compounds such as perfluorotributylamine, perfluoro-N-methylmorpholine, perfluorotripentylamine, and perfluorohexane. Commercially available products of the perfluorinated compounds include FC-40 (3M), FC-43 (3M), FC-70 (3M), FC-72 (3M), FC-770 (3M), FC-3283 (3M), and FC-3284 (3M). In addition, the foaming agent can include a gas-phase foaming agent. For example, the foaming agent can include a solid foaming agent and a gas-phase foaming agent. The gas-phase foaming agent can include an inert gas. When the urethane-based prepolymer reacts with the curing agent, the gas-phase foaming agent is fed to be used as a component for forming pores. 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-based prepolymer and the curing agent. For example, the inert gas can include a gas selected from the group consisting of: nitrogen gas (N 2 )), carbon dioxide gas (CO 2 ), argon gas (Ar), helium gas (He), and combinations thereof. The type and content of the gas-phase foaming agent can be designed according to the desired pore structure and physical properties of the polishing layer. The inert gas may be fed in a volume of 10% to 30% based on the total volume of the composition. In particular, the inert gas may be fed in a volume of 15% to 30% based on the total volume of the composition. In particular, when mixing the urethane-based prepolymer, the solid foaming agent, and the curing agent, the gas-phase foaming agent may be fed via a predetermined feed line. The feed rate of the gas-phase foaming agent is about 0.8 liters / minute to about 2.0 liters / minute, for example, about 0.8 liters / minute to about 1.8 liters / minute, for example, about 0.8 liters / minute to about 1.7 liters / minute, for example, about 1.0 liters / minute to about 2.0 liters / minute, for example, about 1.0 liters / minute to about 1.8 liters / minute, for example, about 1.0 liters / minute to about 1.7 liters / minute. Curing agent The curing agent is a compound used for chemical reaction with the urethane-based prepolymer to form a final cured structure in the polishing layer. For example, it may include an amine compound or an alcohol compound. In particular, the curing agent may include a compound selected from the group consisting of aromatic amines, aliphatic amines, aromatic alcohols, aliphatic alcohols, and combinations thereof. According to specific examples, the curing agent may include a non-chlorinated curing agent that does not include a chlorine component. For example, the content of the non-chlorinated 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 100% by weight or less, or 99.5% by weight or less. For specific embodiments, 80% by weight to 100% by weight, 90% by weight to 100% by weight, or 80% by weight to 99.5% by weight, based on the total weight of the curing agent. In addition, the content of the chlorinated curing agent may be 20% by weight or less, 10% by weight or less, 5% by weight or less, 1% by weight or less, 0.5% by weight or less, or 0.3% by weight or less, and 0% by weight or more, 0.1% by weight or more, 0.5% by weight or more. For specific embodiments, 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, based on the total weight of the curing agent. The curing agent may be at least one selected from solid-phase curing agents and liquid-phase curing agents. The solid-phase curing agent may include an active hydrogen group. The solid-phase curing agent may include an amino group (-NH 2 ) as the active hydrogen group. In addition, the solid-phase curing agent may be an ester compound including two or more benzene rings. In particular, the solid-phase curing agent may contain two or more ester groups in the molecule. The solid-phase curing 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, for example, 300 to 350. The solid-phase curing agent may have a melting point (m.p.) of 100 °C to 150 °C, for example, 100 °C to 140 °C, for example, 110 °C to 130 °C. In a specific example, the solid-phase curing agent comprises at least one selected from the group consisting of: 1,3-propanediol bis(4-aminobenzoate) (PDPAB), 4-aminobenzoic acid 4-(4-aminobenzoyl)oxyphenyl ester, 4-aminobenzoic acid 4-(4-aminobenzoyl)oxybutyl ester, 4-aminobenzoic acid 4-[4-(4-aminobenzoyl)oxy-3-methylbutoxy]butyl ester, and methylene bis(o-aminobenzoate) (MBNA). The liquid-phase curing agent may include an active hydrogen group. The liquid-phase curing agent may include at least one selected from the group consisting of an amino group (-NH 2 ), a hydroxyl group (-OH), a carboxylic acid group (-COOH), an epoxy group, and combinations thereof as the active hydrogen group. In particular, it may include an amino group (-NH 2 ). In addition, the liquid-phase curing agent may include sulfur in the molecule. In particular, it may include two or more sulfur elements in the molecule. The liquid-phase curing agent may have a weight-average molecular weight of 50 to 300, for example, 100 to 250, for example, 150 to 250, for example, 200 to 250. In addition, the liquid-phase curing agent may be a liquid at room temperature. Optionally, the liquid-phase curing agent may have a boiling point (b.p.) of 160 °C to 240 °C, particularly 170 °C to 240 °C, more particularly 170 °C to 220 °C. Examples of the liquid-phase curing agent include at least one selected from the group consisting of: 3,5-dimethylthio-2,6-diaminotoluene (DMTDA), 2,6-bis(methylthio)-4-methyl-1,3-phenylenediamine, and N,N'-bis(secondary butylamino)diphenylmethane. In addition, in addition to the liquid-phase curing agent and the solid-phase curing agent, the curing agent may further include other curing agents. The additional curing agent may be at least one of, for example, an amine compound and an alcohol compound. In particular, the additional curing agent may include at least one compound selected from the group consisting of aromatic amines, aliphatic amines, aromatic alcohols, and aliphatic alcohols. For example, the additional curing agent may be selected from at least one of the group consisting of: diaminodiphenylmethane, diaminodiphenylsulfone, m-phenylene diamine, isophorone diamine, ethylenediamine, diethylenetriamine, triethylenetetramine, polypropylenediamine, polypropylenetriamine, ethylene glycol, diethylene glycol, dipropylene glycol, butanediol, hexanediol, glycerol, and trimethylolpropane. For specific embodiments, the curing agent may comprise at least one 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(secondary butylamino)diphenylmethane, 2,6-bis(methylthio)-4-methyl-1,3-benzenediamine, 4-aminobenzoic acid 4-(4-aminobenzoyloxy)phenyl ester, 4-aminobenzoic acid 4-(4-aminobenzoyloxy)butyl ester, 4-aminobenzoic acid 4-[4-(4-aminobenzoyloxy)-3-methylbutoxy]butyl ester, and bis-methyl orthophthalate (MBNA). The content of the curing agent may be 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, and 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, relative to 100 parts by weight of the urethane-based prepolymer. The content of the curing agent may be 10 parts by weight to 40 parts by weight, more particularly, 15 parts by weight to 35 parts by weight, or 15 parts by weight to 25 parts by weight, relative to 100 parts by weight of the urethane-based prepolymer. Additives The composition for preparing the polishing layer may further comprise other additives such as surfactants and reaction rate control agents. Names such as "surfactant" and "reaction rate control agent" are arbitrary names based on the main roles of such substances. Each substance does not necessarily perform only the functions limited to the roles defined by the name. The surfactant is not particularly limited as long as it functions to prevent pore coalescence and overlap with each other. For example, the surfactant may comprise a silicone-based surfactant. The amount of the surfactant that can be used is 0.2 to 2 parts by weight, relative to 100 parts by weight of the urethane-based prepolymer. In particular, the amount of the surfactant that can be used is 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, for example, 0.5 to 1.5 parts by weight, relative to 100 parts by weight of the urethane-based prepolymer. When the amount of the surfactant is within the above range, the holes derived from the gas foaming agent can be stably formed and maintained in the mold. The reaction rate controller is provided to promote or delay the reaction. A reaction accelerator, a reaction retarder, or both can be used according to the purpose. The reaction rate controller can include a reaction accelerator. For example, the reaction rate controller can be at least one reaction accelerator selected from the group consisting of tertiary amine compounds and organometallic compounds. In particular, the reaction rate controller can include at least one 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-azabicyclonorbornane, dibutyltin dilaurate, stannous octoate, dibutyltin diacetate, dioctyltin diacetate, dibutyltin maleate, dibutyltin bis(2-ethylhexanoate), and dibutyltin dithiolate. In particular, the reaction rate controller can include at least one selected from the group consisting of benzyldimethylamine, N,N-dimethylcyclohexylamine, and triethylamine. The amount of the reaction rate controller that can be used is 0.05 