抛光垫提高化学机械抛光接触压强分布均匀性研究

Contact Pressure Distribution During Chemical Mechanical Polishing with Bionic Cutting Polishing Pad

为了改善单晶硅片化学机械抛光(CMP)接触压强分布的均匀性和实现高平坦化抛光,基于弹性力学的"Winkler地基"理论提出了一个新的CMP接触模型。依据此模型,从葵花籽粒分布的结构特征出发对抛光垫进行了分割,计算分析了分割参数对接触压强分布的影响规律,并实验验证了分割参数对硅片抛光平面度轮廓的影响规律。研究结果表明:当分割参数为顺时针0.008～0.009 mm,逆时针为0.005～0.006 mm时,抛光接触压强分布较为均匀,并使得被抛光晶片的平面度得到改善。

In order to improve the uniformity of the contact pressure distribution of chemical mechanical polishing（CMP） and the effects of chemical mechanical planarization,a new model of contact mechanism on CMP was set up based on the Winkler foundation model of elastic theory,and also a kind of method on cutting polishing pad was invented according as phyllotactic pattern of sunflower seed,and then the effects of cutting parameters on the contact pressure distribution of CMP were calculated and analyzed,lastly,the effects of the cutting parameters on the surface profiles of polished wafers were investigated by experiment.The research results show that the contact pressure distribution on polishing wafer surface becomes more uniform and its flatness errors become smaller when cutting parameters are from 0.008 mm to 0.009 mm in clockwise and from 0.005 mm to 0.006 mm in anticlockwise.