Polishing pad with reduced defect generation and method for manufacturing semiconductor device using same

Abstract

To provide a polishing pad and a method of preparing a semiconductor device which minimize the occurrence of defects and scratches during a chemical mechanical planarization (CMP) process while keeping physical properties and performance of the polishing pad excellent.SOLUTION: In a semiconductor device preparation step, a polishing pad 100 is such that the particle size of debris obtained during conditioning and the zeta potential of a debris solution are adjusted to specific ranges. As a result, it is possible to minimize the occurrence of defects and scratches during a CMP process by reducing the size of debris while keeping physical properties and performance of the polishing pad excellent.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The embodiment relates to a polishing pad that can reduce defects and scratches during a chemical mechanical planarization (CMP) process and a method for manufacturing a semiconductor device using the same. [Background technology]

[0002] Among semiconductor manufacturing processes, the chemical mechanical planarization (CMP) process is a process in which a semiconductor substrate such as a wafer is attached to a head and brought into contact with the surface of a polishing pad formed on a platen. A slurry is supplied to chemically react with the surface of the semiconductor substrate, and the platen and head are moved relative to each other to mechanically planarize the uneven portions of the semiconductor substrate surface.

[0003] Polishing pads are essential components that play a key role in such CMP processes. They are usually made of polyurethane resin and have grooves on their surface that allow for large slurry flow and pores that support fine flow.

[0004] To manufacture the polishing pad, a prepolymer is obtained by reacting a diisocyanate with a polyol, and then the prepolymer is mixed with a curing agent and a foaming agent and cured to obtain a polyurethane foam sheet. The polyurethane foam sheet is then sliced ​​to the desired thickness to obtain an upper pad. A groove is then cut into the surface of the upper pad using a tip or the like to form a specific shape, and the upper pad is then bonded to a polyurethane lower pad to complete the polishing pad.

[0005] The CMP process can be applied in multiple ways during the manufacturing process of semiconductor devices. Semiconductor devices contain multiple layers, each with a complex and fine circuit pattern. In recent years, semiconductor devices have evolved toward smaller chip sizes and increasingly complex and finer patterns. As a result, the purpose of the CMP process has expanded beyond planarizing circuit wiring to include separating circuit wiring and improving wiring surfaces. As a result, more sophisticated and reliable CMP performance is required.

[0006] During the CMP process of such a polishing pad, debris is generated when the polishing surface is rubbed against the semiconductor substrate or when the polishing surface is cut by a diamond disk for conditioning. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Korean Patent Publication No. 2016-0027075 Summary of the Invention [Problem to be solved by the invention]

[0008] During the CMP process of a polishing pad, debris is generated during the friction process between the polishing surface and the semiconductor substrate, or when the polishing surface is cut by a diamond disk for conditioning. This debris can cause defects and scratches on the polishing surface during the CMP process.

[0009] As a result of research conducted by the inventors, it was found that the size and zeta potential characteristics of debris obtained from a polishing pad affect the occurrence of defects. By adjusting these characteristics within a certain range, it was possible to minimize the occurrence of defects and scratches during the CMP process while maintaining the various physical properties and performance of the polishing pad in an excellent state.

[0010] Furthermore, as a result of the inventors' research, they have been able to realize a polishing pad that reduces the particle size of debris by irradiating it with UV light during the CMP process, and by utilizing the characteristics of this polishing pad and irradiating it with UV light during the CMP process, they have been able to minimize the occurrence of defects and scratches in semiconductor devices.

[0011] Therefore, the problem to be solved relates to a polishing pad with reduced defect generation and a method for manufacturing a semiconductor device using the same. [Means for solving the problem]

[0012] According to one embodiment, a polishing pad is provided that includes a polishing layer, the polishing layer comprising a urethane-based prepolymer, a foaming agent, and a curing agent, and when the polishing layer is conditioned for 10 minutes under conditions of a platen speed of 93 rpm, a conditioner load of 9 lb, a conditioner speed of 64 rpm, and 19 sweeps / minute while supplying 300 cc / minute of deionized water, the D50 particle size of the resulting debris is 50 μm or less under pH 5.5 conditions, and the zeta potential of an aqueous solution containing the debris at a concentration of 0.01 wt% is -20 mV to 30 mV under pH 5.5 conditions.

[0013] In another embodiment, a polishing pad is provided, which includes a polishing layer containing a polyurethane resin, and after conditioning the polishing layer under conditions of a platen speed of 93 rpm, a conditioner load of 9 lb, a conditioner speed of 64 rpm, and 19 sweeps / minute while supplying 250 mL / min of ceria slurry, the polishing pad is 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, and the resulting debris satisfies the following formula (1): D50[0 minutes]>D50[4 minutes]...(1) Here, D50[0 min] is the D50 particle size of the debris obtained by conditioning before the UV light irradiation, and D50[4 min] is the D50 particle size of the debris obtained when irradiated with UV light for 4 minutes after the conditioning.

[0014] According to another embodiment, there is provided a method for manufacturing a semiconductor device, the method including polishing a surface of a semiconductor substrate using the polishing pad.

[0015] According to another embodiment, a method for manufacturing a semiconductor device is provided, which includes a step of conditioning the polishing layer of the polishing pad by irradiating UV light having a wavelength of 100 nm to 380 nm while chemically mechanically polishing a semiconductor substrate using the polishing pad. [Effects of the Invention]

[0016] The polishing pad according to the above embodiment can minimize the occurrence of defects and scratches during the CMP process while maintaining excellent physical properties and performance of the polishing pad by adjusting the size and zeta potential characteristics of the resulting debris within a specific range.

[0017] The polishing pad according to the embodiment has a characteristic of reducing the particle size of debris by irradiating it with UV light during the CMP process, and by utilizing this characteristic of the polishing pad, the occurrence of defects and scratches in semiconductor devices can be minimized by irradiating it with UV light during the CMP process. Furthermore, the polishing pad according to the embodiment also has excellent characteristics such as a polishing rate, and therefore, when manufacturing semiconductor devices using the polishing pad, the CMP performance and yield can be improved. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 illustrates a semiconductor device manufacturing process using a polishing pad according to one implementation. [Figure 2] FIG. 2 is a diagram showing the occurrence of defects due to debris during the semiconductor device manufacturing process. [Figure 3] FIG. 3 is a method for measuring particle size of debris obtained from a polishing pad according to one implementation. [Figure 4] FIG. 4 shows a method for measuring the zeta potential of an aqueous debris solution obtained from a polishing pad according to one implementation. [Figure 5]FIG. 5 is a diagram showing the change in particle size of debris obtained from the polishing pad according to the example depending on the UV irradiation time. [Figure 6] FIG. 6 is a diagram showing the change in particle size of debris obtained from a polishing pad according to a comparative example depending on the UV irradiation time. [Figure 7] FIG. 7 is a diagram showing the configuration of an apparatus for irradiating UV light during a CMP process according to one implementation example. [Figure 8] FIG. 8 is a diagram showing the configuration of an apparatus for irradiating UV light during a CMP process according to one implementation example. DETAILED DESCRIPTION OF THE INVENTION

[0019] Various implementations and embodiments will now be described in detail with reference to the drawings.

[0020] In describing the implementation examples, if a detailed description of related known structures or functions is deemed to obscure the gist of the implementation examples, the detailed description will be omitted. In addition, the size of each component in the drawings may be exaggerated or omitted for the purpose of explanation, and may differ from the size actually applied.

[0021] In this specification, when a component is described as being formed above / below another component, or as being connected or coupled to each other, this includes being formed, coupled or coupled directly between these components, or indirectly via other components. It should also be understood that the reference to the above / below of each component may change depending on the direction from which the object is viewed.

[0022] In this specification, terms referring to components are used to distinguish them from other components and are not intended to limit implementation examples. Furthermore, in this specification, the singular expression includes the plural expression unless the context clearly indicates otherwise.

[0023] In this specification, terms such as "first" and "second" are used to describe various components, and the components should not be limited by these terms. These terms are used to distinguish one component from another.

[0024] In this specification, the term "comprises" is intended to embody certain features, regions, steps, processes, elements and / or components, and does not exclude the presence or addition of other features, regions, steps, processes, elements and / or components, unless specifically stated to the contrary.

[0025] As is well known, the molecular weights of the compounds and polymers described herein, such as number average molecular weights and weight average molecular weights, are expressed as relative masses based on carbon-12 without units, but may be understood to be the molar mass (g / mol) of the same numerical value, if necessary.

[0026] In the numerical ranges limiting the size, physical properties, etc. of the components described in this specification, when a numerical range limited only by an upper limit value and a numerical range limited only by a lower limit value are separately exemplified, it should be understood that the numerical range combining these upper and lower limit values ​​is also included in the exemplary range.

[0027] [Chemical mechanical polishing] Semiconductor devices are manufactured by chemical mechanical polishing using a polishing pad. According to one implementation, a method for manufacturing a semiconductor device includes polishing a surface of a semiconductor substrate with a polishing pad.

[0028] Specifically, the method for manufacturing the semiconductor device may include providing a polishing pad according to the embodiment, and polishing the surface of the semiconductor substrate by rotating the polishing pad relative to each other so that the polishing surface of the polishing layer and the surface of the semiconductor substrate abut against each other.

[0029] 1 is a diagram illustrating a semiconductor device manufacturing process using a polishing pad according to one embodiment. Referring to FIG. 1, a polishing pad 100 according to one embodiment is mounted on a platen 200, and then a semiconductor substrate 600 to be polished is placed on the polishing pad 100. At this time, the surface to be polished of the semiconductor substrate 600 directly contacts the polishing surface of the polishing pad 100. For polishing, a polishing slurry 450 may be sprayed onto the polishing pad through a nozzle. The flow rate of the polishing slurry 450 supplied through the nozzle is about 10 cm. 3 / min ~ approx. 1000cm 3 / min. can be selected according to the purpose, for example, about 50 cm 3 / min ~ approx. 500cm 3 / min, but is not limited to this.

[0030] Thereafter, the semiconductor substrate 600 and the polishing pad 100 may rotate relative to each other to polish the surface of the semiconductor substrate 600. At this time, the rotation direction of the semiconductor substrate 600 and the rotation direction of the polishing pad 100 may be the same or opposite. The rotation speeds of the semiconductor substrate 600 and the polishing pad 100 may be selected depending on the purpose within a range of about 10 rpm to about 500 rpm, and may be, for example, about 30 rpm to about 200 rpm, but are not limited thereto.

[0031] The semiconductor substrate 600, attached to the polishing head 510, is pressed against the polishing surface of the polishing pad 100 with a predetermined load, and then the surface of the semiconductor substrate 600 is polished. The load applied by the polishing head 510 to the surface of the semiconductor substrate 600 and the polishing surface of the polishing pad 100 is about 1 gf / cm. 2 ~About 1000gf / cm 2 can be selected depending on the purpose, for example, about 10 gf / cm 2 ~About 800gf / cm 2 It can be, but is not limited to this.

[0032] In one embodiment, the semiconductor substrate 600 to be polished may include an oxide film, a tungsten film, or a composite film thereof. Specifically, the semiconductor substrate 600 may include an oxide film, a tungsten film, or a composite film of oxide and tungsten. The composite film of oxide and tungsten may be a multi-layer film in which the tungsten film is stacked on one side of the oxide film, or a single-layer film in which an oxide region and a tungsten region are mixed within one layer. When the polishing target has such film properties and the polishing pad has the properties according to the embodiment, defects in semiconductor devices manufactured by the method for manufacturing semiconductor devices may be minimized.

[0033] In one embodiment, the method for manufacturing a semiconductor device may further include, in the step of polishing the object to be polished, supplying either the oxide film polishing slurry or the tungsten film polishing slurry, or supplying the oxide film polishing slurry and the tungsten film polishing slurry sequentially to the polishing surface.

[0034] For example, if the semiconductor substrate to be polished includes an oxide film, the method for manufacturing a semiconductor device may include supplying the oxide film polishing slurry. If the semiconductor substrate includes a tungsten film, the method for manufacturing a semiconductor device may include supplying the tungsten film polishing slurry. If the semiconductor substrate includes a composite film of an oxide film and a tungsten film, the method for manufacturing a semiconductor device may include supplying the oxide film polishing slurry and the tungsten film polishing slurry sequentially to the polishing surface. In this case, depending on the process, the oxide film polishing slurry may be supplied first and then the tungsten film polishing slurry may be supplied later, or the tungsten film polishing slurry may be supplied first and then the oxide film polishing slurry may be supplied later.