parts by weight to 2 parts by weight, relative to 100 parts by weight of the urethane-based prepolymer. In particular, the amount of the reaction rate controller that can be used is 0.05 parts by weight to 1.8 parts by weight, for example, 0.05 parts by weight to 1.7 parts by weight, for example, 0.05 parts by weight to 1.6 parts by weight, for example, 0.1 parts by weight to 1.5 parts by weight, for example, 0.1 parts by weight to 0.3 parts by weight, for example, 0.2 parts by weight to 1.8 parts by weight, for example, 0.2 parts by weight to 1.7 parts by weight, for example, 0.2 parts by weight to 1.6 parts by weight, for example, 0.2 parts by weight to 1.5 parts by weight, for example, 0.5 parts by weight to 1 part by weight, relative to 100 parts by weight of the urethane-based prepolymer. When the reaction rate controller is used within the above content range, the curing reaction rate of the prepolymer composition can be appropriately controlled to form a polishing layer having pores and hardness of a desired size. Support layer The support layer constitutes a sub-pad and provides support for the polishing layer and absorbs and disperses the impact applied to the polishing layer. Therefore, it minimizes the damage and defects of the object to be polished during the polishing process using the polishing pad. The support layer may include non-woven fabric or suede, but it is not limited thereto. In a specific example, the support layer may be a resin-impregnated non-woven fabric. The non-woven fabric may be a fibrous non-woven fabric including fibers selected from the group consisting of polyester fibers, polyamide fibers, polypropylene fibers, polyethylene fibers, and combinations thereof. The resin impregnated in the non-woven fabric may include polyurethane resin, polybutadiene resin, styrene-butadiene copolymer resin, styrene-butadiene-styrene copolymer resin, acrylonitrile-butadiene copolymer resin, styrene-ethylene-butadiene-styrene copolymer resin, polysiloxane rubber resin, polyester-based elastomer resin, polyamide-based elastomer resin, and combinations thereof. The support layer may have a thickness of, for example, 0.3 mm or more, or 0.5 mm or more, and 3 mm or less, 2 mm or less, or 1 mm or less. For specific embodiments, the thickness of the support layer may be 0.3 mm to 3 mm, or 0.5 mm to 1 mm. The support layer may have a hardness of, for example, 50 Asker C or greater, 60 Asker C or greater, or 70 Asker C or greater, and 100 Asker C or less, 90 Asker C or less, or 80 Asker C or less. For specific embodiments, the hardness of the support layer may be 50 Asker C to 100 Asker C, or 60 Asker C to 90 Asker C. In addition, an adhesive layer may be inserted between the polishing layer (top pad) and the support layer (sub-pad). The adhesive layer may include a hot melt adhesive. The hot melt adhesive may be at least one selected from the group consisting of: polyurethane resin, polyester resin, ethylene-vinyl acetate resin, polyamide resin, and polyolefin resin. In particular, the hot melt adhesive may be at least one selected from the group consisting of polyurethane resin and polyester resin. In addition, a double-sided tape may be laminated under the support layer. When it is applied to a CMP device, once the release paper of the double-sided tape has been removed, it is attached to the use platform. Method for preparing a polishing pad The method for preparing a polishing pad according to a specific example includes preparing a composition for a polishing pad, which includes a urethane-based prepolymer, a foaming agent, and a curing agent; injecting the composition for a polishing pad into a mold and curing it to prepare a polishing layer; and laminating the polishing layer and a support layer. Specific types and contents of urethane-based prepolymers, curing agents, and foaming agents are exemplified as above. Regarding a specific embodiment, the foaming agent includes a solid-phase foaming agent, and the solid-phase foaming agent includes at least one selected from the group consisting of: acrylonitrile-based copolymer, methyl methacrylate-based copolymer, methacrylonitrile-based copolymer, and acrylic-based copolymer; and the curing agent includes at least one 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(secondary butylamino) diphenylmethane, 2,6-bis(methylthio)-4-methyl-1,3-benzenediamine, 4-aminobenzoic acid 4-(4-aminobenzoyl)oxy phenyl ester, 4-aminobenzoic acid 4-(4-aminobenzoyl)oxy butyl ester, 4-aminobenzoic acid 4-[4-(4-aminobenzoyl)oxy-3-methylbutoxy] butyl ester, and bis-methyl o-aminobenzoic acid methylene ester (MBNA). The composition for a polishing pad may be prepared by successively or simultaneously mixing a urethane-based prepolymer, a foaming agent, and a curing agent. Regarding an embodiment, the step of preparing the composition for a polishing pad may be carried out by mixing the urethane-based prepolymer and the curing agent, and then further mixing with the foaming agent; or by mixing the urethane-based prepolymer and the foaming agent, and then further mixing with the curing agent. For another embodiment, a urethane-based prepolymer, a curing agent, and a blowing agent can be substantially simultaneously introduced into the mixing method. When a blowing agent, a surfactant, and an inert gas are further added, they can be substantially simultaneously introduced into the mixing method. For another embodiment, a prepolymer, a blowing agent, and a surfactant that are pre-based on urethane can be mixed, and a curing agent or a curing agent and an inert gas can be subsequently introduced. The mixing initiates the reaction between the urethane-based prepolymer and the curing agent, and uniformly disperses the blowing agent and the inert gas in the raw materials. In this case, a reaction rate controller can intervene in the reaction between the urethane-based prepolymer and the curing agent from the start of the reaction to thereby control the reaction rate. In particular, the mixing can be performed at a speed of 1,000 to 10,000 rpm or 4,000 to 7,000 rpm. Within the above speed range, it is better to uniformly disperse the inert gas and the blowing agent in the raw materials. In addition, the step of preparing the composition for the polishing pad can be performed under conditions of 50 °C to 150 °C. If necessary, it can be performed under vacuum degassing conditions. If the blowing agent includes a solid-phase blowing agent, the step of preparing the composition for the polishing pad can include mixing the urethane-based prepolymer and the solid-phase blowing agent to prepare a first preliminary composition; and mixing the first preliminary composition and the curing agent to prepare a second preliminary composition. The first preliminary composition can have a viscosity of about 1,000 cps to about 2,000 cps at about 80 °C, for example, about 1,000 cps to about 1,800 cps, for example, about 1,000 cps to about 1,600 cps, for example, about 1,000 cps to about 1,500 cps. If the blowing agent includes a gas-phase blowing agent, the step of preparing the composition for the polishing pad can include preparing a third preliminary composition including the urethane-based prepolymer and the curing agent; and feeding the gas-phase blowing agent to the third preliminary composition to prepare a fourth preliminary composition. In a specific example, the third preliminary composition can further include a solid-phase blowing agent. In a specific example, the step of preparing the polishing layer includes preparing a mold preheated to a first temperature; injecting the composition for the polishing pad into the preheated mold and curing it; and post-curing the cured composition for the polishing pad under a second temperature condition higher than the preheating temperature. In a specific example, the temperature difference between the first temperature and the second temperature can be about 10 °C to about 40 °C, for example, about 10 °C to about 35 °C, for example, about 15 °C to about 35 °C. In a specific example, the first temperature can be about 60 °C to about 100 °C, for example, about 65 °C to about 95 °C, for example, about 70 °C to about 90 °C. In a specific example, the second temperature can be about 100 °C to about 130 °C, for example, about 100 °C to about 125 °C, for example, about 100 °C to about 120 °C. The step of curing the composition for the polishing pad at the first temperature can 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. The step of post-curing the composition for the polishing pad that has been cured at the first temperature at the second temperature can 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. After that, the step of injecting the composition for the polishing pad into a mold and curing it can be carried out under temperature conditions of 60 °C to 120 °C and pressure conditions of 50 kg / m² to 200 kg / m². In addition, the above preparation method may further include the following steps: cutting the surface of the polishing pad thus obtained, mechanically forming grooves on its surface, bonding it to the lower part, inspecting, packaging, and similar steps. These steps can be carried out in a manner known for preparing polishing pads. Regarding the embodiment, the