Porous polyurethane polishing pad and process for preparing a semiconductor device by using the same

A process for preparing a semiconductor device, which comprises providing a porous polyurethane polishing pad;

• disposing an object to be polished on the polishing pad;
• and relatively rotating the object to be polished with respect to the polishing pad to polish the object,
• wherein the polishing pad comprises a urethane-based prepolymer, a solid phase foaming agent in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the urethane-based prepolymer, and a curing agent;
• and
• wherein the polishing pad has a thickness of 1.5 to 2.5 mm, a number of pores whose average diameter is 10 to 60 μm, a specific gravity of 0.7 to 0.9 g/cm3, a surface hardness at 25° C. of 45 to 65 Shore D, a tensile strength of 15 to 25 N/mm2, an elongation of 80 to 250%, an AFM (atomic force microscope) elastic modulus of 101 to 250 MPa measured from a polishing surface in direct contact with the object to be polished to a predetermined depth wherein the predetermined depth is 1 to 10 μm.