ICP深硅刻蚀工艺研究

Experimental Evaluation of Inductively Coupled Plasma Deep Silicon Etching

感应耦合等离子体(ICP)刻蚀技术是微机电系统器件加工中的关键技术之一。利用英国STS公司STS Multiplex刻蚀机,研究了ICP刻蚀中极板功率、腔室压力、刻蚀/钝化周期、气体流量等工艺参数对刻蚀形貌的影响,分析了刻蚀速率和侧壁垂直度的影响原因,给出了深硅刻蚀、侧壁光滑陡直刻蚀和高深宽比刻蚀等不同形貌刻蚀的优化工艺参数。

The inductively coupled plasma（ICP） deep silicon etching,one of the key techniques in fabricating micro electromechanical system（MEMS） devices was experimentally evaluated with UK STS multiplex.The impacts of the ICP etching conditions,such as the power,pressure,etching/passivation cycle,etching rate,and SF6 gas flow rate,on the morphologies of the Si（100） wafer etched were studied.Under the optimized ICP etching conditions,a well-defined,nearly rectangular,micro-trench with smooth sidewalls,340 μm deep and 50 μm wide was etched.We found that an addition of a small amount of oxygen and C4F8 in the ICP etching cycle significantly improved the steepness and smoothness of the sidewalls of the micro trench.Addition of oxygen in the ICP etching cycle was found to increase the aspect ratio of depth and width of the micro trench up to 20∶1.