method for preparing the polishing pad may further include mechanically forming at least one side of the polishing layer. The step of mechanically forming at least one side of the polishing layer may include forming grooves on at least one side of the polishing layer; thread turning at least one side of the polishing layer; and roughening at least one side of the polishing layer. The grooves may include at least one of the following: concentric circular grooves spaced apart from the center of the polishing layer by a certain interval; and radial grooves continuously connecting from the center of the polishing layer to the edge of the polishing layer. The thread turning can be carried out by using a cutting tool to cut a certain thickness of the polishing layer. The roughening can be carried out by forming the surface of the polishing layer with a sanding roller machine. Method for preparing a semiconductor device The semiconductor device can be manufactured by chemical and mechanical polishing using the polishing pad described above. The method of manufacturing a semiconductor device according to a specific example includes conditioning the polishing layer of the polishing pad by irradiating with UV light having a wavelength of 100 nm to 380 nm when chemically and mechanically polishing a semiconductor substrate using the polishing pad. In particular, the method of manufacturing a semiconductor device includes rotating them relative to each other to polish the surface of the semiconductor substrate when the polishing layer of the polishing pad and the surface of the semiconductor substrate are in contact with each other. In addition, the method of manufacturing a semiconductor device includes conditioning the polishing layer of the polishing pad by irradiating with UV light having a wavelength of 100 nm to 380 nm. Figures 7 and 8 show the configuration of a device for irradiating UV light during a CMP method according to a specific example. Referring to Figures 7 and 8, in the device according to a specific example, a UV lamp (700) is installed on the polishing pad (100). The angle and height of the UV lamp can be adjusted for installation. The UV lamp can irradiate light with a wavelength range of 100 nm to 380 nm onto the polishing pad. Figure 2 shows the occurrence of defects caused by debris during the method of manufacturing a semiconductor device. Referring to Figure 2, debris (150) formed from the polishing layer can cause defects (650) or scratches on the surface of the semiconductor device. However, the polishing pad according to a specific example has the characteristic of reducing the particle size of debris when irradiating UV light during the CMP method. Therefore, by irradiating UV light during the CMP method and using these characteristics of the polishing pad, the occurrence of defects and scratches in the semiconductor device can be minimized. Therefore, when manufacturing a semiconductor device by a CMP method using the polishing pad according to a specific example, it can improve CMP performance and productivity. After that, the method of manufacturing a semiconductor device according to a specific example will be described in detail. First, once the polishing pad (100) according to a specific example has been attached to the platform (200), a semiconductor substrate (600) as an object to be polished is disposed on the polishing pad (100). In this case, 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, the CMP slurry (450) can be supplied to the polishing pad through a slurry supplier (400). The flow rate of the CMP slurry (450) supplied through the slurry supplier (400) can be selected within the range of about 10 cubic centimeters per minute to about 1,000 cubic centimeters per minute according to the purpose. For example, it can be about 50 cubic centimeters per minute to about 500 cubic centimeters per minute, but it is not limited thereto. Thereafter, the semiconductor substrate (600) and the polishing pad (100) rotate relative to each other to polish 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 direction or the opposite direction. The rotation speed of each of the semiconductor substrate (600) and the polishing pad (100) can be selected within the range of about 10 rpm to about 500 rpm according to the purpose. For example, it may be about 30 rpm to about 200 rpm, but it is not limited thereto. The semiconductor substrate (600) mounted on the polishing head (510) is pressed against the polishing surface of the polishing pad (100) in contact therewith with a predetermined load, and then its surface can be polished. The load applied by the polishing head (510) to the polishing surface of the polishing pad (100) and the surface of the semiconductor substrate (600) can be selected within the range of about 1 g / cm² to about 1,000 g / cm² according to the purpose. For example, it may be about 10 g / cm² to about 800 g / cm², but it is not limited thereto. In a specific example, the semiconductor substrate (600) as the object to be polished may include an oxide layer, a tungsten layer, or a composite layer thereof. In particular, the semiconductor substrate (600) may include an oxide layer, a tungsten layer, or a composite layer of an oxide layer and a tungsten layer. The composite layer of the oxide layer and the tungsten layer may be a multilayer film in which the tungsten layer is laminated on one side of the oxide layer; or it may be a single-layer film in which the oxide region and the tungsten region are mixed in a single layer. Because the object to be polished has this film material, and at the same time, the polishing pad has characteristics according to specific examples, the semiconductor device manufactured according to the method for manufacturing a semiconductor device may have minimal defects. In a specific example, the method for manufacturing a semiconductor device may further include, in the step of polishing the object to be polished, supplying any one of a slurry for polishing the oxide layer and a slurry for polishing the tungsten layer; or sequentially supplying the slurry for polishing the oxide layer and the slurry for polishing the tungsten layer to the polishing surface. For example, if the semiconductor substrate as the object to be polished includes an oxide layer, the method for manufacturing a semiconductor device may include supplying a slurry for polishing the oxide layer. If the semiconductor substrate includes a tungsten layer, the method for manufacturing a semiconductor device may include supplying a slurry for polishing the tungsten layer. If the semiconductor substrate includes a composite layer of an oxide layer and a tungsten layer, the method for manufacturing a semiconductor device may include sequentially supplying the slurry for polishing the oxide layer and the slurry for polishing the tungsten layer to the polishing surface. Herein, depending on the method, the slurry for polishing the oxide layer may be supplied first, and then the slurry for polishing the tungsten layer may be supplied; or the slurry for polishing the tungsten layer may be supplied first, and then the slurry for polishing the oxide layer may be supplied. In a specific example, in order to maintain the polishing surface of the polishing pad (100) in a state suitable for polishing, the method for preparing a semiconductor device may further include processing the polishing surface of the polishing pad (100) with a conditioner (300) and polishing the semiconductor substrate (600) synchronously. In addition, the method for preparing a semiconductor device includes conditioning the polishing layer of the polishing pad while irradiating UV light having a wavelength of 100 nm to 380 nm. In the device according to a specific example, a UV lamp (700) is installed on the polishing pad (100). The angle and height can be adjusted for assembling the UV lamp. For example, the height of the UV lamp can be 2 cm to 30 cm from the surface of the polishing pad (100), particularly, 3 cm to 10 cm, more particularly, 3 cm to 7 cm. In addition, the UV light intensity on the surface of the polishing pad (100) can be 100 W to 2 kW, more particularly, 500 W to 1.5 kW. In addition, the irradiation time of the UV light can be 1 minute or longer, 2 minutes or longer, or 3 minutes or longer, and 20 minutes or shorter, 10 minutes or shorter, 7 minutes or shorter, 5 minutes or shorter, or 4 minutes or shorter. For example, the irradiation time of the UV light can be 1 minute to 20 minutes, 1 minute to 10 minutes, 2 minutes to 10 minutes, 1 minute to 7 minutes, 1 minute to 5 minutes, or 2 minutes to 5 minutes. For a specific embodiment, the irradiation time of the UV light can be 2 minutes to 4 minutes. Mode of the present invention Although the following embodiments have been described, the possible scope of implementation is not limited thereto. A. Preparation and evaluation of polishing pads Example A1 to A7 and Comparative Example A1 and A2 : Preparation steps of the polishing pad (1) Preparation of prepolymer Charge a four-necked flask with tolylene diisocyanate (TDI), dicyclohexylmethane diisocyanate (H12MDI), polytetramethylene ether glycol (PTMEG), and diethylene glycol (DEG), and then react it at 80 °C for 3 hours to