Mechanical proprieties and residual stress evaluation on heteroepitaxial 3C-SiC/Si for MEMS application

SiC is a candidate material for micro-and nano-electromechanical systems (MEMS and NEMS). The hetero-epitaxial growth of 3C-SiC on silicon substrates allows one to overcome the traditional limitations of SiC micro-fabrication, but the high residual stress created during the film growth limits the development of the material for these applications. In this work, in order to evaluate the amount of residual stress released from the epi-film, different micro-machined structures were developed. Through the measurement of natural resonant frequencies and Raman shift analysis, a strong relationship between the mechanical proprieties of the material (Young's modulus) and the film crystal quality (defect density) was observed.