[0035] In one embodiment, the method for manufacturing a semiconductor device may further include a step of processing the polishing surface of the polishing pad 100 with a conditioner 300 simultaneously with polishing the semiconductor substrate 600 to maintain the polishing surface of the polishing pad 100 in a state suitable for polishing.

[0036] In the polishing pad according to one embodiment, the size and zeta potential characteristics of the debris obtained from the polishing layer are adjusted within a specific range, thereby minimizing the occurrence of defects and scratches during the CMP process while maintaining excellent physical properties and performance of the polishing pad. Therefore, high-quality semiconductor devices can be efficiently manufactured using the polishing pad.

[0037] [Polishing pad] According to one embodiment, the polishing pad includes a polishing layer, specifically, the polishing pad includes a polishing layer including a polyurethane resin.

[0038] Specifically, the polishing pad includes a polishing layer and a support layer, and an adhesive layer may be inserted between the polishing layer and the support layer.

[0039] 2 is a diagram illustrating the generation of defects due to debris during the manufacturing process of a semiconductor device. Referring to FIG. 2, debris 150 generated from the polishing layer generates defects 650 and scratches on the surface of the semiconductor device. In one embodiment, the size and zeta potential of the debris generated from the polishing layer can be adjusted within a specific range to minimize the generation of defects and scratches.

[0040] In one implementation, the polishing pad provides debris having a particular range of particle size.

[0041] 3 is a diagram showing a method for measuring the particle size of debris obtained from a polishing pad according to one embodiment. Referring to FIG. 3, a polishing pad is attached and set on the platen of a CMP polishing apparatus, and the polishing layer is conditioned while supplying deionized water. After 10 minutes of conditioning, debris from the polishing layer is collected in a solution state mixed with deionized water. The pH of the aqueous debris solution is adjusted using a nitric acid solution or a potassium hydroxide solution, and the particle size of the debris is measured using a particle size analyzer.

[0042] Specifically, the debris was obtained by conditioning the polishing layer of the polishing pad under the conditions of a platen speed of 93 rpm, a conditioner load of 9 lb, a conditioner speed of 64 rpm, and 19 sweeps / min while supplying 300 cc / min of deionized water, and the particle size of the debris may be an average particle size, i.e., D50 particle size. As a specific example, the conditioner may be a diamond disc (e.g., a CI45 type disc manufactured by Sesol) with a pad cut rate (PCR) of 80 μm / hr to 90 μm / hr.

[0043] According to one implementation example, the D50 particle size of the debris obtained when conditioning the polishing layer under the above conditions for 10 minutes is 50 μm or less under pH 5.5 conditions.

[0044] Specifically, the D50 particle size of the debris obtained when conditioning the polishing layer under the above conditions for 10 minutes can be 40 μm or less, 30 μm or less, 25 μm or less, 22 μm or less, 20 μm or less, 19 μm or less, 18 μm or less, or 17 μm or less under pH 5.5 conditions, and can also be 5 μm or more, 10 μm or more, or 15 μm or more.

[0045] More specifically, the D50 particle size of the debris obtained when the polishing layer is conditioned under the above conditions for 10 minutes can be 10 μm to 50 μm, 10 μm to 40 μm, 10 μm to 30 μm, 10 μm to 25 μm, 10 μm to 22 μm, 10 μm to 21 μm, 10 μm to 20 μm, 10 μm to 19 μm, 10 μm to 18 μm, or 10 μm to 17 μm under pH 5.5 conditions.

[0046] According to another embodiment, the D50 particle size of the debris obtained when conditioning the polishing layer under the above conditions for 10 minutes is 35 μm or less under pH 10 conditions.

[0047] Specifically, the D50 particle size of the debris obtained when conditioning the polishing layer for 10 minutes under the above conditions may be 35 μm or less, 30 μm or less, 25 μm or less, 24 μm or less, 23 μm or less, 22.3 μm or less, 22 μm or less, or 21 μm or less under pH 10 conditions, and may also be 5 μm or more, 10 μm or more, 15 μm or more, or 20 μm or more.

[0048] More specifically, the D50 particle size of the debris obtained when conditioning the polishing layer under the above conditions for 10 minutes can be 15 μm to 35 μm, 15 μm to 30 μm, 15 μm to 25 μm, 15 μm to 24 μm, 15 μm to 23 μm, 15 μm to 22.3 μm, 15 μm to 22 μm, or 15 μm to 21 μm under pH 10 conditions.

[0049] According to one specific example, the D50 particle size of the debris obtained when conditioning the polishing layer may be 25 μm or less under pH 5.5 conditions and 22.3 μm or less under pH 10 conditions.

[0050] Within the preferred particle size range, the occurrence of defects and scratches during the CMP process can be minimized while maintaining excellent physical properties and performance of the polishing pad.

[0051] Additionally, polishing pads according to the above implementations may result in aqueous solutions of debris having a particular range of zeta potential.

[0052] FIG. 4 illustrates a method for measuring the zeta potential of an aqueous debris solution obtained from a polishing pad according to one embodiment. Referring to FIG. 4, a polishing pad is attached to the platen of a CMP polishing apparatus, and the polishing layer is conditioned by supplying deionized water. After 10 minutes of conditioning, the resulting polishing layer debris is collected in a solution state mixed with deionized water. To ensure particle stability, the aqueous debris solution is stored at room temperature for 24 hours to allow particles with a diameter of 20 μm or greater to settle. The supernatant liquid located within 10 mm from the upper surface of the solution is then collected as a sample. The pH of the sample is then adjusted using an aqueous nitric acid solution or an aqueous potassium hydroxide solution, and the zeta potential of the sample is measured using a Zetasizer. The sample may contain debris at a concentration of 0.01 wt %.

[0053] As an example, the zeta potential of an aqueous solution containing debris at a concentration of 0.01 wt % obtained when conditioning the polishing layer under the above conditions for 10 minutes may be, under pH 5.5 conditions, -20 mV or more, -15 mV or more, -10 mV or more, -5 mV or more, 0 mV or more, 5 mV or more, or 10 mV or more, and may also be 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.

[0054] In one embodiment, the zeta potential of an aqueous solution containing debris at a concentration of 0.01 wt % obtained when conditioning the polishing layer for 10 minutes under the above conditions is −20 mV to 30 mV under pH 5.5 conditions.

[0055] Specifically, the zeta potential of an aqueous solution containing debris at a concentration of 0.01 wt % obtained when conditioning the polishing layer under the above conditions for 10 minutes 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 under pH 5.5 conditions.

[0056] More specifically, the zeta potential of an aqueous solution of the debris may be a positive (+) value.

[0057] Within this desirable range, the zeta potential of the debris is similar to that of the abrasive particles (e.g., ceria particles) in the CMP polishing composition (slurry), which can further reduce the occurrence of defects. Specifically, the zeta potential quantitatively represents the magnitude of the repulsive and attractive forces between particles generated by the cations and anions of the particles in the suspension. When the zeta potentials of the debris and the abrasive particles are similar, the repulsive forces between the particles increase, preventing aggregation, which can reduce the particle size in the composition and reduce the occurrence of defects and scratches.

[0058] As another example, the zeta potential of an aqueous solution containing debris at a concentration of 0.01 wt % obtained when conditioning the polishing layer under the above conditions for 10 minutes may be −50 mV or more, −45 mV or more, −40 mV or more, −35 mV or more, or −30 mV or more under pH 10 conditions, and may also be 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.

[0059] Specifically, the zeta potential of an aqueous solution containing debris at a concentration of 0.01 wt % obtained when conditioning the polishing layer for 10 minutes under the above conditions can be −50 mV to −10 mV under pH 10 conditions.

[0060] More specifically, the zeta potential of an aqueous solution containing debris at a concentration of 0.01 wt % obtained when conditioning the polishing layer for 10 minutes under the above conditions 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 under pH 10 conditions.

[0061] Furthermore, the polishing pad has a certain relationship between the particle size of debris and the zeta potential depending on the pH condition, which can further improve the effect.

[0062] According to one implementation example, the value of the following formula (1) may be −20 μm / mV to 30 μm / mV, and in one specific example, −10 μm / mV to 20 μm / mV. D50[5.5] / Zp[5.5]...(1) Here, D50[5.5] is the D50 particle size (μm) of the debris obtained when conditioning the polishing layer under pH 5.5 conditions, and Zp[5.5] is the zeta potential (mV) of an aqueous solution containing the debris obtained when conditioning the polishing layer at a concentration of 0.01 wt % under pH 5.5 conditions.

[0063] For example, the value of the formula (1) may be -20 μm / mV or more, -10 μm / mV or more, -5 μm / mV or more, or 0 μm / mV or more, or 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. Specifically, the value of the formula (1) may be -10 μm / mV to 15 μm / mV, -5 μm / mV to 20 μm / mV, -5 μm / mV to 15 μm / mV, 0 μm / mV to 15 μm / mV, -5 μm / mV to 10 μm / mV, 0 μm / mV to 10 μm / mV, -5 μm / mV to 5 μm / mV, or 0 μm / mV to 5 μm / mV.

[0064] According to another implementation, the value of the following formula (2) may be 60% to 120%, and in one specific example, 70% to 110%. (D50[5.5] / D50

[10] )×100...(2) Here, D50[5.5] is the D50 particle size (μm) of the debris obtained when conditioning the polishing layer under pH 5.5 conditions, and D50

[10] is the D50 particle size (μm) of the debris obtained when conditioning the polishing layer under pH 10 conditions.

[0065] For example, the value of formula (2) may be 60% or more, 70% or more, or 75% or more, and may be 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. Specifically, the value of formula (2) may be 70% to 105%, 70% to 100%, 70% to 95%, 70% to 90%, 70% to 85%, or 75% to 85%.

[0066] According to another implementation example, the value of the following formula (3) may be 25 mV to 65 mV, and in one specific example, 35.5 mV to 60 mV. Zp[5.5]-Zp

[10] ...(3) Here, Zp[5.5] is the zeta potential (mV) of an aqueous solution containing 0.01 wt% of debris obtained when conditioning the polishing layer at a pH of 5.5, and Zp

[10] is the zeta potential (mV) of an aqueous solution containing 0.01 wt% of debris obtained when conditioning the polishing layer at a pH of 10.

[0067] For example, the value of the formula (3) may be 25 mV or more, 35.5 mV or more, or 36 mV or more, and may be 65 mV or less, 60 mV or less, 55 mV or less, 50 mV or less, or 45 mV or less. Specifically, the value of the formula (3) may be 35.5 mV to 55 mV, 35.5 mV to 50 mV, 35.5 mV to 45 mV, 35.5 mV to 40 mV, 36 mV to 60 mV, 36 mV to 50 mV, 36 mV to 45 mV, or 36 mV to 40 mV.

[0068] Furthermore, the polishing pad according to the above embodiment is excellent in performance and physical properties.

[0069] For example, when the polishing pad is used to polish a silicon oxide film on a silicon wafer with a ceria slurry, the removal rate may be 2000 Å / min or more, 2200 Å / min or more, 2300 Å / min or more, or 2400 Å / min or more, and 3000 Å / min or less, 2800 Å / min or less, 2600 Å / min or less, or 2500 Å / min or less.

[0070] As a specific example, when the polishing pad is used to polish a silicon oxide film on a silicon wafer with ceria slurry, the polishing rate according to the following Equation 1 may be 2200 Å / min to 2600 Å / min. [Number 1] Polishing rate (Å / min) = Change in film thickness before and after polishing (Å) / Polishing time (min)

[0071] Specifically, the polishing rate may be the polishing rate for a silicon wafer having a diameter of 300 mm and deposited with silicon oxide. The polishing rate may be measured under conditions of a polishing load of 4.0 psi, a polishing pad rotation speed of 150 rpm, and a calcined ceria slurry being introduced at 250 mL / min while the platen was rotated at 150 rpm for 60 seconds. The temperature conditions for measuring the polishing rate are not particularly limited, but may be, for example, room temperature.

[0072] The pad removal rate of the polishing layer may be 30 μm / hr to 60 μm / hr, 30 μm / hr to 50 μm / hr, 40 μm / hr to 60 μm / hr, or 40 μm / hr to 50 μm / hr.

[0073] The thickness of the polishing pad may 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. When the thickness is within this range, the particle size deviation between the upper and lower portions of the pores can be minimized, while the basic physical properties of the polishing pad can be fully exhibited.

