Mosaic Structure Evolution in GaN Films with Annealing Time Grown by Metalorganic Chemical Vapour Deposition

Autor:	Chen Zhi-Tao, Pan Yao-Bo, SU Yue-Yong, Guo Li-Ping, Xu Ke, Zhang Han, Yang Zhi-Jian, Shen Bo, Zhang Guo-Yi
Rok vydání:	2006
Předmět:	Diffraction Threading dislocations Materials science Optics Residual stress business.industry Annealing (metallurgy) Sapphire Analytical chemistry General Physics and Astronomy Chemical vapor deposition business Isotropic etching
Zdroj:	Chinese Physics Letters. 23:1257-1260
ISSN:	1741-3540 0256-307X
DOI:	10.1088/0256-307x/23/5/053
Popis:	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.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::f6c847de878d86c23b1e87d083962447 https://doi.org/10.1088/0256-307x/23/5/053 Zobrazit plný text záznamu