Deposition of nanocrystalline translucent h-BN films by chemical vapor deposition at high temperature

Abstract

h-BN layers were deposited on α-SiC and sapphire substrates by chemical vapor deposition at high temperature (1500–1900°C) using B2H6 and NH3 diluted in Ar. Growth rates were in the 6–10μm/h range. In all the conditions studied, the as deposited BN layers were found to be translucent to light, some having a light whitish aspect and other a more yellowish one. It was also observed that the deposit was not always adhesive. Characterizations showed that the layers were nano-crystalline with crystallite size<10nm. The growth rate was found to be temperature and N/B ratio dependent due to an N limited growth regime which is more pronounced above 1700°C.