Polishing pad, polishing pad manufacturing method, and wafer polishing method
AssigneeNoritake Co., Limited
InventorsRyoma ITO, Masatoshi KISHIMOTO
Life of this patent
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Abstract
A polishing pad includes a base material made of a base resin and having pores formed therein, and polishing particles held in the base material or the pores. When any specific pores are selected from the pores, and a short diameter, which is the shortest inner diameter of each of the specific pores, and a long diameter, which is the longest inner diameter thereof, are defined, pore-related areas, each of which is calculated by multiplying the short diameter, the long diameter, pi and ¼, have an average value of 87.7 μm2 or more. The polishing particles are silica particles with a specific surface area of 8.9 to 10.5 m2/g.
Claims9
A polishing pad, comprising:
- a base material comprising a base resin and having a plurality of pores formed therein;
- and
- a plurality of polishing particles held in the base material or in the pores, the polishing particles comprising silica particles with a specific surface area of 8.9 to 10.5 m2/g,
- wherein the base material includes the plurality of pores such that, for any specific pores selected from the plurality of pores, a short diameter, which is the shortest inner diameter of each of the specific pores, and a long diameter, which is the longest inner diameter thereof, satisfy that an average value of pore-related areas is 87.7 μm2 or more,
- where each of the pore-related areas is calculated by multiplying the short diameter, the long diameter, pi and ¼.
A polishing pad manufacturing method comprising:
- preparing a paste including a base resin, a plurality of polishing particles, and a solvent;
- forming the paste into a sheet-shaped formed body;
- immersing the formed body in a replacement liquid to replace the solvent in the formed body with the replacement liquid and obtain a replaced body;
- and
- removing the replacement liquid from the replaced body to obtain a polishing pad that includes a base material comprising the base resin and having a plurality of pores formed therein, and the polishing particles held in the base material or in the pores, the polishing particles comprising silica particles with a specific surface area of 8.9 to 10.5 m2/g,
- wherein
- the preparing includes adjusting proportions of the base resin, the polishing particles, and the solvent such that, for any specific pores selected from the pores, a short diameter, which is the shortest inner diameter of each of the specific pores, and a long diameter, which is the longest inner diameter thereof, satisfy that an average value of pore-related areas is 87.7 μm2 or more, where each of the pore-related areas
- is calculated by multiplying the short diameter, the long diameter, pi and ¼.
A wafer polishing method, comprising:
- polishing a flat plate-shaped wafer by rotating the wafer and a flat plate-shaped polishing pad relative to each other around an axis that extends in a thickness direction of the wafer while the wafer and the polishing pad are in contact with each other at a predetermined surface pressure in presence of a polishing liquid,
- wherein
- the polishing pad includes a base material comprising a base resin and having a plurality of pores formed therein, and polishing particles held in the base material or in the pores, the polishing particles comprising silica particles with a specific surface area of 8.9 to 10.5 m2/g,
- the base material includes the plurality of pores such that, for any specific pores selected from the plurality of pores, a short diameter, which is the shortest inner diameter of each of the specific pores, and a long diameter, which is the longest inner diameter thereof, satisfy that an average value of pore-related areas is 87.7 μm2 or more,
- where each of the pore-related areas is calculated by multiplying the short diameter, the long diameter, pi and ¼.
Dependencies are inferred from the claim text.