Porous polyurethane polishing pad and process for producing the same
AssigneeSK enpulse Co., Ltd.
InventorsHye Young Heo, Jang Won Seo, Jong Wook Yun, Sunghoon Yun, Jaein Ahn
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Abstract
Embodiments relate to a porous polyurethane polishing pad for use in a chemical mechanical planarization (CMP) process of semiconductors and a process for preparing the same. According to the embodiments, the size and distribution of the plurality of pores contained in the porous polyurethane polishing pad can be adjusted. Thus, it is possible to provide a porous polyurethane polishing pad that has enhanced physical properties such as a proper level of withstand voltage, excellent polishing performance (i.e., polishing rate), and the like.
Claims14
A porous polyurethane polishing pad, which is prepared from a reaction mixture comprising a urethane-based prepolymer and a curing agent,
- wherein the porous polyurethane polishing pad comprises a plurality of pores,
- wherein in a cross-sectional area of the polishing pad of 2 cm×2 cm and 2 mm thick the plurality of pores have an area-weighted average pore diameter (AWAPD) of 10 μm to 40 μm,
- wherein in the pore size distribution of the plurality of pores based on a cross-sectional area of the polishing pad, a sum of cross-sectional areas of pores having a diameter of greater than X+10 μm is 5% to 20% based on 100% of a sum of the cross-sectional areas of the plurality of pores, and X equals the AWAPD,
- wherein in the pore size distribution of the plurality of pores based on the cross-sectional area of the polishing pad, the pore diameter of the maximum peak Y is 15 μm to 40 μm, and wherein a sum of cross-sectional areas of pores having a diameter of Y−5 μm or less is 20% to 40% based on 100% of the sum of the cross-sectional areas of the plurality of pores, and
- wherein the porous polyurethane polishing pad has a thickness of 1.5 mm to 2.5 mm, a specific gravity of 0.7 g/cm3 to 0.9 g/cm3, a surface hardness at 25° C. of 50 shore D to 65 shore D, a tensile strength of 15 N/mm2 to 25 N/mm2, an elongation of 80% to 250%, a total pore area of 30% to 60% based on the total area of the polishing pad, and a breakdown voltage of 14 kV to 23 kV.
A process for preparing a porous polyurethane polishing pad, which comprises:
- (1) injecting a mixture comprising a urethane-based prepolymer, a curing agent, and a material for forming a plurality of pores into a mold and molding the mixture;
- and
- (2) curing the mixture,
- wherein in a cross-sectional area of the polishing pad of 2 cm×2 cm and 2 mm thick the plurality of pores have an area-weighted average pore diameter (AWAPD) of 10 μm to 40 μm,
- wherein in the pore size distribution of the plurality of pores based on a cross-sectional area of the polishing pad, a sum of cross-sectional areas of pores having a diameter of greater than X+10 μm is 5% to 20% based on 100% of a sum of the cross-sectional areas of the plurality of pores, and X equals the AWAPD,
- wherein in the pore size distribution of the plurality of pores based on the cross-sectional area of the polishing pad, the pore diameter Y of the maximum peak is 15 μm to 40 μm, and wherein a sum of cross-sectional areas of pores having a diameter of Y−5 μm or less is 20% to 40% based on 100% of the sum of the cross-sectional areas of the plurality of pores, and
- wherein the porous polyurethane polishing pad has a thickness of 1.5 mm to 2.5 mm, a specific gravity of 0.7 g/cm3 to 0.9 g/cm3, a surface hardness at 25° C. of 50 shore D to 65 shore D, a tensile strength of 15 N/mm2 to 25 N/mm2, an elongation of 80% to 250%, a total pore area of 30% to 60% based on the total area of the polishing pad, and a breakdown voltage of 14 kV to 23 kV.
Dependencies are inferred from the claim text.