Grain size and doping effect on structure and electromechanical properties of polycrystalline silicon for MEMS applications

Grain size effect on microhardness and Young modulus of polysilicon layers was obtained by nanoindentation experiments: 14.1-16.3 GPa and 240-300 GPa, respectively, for the particle-diameter of 117-430 nm. The range of grain size correlated to mechanical properties exceed theoretical values was defined. The doping effect was considered. The grain size range of PECVD polysilicon with aspects of hardening and suitable conductivity is presented with the objective to formation of micro- and nanomechanical devices. (paper)