A method is provided for making a MEMS structure (69). In accordance with the method, a CMOS substrate (51) is provided which has interconnect metal (53) deposited thereon. A MEMS structure is created on the substrate through the plasma assisted chemical vapor deposition (PACVD) of a material selected from the group consisting of silicon and silicon-germanium alloys. The low deposition temperatures attendant to the use of PACVD allow these materials to be used for MEMS fabrication at the back end of an integrated CMOS process.