Effects of Technical Parameters on Etching Rate and Selectivity of Si Deep Trench Using ICP Etching

Single crystal P-type silicon was etched with inductively coupled plasma (ICP) in SF6+C2H4 gas mixture. The influence of process conditions,such as reaction gas flow,SF6/C2H4 ratio,and ICP power,on the etching morphology and the etching rate were discussed. Experiment results showed that Si plasma etching with SF6 exhibited isotropy. In order to obtain ideal etching patterning,appropriate content of C2H4 gas should be used. Meanwhile,the ratio of these two gases should be controlled exactly to satisfy the etching rate and the selectivity of deep silicon etching. With Corial 200IL system,the optimum condition is SF6 with 40 sccm and C2H4 with 15 sccm.