激光晶片抛光中磨粒运动轨迹分布均匀性分析

摘要

为分析晶片抛光过程中,转动比α和摆动比β对磨粒轨迹分布均匀性的影响,建立晶片与抛光垫的相对速度模型及磨粒在晶片表面的运动轨迹模型,并分析晶片相对抛光垫的速度的分布规律、统计磨粒轨迹密度.结果表明:晶片转速与抛光垫转速一致时,其对抛光垫的相对速度大小一致;晶片随抛光头的往复运动主要影响相对速度变化的周期性及磨粒轨迹分布的随机性;当α=1.01,β=0.2时,磨粒在晶片上的轨迹分布均匀性最好.%To analyze effect of rotation ratio α and swing ratio β on distribution uniformity of grain trajectory during wafer polishing, two models are established, namely relative velocity between wafer and pad, and grain trajectory on wafer surface.Distribution law of relative velocity and particle trajectory density statistics are studied.Results show that when the rotation speeds of wafer and pad are kept consistent, the relative speed is stable.It is also found that the reciprocating motion of wafer following polishing head mainly influences periodicity of relative speed changes and randomness of grain trajectory distribution.In conclusion, when α =1.01 and β =0.2, the homogeneity of grain trajectory distribution on wafer is the best.