Impact of growth temperature on the structural properties of BGaN films grown by metal-organic vapor phase epitaxy using trimethylboron

BGaN containing boron (B) atoms with a large neutron capture cross section is expected as a novel neutron detecting semiconductor material. Many studies of the BGaN growth mechanism have been conducted in order to fabricate high crystallinity BGaN films. In this study, BGaN films were prepared using trimethylboron (TMB) as a metal-organic B source to investigate the impact of growth temperature. When the growth temperature was increased, the formation and incorporation of cubic phase was observed, voids were formed in the BGaN film, and the growth rate decreased. In order to clarify these phenomena, the decomposition energy and the decomposition temperature in the desorption region of BGaN growth were examined from the evaluation of the temperature dependency of BGaN growth rate. Experimental results showed that the desorption rate of adatoms in BGaN growth is different from that of GaN growth. This could originate from a change in the desorption process at the surface due to different bonding states caused by the adsorption of B atoms.