prepare a urethane-based prepolymer. Measure the NCO% of the prepolymer and show it in Table 1 below. Step (2) Preparation of the polishing pad Provide a casting machine equipped with tanks and feed lines for raw materials such as prepolymers, curing agents, inert gases, and blowing agents. The urethane-based prepolymer prepared above, blowing agent, curing agent, inert gas (N 2 ) and a polysiloxane surfactant (Evonik) are each charged into these tanks. When feeding them to the mixing head at a fixed rate via separate feed lines, the raw materials are stirred. The blowing agents and curing agents listed in Table 1 below are used. The prepolymer and the curing agent are fed at an equal ratio of 1:1 and a total rate of 10 kg / min. Prepare a mold (1,000 mm × 1,000 mm × 3 mm) and preheat it at a temperature of 80 °C. Inject the above-prepared mixed raw materials into the mold and react to obtain a molded article in the form of a solid cake. Then, grind each of the top and bottom of the molded article to obtain a polished layer for the top pad. After that, subject the polished layer to a surface grinding and groove forming step, and laminate it with the sub-pad support layer by a thermally fused adhesive, thereby preparing a polishing pad. Lay a double-sided tape (442JS, 3M) under the support layer so that it can be attached to the platform of the CMP equipment. The curing agents and blowing agents 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 - F-65DE: acrylonitrile / methyl methacrylate / methacrylonitrile copolymer, expanded cell type, Matsumoto - F-80DE: acrylonitrile / methyl methacrylate / methacrylic acid copolymer, expanded cell type, Matsumoto - 051DET40d25: acrylonitrile / methacrylonitrile copolymer, expanded cell type, Nouryon - 051DET40d42: acrylonitrile / methacrylonitrile copolymer, expanded cell type, Nouryon - 461DET40d25: acrylonitrile / dichloroethane, expanded cell type, Nouryon The details of the examples and comparative examples are summarized in Table 1 below. [Table 1] *Seq.: Successively Test Example A1 Test each of the polished layer, the support layer, and the polishing pad laminated therewith prepared as described above as follows. (1) Hardness Cut each sample into 5 cm × 5 cm (thickness: 2 mm) and store them separately at room temperature and at temperatures of 30 °C, 50 °C, and 70 °C for 12 hours, and use a hardness tester to measure the Shore D hardness and Asker C hardness. (2) Specific gravity Cut each sample into 2 cm × 5 cm (thickness: 2 mm) and store it at a temperature of 25 °C for 12 hours, and use a hydrometer to measure the specific gravity. (3) Tensile strength Cut each sample into 4 cm × 1 cm (thickness: 2 mm). When testing the sample using a universal testing machine (UTM) at a rate of 50 mm / min, immediately measure the ultimate strength before fracture. (4) Elongation Cut each sample into 4 cm × 1 cm (thickness: 2 mm). When testing the sample using a universal testing machine (UTM) at a rate of 50 mm / min, immediately measure the maximum deformation before fracture. The ratio of this maximum deformation to the initial length is expressed as a percentage (%). The results are shown in the following table. [Table 2] *NW fabric: non-woven fabric As shown in the above table, in terms of hardness, specific gravity, tensile strength, and elongation, the polishing pads of Examples A1 to A7 are at least equal to the polishing pads of Comparative Examples A1 and A2. Test Example A2 Test each of the above-prepared polishing pads as follows. (1) Polishing rate (removal rate) Place a silicon wafer with a diameter of 300 mm, on which silicon oxide has been deposited by the CVD method, on a porous polyurethane polishing pad placed on the platform of a CMP polishing machine, with the silicon oxide layer of the silicon wafer facing downwards. Then, polish the silicon oxide layer under a polishing load of 4.0 psi, while the polishing pad rotates at a speed of 150 rpm, supply the calcined cerium dioxide slurry to the polishing pad at a rate of 250 ml / min, and the platform rotates at a speed of 150 rpm for 60 seconds. After the polishing is completed, separate the silicon wafer from the carrier, assemble the wafer in a spin dryer, clean it with deionized water (DIW), and then dry it with nitrogen for 15 seconds. Use a spectroscopic reflectometer type thickness measuring instrument (manufacturer: Keyence, model: SI-F80R) to measure the film thickness of the dried silicon wafer before and after polishing. After that, use the following mathematical equation 1 to calculate the polishing rate. [Mathematical equation 1] Polishing rate (Å / min) = Thickness difference before and after polishing (Å) / Polishing time (min) (2) Defects Using the same method as the polishing rate test, perform polishing using a CMP polishing machine. After the polishing is completed, transfer the silicon wafer to a cleaner, and use 1% HF, 1% H 2 NO 3Clean with deionized water (DIW) for 10 seconds. After that, transfer it to a spin dryer, wash with deionized water (DIW), and then dry with nitrogen for 15 seconds. Use a defect measurement device (manufacturer: Tenkor, model: XP+) to measure the change in defects of the dried silicon wafer before and after polishing. In particular, measure the total number of scratches, shock marks, pits, and residues on the surface of the wafer. (3) Chlorine content Prepare a circular sample with a diameter of 3 cm and a height of 0.3 cm from the polishing layer of the polishing pad. Measure the chlorine content in the sample by IEC 62321-3-2, where IEC 62321-3-2 is an international standard for measuring specific substances in polymers by combustion ion chromatography (C-IC). (4) Debris size (D50 particle size) a) Obtain an aqueous solution of debris Attach a porous polyurethane polishing pad to the platform of a CMP polishing machine. After that, exclude the operation of the carrier and collect the debris of the polishing layer only using a conditioner and deionized water (DIW). Under the conditions of a platform speed of 93 rpm, a conditioner load of 9 lbs, a rotation speed of 64 rpm, and a scan speed of 19 times / minute, use a CI45 disk (pad cutting rate 80 to 90 microns / hour, Saesol) to condition the polishing layer while supplying deionized water at 300 cubic centimeters (cc) / minute. The debris formed after conditioning the polishing layer for 10 minutes is collected in the form of a solution mixed with deionized water, thereby obtaining 300 ml of an aqueous solution of debris. b) pH adjustment and analysis of the particle size of debris The aqueous solution of debris has a pH level of 6.0 to 6.5, and the pH is adjusted to 5.5 using an aqueous nitric acid solution. Here, the concentration of the aqueous nitric acid solution used is 35%. Use a particle size analyzer (Mastersize 3000, Malvern) and a medium-capacity automatic disperser (Hydro MV, Malvern) to measure the D50 particle size of the debris in the aqueous solution of debris. The analyzer is set with a refractive index of 1.55 for polyurethane as the refractive index of the material to be analyzed, a refractive index of 1.33 for deionized water as the refractive index of the dispersant, and a stirring speed of 2,500 rpm. (5) ζ potential Obtain an aqueous solution of debris in the same manner as in a) of the above section (4). To ensure the particle stability in the aqueous solution of the debris, it is stored at room temperature for 24 hours to precipitate particles with a particle diameter of 20 microns or larger. Then, the upper layer liquid located within 10 mm from the top surface of the solution is taken as a sample. The obtained sample has a pH level of 6.0 to 6.5. The pH is adjusted to 5.5 using an aqueous nitric acid solution. Here, the concentration of the aqueous nitric acid solution used is 35%. In addition, the concentration of the debris in the liquid sample is measured to be approximately 0.01 wt%. This concentration is measured using a heated moisture meter (MX-50, AND) after placing approximately 5 g of the liquid sample in an aluminum dish. The ζ potential of the sample is measured using a Zetasizer (Nano-ZS90, Malvern). Specifically, 1 ml of the sample is filled into the optical cell of the Zetasizer and measured three times to obtain the ζ potential. In this case, the equipment setting values are set to RI = 1.550 and absorption = 0.010, based on the polyurethane value. The test results are summarized in the following table. [Table 3] As can be seen from the above table, the chlorine (Cl) content of the polishing pads of Examples A1 to A7 measured is within the desired range, and the performance such as the polishing rate is equal to or higher than that of Comparative Examples A1 and A2. Specifically, the particle size of the debris of the polishing pads of Examples A1 to A7 measured is smaller than that of Comparative Examples A1 and A2, and the number of defects and scratches measured is significantly lower. In addition, the ζ potential of the polishing pads of Examples A1 to A7 measured is within the desired range. (6) Variation of debris size and ζ potential with respect to pH For the polishing pads of the examples and comparative examples, the debris particle size (D50 [5.5]) at pH 5.5 and the debris particle size (D50

