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CN-117120213-B - Polishing pad and method for producing polished product

CN117120213BCN 117120213 BCN117120213 BCN 117120213BCN-117120213-B

Abstract

A polishing pad comprising a polyurethane sheet as a polishing layer and an end point detection window provided in an opening of the polyurethane sheet, wherein the end point detection window has a storage modulus E' W90 at 90 ℃ of 1.0X10- 7 Pa or more, a D hardness (D W80 ) at 80 ℃ of 40 or more, and a D hardness (D W20 ) at 20 ℃ of 40-90 in dynamic viscoelasticity measurement of the end point detection window performed in a stretching mode at a frequency of 1.0Hz and at 10-100 ℃.

Inventors

  • TATENO TEPPEI
  • ITOYAMA KOHKI
  • Kyoya Hitoshi
  • Koike Kenchi
  • LI YUANHAO
  • YAMAGUCHI Satsuki
  • Takahiki Yamato

Assignees

  • 富士纺控股株式会社

Dates

Publication Date
20260508
Application Date
20220324
Priority Date
20210330

Claims (14)

  1. 1. A polishing pad having a polishing layer and an end point detection window provided in an opening of the polishing layer, The polishing layer comprises a polyurethane resin P and hollow particles dispersed in the polyurethane resin P, The end point detection window comprises polyurethane resin WI, The polyurethane resin WI comprises structural units derived from alicyclic isocyanate and/or aliphatic isocyanate, structural units derived from a compound having 3 or more hydroxyl groups and structural units derived from polyether polyol, In the dynamic viscoelasticity measurement of the end point detection window performed under the conditions of a stretching mode, a frequency of 1.0Hz and 10-100 ℃, the storage modulus E' W90 at 90 ℃ is 1.0X10 7 Pa or more, The D hardness (D W80 ) of the end point detection window at 80 ℃ is more than 40, The D hardness (D W20 ) of the end point detection window at 20 ℃ is 40-90.
  2. 2. The polishing pad of claim 1, wherein the storage modulus E' W30 at 30 ℃ is 60 x 10 7 ～100×10 7 Pa in a dynamic viscoelasticity measurement of the endpoint detection window.
  3. 3. The polishing pad according to claim 1 or 2, wherein a peak temperature of tan δ is 70 to 100 ℃ in the dynamic viscoelasticity measurement of the end point detection window.
  4. 4. A polishing pad having a polishing layer and an end point detection window provided in an opening of the polishing layer, The polishing layer comprises a polyurethane resin P and hollow particles dispersed in the polyurethane resin P, The end point detection window comprises polyurethane resin WI, The polyurethane resin WI comprises structural units derived from alicyclic isocyanate and/or aliphatic isocyanate, structural units derived from a compound having 3 or more hydroxyl groups and structural units derived from polyether polyol, In the dynamic viscoelasticity measurement under conditions of a stretching mode, a frequency of 1.0Hz and 10-100 ℃, the ratio (E ' P30 /E' W30 ) of the storage modulus E ' W30 at 30 ℃ of the end point detection window to the storage modulus E ' P30 at 30 ℃ of the polishing layer is 0.60-1.50.
  5. 5. The polishing pad according to claim 4, wherein a ratio (E ' P50 /E' W50 ) of a storage modulus E ' W50 at 50 ℃ of the end point detection window to a storage modulus E ' P50 at 50 ℃ of the polishing layer in the dynamic viscoelasticity measurement is 0.70 to 2.00.
  6. 6. The polishing pad of claim 4 or 5, wherein the storage modulus E' W30 at 30 ℃ is 10 x 10 7 ～60×10 7 Pa in a dynamic viscoelasticity measurement of the endpoint detection window.
  7. 7. The polishing pad of claim 4 or 5, wherein the endpoint detection window has a D hardness (D W20 ) of 40-70 at 20 ℃.
  8. 8. A polishing pad having a polishing layer and an end point detection window provided in an opening of the polishing layer, The polishing layer comprises a polyurethane resin P and hollow particles dispersed in the polyurethane resin P, The end point detection window comprises polyurethane resin WI, The polyurethane resin WI comprises structural units derived from alicyclic isocyanate and/or aliphatic isocyanate, structural units derived from a compound having 3 or more hydroxyl groups and structural units derived from polyether polyol, When the free induction decay curve of spin-spin relaxation of 1H obtained by measurement by the Solid Echo method using pulse NMR is separated into 3 curves from 3 components of a crystalline phase, an intermediate phase and an amorphous phase in a sequential waveform from short to long in relaxation time, The ratio of the presence ratio Lw20 of the amorphous phase of the end point detection window to the presence ratio Lp20 of the amorphous phase of the polishing layer (Lp 20/Lw 20) at 20 ℃ is 0.5 to 2.0, The ratio (Sp 80/Sw 80) of the presence ratio Sw80 of the crystal phase of the end point detection window to the presence ratio Sp80 of the crystal phase of the polishing layer at 80 ℃ is 0.5 to 2.0.
  9. 9. The polishing pad according to claim 8, wherein a ratio of an intermediate phase present ratio Mw20 of the end point detection window to an intermediate phase present ratio Mp20 of the polishing layer (Mp 20/Mw 20) at 20 ℃ is 0.7 to 1.5.
  10. 10. The polishing pad according to claim 8 or 9, wherein a ratio of an existence ratio Mw80 of the intermediate phase of the end point detection window to an existence ratio Mp80 of the intermediate phase of the polishing layer (Mp 80/Mw 80) at 80 ℃ is 0.5 to 1.5.
  11. 11. The polishing pad according to claim 8 or 9, wherein a difference (|Lp20-Lw20|) between the presence ratio Lw20 and the presence ratio Lp20 is 10 or less.
  12. 12. The polishing pad according to claim 8 or 9, wherein a difference between the presence ratio Sw80 and the presence ratio Sp80 (|sp 80-Sw 80|) is 15 or less.
  13. 13. The polishing pad according to claim 8 or 9, wherein the polyurethane resin P comprises a structural unit derived from an aromatic isocyanate.
  14. 14. A method for producing a polished product, comprising: a polishing step of polishing an object to be polished with the polishing pad according to any one of claims 1 to 13 in the presence of a polishing slurry to obtain a polished object, and An end point detection step of performing end point detection by an optical end point detection method during the polishing.

