小振幅兆声对硅片化学机械抛光效果的影响  

Influence of Low-amplitude Megasonic on Chemical-Mechanical Polishing for Silicon Wafers

作　　者：李亮[1] 何勍 郑冕[1] 任奕 李小龙 LI Liang;HE Qing;ZHENG Mian;REN Yi;LI Xiao-long(College of Science and Institute of Vibration Engineering,Liaoning University of Technology, Jinzhou 121001, China)

机构地区：[1]辽宁工业大学理学院和振动工程研究所,锦州121001

出　　处：《科学技术与工程》2018年第14期111-115,共5页Science Technology and Engineering

基　　金：辽宁省教育厅高校基本科研业务费(JL201615408);辽宁省科学技术计划(2015020159)资助

摘　　要：为了改善硅片化学机械抛光效果,提高硅片表面质量,一小振幅兆声振子引入化学机械抛光系统,通过对比表面粗糙度大小和分布,发现该振子对改善硅片化学机械抛光效果有明显促进作用。测试表明:振子频率为1.7 MHz,中心最大振幅约为70 nm;硅片表面振动频率为1.7 MHz,中心最大振幅小于10 nm;该振子独立抛光时,未发现硅片表面粗糙度明显降低,但它能引起抛光液微流动,使储存在抛光垫窠室中更多的抛光液进入接触区参与抛光。无振动抛光时,硅片中心区域抛光液供给不足,造成该区抛光效果较差;兆声致微流动能有效缓解这种不足,改善硅片中心区域抛光效果,不仅如此,它还能有效降低其他区域的表面粗糙度。与无振动抛光的硅片相比,经过兆声辅助抛光的硅片,表面粗糙度更小,分布更均匀。A low-amplitude megasonic vibrator was introduced into chemical-mechanical polishing system so as to improve the polishing effect and promote the flatness of the surface of silicon wafer. The contribution of such megasonic to polishing effect was investigated by comparing the surface roughness. This vibrator has the frequency of 1. 7 MHz and the greatest amplitude of 70 nm in the its center; the frequency of silicon wafer is equal to the vibrator but its greatest amplitude is less than 10 nm in its center. It is found from the experiments that such vibrator could not complete chemical-mechanical polishing independently but lead to the micro-flow of the polishing slurries in the cells of polishing pad,which results in the increase of the polishing slurry involved in polishing. In the process of the polishing without vibration,the polishing slurry in the center area is not enough to obtain an idea polishing effect. The micro-flow generated by megasonic could not only effectively alleviate this problem and improve the polishing effect of the center region,but also decrease the surface roughness of the rest region of the silicon wafer. Therefore,the silicon wafer after megasonic-assisted polishing has smaller and more uniform roughness than that polished without vibration.

关 键 词：兆声 压电振子 化学机械抛光 硅片 表面粗糙度 

分 类 号：TB559[理学—物理]