Optimization of design of experiment for chemical mechanical polishing of a 12-inch wafer

Chemical-mechanical polishing (CMP) is a critical process for the metallization of copper interconnections in ultra-large-scale integrated circuit manufacturing. This study aimed to maximize the material removal rate (MRR) and minimize the within wafer non-uniformity (WIWNU) simultaneously. The design of experiment approach was used to optimize the process parameters for the multi-zone CMP of a 12-inch wafer. Range analysis, ANOVA, and the overall balance method were conducted to identify the significant factors and optimum combination. The most common parameters during copper CMP were also investigated. Confirmation tests were performed as well, and the results indicated that an MRR of 6551 angstrom/min and a WIWNU of 4.72% can be obtained using the optimum combination. (C) 2013 Elsevier B.V. All rights reserved.