硅晶片的液流悬浮超光滑加工机理与实验

建立了基于机器人的液流悬浮超光滑加工系统。配置出了适用的悬浮加工液,通过对硅晶片的大量加工实验研究,得到了加工时间、工具转速和粒子浓度对工件表面质量的影响规律。实验结果表明:当加工时间在60 min、工具转速为6 000 r/min上下、粒子浓度为30 g/L左右时,加工效果最佳。加工后的硅晶片表面粗糙度Ra能达到1.55 nm。深入分析了液流悬浮超光滑加工的去除机理,硅晶片的液流悬浮超光滑加工是机械冲击作用和化学作用的综合结果,加工液中的磨料颗粒有对工件表面的机械冲击作用和对化学反应的催化作用。理论分析和实验结果表明,通过采用液流悬浮加工新技术,可以实现对半导体材料硅晶片的纳米水平的超光滑加工,获得表面无塑性变形和晶格缺陷的纳米精度表面。

Theory and experiment on hydrodynamic suspension ultra-smooth machining for silicon wafers

In order to realize nano-scale ultra-smooth machining for silicon wafers,a hydrodynamic suspension machining system based on robot was established,and the nanometer SiO2 suspension liquid with good dispersibility and stability was developed.By conducting experiments,the correlation between the surface roughness of workpiece and the machining time,motor rotate speed,density of abrasive particles were revealed.Experimental results indicate that the machining effects are the best when the machining time,motor rotate speed and density of abrasive particle are 60 min/s,6 000 r/min and 30 g/L,respectively.The surface roughness after machining can be 1.55 nm.Based on the conducting experiments,the machining mechanism was analyzed.The results show that the hydrodynamic suspension ultra-smooth machining for silicon wafers is the combination of mechanical impacting and chemical function.The nano-scale ultra-smooth surface of silicon wafers can be realized after hydrodynamic suspension machining and high quality surfaces without plastic deformation and damage are achieved.