Description

Polishing pad and method for producing polished product Technical Field The present invention relates to a polishing pad and a method for producing a polished product using the same. Background In the semiconductor manufacturing process, chemical Mechanical Polishing (CMP) is used in planarization after the formation of an insulating film and in the formation of metal wiring. One of important technologies required for chemical mechanical polishing is polishing endpoint detection for detecting whether or not a polishing process is completed. For example, over-grinding or under-grinding relative to the targeted grinding endpoint directly results in poor product. Therefore, in chemical mechanical polishing, it is necessary to strictly control the polishing amount by polishing end point detection. Chemical mechanical polishing is a complicated process, and changes in polishing rate (polishing rate) occur due to the influence of variations in the operating state of a polishing apparatus, the quality of consumables (slurry, polishing pad, dresser, etc.), and the state of polishing with time. In recent years, the accuracy and in-plane uniformity of the residual film thickness required in the semiconductor manufacturing process have become more and more stringent. In this case, it becomes more difficult to detect the polishing end point with sufficient accuracy. As a main method of polishing end point detection, an optical end point detection method, a torque end point detection method, an eddy current end point detection method, and the like are known, in which a wafer is irradiated with light through a transparent window member provided on a polishing pad, and reflected light is monitored to perform end point detection. As a polishing pad using such an optical endpoint detection method, for example, patent document 1 discloses a polishing pad having a pad body and a transparent window member integrally formed with a part of the pad body, in which the surface of the window member is recessed from the surface of the pad body, with the aim of providing a polishing pad capable of suppressing slurry from being retained in a groove of the window member and improving detection accuracy of a polishing rate. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2002-001647 Disclosure of Invention Problems to be solved by the invention However, as one of the methods for producing the polishing pad having the window, there is a method in which the resin composition is filled and cured in a state in which the window member is fixed to a mold, and then the obtained cured product is sliced and thereafter subjected to a finishing treatment. Here, since the window member and the cured product of the resin composition are formed of different materials, there are some differences in physical properties, but there is a possibility that the window portion will be dented or broken when dicing is performed, for example. In addition, when the dressing treatment is performed, the window may be recessed due to a difference in the abrasion amount between the window and the polishing layer. If such dishing occurs, slurry and polishing dust are likely to accumulate therein, and scratches and the like may occur, which may reduce the surface quality of the workpiece. In addition, when the abrasion amount of the window portion is small, the window portion is more likely to remain than the polishing layer as polishing proceeds, and as a result, it is considered that the window portion becomes convex. Such a convex window portion may also cause scratches or the like, which may reduce the surface quality of the workpiece. The present invention has been made in view of the above problems, and one of the objects of embodiments 1 and 3 is to provide a polishing pad having excellent flatness in slicing and dressing processes, and a method for producing a polished product using the polishing pad. Further, when the characteristics of the polishing layer and the end point detection window are different as in patent document 1, for example, the end point detection window is polished faster than the polishing layer and becomes recessed, and slurry and polishing dust are likely to accumulate therein, and defects (surface defects) may occur. Further, when the polishing of the polishing layer is slower than the portion of the end point detection window, the end point detection window becomes a convex portion as the polishing proceeds, and defects may occur, which may reduce the surface quality of the object to be polished. The present invention has been made in view of the above-described problems, and an object thereof is to provide a polishing pad and a method for producing a polished product using the same, which are less likely to cause defects and have excellent surface quality even when the polishing pad has an end point detection window, in embodiments 2 and 4. Means for solving the problems [ Embodiment 1]