Establishing a theoretical model for abrasive removal depth of silicon wafer chemical mechanical polishing by integrating a polishing times analytical model and specific down force energy theory

Abstract

This study uses the polishing pad with cross pattern, and it is supposed that the contact area between polishing pad surface of cross pattern and wafer is Gaussian distribution to establish and analyze an innovative abrasive removal depth theoretical model of chemical mechanical polishing (CMP) silicon wafer. In this model, it uses the binary image pixel division to calculate polishing times and it derives the contact force of each abrasive particle and uses the specific down force energy (SDFE) theoretical equation to calculate the abrasive removal depth on each abrasive particle after down force being applied. This study carries out CMP silicon wafer experiment as well as atomic force microscopy (AFM) measurement experiment of SDFE of silicon wafer. The abrasive removal depth of silicon wafer acquired from simulation analysis is compared with the abrasive removal depth of silicon wafer obtained from CMP experiment of silicon wafer, and the difference in between will also be analyzed. It shows that the difference between the results of simulation and experiment is in the acceptable range.