OPTICAL SYSTEM FOR IN-LINE SLURRY MONITORING

摘要

Chemical-mechanical polishing (CMP) is a process used to remove surface irregularities and to obtain uniform planarization of a silicon wafer surface. To achieve uniform and efficient wafer planarization, the CMP slurry particles must be controlled. Effective CMP slurry control requires continuous in-line sampling of undiluted slurry to detect changes in slurry behaviour. This thesis is realized in collaboration with many companies (ST microelectronics, Atmel, Kemesys, Silios Technologies and Rockwood) and aims to develop an optical sensor for in line monitoring slurry which detects real-t'ime changes in slurry PSD and concentration. Results of off-line size and concentration monitoring with an optical bench are presented for commonly used Silica slurry.