[0074] [Polishing pad characteristics when exposed to UV light] In one embodiment, the polishing pad has the property of reducing the particle size of debris when irradiated with UV light during the CMP process. Therefore, by utilizing this property of the polishing pad and irradiating UV light during the CMP process, the occurrence of defects and scratches in semiconductor devices can be minimized.

[0075] 5 and 6 show the change in particle size of debris obtained from the polishing pads according to the example and comparative example with respect to the UV irradiation time, respectively.

[0076] 5, the polishing pad according to the example showed a decrease in debris particle size as the UV light irradiation time increased, reaching its smallest value after 2 to 4 minutes, and then showed a slight increase after 6 to 8 minutes of UV light irradiation, but overall the debris particle size tended to decrease as the UV light irradiation time increased. On the other hand, the polishing pad according to the comparative example showed a tendency for the debris particle size to generally increase as the UV light irradiation time increased, and after 10 minutes it was measured to be nearly twice as large as the initial size.

[0077] During UV irradiation, molecular bonds are broken and particles aggregate simultaneously. Depending on which of these phenomena prevails, the particle size of the debris may tend to increase or decrease. This tendency may occur depending on the composition and characteristics of the polishing pad.

[0078] To measure the particle size of the debris, a polishing pad is attached and set on the platen of a CMP polishing apparatus, the polishing layer is conditioned while CMP slurry is supplied, and the debris from the polishing layer generated 10 minutes after conditioning is collected in a solution state mixed with the CMP slurry.The debris solution is then irradiated with UV light of 100 nm to 380 nm wavelength at an intensity of 1 kW from a predetermined distance, and the particle size of the debris is measured using a particle size analyzer.

[0079] Specifically, the debris was obtained by conditioning the polishing layer of the polishing pad under the conditions of a platen speed of 93 rpm, a conditioner load of 9 lb, a conditioner speed of 64 rpm, and 19 sweeps / min while supplying 250 ml / min of ceria slurry, and the particle size of the debris may be an average particle size, i.e., D50 particle size. As a specific example, the conditioner may be a diamond disc (e.g., a CI45 type disc from Sesol) with a pad wear rate (PWR) of 80 μm / hr to 90 μm / hr.

[0080] In one embodiment of the polishing pad, the polishing layer is conditioned by supplying 250 mL / min of ceria slurry under the conditions of a platen speed of 93 rpm, a conditioner load of 9 lb, a conditioner speed of 64 rpm, and 19 sweeps / 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, such that the debris obtained satisfies the following formula (1). D50[0 minutes]>D50[4 minutes]...(1) Here, D50[0 min] is the D50 particle size of the debris obtained by conditioning before the UV light irradiation, and D50[4 min] is the D50 particle size of the debris obtained when irradiated with UV light for 4 minutes after the conditioning.

[0081] In particular, in the formula (1), the difference between D50[0 min] and D50[4 min] may be at a certain level or more. For example, if ΔD50[0-4 min] calculated by the following formula is 5 μm or more, it is more advantageous in terms of the debris reduction effect due to UV irradiation.

[0082] D50[0-4 minutes]=D50[0 minutes]-D50[4 minutes] Here, D50[0 min] is the D50 particle size of the debris obtained by conditioning before the UV light irradiation, and D50[4 min] is the D50 particle size of the debris obtained when irradiated with UV light for 4 minutes after the conditioning.

[0083] Specifically, the ΔD50[0-4 min] is 5 μm or more, 7 μm or more, 10 μm or more, or 13 μm or more, and can be 35 μm or less, 30 μm or less, 25 μm or less, or 20 μm or less. More specifically, the ΔD50[0-4 min] can be 5 μm to 30 μm, 5 μm to 25 μm, 10 μm to 30 μm, or 10 μm to 25 μm.

[0084] The D50[4 min] is, for example, 40 μm or less, 35 μm or less, 30 μm or less, 27 μm or less, or 25 μm or less, and can be 5 μm or more, 10 μm or more, 15 μm or more, or 20 μm or more. As a specific example, the D50[4 min] can be 30 μm or less. As a more specific example, the D50[4 min] can be 5 μm to 30 μm. Within the preferred range, the occurrence of defects in the semiconductor element due to debris can be further minimized.

[0085] The D50[0 min] is, for example, 20 μm or more, 25 μm or more, 30 μm or more, or 35 μm or more, and can be 65 μm or less, 60 μm or less, 55 μm or less, or 45 μm or less. Specifically, the D50[0 min] can be 20 μm to 60 μm or 30 μm to 50 μm. More specifically, the D50[0 min] can be 35 μm or more, and the D50[4 min] can be 30 μm or less.

[0086] In other embodiments, the polishing pad may satisfy the following formula (2). D50[4 min]<D50[8 min]...(2) Here, D50[4 min] is the D50 particle size of the debris obtained when irradiating UV light for 4 minutes after the conditioning, and D50[8 min] is the D�0 particle size of the debris obtained when irradiating UV light for 8 minutes after the conditioning.

[0087] In the formula (2), the difference between D50[8 min] and D50[4 min] can be within a certain range. For example, it is advantageous for ΔD50[8-4 min] calculated by the following formula to be 20 μm or less in order to maintain the tendency for the debris particle size to decrease due to UV irradiation. △D50[8-4 minutes]=D50[8 minutes]-D50[4 minutes] Here, D50[4 min] is the D50 particle size of the debris obtained when irradiated with UV light for 4 minutes after the conditioning, and D50[8 min] is the D50 particle size of the debris obtained when irradiated with UV light for 8 minutes after the conditioning.

[0088] Specifically, the ΔD50[8-4 min] may be 20 μm or less, 15 μm or less, or 10 μm or less, or 3 μm or more, or 5 μm or more. More specifically, the ΔD50[8-4 min] may be 3 μm to 20 μm, 3 μm to 15 μm, 3 μm to 10 μm, or 5 μm to 15 μm.

[0089] The D50[8 min] may be, for example, 55 μm or less, 50 μm or less, 45 μm or less, or 40 μm or less, or 15 μm or more, 20 μm or more, 25 μm or more, or 30 μm or more. Specifically, the D50[8 min] may be 20 μm to 50 μm or 25 μm to 40 μm.

[0090] More specifically, the D50[8 min] may be 30 μm to 40 μm, and the D50[4 min] may be 20 μm to 30 μm.

[0091] In another embodiment, the polishing pad may satisfy the following formula (3): (D90[0 min]-D10[0 min])>(D90[4 min]-D10[4 min])...(3) Here, D10[0 min] and D90[0 min] are the D10 and D90 particle sizes of the debris obtained by conditioning before the UV irradiation, and D10[4 min] and D90[4 min] are the D10 and D90 particle sizes of the debris obtained when irradiated with UV light for 4 minutes after the conditioning.

[0092] In the formula (3), the difference between (D90[0 min]-D10[0 min]) and (D90[4 min]-D10[4 min]) may be equal to or greater than a certain level.

[0093] For example, it is more advantageous in terms of the effect of reducing the particle size of debris by UV irradiation if ΔD90-10 [4 min] calculated by the following formula is 50 μm or more. D90-10[4 minutes]=(D90[0 minutes]-D10[0 minutes])-(D90[4 minutes]-D10[4 minutes]) Here, D10[0 min] and D90[0 min] are the D10 and D90 particle sizes of the debris obtained by conditioning before the UV irradiation, and D10[4 min] and D90[4 min] are the D10 and D90 particle sizes of the debris obtained when irradiated with UV light for 4 minutes after the conditioning.

[0094] Specifically, the ΔD90-10[4min] may be 50 μm or more, 70 μm or more, 100 μm or more, or 120 μm or more, and may be 300 μm or less, 250 μm or less, 200 μm or less, or 150 μm or less. More specifically, the ΔD90-10[4min] may be 50 μm to 300 μm, 100 μm to 200 μm, or 100 μm to 150 μm.

[0095] In the formula (3), (D90[0 min]-D10[0 min]) may be 80 μm or more, 100 μm or more, 120 μm or more, or 140 μm or more, and may be 220 μm or less, 200 μm or less, or 180 μm or less. Specifically, (D90[0 min]-D10[0 min]) may be 100 μm to 200 μm or 140 μm to 180 μm.

[0096] In the formula (3), (D90[4 min]-D10[4 min]) may be 10 μm or more, 20 μm or more, or 30 μm or more, and may be 80 μm or less, 70 μm or less, 60 μm or less, or 50 μm or less. Specifically, (D90[4 min]-D10[4 min]) may be 20 μm to 60 μm or 30 μm to 50 μm.

[0097] Furthermore, the polishing pads according to the above examples have excellent properties. For example, when polishing a silicon oxide film on a silicon wafer with a ceria slurry using the polishing pad while irradiating it 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 can be 1700 Å / min or more, 1800 Å / min or more, 1900 Å / min or more, or 2000 Å / min or more, and 2600 Å / min or less, 2400 Å / min or less, 2300 Å / min or less, 2200 Å / min or less, or 2100 Å / min or less.

[0098] As a specific example, when a silicon oxide film on a silicon wafer is polished with a ceria slurry using the polishing pad while irradiating 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 formula 1 may be 1800 Å / min to 2200 Å / min. [Number 1] Polishing rate (Å / min) = Change in film thickness before and after polishing (Å) / Polishing time (min)

[0099] Specifically, the polishing rate may be the polishing rate for a silicon wafer having a diameter of 300 mm and deposited with silicon oxide. The polishing rate may be measured under conditions of a polishing load of 4.0 psi, a polishing pad rotation speed of 150 rpm, and a calcined ceria slurry being introduced at a rate of 250 mL / min while the platen is rotated at 150 rpm for 60 seconds. The temperature conditions for measuring the polishing rate are not particularly limited, but may be, for example, room temperature.

[0100] The polishing pad may have a pad wear rate (PWR) of 15 μm / hr to 40 μm / hr when tested at a conditioning pressure of 6 lbf and a rotation speed of 100 to 110 rpm. Specifically, the pad wear rate of the polishing layer may be 15 μm / hr to 35 μm / hr, 15 μm / hr to 30 μm / hr, 20 μm / hr to 40 μm / hr, or 15 μm / hr to 22 μm / hr.

[0101] The thickness of the polishing pad may 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. When the thickness is within this range, the particle size deviation between the upper and lower portions of the pores can be minimized, and the basic physical properties of the polishing pad can be fully exhibited.

[0102] [Polishing layer] The polishing layer provides a polishing surface that contacts a semiconductor substrate during a CMP process, and constitutes a top pad of a polishing pad.

[0103] According to one implementation, the polishing layer includes a polyurethane resin. The polishing layer includes a urethane-based prepolymer, a foaming agent, and a curing agent. Specifically, the polyurethane resin is obtained from a composition including a urethane-based prepolymer, a foaming agent, and a curing agent.

[0104] Specifically, the polishing layer includes a polyurethane resin, which is a reaction product of a urethane prepolymer, a foaming agent, and a curing agent, i.e., a cured product of the mixed composition of the components, and more specifically, a porous polyurethane resin. The polishing layer may also include a plurality of pores formed by the foaming agent.

[0105] The thickness of the polishing layer may be, for example, 0.8 mm or more, 1 mm or more, 1.2 mm or more, or 1.5 mm or more, and 5 mm or less, 3 mm or less, 2.5 mm or less, or 2 mm or less. As a specific example, the thickness of the polishing layer may be 0.8 mm to 5 mm, or 1.5 mm to 3 mm.

[0106] The specific gravity of the polishing layer is, for example, 0.6 g / cm 3 More than 0.7g / cm 3 or more than 0.75g / cm 3 and above, and 0.9 g / cm 3 Below, 0.85g / cm 3 or less, or 0.8g / cm 3In one specific example, the specific gravity of the polishing layer may be 0.6 g / cm or less. 3 ~0.9g / cm 3 or 0.7 g / cm 3 ~0.9g / cm 3 It could be.

[0107] The hardness of the polishing layer may be, for example, 30 Shore D or more, 40 Shore D or more, or 50 Shore D or more, and 80 Shore D or less, 70 Shore D or less, 65 Shore D or less, or 60 Shore D or less. As a specific example, the hardness of the polishing layer may be 30 Shore D to 80 Shore D, or 50 Shore D to 65 Shore D.

