Mosaic Structure Evolution in GaN Films with Annealing Time Grown by Metalorganic Chemical Vapour Deposition
CHEN Zhi-Tao1,2,3, XU Ke1,2,3, GUO Li-Ping4, YANG Zhi-Jian1,2,3, PAN Yao-Bo1,2,3, SU Yue-Yong1,2,3, ZHANG Han1,2,3, SHEN Bo1,2,3, ZHANG Guo-Yi1,2,3
1School of Physics, Peking University, Beijing 100871
2State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Peking University, Beijing 100871
3Research Center for Wide-band Semiconductors, Peking University, Beijing 100871
4Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049
Mosaic Structure Evolution in GaN Films with Annealing Time Grown by Metalorganic Chemical Vapour Deposition
1School of Physics, Peking University, Beijing 100871
2State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Peking University, Beijing 100871
3Research Center for Wide-band Semiconductors, Peking University, Beijing 100871
4Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049
Abstract： We investigate mosaic structure evolution of GaN films annealed for a long time at 800°C grown on sapphire substrates by metalorganic chemical vapour deposition by high-resolution x-ray diffraction. The result show that residual stress in GaN films is relaxed by generating edge-type threading dislocations (TDs) instead of screw-type TDs. Compared to as-grown GaN films, the annealed ones have larger mean twist angles corresponding to higher density of edge-type TDs but smaller mean tilt angles corresponding to lower density of screw-type TDs films. Due to the increased edge-type TD density, the lateral coherence lengths of the annealed GaN films also decrease. The results obtained from chemical etching experiment and grazing-incidence x-ray diffraction (GIXRD) also support the proposed structure evolution.
CHEN Zhi-Tao;;XU Ke;;GUO Li-Ping;YANG Zhi-Jian;;PAN Yao-Bo;;SU Yue-Yong;;ZHANG Han;;SHEN Bo;;ZHANG Guo-Yi;. Mosaic Structure Evolution in GaN Films with Annealing Time Grown by Metalorganic Chemical Vapour Deposition[J]. 中国物理快报, 2006, 23(5): 1257-1260.
CHEN Zhi-Tao, , XU Ke, , GUO Li-Ping, YANG Zhi-Jian, , PAN Yao-Bo, , SU Yue-Yong, , ZHANG Han, , SHEN Bo, , ZHANG Guo-Yi,. Mosaic Structure Evolution in GaN Films with Annealing Time Grown by Metalorganic Chemical Vapour Deposition. Chin. Phys. Lett., 2006, 23(5): 1257-1260.
2006, Vol. 23 