[10] ) at pH 10 are measured in the same manner as in the above section (4). In addition, for the polishing pads of the examples and comparative examples, the ζ potential (Zp[5.5]) of the aqueous solution of the debris at pH 5.5 and the ζ potential (Zp

[10] ) of the aqueous solution of the debris at pH 10 are measured in the same manner as in the above section (5). Here, the pH of the aqueous solution of the debris is adjusted by adding an aqueous nitric acid solution or an aqueous potassium hydroxide solution. Specifically, when adjusting the initially obtained aqueous solution of the debris (pH 6.0 to 6.5) to pH 5.5, an aqueous nitric acid solution is added; and when it is adjusted to pH 10, an aqueous potassium hydroxide solution is added. Here, the concentration of the aqueous nitric acid solution used is 35%, and the concentration of the aqueous potassium hydroxide solution is 10%. Use the measured debris size and ζ potential described above to calculate the following equations (1) to (3). D50 [5.5] / Zp[5.5]…(1) (D50 [5.5] / D50

[10] )×100…(2) Zp[5.5]-Zp

[10] …(3) Here, D50 [5.5] is the D50 particle size (micrometers) of the debris obtained during the conditioning of the polishing layer at pH 5.5, and D50

[10] is the D50 particle size (micrometers) of the debris obtained during the conditioning of the polishing layer at pH 10. Zp[5.5] is the ζ potential (millivolts) of an aqueous solution containing 0.01 wt% of the debris obtained during the conditioning of the polishing layer at pH 5.5, and Zp

