ECR-MBE GROWTH OF GAN ON LIGAO2

GaN thin films were grown at relatively low temperatures on multi-doma in LiGaO2 substrates by electron-cyclotron-resonance plasma-excited mo lecular beam epitaxy (ECR-MBE). LiGaO2 is one of the most promising su bstrates for GaN epitaxial growth because of its small lattice mismatc h of around 0.9%. The multi-domain LiGaO2 substrate has two different polarity domains in the (0 0 1) surface. Two different GaN surface mor phologies depending on the surface polarities were observed by atomic force microscopy (AFM). The difference was also observed in the shift of photoluminescence (PL) spectra. Each peak corresponding to two inve rsion domains was shifted in parallel around 2 nm. One possible explan ation for the cause of the peak wavelength shift is cue io the differe nce of the strains in GaN thin films. (C) 1998 Elsevier Science B.V. A ll rights reserved.