The study of WCMP endpoint detection by motor current for different glue layer

摘要

Endopint detection is important in WCMP process, good endpoint detection reduces the over polishing and dishing/erosion, poor polish control can make the overlay and alighnment mark damaged. Several endopint control method have been developed, including temperature, voltage, optical and torque current[1]. In this report we examine the effect of different glue layer on turn-table torque current as an end point detection method. Different glue layer process will influence the endpoint detection performance.