[10] is the ζ potential (millivolts) of an aqueous solution containing 0.01 wt% of the debris obtained during the conditioning of the polishing layer at pH 10. The results are shown in the following table. In addition, the test results of defects and scratches are also shown in the following table. [Table 4] As can be seen from the above table, for the polishing pads of Examples A1 to A7, the D50 particle size of the debris obtained from the polishing layer is 50 micrometers or less at pH 5.5, and the ζ potential of the aqueous solution of the measured debris is in the range of -20 millivolts to 30 millivolts at pH 5.5. In addition, for the polishing pads of Examples A1 to A7, the measured values under different pH conditions and the values of the equations (1) to (3) are all within the desired ranges. As a result, during the CMP process, the number of defects and scratches occurring on the silicon wafer is less than 20. In particular, for the polishing pads of Examples A1 to A3, the D50 particle size of the debris obtained from the polishing layer is 20 micrometers or less at pH 5.5, and the ζ potential of the aqueous solution of the measured debris is in the range of 0 millivolts to 20 millivolts at pH 5.5. In addition, for the polishing pads of Examples A1 to A3, the measured values under different pH conditions and the values of the equations (1) to (3) are all within the desired ranges. As a result, during the CMP process, the number of defects and scratches occurring on the silicon wafer is very small, less than 10. In comparison, for the polishing pads of Comparative Examples A1 and A2, the ζ potential value of the aqueous solution of the debris obtained from the polishing layer is measured to be less than -20 millivolts at pH 5.5. It is also confirmed that the other measured values and the values of the equations (1) to (3) are outside the desired ranges. As a result, during the CMP process, the number of defects and scratches occurring on the silicon wafer increases significantly to 25 or more. B. Preparation and Evaluation of a Polishing Pad When Irradiated with UV Example B1 : Preparation Steps of the Polishing Pad (1) Preparation of a Urethane-Based Prepolymer Charge a four-necked flask with 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), dicyclohexylmethane diisocyanate (H12MDI), polytetramethylene ether glycol (PTMEG), and diethylene glycol (DEG), and then react them at 80 °C for 3 hours to prepare a urethane-based prepolymer having a terminal NCO group content (NCO%) of 10 wt%. Step (2) Preparation of the Polishing Layer Provide a casting machine equipped with tanks and feed lines for raw materials such as prepolymers, curing agents, inert gases, and blowing agents. Charge the urethane-based prepolymer prepared above, a curing agent (DMTDA), a solid blowing agent (F-65DE, Matsumoto), an inert gas (N 2 ) and a polysiloxane-based surfactant (Evonik) into these tanks. In particular, charge 32 parts by weight of the curing agent, 1 part by weight of the solid blowing agent, and 1 part by weight of the surfactant, relative to 100 parts by weight of the prepolymer, and feed the inert gas at 1.5 liters per minute. When feeding the raw materials to the mixing head at a fixed rate through separate feed lines, stir them. The rotational speed of the mixing head is about 5,000 rpm. Then, inject the mixture composition of the raw materials mixed in the mixing head into a mold having a width of 1,000 mm, a length of 1,000 mm, and a height of 3 mm. Adjust the temperature of the mold to about 80 (±5) °C. In the mold to be cast, cure the mixture composition into a thin sheet. Post-cure the thin sheet at about 110 (±5) °C for about 18 hours to prepare a polishing layer. Step (3) Preparation of the Polishing Pad Use a cutting tool to subject one side of the polishing layer to thread turning and use a tip having an average thickness of 2 mm to open a groove. Impregnate a polyester fiber non-woven fabric with a polyurethane resin to prepare a buffer layer. Apply a heat-sealing adhesive to one side of the buffer layer and to the side of the polishing layer opposite the polishing surface, respectively. Laminate the buffer layer and the polishing layer such that the sides to which the heat-sealing adhesive has been applied are in contact, and then use a pressure roller to apply pressure at a temperature of about 140 (±5) °C and a pressure of 2 kgf / cm² to prepare a polishing pad. Comparative Example B1 : Preparation Steps of the Polishing Pad (1) Preparation of a Urethane-Based Prepolymer ​Charge a four-necked flask with 2,4-toluene diisocyanate (2,4-TDI), 2,6-toluene diisocyanate (2,6-TDI), dicyclohexylmethane diisocyanate (H12MDI), polytetramethylene ether glycol (PTMEG), and diethylene glycol (DEG), and then react them at 80 °C for 3 hours to prepare a urethane-based prepolymer having a terminal NCO group content (NCO%) of 9.1 wt%. Step (2) Preparation of the polishing layer Provide a casting machine equipped with tanks and feed lines for raw materials such as prepolymers, curing agents, inert gases, and blowing agents. Charge the urethane-based prepolymer prepared above, a curing agent (4,4'-methylenebis(2-chloroaniline), MOCA), a solid blowing agent (Expancel™ 551 DE 40 d42, Akzonobel), an inert gas (N 2 ) and a polysiloxane-based surfactant (Evonik) into these tanks. In particular, charge 25 parts by weight of the curing agent, 2.2 parts by weight of the solid blowing agent, and 1 part by weight of the surfactant, relative to 100 parts by weight of the prepolymer, and feed the inert gas at 1.5 liters per minute. When feeding the raw materials to the mixing head at a fixed rate through separate feed lines, stir them. The rotational speed of the mixing head is about 5,000 rpm. Then, inject the mixture composition of the raw materials mixed in the mixing head into a mold having a width of 1,000 mm, a length of 1,000 mm, and a height of 3 mm. Adjust the temperature of the mold to about 80 (±5) °C. In the mold to be cast, cure the mixture composition into a thin sheet. Post-cure the thin sheet at about 110 (±5) °C for about 18 hours to prepare a polishing layer. Step (3) Preparation of the polishing pad Use a cutting tool to subject one side of the polishing layer to thread turning and use a tip having an average thickness of 2 mm to open a groove. Impregnate a polyester fiber non-woven fabric with a polyurethane resin to prepare a buffer layer. Apply a heat-sealing adhesive to one side of the buffer layer and to the side of the polishing layer opposite the polishing surface, respectively. Laminate the buffer layer and the polishing layer such that the sides to which the heat-sealing adhesive has been applied are in contact, and then use a pressure roller to apply pressure at a temperature of about 140 (±5) °C and a pressure of 2 kgf / cm² to prepare a polishing pad. Test Example B1 : Measurement of the physical properties of the polishing pad Test each of the polishing layer, the support layer, and the polishing pad laminated therewith prepared as described above as follows. (1) Hardness Each sample was cut into 5 cm × 5 cm (thickness: 2 mm) and stored separately at room temperature and at 30 °C, 50 °C, and 70 °C for 12 hours. A hardness tester was used to measure the Shore D hardness and Asker C hardness. (2) Specific gravity Each sample was cut into 2 cm × 5 cm (thickness: 2 mm) and stored at 25 °C for 12 hours. A hydrometer was used to measure the specific gravity. (3) Tensile strength Each sample was cut into 4 cm × 1 cm (thickness: 