High-Porosity CMP Pad Formulation for Hardness-Defectivity Balance

The patent applies porous materials by incorporating a porogen (such as hollow glass beads or porous particles) into the polyurethane composition during foam formation. This creates a controlled porous structure within the polishing pad that reduces its effective hardness and density while maintaining the underlying polymeric hardness. The porosity allows the pad to be more compliant and less likely to generate defects, thereby resolving the contradiction between removal rate and defectivity by enabling a softer operating surface from a harder base material.

The patent employs composite materials by combining polyurethane polymer matrix with porogen particles (hollow glass beads, porous silica, or other porous fillers) to create a multi-phase composite structure. This composite approach allows the pad to exhibit tailored mechanical properties where the polyurethane provides structural integrity and the porogen creates void spaces that reduce hardness and improve compliance. The composite structure enables simultaneous achievement of high removal rate and low defectivity.

The patent utilizes porous materials by incorporating porogens that create controlled void spaces within the polishing pad matrix. This porous structure reduces the effective density and hardness of the pad, making it more compliant and less defect-generating during polishing. The porosity is optimized to balance compliance (reducing defects) with sufficient structural support (maintaining removal rate).

The patent applies parameter changes by carefully controlling the amount, size distribution, and morphology of porogen particles incorporated into the polyurethane foam. By adjusting porogen content (typically 10-50 wt%), particle size (1-100 micrometers), and foam cell structure, the patent optimizes the balance between pad density, hardness, and compliance to simultaneously achieve low defectivity and high removal rate.

The patent employs composite materials by creating a hybrid structure where a polyurethane polymer matrix provides mechanical strength and structural integrity, while embedded porogen particles (hollow glass beads, porous silica, etc.) create compliant porous regions. This composite architecture allows the pad to maintain sufficient tensile and compressive strength from the continuous polymer phase while the porous regions provide compliance and defect reduction. The interfacial bonding between porogen and matrix is optimized to prevent premature failure.

The patent applies local quality by creating spatially differentiated properties within the polishing pad: the polyurethane matrix regions provide mechanical strength and structural support, while the porous regions surrounding porogen particles provide compliance and defect reduction. This local differentiation of material properties allows simultaneous achievement of high strength and low defectivity in different zones of the same material structure.