CMP Pad Break-in Time Reduction in Silicon Wafer Polishing

This paper investigated the correlation between the surface conditions of the polishing pad and the break-in phenomena during silicon wafer polishing. The break-in is defined as pad conditioning to insure first polishing is consistent with second and following wafer polishing. A piezoelectric force sensor and an infrared (IR) sensor were installed on a silicon wafer polisher. The signals for friction force and temperature of the pad surface were measured simultaneously for monitoring the break-in phenomena during the polishing process. As a result of monitoring, the pad surface condition had the most significant effect on the break-in phenomena than compared to the other polishing parameters. Therefore, the control of the surface condition of the pad ensures the reduction of the break-in time during silicon wafer polishing.