基于叶序仿生抛光垫的化学机械抛光的运动分析

为了改善化学机械抛光的接触状态和被加工工件的表面形态,基于生物学的叶序理论设计了仿生结构的抛光垫。从单颗磨粒切削理论出发,建立了抛光运动方程和材料去除率分布模型。利用所建立的运动方程和材料去除率分布模型进行了晶片表面材料去除率分布的计算分析,得到抛光机的运动参数及抛光垫的叶序参数对材料去除率的影响规律。结果表明:当抛光盘的转速较大、工件转速适中、摆臂摆动频率较小、摆臂中心角较小及叶序参数取值较小时可以获得更好的材料去除分布。

A kinematical analysis on chemical mechanical polishing by bionic polishing pad with phyllotexis pattern

In order to improve the contact form between the polishing pad and wafer and the surface texture of polished wafer during chemical mechanical polishing （CMP） , a new kind of polishing pad was designed based on the phyllotaxis theory of biology. The kinematical equation and the distribution model of material removal rate （MRR）were established on the basis of the cutting theory of single abrasive gain. By means of those equation and model, the material removal volume distribution （MRVD） was calculated and analyzed. The effects of the movement parameters of polishing machine and the phyllotaxis parameters of polishing pad on the cutting trajectory and the MRVD were obtained. The results show that the uniformity of the dimensionless distribution of the material removal volume （DDMRV） on wafer surfaces can be improved when the revolution speed of the polishing platen is high, the swing speed of the swing shank and its center angle is small, the phyllotaxis parameters are small, and the rotation speed of the workpiece is proper.