Surface evolution during low temperature epitaxial silicon growth by hot-wire chemical vapor deposition: Structural and electronic properties

摘要

We report the surface and structural evolution of hotwire\udchemical vapor deposited (HWCVD) crystalline Si thin\udfilms with temperature, thickness, and hydrogen dilution\udand the resulting growth regimes and electronic\udproperties. We focus on a low silane partial pressure\udregime that leads to epitaxial growth with a polycrystalline,\udrather than an amorphous transition. Using scanning\udelectron microscopy and atomic force microscopy, we find\udthe relationship between the deposition conditions and the\udevolution of the surface roughness. Increasing the\udhydrogen dilution changes the kinetic growth regime from\udgrowth predominantly from the wire to shadow-dominated\udetch and finally to a regime dominated by desorption and\udre-deposition of growth species. Transitions between\udthese kinetic regimes are the dominant factors governing\udthe epitaxial–polycrystalline transition in low temperature\udHWCVD growth along with their electronic properties.