In-situ Monitoring Hydrodynamic Pressure Distribution during Chemical Mechanical Polishing

The hydrodynamic pressure distribution on the wafer surface in the chemical mechanical polishing process is evaluated with a various condition such as load pressure, flow rate, and slurry viscosity. To measure the hydrodynamic pressure in-situ process, a new head fixture was fabricated and Zigbee wireless communication is adopted, which can make it enable to interconnect between many sensors and monitoring PC. Finally, the measured results are compared with the non-uniformity of the polished wafer and modified Preston equation is suggested.