Study of selective and non-selective deposition of single-and polycrystalline silicon layers in an epitaxial reactor

Characterization of single- and polycrystalline silicon deposition in an epitaxial reactor aimed at MEMS applications is presented. HCl addition to the H₂-SiH₂Cl₂ gas system is used to control selectivity and growth rate ratios between different crystallographic faces on a (100) silicon substrate, which is locally covered with a masking dielectric layer and/or a thin LPCVD poly-Si nucleation layer. This allows forming of local single- and/or polycrystalline regions above the sacrificial oxide layer and a conventional epilayer in the same fabrication step. Potential for MEMS applications is demonstrated