IN-SITU REAL-TIME STUDIES OF GAN GROWTH ON 6H-SIC(0001) BY LOW-ENERGY-ELECTRON MICROSCOPY (LEEM)

We report in situ growth experiments of GaN on 6H-SiC(0 0 0 1) substra tes conducted in the low-energy electron microscope (LEEM). The Ga flu x species were supplied by an evaporative source while the nitrogen wa s supplied by either a N-atom RF plasma source or a supersonic seeded- beam jet (SSJ) sourer. The surfaces of the 6H-SiC(0 0 0 1) substrates were prepared by high-temperature hydrogen etching prior to installati on in the LEEM for deposition. On regions of the substrate surface whe re well-defined steps and terraces were observed, the LEEM video image s showed initial nucleation at the steps and subsequent growth across the terraces. The LEED patterns indicated three-dimensional crystal gr owth with pronounced formation of facets. Such growth behavior occurre d irrespective of the method of deposition (C) 1998 Elsevier Science B .V. All rights reserved.