Polar Dependence of Threading Dislocation Density in GaN Films Grown by Metal-Organic Chemical Vapor Deposition
Zhi-Yu Lin1, Zhi-Bin Chen1, Jin-Cheng Zhang1**, Sheng-Rui Xu1, Teng Jiang1, Jun Luo1, Li-Xin Guo2, Yue Hao1
1Key Lab of Wide Band-Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi'an 710071 2School of Physics and Optoeletronic Engineering, Xidian University, Xi'an 710071
Abstract：We investigate the threading dislocation (TD) density in N-polar and Ga-polar GaN films grown on sapphire substrates by metal-organic chemical vapor deposition. X-ray diffraction results reveal that the proportion of screw type TDs in N-polar GaN is much larger and the proportion of edge type TDs is much smaller than that in Ga-polar. Transmission electron microscope results show that the interface between the AlN nucleation layer and the GaN layer in N-polar films is smoother than that in Ga-polar films, which suggests different growth modes of GaN. This observation explains the encountered difference in screw and edge TD density. A model is proposed to explain this phenomenon.
. [J]. 中国物理快报, 2018, 35(2): 26104-.
Zhi-Yu Lin, Zhi-Bin Chen, Jin-Cheng Zhang, Sheng-Rui Xu, Teng Jiang, Jun Luo, Li-Xin Guo, Yue Hao. Polar Dependence of Threading Dislocation Density in GaN Films Grown by Metal-Organic Chemical Vapor Deposition. Chin. Phys. Lett., 2018, 35(2): 26104-.
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2018, Vol. 35 
