標題: | X-ray crystallographic study of GaN epitaxial films on Al2O3(0001) substrates with GaN buffer layers |
作者: | Lee, CH Chi, GC Lin, CF Feng, MS Guo, JD 材料科學與工程學系 電子工程學系及電子研究所 Department of Materials Science and Engineering Department of Electronics Engineering and Institute of Electronics |
公開日期: | 10-六月-1996 |
摘要: | Samples of GnN(0001) epitaxial films on sapphire Al2O3(0001) with different thicknesses of GaN buffer layers were characterized by x-ray diffraction method in both in-plane and plane-normal directions. The results show that all the epitaxial films Me of good quality with the GaN[<10(1)over bar 0>] parallel to Al2O3[<11(2)over bar 0>] and GaN[<1(2)over bar 10>]parallel to Al2O3[<1(1)over bar 00>]. This arrangement of crystal orientation can be attributed to the chemical potential overriding the lattice spacing mismatch. The x-my results also indicate that the crystal coherence lengths; in the in-plane direction are smaller than those measured in the plane-normal direction, i.e., a columnar-like structure normal to the film is observed; The rocking curve widths in the in-plane direction are also larger than those measured in the plane-normal direction. In-plane measurement of rocking curve and coherence length are essential physical quantities directly related to the electron mobility which was measured predominantly in the in-plane direction. The best epitaxial structure is the one grown with 10 nm buffer layer. (C) 1996 American Institute of Physics. |
URI: | http://dx.doi.org/10.1063/1.115786 http://hdl.handle.net/11536/1227 |
ISSN: | 0003-6951 |
DOI: | 10.1063/1.115786 |
期刊: | APPLIED PHYSICS LETTERS |
Volume: | 68 |
Issue: | 24 |
起始頁: | 3440 |
結束頁: | 3442 |
顯示於類別: | 期刊論文 |