Influence of rapid thermal annealing on the optical properties of gallium nitride grown by gas-source molecular-beam epitaxy
Influence of rapid thermal annealing on the optical properties of gallium nitride grown by gas-source molecular-beam epitaxy
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快速热退火对气源分子束外延生长氮化镓光学性能的影响
DOI：
10.1063/1.120878
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
S. Yoon
中科院分区：
文献类型：
--
作者：
Xingxin Li;Dongfei Sun;J. Zhang;M. Kong;S. Yoon
利用拉曼散射、光致发光（PL）和核反应分析（NRA）研究了快速热退火（RTA）对蓝宝石（0001）衬底上气体源分子束外延GaN薄膜的影响。拉曼光谱显示GaN的E2（高）模式的存在以及该模式由退火引起的从572 cm-1到568 cm-1的偏移。结果表明，RTA对GaN外延层与衬底之间的晶格失配和热膨胀失配引起的应变弛豫有显著的影响。PL峰的能量位置发生蓝移，退火后半峰全宽减小，表明薄膜的光学质量得到改善。此外，退火后出现绿色发光，并随着退火时间的增加而增强。这种效应归因于GaN膜中的H浓度变化，其通过NRA测量。生长态GaN中存在高的H浓度，这可以中和生长态GaN中的H。
Raman scattering, photoluminescence (PL), and nuclear reaction analysis (NRA) have been employed to investigate the effects of rapid thermal annealing (RTA) on GaN films grown on sapphire (0001) substrates by gas-source molecular-beam epitaxy. The Raman spectra showed the presence of the E2 (high) mode of GaN and shift of this mode from 572 to 568 cm−1 caused by annealing. The results showed that RTA has a significant effect on the strain relaxation caused by the lattice and thermal expansion misfit between the GaN epilayer and the substrate. The PL peak exhibited a blueshift in its energy position and a decrease in the full width at half maximum after annealing, indicating an improvement in the optical quality of the film. Furthermore, a green luminescence appeared after annealing and increased in intensity with increasing annealing time. This effect was attributed to H concentration variation in the GaN film, which was measured by NRA. A high H concentration exists in as-grown GaN, which can neutralize ...