300mm硅片双面抛光运动轨迹模拟和优化

Simulation and Optimization of Motion Paths in Double-Sided Polishing Process of 300 mm Wafers

通过建立300 mm硅片双面化学机械抛光中硅片上定点相对于上下抛光垫的运动轨迹方程,分析了内外齿轮转速、抛光布转速对运动轨迹分布的影响,调整三者大小使得运动轨迹分布较均匀。实验证明运动轨迹路径长度与抛光去除厚度成正比关系,计算运动轨迹路径长度确定抛光垫的转速以达到上下表面具有相同的抛光速率。研究结果为300 mm硅片双面化学机械抛光找出优化工艺参数、提高硅片抛光后表面质量提供了理论依据。

A mathematical model based on motion paths relative to upper platen and lower platen for Double-sided polishing of 300 mm wafers was established.The effects of rotational speeds of inner gear,outer gear and platen on the distribution of trace were investigated.The trace could be uniform distributed if three rotational speeds were adjusted properly.The experimental results indicated that the travel distance was linearly correlated to the amount of removed material.Based on this result,the rotational speeds of inner gear,outer gear and platen can be determined to let each side of wafer has the same removal rate.With this study results,to find the best technologic parameters in double sided polishing process and to improve the quality of the polished wafer surface are impossible.