不同抛光参数对蓝宝石衬底CMP质量的影响

Effects of Different Polishing Parameters on the CMP Quality of Sapphire Substrate

蓝宝石衬底化学机械抛光(CMP)质量直接影响器件的成品率和可靠性。抛光液和抛光工艺参数是影响CMP质量的决定性因素。为了得到更优的抛光液利用率以及更好的抛光效果,系统研究了自主研制的抛光液pH值、抛光压力、转速和流量等抛光参数对c面蓝宝石衬底化学机械抛光去除速率和表面粗糙度的影响。结果表明,去除速率随pH值、抛光压力、转速和流量的升高先增加后减小;表面粗糙度随pH值、抛光压力、转速的升高先减小后增加,随流量升高而慢慢降低。通过实验进行优化,当pH值为10.5、抛光压力为27.6kPa、抛光头转速为40r/min、抛光盘转速为45r/min、流量为160mL/min时,去除速率能稳定在2.69μm/h,表面粗糙度为0.184nm。此规律对指导工业生产具有重要的意义。

Chemical mechanical polishing（CMP）quality of sapphire substrate directly affects the yield and reliability of devices.The slurry and polishing technological parameters are the decisive factors for influencing the CMP quality.In order to gain better utilization rates of slurry and better polishing effects,the effects of the domestically developed slurry’s polishing parameters,such as pH value,polishing pressure,rotational speed and slurry flow rate,on the removal rate and surface roughness of c-plane sapphire substrate were systematically studied.The results indicated that the removal rate increased first and then decreased with the increasing of pH value,polishing pressure,rotational speed and slurry flow rate.At the same time,the surface roughness decreased first and then increased with the increasing of pH value,polishing pressure and rotational speed,and it slew down with the increasing of slurry flow rate.Under the condition of optimal parameters of 10.5 pH,27.6 kPa polishing pressure,40 r/min polishing head speed,45 r/min platen rotation speed and 160 mL/min slurry flow rate,the removal rate could be stable at 2.69μm/h and the surface roughness was 0.184 nm.This regularity was of great significance to guide the industrial production.