Difference Between GaN Films Grown on Two Opposite Oriented c-Al2O3 Substrates
在蓝宝石衬底两个相反c面同时生长氮化镓薄膜的差异

Two pairs of GaN films are grown on two o p posite c -Al 2O 3 substrates by metal-organic vapor phase epitaxy.These f ilms are studied by scanning electron microscopy,Auger electron spectrosco py and converged beam electron diffraction.It was found that the GaN film on the c -face forward to Al 2O 3 seed had polarity and its surface-pi ts relat ed to the film defects and its N/Ga atom-ratio was small.But the GaN film on th e c-face backward to the seed had ooo1] polarity and its surface pits realted to the substrat morphology and its N/Ga atom-tatio was large .The mechanism for forming different color in both buffer layers is also discussed