APPROACH TO OBTAIN HIGH-QUALITY GAN ON SI AND SIC-ON-SILICON-ON-INSULATOR COMPLIANT SUBSTRATE BY MOLECULAR-BEAM EPITAXY

Crystalline SiC thin layers have been grown on 125 mm silicon-on-insulator (SOI) substrates as a promising and economical substrate for the growth of GaN epilayers. Through the use of an AlN/GaN strained superlattice buffer layer, high quality GaN layers as thin as 2000 angstrom on Si(111) substrates have been achieved. X-ray diffraction curves with a full width at half-maximum (FWHM) as narrow as 25 arcmin were obtained. The associated low-temperature photoluminescence (PL) spectrum showed a dominant bound-exciton peak with a FWHM of 8 meV. We have further combined these two techniques to synthesize the first GaN on SiC on a SOI structure.