文献类型： 会议论文

第一作者： Gregory P. Muldowney

作者： Gregory P. Muldowney ¹ ;

作者机构： 1.Rohm and Haas Electronic Materials CMP Technologies, Newark, DE 19713 USA

会议名称： International Symposium on Electrochemical Processes in ULSI and MEMS

主办单位：

页码： 318-326

摘要： Backmixing is a reverse flow of slurry that occurs at some pad-wafer speed combinations common in CMP practice. Both dual-axis and belt polishers can achieve consistent pad-wafer relative velocity point-to-point, but may also induce backmixing that preferentially affects the wafer edge and imparts non-uniformity. A theoretical model was developed to predict the onset of backmixing in terms of critical platen and carrier speeds for dual-axis polishers, and critical belt and carrier speeds for belt polishers, including the effect of pad texture. A dramatic removal rate shift was observed upon switching between un-backmixed and backmixed processes via carrier speed, and model predictions exactly matched the observed threshold carrier speed. The findings provide a consistent interpretation across rotary^d belt polishers of the impact of relative motion on wafer-scale convective transport and polish uniformity. Polishing pad grooving and texturing are re-examined as design variables to be fine-tuned for favorable interplay with slurry backmixing effects.

分类号： O646