基于高深宽比Si干法刻蚀参数优化

为满足体硅MEMS制造工艺进一步发展的需要,对电感耦合等离子体(ICP)刻蚀工艺参数进行了深入分析,着重分析了平板功率对Si干法刻蚀的影响。通过对Si干法刻蚀的主要工艺参数进行正交试验,得出了一组较为理想的刻蚀工艺参数:刻蚀气体SF6和保护气体C4F8的流量均为13cm3·min-1,在一个周期内通入刻蚀气体SF6的时间为4s,通入钝化气体C4F8的时间为3s;线圈功率为400W,平板功率为110W。利用这组优化的工艺参数进行Si的干法刻蚀,所得到的微结构的深宽比将大于20∶1,同时侧壁垂直度能够很好地控制在90°±1°。

Parameter Optimization Based on High-Aspect Ratio Si Dry Etching

In order to satisfy the development of bulk silicon MEMS manufacturing process,the process parameters of ICP-RIE,especially the effect of platen power on the silicon dry etching,were intensively analyzed.A set of perfect processing parameters was obtained through the orthogonal test about the primary processing parameters.The flow of etching gas SF6 and protectable gas C4F8 were both 13 cm3·min-1,and the flow times of SF6 and C4F8 were 4 s and 3 s in one period,respectively.The platen power was 400 W,and the coil power was 110 W.The bulk silicon was dry etched with these parameters.The results show that the aspect ratio is greater than 20∶1 and the angle of sidewall can be controlled well in the range of 90°±1°.