Low-temperature (450 deg C) poly-Si thin film deposition on SiO_2 and glass using a microcrystalline-Si seed layer

摘要

A low-temperatuer (450 deg C), remote plasma-assisted CVD process for deposition of poly-Si thin films on SiO_2 and corning 7059 glass in which interface formation is separated from bulk films growth has been developed. This approach is based on first depositing an ultra-thin (<100A) microscryystalline-Si seed layer onto the oxide in orde rto provide nucleation sites at which low temperature poly-Si film growth can be initiated. Conditions for poly-Si film deposition were optimized by using a low-temperature, remote plasma process that had previously yielded epitaxial growth of Si thin films on crystalline Si substrates. Microstructural characterizationally with exposure of this seed layer to a predeposition hydrogen plasma treatment. Results demonstrated crystallinity in the poly-Si overlayer. For example using deposition conditions that yielded epitaxial film growth on Si substrates, films deposited on un-seeded oxide substrates were amorphous,, whereas those deposited using a seed layer were polycrystalline. This indicated that interfacial nucleation was the rate limiting step in promoting the low-temperature deposition of poly-Si thin films.