Metal organic vapour phase epitaxy (MOVPE) growth of GaN(n)/SiC(p) heterostructures

GaN epilayers about 600 nm thick were grown directly on 6H-SiC by metal-org anic vapour phase epitaxy (MOVPE) with a three-step process. A thin GaN nuc leation layer grown at 1080 degrees C, initially 3D, is smoothed in several minutes under ammonia flux when the growth is interrupted. A flat layer is obtained through a large mass transport mechanism. The subsequent growth o f GaN is 2D and 600 nm thick GaN films were grown on both on-axis and 3.5 d egrees off substrates. The structural properties of:the samples were charac terised by High Resolution X-Ray Diffraction (HRXRD) and Transmission Elect ron Microscopy (TEM). The full width at half maximum (fwhm) in omega-scan r ocking curve:df the (0002) and (1015) lines of GaN are 124 and 188 arcsec, respectively. The defect structure of the GaN film away from the substrate consists mostly of threading dislocations with a density of 3 x 10(9) cm(-2 ) and of (1120) prismatic defects.