[0108] The tensile strength of the polishing layer is, for example, 5 N / mm 2 More than 10N / mm 2 or more than 15N / mm 2 and above, and 30N / mm 2 Below, 25N / mm 2 or less than 20N / mm 2 As a specific example, the tensile strength of the polishing layer may be 5 N / mm 2 ~30N / mm 2 or 15N / mm 2 ~25N / mm 2 It could be.

[0109] The elongation of the polishing layer may be, 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. Specific examples of the elongation of the polishing layer include 50% to 300% and 90% to 130%. The elongation may be the elongation at break.

[0110] As a specific example, the abrasive layer has a hardness of 50 Shore D to 65 Shore D and a surface roughness of 15 N / mm 2 ~25N / mm 2 and an elongation of 90% to 130%.

[0111] The pores are dispersed within the polishing layer. The average diameter of the pores can 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.

[0112] The total area of ​​the pores may be 30% to 60%, 35% to 50%, or 35% to 43% of the total area of ​​the polishing layer, and the total volume of the pores may be 30% to 70%, or 40% to 60% of the total volume of the polishing layer.

[0113] The polishing layer may have grooves on its surface for mechanical polishing, and the grooves may have a depth, width, and interval appropriate for mechanical polishing, without being particularly limited.

[0114] In one embodiment of the polishing pad, the polishing layer has a chlorine (Cl) content of 10,000 ppm or less when analyzed according to the IEC 62321-3-2 standard.

[0115] Specifically, the chlorine content can be measured by measuring the chlorine content of a sample according to IEC 62321-3-2, 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 may be a circular sample having a diameter of 3 cm and a height of 0.3 cm taken from the polishing layer of the polishing pad.

[0116] IEC62321-3-2 is a halogen component screening test method developed to comply with regulations on halogen use. This test method is more precise, accurate, and reproducible than conventional halogen analysis methods (e.g., oxygen bomb-IC, oxygen flask-IC), and its automated nature means that test results are more reliable. In one embodiment, a method for measuring the chlorine content of a polishing pad involves first placing a sample containing organic chlorine (C-Cl) components in a combustion tube, burning it in an electric furnace, and then sending the resulting material to an adsorption tube to measure the chlorine ions (Cl - The amount of ) will be measured by ion chromatography.

[0117] In the polishing pad according to the above embodiment, the chlorine content in the polishing layer is 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. By adjusting the chlorine content within this range, the size of debris can be reduced while maintaining excellent physical properties and performance of the polishing pad, thereby minimizing the occurrence of defects and scratches during the CMP process.

[0118] Furthermore, the lower limit of the chlorine content range in the polishing layer according to the above embodiment can be, for example, 0 ppm or more, more 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, debris aggregates to an appropriate size, adjusting the surface area and adhesive force, facilitating adhesion and desorption to the wafer and pad, and adjusting the electrical attractive force / chucking force, resulting in more appropriate polishing performance.

[0119] As a specific example, the chlorine (Cl) content of the polishing layer, when analyzed according to IEC 62321-3-2, may be 10 ppm to 1,000 ppm. As another specific example, the chlorine (Cl) content of the polishing layer, when analyzed according to IEC 62321-3-2, may be 10 ppm to 100 ppm, 20 ppm to 80 ppm, or 20 ppm to 50 ppm. As yet another specific example, the chlorine (Cl) content of the polishing layer, when analyzed according to IEC 62321-3-2, may be 50 ppm to 10,000 ppm, or 100 ppm to 10,000 ppm.

[0120] As such, the polishing pad according to the above embodiment can reduce the size of debris by adjusting the chlorine content within a specific range, thereby minimizing the occurrence of defects and scratches during the CMP process.

[0121] [Urethane prepolymer] The polishing pad according to one implementation includes a urethane-based prepolymer. A prepolymer is a polymer with a relatively low molecular weight whose polymerization degree has been stopped at an intermediate stage to facilitate molding during the production of a cured product. A prepolymer can be molded into a final cured product by itself or after reacting with other polymerizable compounds.

[0122] In one implementation, the urethane-based prepolymer can be prepared by reacting an isocyanate compound with a polyol.

[0123] The isocyanate compound used in preparing the urethane-based prepolymer may be one selected from the group consisting of aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and combinations thereof.

[0124] The isocyanate compound may include, for example, one selected from the group consisting of toluene 2,4-diisocyanate (2,4-TDI), toluene 2,6-diisocyanate (2,6-TDI), naphthalene-1,5-diisocyanate, para-phenylene diisocyanate, tolidine diisocyanate, 4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and combinations thereof.

[0125] The polyol is a compound containing at least two hydroxy groups (—OH) per molecule, and may include, for example, one selected from the group consisting of polyether polyols, polyester polyols, polycarbonate polyols, polycaprolactone polyols, and combinations thereof.

[0126] The polyol may include, for example, one selected from the group consisting of polytetramethylene ether glycol, polypropylene ether glycol, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, tripropylene glycol, and combinations thereof.

[0127] The polyol may have a weight average molecular weight (Mw) of 100 to 3000. The polyol may have a weight average molecular weight (Mw) of, for example, 100 to 3000, for example, 100 to 2000, for example, 100 to 1800.

[0128] In one embodiment, 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 1800.

[0129] The urethane-based prepolymer may have a weight average molecular weight of 500 to 3000. The urethane-based prepolymer may have a weight average molecular weight (Mw) of, for example, 1000 to 2000, such as 1000 to 1500.

[0130] In one embodiment, the isocyanate compound for preparing the urethane-based prepolymer includes an aromatic diisocyanate compound, and the aromatic diisocyanate compound may include, for example, 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI).The polyol compound for preparing the urethane-based prepolymer may include polytetramethylene ether glycol (PTMEG) and diethylene glycol (DEG).

[0131] In another embodiment, the isocyanate compound for preparing the urethane-based prepolymer may include an aromatic diisocyanate compound and an alicyclic diisocyanate compound, for example, the aromatic diisocyanate compound may include 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI), and the alicyclic diisocyanate compound may include dicyclohexylmethane diisocyanate (H12MDI).The polyol compound for preparing the urethane-based prepolymer may include polytetramethylene ether glycol (PTMEG) and diethylene glycol (DEG).

[0132] The urethane-based prepolymer may have an isocyanate terminal group content (NCO%) of 5% by weight or more, 8% by weight or more, or 10% by weight or more, and 13% by weight or less, 12% by weight or less, or 11% by weight or less. As a specific example, the urethane-based prepolymer may have an isocyanate terminal group content (NCO%) of 10% by weight to 11% by weight.

[0133] The isocyanate terminal group content (NCO%) of the urethane-based prepolymer can be designed by comprehensively adjusting the types and contents of the isocyanate compound and polyol compound used to prepare the urethane-based prepolymer, process conditions such as temperature, pressure, and time in the process of preparing the urethane-based prepolymer, and the types and contents of additives used in the preparation of the urethane-based prepolymer.

[0134] When the isocyanate terminal group content (NCO%) of the urethane-based prepolymer satisfies the above range, the reaction rate, reaction time, and final cured structure when the urethane-based prepolymer is subsequently reacted with a curing agent can be adjusted in a direction that is advantageous for the polishing performance depending on the application and purpose of the final polishing pad.

[0135] In one embodiment, the isocyanate terminal group content (NCO%) of the urethane-based prepolymer may be 8% by weight to 10% by weight, for example, 8% by weight to 9.4% by weight. If the NCO% is below this range, the electrical characteristics based on the chemically cured structure in the polishing pad may be such that the desired polishing performance in terms of polishing rate and flatness cannot be achieved, and there may be problems such as an excessive increase in the cutting rate or wear rate, which shortens the life of the polishing pad. On the other hand, if the NCO% exceeds this range, surface defects such as scratches and chatter marks on the semiconductor substrate may increase.

[0136] [Foaming agent] The foaming agent may include one selected from the group consisting of a solid-phase foaming agent, a gas-phase foaming agent, a liquid-phase foaming agent, and combinations thereof as a component for forming a pore structure in the polishing layer.

[0137] According to one embodiment, the foaming agent is a non-chlorine-based foaming agent that does not contain chlorine components, and in particular, it may not contain or minimize the use of chlorine-based foaming agents commonly used in polishing pad manufacturing, such as vinylidene chloride (VDC). For example, the content of the non-chlorine-based foaming agent based on the total weight of the foaming agent may be 50 wt% or more, 80 wt% or more, 90 wt% or more, 95 wt% or more, 97 wt% or more, 99 wt% or more, or 99.5 wt% or more, or 100 wt% or less, or 99.5 wt% or less, and specifically, 80 wt% to 100 wt%, 90 wt% to 100 wt%, or 80 wt% to 99.5 wt%. The content of the chlorine-based blowing agent based on the total weight of the blowing agent is 20% by weight or less, 10% by weight or less, 5% by weight or less, 1% by weight or less, 0.5% by weight or less, 0.3% by weight or less, or 0% by weight or more, 0.1% by weight or more, 0.5% by weight or more, and specific examples thereof may be 0% by weight to 20% by weight, 0% by weight to 1% by weight, 0% by weight to 0.5% by weight, or 0.5% by weight to 20% by weight.

[0138] The foaming agent may be one or more selected from a solid-phase foaming agent containing particles with a hollow structure, a liquid-phase foaming agent using a volatile liquid, and an inert gas.

[0139] For example, the solid foaming agent may include particles having a hollow structure whose size is adjusted by thermal expansion. Such a solid foaming agent is added to the raw material in a pre-expanded state and has a uniform particle size, which has the advantage of enabling the particle size of pores to be adjusted uniformly.

[0140] The solid-phase foaming agent may also include expandable particles. The expandable particles are particles that can expand under heat or pressure, and their final size in the polishing layer can be determined by the heat or pressure applied during the polishing layer manufacturing process. The expandable particles are added to the raw material in a pre-expanded state, and are expanded by the heat or pressure applied during the polishing layer manufacturing process, thereby determining their final size.

[0141] The average particle size of the solid-phase blowing agent may be, for example, 5 μm to 100 μm, specifically 5 μm to 50 μm or 20 μm to 50 μm. The average particle size of the solid-phase blowing agent refers to the average particle size of the expanded particles themselves when the solid-phase blowing agent is added to the raw material in an expanded state as described below. Alternatively, the average particle size of the solid-phase blowing agent refers to the average particle size of the particles after expansion by heat or pressure during the manufacturing process when the solid-phase blowing agent is added to the raw material in an unexpanded state as described below.

[0142] The expandable particle-type solid-phase blowing agent may include a resin outer shell and an expansion-inducing component present inside the shell. The expandable particle may be formed into a hollow structure by vaporizing the expansion-inducing component inside due to heat during the manufacturing process.

[0143] For example, the outer shell may contain a thermoplastic resin, which may be one or more selected from the group consisting of an acrylonitrile copolymer, a methacrylonitrile copolymer, and an acrylic copolymer.

[0144] The thickness of the outer skin is, for example, 0.1 μm or more, 0.5 μm or more, 1 μm or more, 2 μm or more, or 3 μm or more, and 15 μm or less, 12 μm or less, or 10 μm or less, and a specific example is 2 μm to 15 μm.

[0145] The expansion-inducing component may include one selected from the group consisting of a hydrocarbon compound, a tetraalkylsilane compound, and a combination thereof. Specifically, the hydrocarbon compound may include one selected from the group consisting of ethane, ethylene, propane, propene, n-butane, isobutane, n-butene, isobutene, n-pentane, isopentane, neopentane, n-hexane, heptane, petroleum ether, and a combination thereof. The tetraalkylsilane compound may include one selected from the group consisting of tetramethylsilane, trimethylethylsilane, trimethylisopropylsilane, trimethyl-n-propylsilane, and a combination thereof.

[0146] The solid-phase blowing agent may include inorganically treated particles. In one embodiment, the solid-phase blowing agent may have a surface treated with silica (SiO2) particles. The inorganic treatment of the solid-phase blowing agent may prevent aggregation between multiple particles. The inorganic-treated solid-phase blowing agent may have different chemical, electrical, and / or physical properties of the blowing agent surface from a solid-phase blowing agent that is not inorganically treated.

[0147] Commercially available solid-phase blowing agents include 920DE20d70, 051DET40d25, 051DET40d42, etc. manufactured by Nouryon, and F-65DE, F-80DE, FN-80SDE, etc. manufactured by Matsumoto.

[0148] As a specific example, the foaming agent used in the polishing pad according to the embodiment includes a solid-phase foaming agent, and the solid-phase foaming agent may include one or more selected from the group consisting of acrylonitrile-based copolymers, methyl methacrylate-based copolymers, methacrylonitrile-based copolymers, and acrylic-based copolymers.