2 mm). When the sample was tested using a universal testing machine (UTM) at a rate of 50 mm / min, the ultimate strength before fracture was measured immediately. (4) Elongation Each sample was cut into 4 cm × 1 cm (thickness: 2 mm). When the sample was tested using a universal testing machine (UTM) at a rate of 50 mm / min, the maximum deformation before fracture was measured immediately. The ratio of the maximum deformation to the initial length was expressed as a percentage (%). The results are shown in the following table. [Table 5] As can be seen from the above table, it has been confirmed that the polishing pad of Example B1 has properties suitable for the CMP method. Test of Example B2 : Using UV Change in debris size upon irradiation (1) Conditioning method A porous polyurethane polishing pad was attached to the platform of a CMP polishing machine. Thereafter, the operation of the carrier was excluded, and only the conditioner and cerium dioxide slurry were used to collect the debris of the polishing layer. When cerium dioxide slurry was supplied at 250 ml / min under the conditions of a platform speed of 93 rpm, a conditioner load of 9 lbs, a rotational speed of 64 rpm, and a scanning speed of 19 times / min, a CI45 disk (pad cutting rate 80 to 90 μm / hour, Saesol) was used to condition the polishing layer. The debris of the polishing layer formed after 10 minutes of conditioning was collected in the form of a solution mixed with cerium dioxide slurry, thereby obtaining 300 ml of a debris solution. (2) UV irradiation When the obtained debris solution was irradiated with UV light (wavelength 100 to 380 nm) at an intensity of 1 kW at a distance of 5 cm for 10 minutes using a UV lamp (light source type: mercury lamp), the debris solution was collected at 2-minute intervals. In this case, the collected debris solution had a pH of approximately 10. (4) Analysis of debris particle size The D50 particle size of the debris in the debris solution was measured using a particle size analyzer (Mastersize 3000, Malvern) and a medium-capacity automatic disperser (Hydro MV, Malvern). The analyzer was set with a refractive index of 1.55 for polyurethane as the material to be analyzed, a refractive index of 1.33 for deionized water as the dispersant, and a stirring speed of 2,500 rpm. The results are shown in FIGS. 5 and 6 and Tables 6 and 7 below. [Table 6] [Table 7] As can be seen from Tables 6 and 7 and FIGS. 5 and 6 above, for the polishing pad according to Example B1, as the time of UV light irradiation elapses, the debris particle size decreases, and it is the smallest when measured at 2 to 4 minutes. After that, when the time of UV light irradiation further elapses to 6 to 8 minutes, a slightly increasing trend is shown. Overall, as the time of UV light irradiation elapses, the debris particle size tends to decrease. On the other hand, the polishing pad B1 according to the comparative example shows a general increasing trend in the debris particle size as the time of UV light irradiation elapses. When 10 minutes have elapsed, an almost two-fold increase has been measured compared to the initial stage. Test Example B3 : Performance evaluation of the polishing pad (CMP and UV irradiation) As shown in FIGS. 7 and 8, a UV lamp (700) with adjustable angle and height was installed in the CMP polishing machine. A silicon wafer with a diameter of 300 mm and a silicon oxide layer deposited thereon by the CVD method was placed on a porous polyurethane polishing pad on a platform assembled in the CMP polishing machine, with the silicon oxide layer of the silicon wafer facing down. Then, the silicon oxide layer was polished under a polishing load of 4.0 pounds per square inch, while the polishing pad was rotated at a speed of 150 rpm, the calcined cerium dioxide slurry was supplied to the polishing pad at a rate of 250 ml / minute, and the platform was rotated at a speed of 150 rpm for 60 seconds. During the CMP polishing, the UV lamp (700) was activated to irradiate the polishing layer surface of the polishing pad with UV light (wavelength 100 to 380 nm) at an intensity of 1 kW from a distance of 5 cm. (1) Polishing rate (removal rate) Similar to the above, after the polishing is completed, the silicon wafer is separated from the carrier, and the wafer is assembled on a spin dryer, cleaned with deionized water (DIW), and then dried with nitrogen for 15 seconds. A spectroscopic reflectometer type thickness measuring instrument (manufacturer: Keyence, model: SI-F80R) is used to measure the film thickness of the dried silicon wafer before and after polishing. After that, the following mathematical equation 1 is used to calculate the polishing rate. [Mathematical equation 1] Polishing rate (angstroms / minute) = thickness difference before and after polishing (angstroms) / polishing time (minutes) (2) Defects Polishing is carried out in the same manner as the polishing rate test using a CMP polishing machine. After the polishing is completed, the silicon wafer is transferred to a cleaner, and each is cleaned with 1% HF, 1% H 2 NO 3 and deionized water (DIW) for 10 seconds. After that, it is transferred to a spin dryer, cleaned with deionized water (DIW), and then dried with nitrogen for 15 seconds. A defect measuring device (manufacturer: Tenkor, model: XP+) is used to measure the change in defects in the dried silicon wafer before and after polishing. In particular, the total number of scratches, chatter marks, pits, and residues on the surface of the wafer is measured. (3) Pad wear rate (PWR) In the initial stage, each polishing pad is pre-conditioned with deionized water for 10 minutes and then conditioned while spraying deionized water for 1 hour. In this case, the thickness change during the 1-hour conditioning period is measured. The equipment used for conditioning is the AP-300HM of CTS. The conditioning pressure is 6 pounds-force, the rotation speed is 100 to 110 rpm, and the disk used for conditioning is CI-45 of Sasol. [Table 8] From the results of the test, the polishing pad of this example has both the polishing rate and the pad wear rate within the desired range, and has a very small number of defects. At the same time, the polishing pad of the comparative example has a polishing rate outside the desired range, and the occurrence of defects increases. 100: Polishing pad 150: Debris 200: Platform 300: Conditioner 400: Slurry feeder 450: Polishing slurry (CMP slurry) 510: Polishing head 520: Carrier 600: Semiconductor substrate (wafer) 650: Defect 700: UV lamp 750: UV light Figure 1 illustrates a method for fabricating a semiconductor device using a polishing pad according to a specific example. Figure 2 shows the occurrence of defects caused by debris during the method of fabricating the semiconductor device. Figure 3 shows a method of measuring the particle size of debris obtained from a polishing pad according to a specific example. Figure 4 shows a method of measuring the ζ potential of an aqueous solution of debris obtained from a polishing pad according to a specific example. Each of Figures 5 and 6 shows the change in the particle size of debris obtained from polishing pads according to Examples and Comparative Examples with respect to the UV irradiation time. Figures 7 and 8 show the device configurations for irradiating UV light during the CMP method according to specific examples. 100: Polishing pad 200: Platform 300: Conditioner 450: Polishing slurry (CMP slurry) 510: Polishing head 520: Carrier 600: Semiconductor substrate (wafer)

