Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : October 25, 2023 - October 27, 2023
As silicon semiconductor devices are more integrated and miniaturized, silicon wafers for substrates used in the devices are required to be even flatter. Chemical-Mechanical Polishing (CMP) is an essential process in the manufacturing of silicon wafers to determine wafer’s flatness. Predictive simulation technology of polishing amount distribution is needed to improve wafer’s flatness efficiently. Especially this distribution depends on mechanical of properties of polishing pad. However, the pad’s compressive deformation in CMP process remains to be delineated. In this study, we have measured the pad’s deformation in situ and identified pad’s properties by viscoelastic characteristics formulation. Then, we have developed a simulation model of dynamic pressure on a wafer in consideration of pad’s viscoelastic characteristics using finite element method (FEM). As a result, the simulation model has reproduced the measured values and confirmed validity. Therefore, it is clarified that one of the keys for the accurate prediction of polishing amount distribution is the pad’s deformation in CMP process.