[0149] The content of the solid-phase blowing agent may be 0.1 parts by weight or more, 0.5 parts 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, based on 100 parts by weight of the urethane-based prepolymer. As a specific example, the content of the solid-phase blowing agent may be 0.1 to 5 parts by weight or 0.5 to 2 parts by weight, based on 100 parts by weight of the urethane-based prepolymer.

[0150] The type and content of the solid-phase foaming agent can be designed depending on the desired pore structure and physical properties of the polishing layer.

[0151] Meanwhile, the liquid foaming agent is added during the reaction process of the prepolymer and the curing agent to form pores, but does not participate in the reaction between the prepolymer and the curing agent. The liquid foaming agent is physically vaporized by the heat generated during the reaction process of the prepolymer and the curing agent to form pores.

[0152] The volatile liquid-phase blowing agent does not react with isocyanate groups, amide groups, or alcohol groups and may be in a liquid phase at 25°C. Specifically, the volatile liquid-phase blowing agent may be selected from the group consisting of perfluoro compounds such as cyclopentane, n-pentane, cyclohexane, n-butyl acetate, bis(nonafluorobutyl)(trifluoromethyl)amine, perfluorotributylamine, perfluoro-N-methylmorpholine, perfluorotripentylamine, and perfluorohexane. Commercially available perfluoro compounds include FC-40, FC-43, FC-70, FC-72, FC-770, FC-3283, and FC-3284 from 3M.

[0153] In addition, the blowing agent may include a gas phase blowing agent. For example, the blowing agent may include a solid phase blowing agent and a gas phase blowing agent.

[0154] The gas-phase blowing agent may include an inert gas, and may be used as a pore-forming agent when the urethane-based prepolymer and the curing agent react with each other.

[0155] The inert gas may be any gas that does not participate in the reaction between the urethane prepolymer and the curing agent, and may include, for example, one selected from the group consisting of nitrogen gas (N), carbon dioxide gas (CO), argon gas (Ar), helium gas (He), and combinations thereof.

[0156] The type and content of the gas-phase foaming agent can be designed depending on the desired pore structure and physical properties of the polishing layer.

[0157] The inert gas may be added in a volume equivalent to 10% to 30% of the total volume of the composition. Specifically, the inert gas may be added in a volume equivalent to 15% to 30% of the total volume of the composition. Specifically, the gas-phase blowing agent may be injected through a predetermined injection line during the process of mixing the urethane prepolymer, the solid-phase blowing agent, and the curing agent. The injection rate of the gas-phase blowing agent may be about 0.8 L / min to about 2.0 L / min, for example, about 0.8 L / min to about 1.8 L / min, for example, about 0.8 L / min to about 1.7 L / min, for example, about 1.0 L / min to about 2.0 L / min, for example, about 1.0 L / min to about 1.8 L / min, for example, about 1.0 L / min to about 1.7 L / min.

[0158] [Hardening agent] The curing agent is a compound that chemically reacts with the urethane-based prepolymer to form a final cured structure in the polishing layer, and may include, for example, an amine compound or an alcohol compound. Specifically, the curing agent may include one selected from the group consisting of aromatic amines, aliphatic amines, aromatic alcohols, aliphatic alcohols, and combinations thereof.

[0159] According to one embodiment, the curing agent may include a non-chlorine-based curing agent that does not contain a chlorine component. For example, the content of the non-chlorine-based curing agent based on the total weight of the curing agent may be 50 wt% or more, 80 wt% or more, 90 wt% or more, 95 wt% or more, 97 wt% or more, 99 wt% or more, or 100 wt% or less, or 99.5 wt% or less. Specific examples include 80 wt% to 100 wt%, 90 wt% to 100 wt%, or 80 wt% to 99.5 wt%. The content of the chlorine-based curing agent based on the total weight of the curing agent is 20% by weight or less, 10% by weight or less, 5% by weight or less, 1% by weight or less, 0.5% by weight or less, 0.3% by weight or less, or 0% by weight or more, 0.1% by weight or more, 0.5% by weight or more, and specific examples thereof may be 0% by weight to 20% by weight, 0% by weight to 1% by weight, 0% by weight to 0.5% by weight, or 0.5% by weight to 20% by weight.

[0160] The curing agent may be at least one selected from a solid-phase curing agent and a liquid-phase curing agent.

[0161] The solid-phase hardener may contain an active hydrogen group. The solid-phase hardener may include an amine group (—NH2) as the active hydrogen group.

[0162] The solid-phase hardener may be an ester compound having two or more benzene rings. Specifically, the solid-phase hardener may contain two or more ester groups in the molecule.

[0163] 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 (mp) of 100°C to 150°C, for example, 100°C to 140°C, for example, 110°C to 130°C.

[0164] In one implementation, the solid-state curing agent may include one or more selected from the group consisting of 1,3-propanediol bis(4-aminobenzoate) (PDPAB), 4-(4-aminobenzoyl)oxyphenyl 4-aminobenzoate, 4-(4-aminobenzoyl)oxybutyl 4-aminobenzoate, 4-[4-(4-aminobenzoyl)oxy-3-methylbutoxy]butyl 4-aminobenzoate, and methylene bis-methylanthranilate (MBNA).

[0165] The liquid-phase curing agent may contain an active hydrogen group, which may include at least one selected from the group consisting of an amine group (-NH), a hydroxyl group (-OH), a carboxylic acid group (-COOH), an epoxy group, and combinations thereof, and may specifically include an amine group (-NH).

[0166] The liquid phase curing agent may contain sulfur in the molecule, specifically, may contain two or more sulfur elements in the molecule.

[0167] The liquid phase curing agent has a weight average molecular weight of 50 to 300, for example, 100 to 250, for example, 150 to 250, for example, 200 to 250.

[0168] The liquid-phase curing agent may be in a liquid phase at room temperature, or may have a boiling point (bp) of 160°C to 240°C, specifically 170°C to 240°C, more specifically 170°C to 220°C.

[0169] Examples of the liquid phase curing agent may include one or more selected from the group consisting of 3,5-dimethylthio-2,6-diaminotoluene (DMTDA), 2,6-bis(methylthio)-4-methyl-1,3-benzenediamine, and N,N′-bis(sec-butylamino)diphenylmethane.

[0170] The curing agent may further include other curing agents in addition to the liquid-phase curing agent and the solid-phase curing agent. The other curing agents may be, for example, one or more of an amine compound and an alcohol compound. Specifically, the other curing agent may include one or more compounds selected from the group consisting of an aromatic amine, an aliphatic amine, an aromatic alcohol, and an aliphatic alcohol.

[0171] For example, the other curing agent may be one or more selected from the group consisting of diaminodiphenyl methane, diaminodiphenyl sulphone, m-xylylene diamine, isophoronediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, polypropylenediamine, polypropylenetriamine, ethylene glycol, diethyleneglycol, dipropyleneglycol, butanediol, hexanediol, glycerine, and trimethylolpropane.

[0172] As a specific example, the curing agent may include one or more selected from the group consisting of diethyltoluenediamine (DETDA), 3,5-dimethylthio-2,6-diaminotoluene (DMTDA), 1,3-propanediol bis(4-aminobenzoate) (PDPAB), N,N'-bis(sec-butylamino)diphenylmethane, 2,6-bis(methylthio)-4-methyl-1,3-benzenediamine, 4-(4-aminobenzoyl)oxyphenyl 4-aminobenzoate, 4-(4-aminobenzoyl)oxybutyl 4-aminobenzoate, 4-[4-(4-aminobenzoyl)oxy-3-methylbutoxy]butyl 4-aminobenzoate, and methylene bis-methylanthranilate (MBNA).

[0173] 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, based on 100 parts by weight of the urethane prepolymer. Specifically, the content of the curing agent may be 10 parts by weight to 40 parts by weight, more specifically 15 parts by weight to 35 parts by weight or 15 parts by weight to 25 parts by weight, based on 100 parts by weight of the urethane prepolymer.

[0174] [Additives] The composition for preparing the polishing layer may further contain other additives such as a surfactant, a reaction rate modifier, etc. The terms "surfactant," "reaction rate modifier," etc. are arbitrarily used based on the main role of the corresponding substance, and each corresponding substance does not necessarily perform only the function limited to the role designated by the term.

[0175] The surfactant is not particularly limited as long as it is a substance that prevents phenomena such as pore aggregation or overlapping, etc. For example, the surfactant may include a silicone-based surfactant.

[0176] The surfactant may be used in an amount of 0.2 to 2 parts by weight, based on 100 parts by weight of the urethane-based prepolymer. Specifically, the surfactant may be used in an amount of 0.2 to 1.9 parts by weight, for example, 0.2 to 1.8 parts by weight, for example, 0.2 to 1.7 parts by weight, for example, 0.2 to 1.6 parts by weight, for example, 0.2 to 1.5 parts by weight, for example, 0.5 to 1.5 parts by weight, based on 100 parts by weight of the urethane-based prepolymer. When the surfactant is used in an amount within this range, pores derived from the gas-phase blowing agent can be stably formed and maintained in the mold.

[0177] The reaction rate adjuster functions to accelerate or retard the reaction, and may be a reaction accelerator, a reaction retarder, or both, depending on the purpose. The reaction rate adjuster may include a reaction accelerator. For example, the reaction accelerator may be one or more reaction accelerators selected from the group consisting of tertiary amine compounds and organometallic compounds.

[0178] Specifically, the reaction rate regulator may include one or more selected from the group consisting of triethylenediamine, dimethylethanolamine, tetramethylbutanediamine, 2-methyl-triethylenediamine, dimethylcyclohexylamine, triethylamine, triisopropanolamine, 1,4-diazabicyclo(2,2,2)octane, bis(2-methylaminoethyl)ether, trimethylaminoethylethanolamine, N,N,N,N,N″-pentamethyldiethylenetriamine, dimethylaminoethylamine, dimethylaminopropylamine, benzyldimethylamine, N-ethylmorpholine, N,N-dimethylaminoethylmorpholine, N,N-dimethylcyclohexylamine, 2-methyl-2-azanorbornene, dibutyltin dilaurate, stannous octoate, dibutyltin diacetate, dioctyltin diacetate, dibutyltin maleate, dibutyltin di-2-ethylhexanoate, and dibutyltin dimercaptide. Specifically, the reaction rate adjuster may include one or more selected from the group consisting of benzyldimethylamine, N,N-dimethylcyclohexylamine, and triethylamine.

[0179] The reaction rate modifier may be used in an amount of 0.05 to 2 parts by weight, based on 100 parts by weight of the urethane-based prepolymer. Specifically, the reaction rate modifier may be used in an amount of 0.05 to 1.8 parts by weight, for example, 0.05 to 1.7 parts by weight, for example, 0.05 to 1.6 parts by weight, for example, 0.1 to 1.5 parts by weight, for example, 0.1 to 1.3 parts by weight, for example, 0.2 to 1.8 parts by weight, for example, 0.2 to 1.7 parts by weight, for example, 0.2 to 1.6 parts by weight, for example, 0.2 to 1.5 parts by weight, for example, 0.5 to 1 part by weight, based on 100 parts by weight of the urethane-based prepolymer. When the reaction rate modifier is used in the above content range, the curing reaction rate of the prepolymer composition can be appropriately adjusted to form a polishing layer with the desired pore size and hardness.

[0180] [Support layer] The support layer constitutes a sub-pad and supports the polishing layer while absorbing and dispersing external impacts applied to the polishing layer, thereby minimizing damage and defects to the object to be polished during the polishing process using the polishing pad.

[0181] The support layer may include, but is not limited to, nonwoven fabric or suede. In one embodiment, the support layer may be a resin-impregnated nonwoven fabric, which may be a fibrous nonwoven fabric containing one selected from the group consisting of polyester fibers, polyamide fibers, polypropylene fibers, polyethylene fibers, and combinations thereof.

[0182] The resin impregnated into the nonwoven fabric may include one selected from the group consisting of polyurethane resin, polybutadiene resin, styrene-butadiene copolymer resin, styrene-butadiene-styrene copolymer resin, acrylonitrile-butadiene copolymer resin, styrene-ethylene-butadiene-styrene copolymer resin, silicone rubber resin, polyester-based elastomer resin, polyamide-based elastomer resin, and combinations thereof.

[0183] The thickness of the support layer may be, 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. As a specific example, the thickness of the support layer may be 0.3 mm to 3 mm, or 0.5 mm to 1 mm.

