Single-material MEMS using polycrystalline diamond

The multi-material MEMS fabrication process often requires a larger number of masks making it more expensive as compared to single-material MEMS (SMM) technology. By varying the doping level in poly-C, semi-conducting, metallic and insulating (undoped) properties are achieved that are needed for poly-C SMM. However, the development of diamond-based SMM technology faces a number of challenges including (a) producing highly-insulating and highly-conducting poly-C films, (b) creating ohmic contacts and (c) patterning by dry etching of poly-C films grown on Si or SiO₂. These challenges are addressed in this paper.