Claims

1. A polishing pad comprising a polishing layer, wherein the polishing layer comprises a prepolymer based on an aminocarbamate, a foaming agent, and a curing agent; when the polishing layer is conditioned for 10 minutes at a platform speed of 93 rpm, a conditioner load of 9 lbs, a conditioner speed of 64 rpm, and a sweep rate of 19 times / min, while deionized water is supplied at a rate of 300 cc / min, the resulting debris has a D50 particle size of 50 micrometers or less at pH 5.5; and the aqueous solution containing 0.01% by weight of the debris has a zeta potential of -20 mV to 30 mV at pH 5.

5.

2. The polishing pad of claim 1, wherein the D50 particle size of the debris obtained during the conditioning of the polishing layer is 25 micrometers or less at pH 5.5 and 22.3 micrometers or less at pH 10.

3. The polishing pad of claim 1, wherein when the polishing layer is conditioned for 10 minutes, the resulting aqueous solution containing 0.01% by weight of debris has a zeta potential of -50 mV to -10 mV at pH 10.

4. The polishing pad of claim 1, wherein when the silicon oxide layer of a silicon wafer is polished with cerium dioxide slurry using the polishing pad, the polishing rate is 2,200 angstroms / minute to 2,600 angstroms / minute according to the following mathematical equation 1: [Mathematical Equation 1] Polishing rate (angstroms / minute) = thickness difference before and after polishing (angstroms) / polishing time (minutes).

5. A polishing pad comprising a polishing layer containing polyurethane resin, wherein when the polishing layer is prepared at a platform speed of 93 rpm, a conditioner load of 9 lbs, a conditioner speed of 64 rpm and a scan rate of 19 times / min, while a cerium dioxide slurry is supplied at 250 ml / min, and then irradiated with UV light having a wavelength of 100 nm to 380 nm at an intensity of 1 kW from a distance of 5 cm, the obtained debris satisfies the following relationship (1): D50 [0 min] > D50 [4 min]…(1) where D50 [0 min] is the D50 particle size of the debris obtained in the preparation before UV irradiation, and D50 [4 min] is the D50 particle size of the debris obtained after UV irradiation for 4 minutes after the preparation.

6. The polishing pad of claim 5, wherein ΔD50 [0-4 minutes] calculated according to the following equation is 10 micrometers or more: ΔD50 [0-4 minutes] = D50 [0 minutes] - D50 [4 minutes] where D50 [0 minutes] is the D50 particle size of the debris obtained in the conditioning before UV irradiation, and D50 [4 minutes] is the D50 particle size of the debris obtained after UV irradiation for 4 minutes after the conditioning.

7. The polishing pad as requested in item 5, wherein D50 [4 minutes] is 30 microns or less.

8. The polishing pad as requested in item 5, wherein when the polishing pad is tested at a conditioning pressure of 6 pounds and a rotational speed of 100 to 110 rpm, the pad wear rate (PWR) is 15 micrometers / hour to 40 micrometers / hour.

9. A method of fabricating a semiconductor device, comprising polishing the surface of a semiconductor substrate using a polishing pad as claimed in claim 1.

10. A method of fabricating a semiconductor device, comprising conditioning a polishing layer of the polishing pad by irradiation with UV light having a wavelength of 100 nanometers to 380 nanometers when chemically and mechanically polishing a semiconductor substrate using a polishing pad as claimed in claim 5.

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