Surface evolution during low temperature epitaxial silicon growth by hot-wire chemical vapor deposition: Structural and electronic properties
We report the surface and structural evolution of hotwire chemical vapor deposited (HWCVD) crystalline Si thin films with temperature, thickness, and hydrogen dilution and the resulting growth regimes and electronic properties. We focus on a low silane partial pressure regime that leads to epitaxial growth with a polycrystalline, rather than an amorphous transition. Using scanning electron microscopy and atomic force microscopy, we find the relationship between the deposition conditions and the evolution of the surface roughness. Increasing the hydrogen dilution changes the kinetic growth regime from growth predominantly from the wire to shadow-dominated etch and finally to a regime dominated by desorption and re-deposition of growth species. Transitions between these kinetic regimes are the dominant factors governing the epitaxial–polycrystalline transition in low temperature HWCVD growth along with their electronic properties.
Additional Information© 2006 IEEE. Issue Date: May 2006. Date of Current Version: 15 January 2007. The authors would like to thank Melissa Griggs for the height-height correlation function code and Liz Miura for Raman measurements. This work was supported by BP Solar and the National Renewable Energy Laboratory; CER would like to thank Corning Inc. for their NPSC Fellowship support.