CMP加工过程中晶片形状对抛光液流动特性的影响

Effect of Wafer Shape on Polishing Liquid Flow Characteristic in Chemical Mechanical Polishing

化学机械抛光过程中抛光液的流动特性取决于被抛光晶片的形状和抛光参数。采用LIF技术来实验研究晶片形状及抛光参数对抛光液液膜厚度的影响。研究表明,凸面晶片与抛光垫摩擦过程中,抛光液膜厚度随着抛光盘转速的增加而增加,随着下压力的增加而减少。而凹面晶片的抛光液膜厚度随着转速的增加而减少,随着加工载荷的增加也减小。通过对晶片形状和加工参数对抛光液流动特性的影响分析,为改善CMP加工工艺提供理论性的依据。

The flow characteristics of polishing liquid during chemical mechanical polishing are largely dependent on the shape of the wafer polished and polishing parameters. In this paper LIF is used to study the effect of wafer shape and polishing parameters on liquid layer film thickness of polishing liquid. The study indicates that with a convex wafer in contact with the polishing pad, the polishing liquid layer increases with increasing polishing plate rotating speed and decreases with increasing polishing load. However, with the concare wafer, the polishing liquid decreases layer with increasing rotating speed and polishing load. By analyzing the effects of CMP process parameters involving load and speed on polishing liquid flow characterictic, the better CMP process is practical based on theoretical principle.