Advanced silicon etching using high-density plasmas

High density plasmas are beginning to dominate the market for advanced anisotropic silicon etching for MEMS applications. This paper looks at the reasons behind this dominance for high etch rate, deep anisotropic etching. A discussion of anisotropic etch mechanisms highlights the need for sidewall passivation to meet these requirements. Results are presented of a novel room temperature advanced silicon etch process: >= 2 micrometers /min; >= 70:1 selectivity to resist (and >= 150:1 to oxide); up to 30:1 aspect ratio; 500 micrometers depth capability; using a non-toxic, non-corrosive environmentally acceptable fluorine-based chemistry.