Significant improvement in silicon chemical vapor deposition epitaxy above the surface dehydrogenation temperature

We observe an order of magnitude increase in both the rate and achievable thickness of epitaxy by hot-wire chemical vapor deposition at temperatures above the dehydrogenation temperature of the silicon surface. We deposit silicon films on (100) silicon at 110 nm/min at substrate temperatures between 520 and 645 degrees C. At the glass compatible temperature of 610 degrees C, we observe phase-pure epitaxial growth of more than 10 mu m, as observed by x-ray diffraction and transmission electron microscopy, in contrast to the mixed-phase breakdown seen at lower temperatures. In 610 degrees C films thicker than 4 mu m, a stable (100)-epitaxial growth mode produces regular surface pyramids with vicinal < 311 > facets. On the low-energy (111) face of Si, more than 2 mu m of epitaxial Si were grown at 645 degrees C, but some twinning is observed. The temperature of this new growth regime suggests that rapid dehydrogenation of the growing surface is critical for silicon epitaxy by CVD. (c) 2006 American Institute of Physics.