,The influence of AlN/GaN superlattice intermediate layer on the properties of GaN grown on Si(111)

• 作 者: Liu Zhe Wang Xiao-Liang Wang Jun-Xi Hu Guo-Xin Guo Lun-Chun Li Jin-Min
• 机 构: Novel Semiconductor Material Laboratory, Institute of Semiconductors, Chinese Academy of Sciences, B
• 出 处: 中国物理（英文版）
• 发表日期: 2007年5期
• 关键词: GaN Si substrate metalorganic chemical vapour deposition superlattice buffer

AIN/GaN superlattice buffer is inserted between GaN epitaxial layer and Si substrate before epitaxial growth of GaN layer. High-quality and crack-free GaN epitaxial layers can be obtained by inserting AIN/GaN superlattice buffer layer. The influence of AIN/GaN superlattice buffer layer on the properties of GaN films are investigated in this paper. One of the important roles of the superlattice is to release tensile strain between Si substrate and epilayer. Raman spectra show a substantial decrease of in-plane tensile strain in GaN layers by vising AIN/GaN superlattice buffer layer. Moreover, TEM cross-sectional images show that the densities of both screw and edge dislocations are significantly reduced. The GaN films grown on Si with the superlattice buffer also have better surface morphology and optical properties.