Characterization of silicon isotropic etch by inductively coupled plasma etch in post-CMOS processing

In this paper, a novel post-CMOS micromachining technique using inductively coupled plasma (ICP) etching is described and the processing space is explored and characterized. Unlike most ICP processes using photoresist as a mask, we demonstrated that aluminum can be used in this type of system. Also, we demonstrated in this hybrid process that vertical and lateral etching can be specified separately. This bulk micromachining process gives more freedom for designing CMOS-MEMS structures, and enhances the reliability and yield of post-CMOS micromachining. The design rules are furthermore extracted from the characterization of the process.