Etch pits and threading dislocations in GaN films grown by metal-organic chemical vapour deposition

被引:0
作者
Lu, M [1 ]
Chang, X
Li, ZL
Yang, ZJ
Zhang, GY
Zhang, B
机构
[1] Peking Univ, Natl Key Lab Artificial Microstruct & Mesoscop Ph, Beijing 100871, Peoples R China
[2] Peking Univ, Res Ctr Wide Band Semicond Mat, Beijing 100871, Peoples R China
[3] Peking Univ, Sch Phys, Inst Condense State Phys & Mat Phys, Beijing 100871, Peoples R China
[4] Peking Univ, Hlth Sci Ctr, Ctr Electron Microscopy, Beijing 100083, Peoples R China
关键词
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中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
High quality epitaxial GaN films on (0001) sapphire substrates were grown by a commercial metal-organic chemical vapour deposition system. The, etch pits and threading dislocations in GaN films is studied by a scanning electron microscope (SEM) and a transmission-electron microscope (TEM). The SEM images of GaN films, etched in mixed acid solution (H3PO4:H2SO4 = 1 : 3) and molten KOH exhibit notably different, etching pit densities of 5 x 10(8)/cm(2) and 4 x 10(7)/cm(2), respectively, which probably indicate that more kinds of, etching pits were revealed when, etched in mixed acid solution (H3PO4:H2SO4 = 1 : 3). Cross section TEM of GaN films with different g vectors showed the portions of different threading dislocations. Theoretical calculation indicates that the lattice and thermal expansion coefficient mismatch may be the main origins of pure edge threading dislocations.
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页码:398 / 400
页数:3
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