Optimization of CMP process for TSV reveal in consideration of critical defect

In this paper, we discuss the optimization of CMP process for mid-end-of-line (MEOL). TSV breaking and blister are the two types of critical defects during CMP. TSV breaking occurs due to high principle stress at the bottom of TSV and blister occurs because of adhesive deformation. Therefore, we suggest a new process schematic for CMP and the use of thermally stable adhesive material to prevent these critical defects. Later we optimized CMP process in consideration of via height, throughput and non-uniformity without any critical defects. TSV was successfully revealed without TSV breaking. The result shows less 10 % WIWNU, WIDNU and less 10 nm TSV dishing.