硅基GaN外延层的SIMS及XPS研究

采用真空反应法在硅基上制备出了GaN外延层。利用二次离子质谱和X射线光电子能谱对GaN外延层进行了深度剖析和表面分析。结果表明 ,外延层中Ga和N分布均匀 ;在表面处Ga发生了偏聚 ;外延层中还存在Si,O等杂质 ,但这些并未影响到GaN外延层的物相及发光性能。实验还表明 ,在外延生长前采用原位清洗可去除Si衬底表面的氧

SIMS and XPS Studies of GaN Epilayers Grown On Si Substrates

GaN epilayers were grown on Si substrates by reactive deposition in vacuum.The depth profile and surface composition of the GaN films were studied with secondary ion mass spectroscopy and X ray photoelectron spectroscopy.The results show that Ga atoms segregate to the surface,whereas below the surface layers Ga and N atoms uniformly distribute in the epilayers.Si and O impurities existing in the epilayers do not affect crystal phase and photoluminescence of the GaN epilayers. In situ cleaning can effectively remove surface oxygen on the Si substrate.