[0184] The hardness of the support layer may be, for example, 50 Asker C or more, 60 Asker C or more, or 70 Asker C or more, and 100 Asker C or less, 90 Asker C or less, or 80 Asker C or less. As a specific example, the hardness of the support layer may be 50 Asker C to 100 Asker C or 60 Asker C to 90 Asker C.

[0185] In addition, an adhesive layer may be inserted between the polishing layer (upper pad) and the support layer (lower pad).

[0186] The adhesive layer may include a hot melt adhesive. The hot melt adhesive may be one or more selected from the group consisting of polyurethane-based resins, polyester-based resins, ethylene-vinyl acetate-based resins, polyamide-based resins, and polyolefin-based resins. Specifically, the hot melt adhesive may be one or more selected from the group consisting of polyurethane-based resins and polyester-based resins.

[0187] Also, a double-sided tape is attached to the lower part of the support layer, and when the support layer is applied to a CMP device, the release paper of the double-sided tape can be removed and the support layer can be attached to a platen.

[0188] [Polishing pad manufacturing method] A method for manufacturing a polishing pad according to one embodiment includes the steps of preparing a polishing pad composition containing a urethane-based prepolymer, a foaming agent, and a curing agent, injecting the polishing pad composition into a mold and curing it to produce a polishing layer, and bonding the polishing layer to a support layer.

[0189] The specific types and contents of the urethane-based prepolymer, curing agent, and foaming agent are as exemplified above.

[0190] As a specific example, the blowing agent may include a solid-phase blowing agent, and the solid-phase blowing agent may include one or more selected from the group consisting of acrylonitrile-based copolymers, methyl methacrylate-based copolymers, methacrylonitrile-based copolymers, and acrylic-based copolymers. The curing agent may include one or more selected from the group consisting of diethyltoluenediamine (DETDA), 3,5-dimethylthio-2,6-diaminotoluene (DMTDA), 1,3-propanediol bis(4-aminobenzoate) (PDPAB), N,N'-bis(sec-butylamino)diphenylmethane, 2,6-bis(methylthio)-4-methyl-1,3-benzenediamine, 4-(4-aminobenzoyl)oxyphenyl 4-aminobenzoate, 4-(4-aminobenzoyl)oxybutyl 4-aminobenzoate, 4-[4-(4-aminobenzoyl)oxy-3-methylbutoxy]butyl 4-aminobenzoate, and methylene bis-methylanthranilate (MBNA).

[0191] The polishing pad composition can be prepared by sequentially or simultaneously mixing the urethane-based prepolymer, the foaming agent, and the curing agent.

[0192] For example, the step of preparing the polishing pad composition may be performed by mixing a urethane-based prepolymer with a curing agent and then further mixing with a foaming agent, or by mixing the urethane-based prepolymer with the foaming agent and then further mixing with the curing agent.

[0193] As another example, the urethane-based prepolymer, the curing agent, and the blowing agent may be added to the mixing process substantially at the same time, and if a blowing agent, a surfactant, and an inert gas are further added, they may also be added to the mixing process substantially at the same time.

[0194] As another example, the urethane-based prepolymer, the foaming agent, and the surfactant may be mixed in advance, and then the curing agent may be added, or the curing agent and the inert gas may be added together.

[0195] During the mixing, the urethane prepolymer and the curing agent are mixed to initiate the reaction, and the blowing agent and inert gas are uniformly dispersed within the raw materials. In this case, a reaction rate modifier can be added to the reaction between the urethane prepolymer and the curing agent from the initial stage of the reaction to adjust the reaction rate. Specifically, the mixing can be performed at a speed of 1,000 rpm to 10,000 rpm or 4,000 rpm to 7,000 rpm. This speed range is more advantageous for uniformly dispersing the inert gas and blowing agent within the raw materials.

[0196] The step of preparing the polishing pad composition may be carried out at a temperature of 50° C. to 150° C., and may be carried out under vacuum degassing conditions as needed.

[0197] When the foaming agent includes a solid-phase foaming agent, the step of preparing the polishing pad composition may include the steps of mixing the urethane-based prepolymer and the solid-phase foaming agent to prepare a first preliminary composition, and mixing the first preliminary composition with a curing agent to prepare a second preliminary composition.

[0198] The viscosity of the first preliminary composition at about 80° C. may be about 1000 cps to about 2000 cps, for example, about 1000 cps to about 1800 cps, for example, about 1000 cps to about 1600 cps, for example, about 1000 cps to about 1500 cps.

[0199] When the foaming agent includes a gas-phase foaming agent, the step of preparing the polishing pad composition may include the steps of preparing a third preliminary composition including the urethane-based prepolymer and the curing agent, and injecting the gas-phase foaming agent into the third preliminary composition to prepare a fourth preliminary composition. In one embodiment, the third preliminary composition may further include a solid-phase foaming agent.

[0200] In one embodiment, the process for manufacturing the polishing layer may include preparing a mold preheated to a first temperature, injecting the polishing pad composition into the preheated mold and curing it, and post-curing the cured polishing pad composition under a second temperature condition higher than the preheat temperature.

[0201] In one embodiment, the temperature difference between the first temperature and the second temperature is 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 one embodiment, the first temperature is 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 one embodiment, the second temperature is 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.

[0202] The step of curing the polishing pad composition at the first temperature may be carried out for about 5 minutes to about 60 minutes, for example, about 5 minutes to about 40 minutes, for example, about 5 minutes to about 30 minutes, for example, about 5 minutes to about 25 minutes.

[0203] The step of post-curing the polishing pad composition cured at the first temperature at the second temperature may be carried out for about 5 hours to about 30 hours, for example, about 5 hours to about 25 hours, for example, about 10 hours to about 30 hours, for example, about 10 hours to about 25 hours, for example, about 12 hours to about 24 hours, for example, about 15 hours to about 24 hours.

[0204] Then, the step of injecting the polishing pad composition into a mold and then curing it is performed under the temperature condition of 60°C to 120°C and a pressure of 50 kg / m 2 ~200kg / m 2 The reaction can be carried out under pressure conditions of 0.1 to 1000 kJ / min.

[0205] The manufacturing method may further include a step of cutting the surface of the obtained polishing pad, a step of processing grooves in the surface, a step of bonding to a lower layer, a step of inspecting, a step of packaging, etc. These steps may be performed by a conventional polishing pad manufacturing method.

[0206] For example, the method for manufacturing the polishing pad may include processing at least one surface of the polishing layer, which may include at least one of forming grooves on the at least one surface of the polishing layer, turning the at least one surface of the polishing layer, and roughening the at least one surface of the polishing layer.

[0207] The grooves may include at least one of concentric grooves spaced apart from the center of the polishing layer at a predetermined interval and radial grooves extending continuously from the center of the polishing layer to the edge of the polishing layer. The turning may be performed by removing a predetermined thickness of the polishing layer using a cutting tool. The roughening may be performed by processing the surface of the polishing layer with a sanding roller.

[0208] [Method of manufacturing semiconductor devices] The polishing pad described above can be used to manufacture semiconductor devices by chemical mechanical polishing. According to one embodiment, a method for manufacturing a semiconductor device includes chemically and mechanically polishing a semiconductor substrate using the polishing pad described above, and conditioning the polishing layer of the polishing pad by irradiating it with UV light having a wavelength of 100 nm to 380 nm.

[0209] Specifically, the method for manufacturing a semiconductor device includes polishing the surface of the semiconductor substrate by rotating the polishing layer of the polishing pad relative to the surface of the semiconductor substrate so that the polishing layer and the surface of the semiconductor substrate contact each other, and conditioning the polishing layer of the polishing pad by irradiating it with UV light having a wavelength of 100 nm to 380 nm.

[0210] 7 and 8 show the configuration of an apparatus for irradiating UV light during CMP according to one embodiment. Referring to FIGS. 7 and 8, in one embodiment of the apparatus, a UV lamp 700 is installed above a polishing pad 100. The UV lamp can be configured to be adjustable in angle and height. The UV lamp can irradiate the polishing pad with light in the wavelength range of 100 nm to 380 nm. FIG. 2 illustrates the generation of defects due to debris during the manufacturing process of a semiconductor device. Referring to FIG. 2, debris 150 generated from the polishing layer can cause defects 650 and scratches on the surface of a semiconductor device. However, the polishing pad according to the embodiment has the property of reducing the particle size of debris by irradiating UV light during the CMP process. Therefore, by utilizing this property of the polishing pad and irradiating UV light during the CMP process, the generation of defects and scratches on the semiconductor device can be minimized. Therefore, manufacturing semiconductor devices through a CMP process using a polishing pad according to the embodiment can improve CMP performance and yield.

[0211] A method for manufacturing a semiconductor device according to one embodiment will now be described in detail. First, the polishing pad 100 according to one embodiment is mounted on the platen 200, and then the semiconductor substrate 600 to be polished is placed on the polishing pad 100. At this time, the surface to be polished of the semiconductor substrate 600 directly contacts the polishing surface of the polishing pad 100. For polishing, a CMP slurry 450 may be supplied onto the polishing pad through a slurry supplier 400. The flow rate of the CMP slurry 450 supplied through the slurry supplier 400 is about 10 cm. 3 / min ~ approx. 1000cm 3 / min. can be selected according to the purpose, for example, about 50 cm 3 / min ~ approx. 500cm 3 / min, but is not limited to this.

[0212] Thereafter, the semiconductor substrate 600 and the polishing pad 100 may rotate relative to each other to polish the surface of the semiconductor substrate 600. At this time, the rotation direction of the semiconductor substrate 600 and the rotation direction of the polishing pad 100 may be the same or opposite. The rotation speeds of the semiconductor substrate 600 and the polishing pad 100 may be selected depending on the purpose within a range of about 10 rpm to about 500 rpm, and may be, for example, about 30 rpm to about 200 rpm, but are not limited thereto.

[0213] The semiconductor substrate 600 is attached to the polishing head 510 and brought into contact with the polishing surface of the polishing pad 100 under a predetermined load, and then the surface of the semiconductor substrate 600 is polished. The load applied by the polishing head 510 to the surface of the semiconductor substrate 600 and the polishing surface of the polishing pad 100 is about 1 gf / cm. 2 ~About 1000gf / cm 2 can be selected depending on the purpose, for example, about 10 gf / cm 2 ~About 800gf / cm 2 It can be, but is not limited to, the following.

[0214] In one embodiment, the semiconductor substrate 600 to be polished may include an oxide film, a tungsten film, or a composite film thereof. Specifically, the semiconductor substrate 600 may include an oxide film, a tungsten film, or a composite film of oxide and tungsten. The composite film of oxide and tungsten may be a multi-layer film in which the tungsten film is stacked on one side of the oxide film, or a single-layer film in which an oxide region and a tungsten region are mixed within one layer. When the polishing target has such film quality characteristics and the polishing pad has the characteristics according to the embodiment, defects in semiconductor devices manufactured by the semiconductor device manufacturing method may be minimized.

[0215] In one embodiment, the method for manufacturing a semiconductor device may further include, in the step of polishing the object to be polished, supplying either one of the oxide film polishing slurry and the tungsten film polishing slurry, or supplying the oxide film polishing slurry and the tungsten film polishing slurry sequentially to the polishing surface.

[0216] For example, if the semiconductor substrate to be polished includes an oxide film, the method for manufacturing a semiconductor device may include supplying the oxide film polishing slurry. If the semiconductor substrate includes a tungsten film, the method for manufacturing a semiconductor device may include supplying the tungsten film polishing slurry. If the semiconductor substrate includes a composite film of an oxide film and a tungsten film, the method for manufacturing a semiconductor device may include supplying the oxide film polishing slurry and the tungsten film polishing slurry sequentially to the polishing surface. In this case, depending on the process, the oxide film polishing slurry may be supplied first and then the tungsten film polishing slurry may be supplied later, or the tungsten film polishing slurry may be supplied first and then the oxide film polishing slurry may be supplied later.

[0217] In one embodiment, the method for manufacturing a semiconductor device further includes a step of processing the polishing surface of the polishing pad 100 with a conditioner 300 simultaneously with polishing the semiconductor substrate 600 to maintain the polishing surface of the polishing pad 100 in a state suitable for polishing.

[0218] The method for manufacturing a semiconductor device also includes conditioning the polishing layer of the polishing pad by irradiating it with UV light having a wavelength of 100 nm to 380 nm. In one embodiment, a UV lamp 700 is installed above the polishing pad 100. The UV lamp may be configured to be adjustable in angle and height.

