US Patent 7445847 Chemical mechanical polishing pad

The invention provides a polishing pad suitable for planarizing at least one of semiconductor, optical and magnetic substrates. The polishing pad includes a polymeric matrix having a top polishing surface. The top polishing surface has polymeric polishing asperities or forms polymeric polishing asperities upon conditioning with an abrasive. The polymeric polishing asperities are from a polymeric material having at least 45 weight percent hard segment and a bulk ultimate tensile strength of at least 6,500 psi (44.8 MPa). And the polymeric matrix has a two phase structure, a hard phase and a soft phase with an average area of the hard phase to average area of the soft phase ratio of less than 1.6.