Synthesis of hexagonal AlN и GaN layers on a Si(100) substrate by chloride vapor-phase epitaxy

Synthesis of AlN and GaN layers on a Si(100) substrate by chloride vapor-phase epitaxy has been considered. The process includes sulfidizing of the silicon surface, nucleation and growth of an AlN layer, and then formation of a GaN/AlN structure. It has been found that in the case of a (100)Si substrate, GaN nucleates on buffer AlN layers that may have two crystallographic orientations in contrast to a Si(111) substrate, on which a buffer layer may have only one orientation. It has been shown that the treatment of the Si(100) substrate in an aqueous solution of (NH$_4$)$_2$S decreases the FWHM of the rocking curve for GaN(0002) by a factor of 1.5.