Optimization of tribological properties of silicon dioxide during the chemical mechanical planarization process

Chemical mechanical planarization (CMP) has been proved to achieve excellent global and local planarity, and, as feature sizes shrink, the use of CMP will be critical for planarizing multilevel structures. Understanding the tribological properties of a dielectric layer in the CMP process is critical for successful evaluation and implementation of the materials. In this paper, we present the tribological properties of silicon dioxide during the CMP process. A CMP tester was used to study the fundamental aspects of the CMP process. The accessories of the CMP tester were first optimized for the reproducibility of the results. The coefficient of friction (COF) was measured during the process and was found to decrease with both down pressure and platen rotation. An acoustic sensor attached to this tester is used to detect endpoint, delamination, and uniformity. The effects of machine parameters on the polishing performance and the correlation of physical phenomena with the process have been discussed.