The novel use of low temperature hydrogenated microcrystalline silicon germanium (?cSiGe:H) for MEMS applications
In this paper, we propose hydrogenated microcrystalline silicon germanium (?cSiGe:H) as a MEMS structural material deposited at temperatures of 300400 C, showing good mechanical and electrical properties. This range of deposition temperatures is investigated in order to allow post-processing of MEMS on top of CMOS with low-permittivity inter-metal dielectrics. Plasma enhanced chemical vapor deposition (PECVD) is used to deposit in situ Boron doped SiGe films with low tensile stress (down to +25 MPa) and low electrical resistivity (down to 7 m?cm). The use of a multilayer film deposition technique is investigated as a means to obtain films with low stress gradient values suitable for MEMS surface micromachining.
microcrystalline sige pecvd stress growth mechanism low temperature processing microelectromechanical systems