[0219] For example, the height of the UV lamp from the surface of the polishing pad 100 may be 2 cm to 30 cm, specifically 3 cm to 10 cm, and more specifically 3 cm to 7 cm.

[0220] The intensity of the UV light on the surface of the polishing pad 100 may be 100W to 2kW, more specifically, 500W to 1.5kW.

[0221] The UV light irradiation time may be 1 minute or more, 2 minutes or more, or 3 minutes or more, and may be 20 minutes or less, 10 minutes or less, 7 minutes or less, 5 minutes or less, or 4 minutes or less. For example, the UV light irradiation time may be 1 to 20 minutes, 1 to 10 minutes, 2 to 10 minutes, 1 to 7 minutes, 1 to 5 minutes, or 2 to 5 minutes. As a specific example, the UV light irradiation time may be 2 to 4 minutes.

[0222] (Example) Examples will be described below, but the feasible scope is not limited to these.

[0223] A. Polishing Pad Production and Evaluation (Examples A1 to A7 and Comparative Examples A1 and A2: Production of Polishing Pads) Step (1) Preparation of prepolymer Toluene diisocyanate (TDI), dicyclohexylmethane diisocyanate (H12MDI), polytetramethylene ether glycol (PTMEG), and diethylene glycol (DEG) were placed in a four-neck flask and reacted at 80°C for 3 hours to prepare a urethane prepolymer. The NCO% of the prepolymer was measured and is shown in Table 1 below.

[0224] Step (2) Manufacturing the Polishing Pad A casting machine was prepared, equipped with tanks and supply lines for the prepolymer, curing agent, inert gas, and blowing agent. The prepared urethane prepolymer, blowing agent, curing agent, inert gas (N), and silicone surfactant (EVONIK) were each filled into their respective tanks. The raw materials were fed into the mixing head at a constant rate through the respective supply lines while being stirred. The blowing agent and curing agent used were those listed in Table 1 below. The prepolymer and curing agent were fed at an equivalent ratio of 1:1 at a total rate of 10 kg / min.

[0225] A mold (1000 mm × 1000 mm × 3 mm) was prepared and preheated to 80°C, and the stirred raw materials were discharged into the mold and reacted to obtain a solid cake-like compact. The upper and lower ends of the compact were then cut to obtain a polishing layer for the top pad.

[0226] Thereafter, the polishing layer was subjected to a surface milling and groove forming process, and then attached to a support layer for a sub-pad with a hot melt adhesive to produce a polishing pad.

[0227] A double-sided tape (442JS, 3M) was attached to the bottom of the support layer so that it could be attached to the platen of a CMP device.

[0228] The curing agents and foaming 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 / methacrylonitrile 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

[0229] The configurations of the examples and comparative examples are summarized in Table 1 below.

[0230] JPEG0007796812000001.jpg135162

[0231] (Test Example A1) The polishing layer, support layer, and polishing pad formed by laminating these layers were tested as follows.

[0232] (1)Hardness The samples were cut into 5cm x 5cm pieces (thickness: 2mm) and stored at room temperature, 30°C, 50°C, and 70°C for 12 hours, respectively, and then the Shore D hardness and Asker C hardness were measured using a hardness tester.

[0233] (2) Specific gravity The sample was cut into a piece of 2 cm x 5 cm (thickness: 2 mm), and after storing at a temperature of 25°C for 12 hours, the specific gravity was measured using a hydrometer.

[0234] (3) Tensile strength The sample was cut into a size of 4 cm x 1 cm (thickness: 2 mm), and the maximum strength value just before the breakage of the polishing pad was measured using a universal testing meter (UTM) at a speed of 50 mm / min.

[0235] (4) Growth rate The sample was cut into a 4 cm x 1 cm (thickness: 2 mm) piece, and the maximum deformation just before the abrasive pad broke was measured using a universal testing meter (UTM) at a speed of 50 mm / min. The ratio of the maximum deformation to the initial length was then expressed as a percentage (%). The results are summarized in the table below.

[0236] JPEG0007796812000002.jpg109160

[0237] As can be seen from the table above, the polishing pads of Examples A1 to A7 were at levels equal to or higher than the polishing pads of Comparative Examples A1 and A2 in terms of hardness, specific gravity, tensile strength, and elongation.

[0238] (Test Example A2) Each of the polishing pads produced above was tested as follows.

[0239] (1)Removal rate A silicon wafer with a diameter of 300 mm, on which silicon oxide had been deposited by a CVD process, was placed in a CMP polishing apparatus, and then the silicon wafer was placed with the silicon oxide film facing downwards on a platen to which the porous polyurethane polishing pad had been attached.

[0240] Thereafter, the silicon oxide film was polished by rotating the platen at 150 rpm for 60 seconds under the conditions of a polishing load of 4.0 psi and a polishing pad rotation speed of 150 rpm while feeding calcined ceria slurry onto the polishing pad at a rate of 250 mL / min.

[0241] After polishing, the silicon wafer was removed from the carrier, loaded into a spin dryer, washed with deionized water (DIW), and then dried with nitrogen for 15 seconds. The change in film thickness of the dried silicon wafer before and after polishing was measured using a spectral interference wafer thickness meter (model: SI-F80R, Keyence Corporation).

[0242] Then, the polishing rate was calculated using the following mathematical formula 1. [Number 1] Polishing rate (Å / min) = Change in film thickness before and after polishing (Å) / Polishing time (min)

[0243] (2) Defects Polishing was performed using a CMP polishing machine in the same manner as in the polishing rate test. After polishing, the silicon wafer was transferred to a cleaner and washed with 1% HF, 1% H2NO3, and deionized water (DIW) for 10 seconds each. It was then transferred to a spin dryer, washed with deionized water (DIW), and then dried with nitrogen for 15 seconds. The dried silicon wafer was measured for defect changes before and after polishing using a defect measurement system (model: XP+, KLA-Tencor). Specifically, the total number of scratches, chatter marks, pits, and residues on the wafer was measured.

[0244] (3) Chlorine content A circular sample measuring 3 cm in diameter and 0.3 cm in height was prepared from the polishing layer of the polishing pad. The chlorine content of the sample was measured according to IEC 62321-3-2, an international standard for measuring specific substances in polymers by combustion ion chromatography (C-IC).

[0245] (4) Debris size (D50 particle size) a) Collection of debris aqueous solution A porous polyurethane polishing pad was attached to the platen of a CMP polishing system. The carrier was then removed and the polishing layer debris was collected using only a conditioner and deionized water (DIW). The platen speed was set at 93 rpm, the conditioner load was 9 lb, the rotation speed was 64 rpm, and the sweep rate was 19 times / min. Conditioning of the polishing layer was performed using a CI45 conditioner disk (pad removal rate: 80-90 μm / hr, Sesol Co., Ltd.) while injecting deionized water at 300 cc / min. After 10 minutes of conditioning, the polishing layer debris was collected in a solution mixed with deionized water to obtain 300 mL of debris aqueous solution.

[0246] b) pH adjustment and particle size analysis of debris The aqueous debris solution had a pH of 6.0 to 6.5, and was adjusted to pH 5.5 using an aqueous nitric acid solution. The concentration of the aqueous nitric acid solution used was 35%. The D50 particle size of the debris in the aqueous debris solution was obtained using a particle size analyzer (Mastersize 3000, Malvern) and a medium-capacity automatic wet disperser (Hydro MV, Malvern). The analyzer settings were: polyurethane 1.55 as the refractive index of the analyte, deionized water 1.33 as the refractive index of the dispersant, and a stirring speed of 2500 rpm.

[0247] (5) Zeta potential An aqueous debris solution was obtained by the same method as in (4) a) above. To ensure particle stability, the debris aqueous solution was stored at room temperature for 24 hours to allow particles with a diameter of 20 μm or greater to settle. The supernatant liquid located within 10 mm of the upper surface of the solution was then collected as a sample. The resulting sample had a pH level of 6.0-6.5 and was adjusted to 5.5 using a nitric acid aqueous solution. The concentration of the nitric acid aqueous solution used was 35%. The debris concentration in the liquid sample was confirmed to be approximately 0.01 wt%. The concentration was measured by placing approximately 5 g of the liquid sample in an aluminum dish and using a heated moisture meter (MX-50, AND). The zeta potential of the sample was measured using a Zetasizer (Nano-ZS90, Malvern). Specifically, 1 mL of sample was placed in a Zetasizer cuvette and the measurement was repeated three times to obtain the zeta potential. The instrument settings were set to an RI of 1.550 and an absorption of 0.010 based on the polyurethane value. The test results are summarized in the table below.

[0248] JPEG0007796812000003.jpg79165

[0249] As can be seen from the table, the polishing pads of Examples A1 to A7 were measured to have chlorine (Cl) contents within the preferred range, and performance such as removal rate was at a level equal to or greater than that of Comparative Examples A1 and A2. In particular, the debris particle size of the polishing pads of Examples A1 to A7 was measured to be smaller than that of Comparative Examples A1 and A2, and the number of defects / scratches was measured to be significantly smaller. Furthermore, the zeta potential of the polishing pads of Examples A1 to A7 was also measured to be within the preferred range.

[0250] (6) Debris size and zeta potential due to pH change For the polishing pads of the examples and comparative examples, the debris particle size (D50[5.5]) under pH 5.5 conditions and the debris particle size (D50

[10] ) under pH 10 conditions were measured using the same method as in (4) above.

[0251] In addition, for the polishing pads of the examples and comparative examples, the zeta potential (Zp[5.5]) of the debris aqueous solution under pH 5.5 conditions and the zeta potential (Zp

[10] ) of the debris aqueous solution under pH 10 conditions were measured using the same method as in (5) above.

[0252] At this time, the pH of the debris aqueous solution was adjusted by adding a nitric acid aqueous solution or a potassium hydroxide aqueous solution. Specifically, when adjusting the initially obtained debris aqueous solution (pH 6.0 to 6.5) to pH 5.5, a nitric acid aqueous solution was added, and when adjusting to pH 10, a potassium hydroxide aqueous solution was added. The concentration of the nitric acid aqueous solution used at this time was 35%, and the concentration of the potassium hydroxide aqueous solution was 10%.

[0253] Using the debris size and zeta potential measured in this way, the following formulas (1) to (3) were calculated. D50[5.5] / Zp[5.5]...(1) (D50[5.5] / D50

[10] )×100...(2) Zp[5.5]-Zp

[10] ...(3) where: D50[5.5] is the D50 particle size (μm) of the debris obtained when conditioning the polishing layer under a pH of 5.5 condition, D50

[10] is the D50 particle size (μm) of debris obtained when conditioning the polishing layer under a pH of 10 condition, Zp[5.5] is the zeta potential (mV) of an aqueous solution containing debris obtained during conditioning of the polishing layer at a concentration of 0.01 wt % under a pH of 5.5 condition; Zp

[10] is the zeta potential (mV) of an aqueous solution containing debris obtained during conditioning of the polishing layer at a concentration of 0.01 wt % at a pH of 10.

[0254] The results are summarized in the table below. The results of the defect / scratch test mentioned above are also shown in the table below. JPEG0007796812000004.jpg109163

[0255] As can be seen from the table, the polishing pads of Examples A1 to A7 had a D50 particle size of 50 μm or less of debris obtained from the polishing layer under pH 5.5 conditions, and the zeta potential of the debris aqueous solution was measured within the range of -20 mV to 30 mV under pH 5.5 conditions. Furthermore, the polishing pads of Examples A1 to A7 had values ​​measured under other pH conditions and values ​​of formulas (1) to (3) all within the preferred ranges, and as a result, the number of defects / scratches generated on the silicon wafer during the CMP process was low, at less than 20.

[0256] In particular, the polishing pads of Examples A1 to A3 had a D50 particle size of 20 μm or less of debris obtained from the polishing layer under pH 5.5 conditions, and the zeta potential of the debris aqueous solution was measured within the range of 0 mV to 20 mV under pH 5.5 conditions. Furthermore, the polishing pads of Examples A1 to A3 had values ​​measured under other pH conditions and values ​​of formulas (1) to (3) all within the preferred ranges, and as a result, the number of defects / scratches generated on the silicon wafer during the CMP process was very low, at less than 10.

[0257] On the other hand, for the polishing pads of Comparative Examples A1 and A2, the zeta potential value of the debris aqueous solution obtained from the polishing layer was measured at less than -20 mV under pH 5.5 conditions, and it was confirmed that other measured values ​​and the values ​​of equations (1) to (3) were also outside the preferred ranges. As a result, the number of defects / scratches occurring on the silicon wafer during the CMP process significantly increased to 25 or more.

[0258] B. Polishing Pad Production and Evaluation During UV Irradiation (Example B1: Production of polishing pad) Step (1) Preparation of urethane prepolymer 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) were placed in a four-neck flask and reacted at 80°C for 3 hours to produce a urethane prepolymer with a terminal NCO group content (NCO%) of 10% by weight.

[0259] Step (2) Preparation of the polishing layer A casting machine equipped with tanks and supply lines for supplying raw materials such as prepolymer, curing agent, inert gas, and blowing agent was prepared. The prepared urethane prepolymer, curing agent (DMTDA), solid-phase blowing agent (F-65DE, Matsumoto), inert gas (N), and silicone surfactant (EVONIK) were charged into their respective tanks. Specifically, 32 parts by weight of curing agent, 1 part by weight of solid-phase blowing agent, and 1 part by weight of surfactant were charged per 100 parts by weight of the prepolymer, and the inert gas was supplied at a rate of 1.5 L / min.

[0260] The raw materials were fed into the mixer head through their respective feed lines at a constant rate while being stirred. The rotation speed of the mixer head was approximately 5000 rpm. After the raw material mixture was mixed in the mixer head, it was poured into a mold measuring 1000 mm in length, 1000 mm in width, and 3 mm in height. The temperature of the mold was adjusted to approximately 80 (±5)°C. The mixture was solidified in the mold and cast into a sheet. The sheet was post-cured at approximately 110 (±5)°C for approximately 18 hours to produce a polishing layer.

[0261] Step (3) Manufacturing the Polishing Pad One surface of the polishing layer was turned using a cutting tool, and grooves were machined using a tip to an average thickness of 2 mm. A cushion layer made of polyester fiber nonwoven fabric impregnated with polyurethane resin was provided, and a heat-sealing adhesive was applied to one surface of the cushion layer and the back surface of the groove-forming surface of the polishing layer. The cushion layer and the polishing layer were laminated so that the surfaces coated with the heat-sealing adhesive were in contact with each other, and a pressure roller was used to apply heat at a temperature of approximately 140 (±5) ° C and a pressure of 2 kgf / cm. 2 The resulting mixture was laminated under pressure to produce a polishing pad.

[0262] (Comparative Example B1: Production of Polishing Pad) Step (1) Preparation of urethane-based prepolymer 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) were placed in a four-neck flask and reacted at 80°C for 3 hours to prepare a urethane prepolymer with a terminal NCO group content (NCO%) of 9.1% by weight.

[0263] Step (2) Preparation of the polishing layer A casting machine equipped with tanks and supply lines for the prepolymer, curing agent, inert gas, and blowing agent was prepared. The urethane-based prepolymer prepared above, curing agent (4,4'-methylenebis(2-chloroaniline, MOCA)), solid-phase blowing agent (Expancel® 551 DE 40 d42, Akzonobel), inert gas (N), and silicone-based surfactant (EVONIK) were charged into their respective tanks. Specifically, 25 parts by weight of curing agent, 2.2 parts by weight of solid-phase blowing agent, and 1 part by weight of surfactant were charged per 100 parts by weight of the prepolymer, and the inert gas was supplied at a rate of 1.5 L / min.

[0264] The raw materials were fed into the mixer head through their respective feed lines at a constant rate while being stirred. The rotation speed of the mixer head was approximately 5000 rpm. After the raw material mixture was mixed in the mixer head, it was poured into a mold measuring 1000 mm in length, 1000 mm in width, and 3 mm in height. The temperature of the mold was adjusted to approximately 80 (±5)°C. The mixture was solidified in the mold and cast into a sheet. The sheet was post-cured at approximately 110 (±5)°C for approximately 18 hours to prepare a polishing layer.

[0265] Step (3) Manufacturing the Polishing Pad One surface of the polishing layer was turned using a cutting tool, and grooves were machined using a tip to an average thickness of 2 mm. A cushion layer made of polyester fiber nonwoven fabric impregnated with polyurethane resin was provided, and a heat-sealing adhesive was applied to one surface of the cushion layer and the back surface of the groove-forming surface of the polishing layer. The cushion layer and the polishing layer were laminated so that the surfaces coated with the heat-sealing adhesive were in contact with each other, and a pressure roller was used to apply a temperature of approximately 140 (±5) ° C and a pressure of 2 kgf / cm 2 The resulting mixture was laminated under pressure to produce a polishing pad.

[0266] (Test Example B1: Polishing Pad Physical Property Measurement) The polishing layer, support layer, and polishing pad obtained by laminating these layers were subjected to the following tests.

[0267] (1)Hardness The samples were cut into 5 cm x 5 cm pieces (thickness: 2 mm) and stored at room temperature, 30°C, 50°C, and 70°C for 12 hours, respectively, and then the Shore D hardness and Asker C hardness were measured using a hardness tester.

[0268] (2) Specific gravity The sample was cut into a piece of 2 cm x 5 cm (thickness: 2 mm) and stored at 25°C for 12 hours, after which the specific gravity was measured using a hydrometer.

[0269] (3) Tensile strength The sample was cut into a size of 4 cm x 1 cm (thickness: 2 mm), and the maximum strength value just before the breakage of the polishing pad was measured using a universal testing machine (UTM) at a speed of 50 mm / min.

[0270] (4) Growth rate The sample was cut into a 4 cm x 1 cm (thickness: 2 mm) piece, and the maximum deformation just before the abrasive pad broke was measured using a universal testing machine (UTM) at a speed of 50 mm / min. The ratio of the maximum deformation to the initial length was then expressed as a percentage (%). The results are summarized in the table below. JPEG0007796812000005.jpg103102

[0271] As can be seen from the table, the polishing pad of Example B1 was determined to have physical properties suitable for the CMP process.

[0272] (Test example B2: Change in debris size due to UV irradiation) (1) Conditioning process A porous polyurethane polishing pad was attached to the platen of a CMP polishing system. The carrier was then removed and the polishing layer debris was collected using only the conditioner and ceria slurry. The conditions were set as follows: platen speed 93 rpm, conditioner load 9 lb, conditioner speed 64 rpm, sweep rate 19 times / min. The polishing layer was conditioned using a CI45 conditioner disk (pad removal rate 80-90 μm / hr, Sesol Co., Ltd.) while injecting ceria slurry at 250 mL / min. After 10 minutes of conditioning, the polishing layer debris was mixed with the ceria slurry and collected in solution to obtain 300 mL of debris solution.

[0273] (2)UV irradiation Using a UV lamp (light source type: mercury lamp), the obtained debris solution was irradiated with UV light (wavelength 100 to 380 nm) at an intensity of 1 kW from a distance of 5 cm for 10 minutes, while the debris solution was sampled at 2-minute intervals. The debris solution sampled at this time had a pH level of approximately 10.

[0274] (3) Debris particle size analysis The D50 particle size of the debris in the debris solution was obtained using a particle size analyzer (Mastersize 3000, Malvern) and a medium-capacity automatic wet disperser (Hydro MV, Malvern). The analyzer settings were: 1.55 refractive index for polyurethane as the analyte, 1.33 refractive index for deionized water as the dispersant, and a stirring speed of 2500 rpm. The results are shown in Figures 5 and 6 and Tables 6 and 7 below. JPEG0007796812000006.jpg6385

[0275] JPEG0007796812000007.jpg7185

[0276] As can be seen from Tables 6 and 7 and Figures 5 and 6, the debris particle size of the polishing pad of Example B1 decreased as the UV light irradiation time increased, reaching its smallest measurement after 2 to 4 minutes.After that, as the UV light irradiation time increased to 6 to 8 minutes, the debris particle size tended to increase slightly, but overall, the debris particle size tended to decrease as the UV light irradiation time increased.

[0277] On the other hand, the polishing pad of Comparative Example B1 showed a tendency for the debris particle size to generally increase as the UV light irradiation time passed, and after 10 minutes it was measured to have increased to nearly twice the initial size.

[0278] (Test Example B3: Polishing Pad Performance Evaluation (CMP and UV Irradiation)) As shown in Figures 7 and 8, a UV lamp 700 with adjustable angle and height was installed in a CMP polishing apparatus. A 300 mm diameter silicon wafer, on which silicon oxide had been deposited by a CVD process, was placed in the CMP polishing apparatus. The silicon wafer was then placed, with the silicon oxide film facing down, on a platen with the porous polyurethane polishing pad attached. The silicon oxide film was then polished by rotating the platen at 150 rpm for 60 seconds under conditions of a polishing load of 4.0 psi and a polishing pad rotation speed of 150 rpm, while calcined ceria slurry was dispensed onto the polishing pad at a rate of 250 mL / min. During CMP polishing, the UV lamp 700 was operated, and UV light (wavelength 100-380 nm) was irradiated onto the polishing layer surface of the polishing pad at an intensity of 1 kW from a distance of 5 cm.

[0279] (1)Removal rate After polishing as described above, the silicon wafer was removed from the carrier, loaded into a spin dryer, washed with deionized water (DIW), and then dried with nitrogen for 15 seconds. The change in film thickness of the dried silicon wafer before and after polishing was measured using a spectral interference wafer thickness meter (model: SI-F80R, Keyence Corporation).

[0280] Then, the polishing rate was calculated using the following mathematical formula 1. [Number 1] Polishing rate (Å / min) = Change in film thickness before and after polishing (Å) / Polishing time (min)

[0281] (2) Defects Polishing was performed using a CMP polishing machine in the same manner as in the polishing rate test. After polishing, the silicon wafer was transferred to a cleaning machine and washed with 1% HF, 1% H2NO3, and deionized water (DIW) for 10 seconds each. It was then transferred to a spin dryer, washed with deionized water (DIW), and then dried with nitrogen for 15 seconds. The dried silicon wafer was measured for defect changes before and after polishing using a defect measurement system (model: XP+, KLA-Tencor). Specifically, the total number of scratches, chatter marks, pits, and residues on the wafer was measured.

[0282] (3) Pad wear rate (PWR) The polishing pad was preconditioned with deionized water for the first 10 minutes, and then conditioned for one hour by spraying deionized water. The thickness change was measured during this time. The conditioning device used was a CTS AP-300HM, with a conditioning pressure of 6 lbf and a rotation speed of 100-110 rpm. The conditioning disc used was a Sesol CI-45. JPEG0007796812000008.jpg36147

[0283] The test results showed that the polishing pads of the examples had a polishing rate and pad wear rate both within the preferred range and had very few defects, while the polishing pads of the comparative examples had a polishing rate outside the preferred range and also had an increased occurrence of defects. [Explanation of symbols]

[0284] 100: Polishing pad 150: Debris 200: Platen 300: Conditioner 400: Slurry feeder 450: Polishing slurry (CMP slurry) 510: Polishing head 520: Career 600: Semiconductor substrate (wafer) 650: Defect 700:UV lamp 750:UV light

Claims

1. including an abrasive layer; the polishing layer contains a urethane-based prepolymer, a foaming agent, and a curing agent; A polishing pad in which, when the polishing layer is conditioned for 10 minutes while supplying deionized water at 300 cc / min under conditions of a platen speed of 93 rpm, a conditioner load of 9 lb, a conditioner speed of 64 rpm, and 19 sweeps / min, the D50 particle size of the resulting debris is 50 μm or less under conditions of pH 5.5, and the zeta potential of an aqueous solution containing the debris at a concentration of 0.01 wt % is −20 mV to 30 mV under conditions of pH 5.

5.

2. The D50 particle size of the debris obtained when conditioning the polishing layer is 25 μm or less under pH 5.5 conditions, 2. The polishing pad according to claim 1, wherein the polishing pad has a particle size of 22.3 μm or less under a pH 10 condition.

3. 2. The polishing pad according to claim 1, wherein the zeta potential of an aqueous solution containing debris obtained during conditioning of the polishing layer at a concentration of 0.01% by weight is −50 mV to −10 mV under a pH 10 condition.

4. 2. The polishing pad of claim 1, wherein when a silicon oxide film on a silicon wafer is polished using the polishing pad with a ceria slurry, the polishing rate is 2200 Å / min to 2600 Å / min according to the following mathematical formula 1: [Equation 1] Polishing rate (Å / min) = change in film thickness before and after polishing (Å) / polishing time (min).

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

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