Surface composition and structure of GaN epilayers on sapphire
Surface composition and structure of GaN epilayers on sapphire
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DOI：
10.1063/1.475255
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发表时间：
1997-12
影响因子：
4.4
通讯作者：
J. Ahn;M. Sung;J. Rabalais;D. Koleske;A. Wickenden
中科院分区：
文献类型：
--
作者：
J. Ahn;M. Sung;J. Rabalais;D. Koleske;A. Wickenden
通过飞行时间散射和反冲光谱（TOF-SARS）、经典离子轨迹模拟和低能电子衍射（LEED）等方法，研究了有机金属气相外延（OMVPE）在蓝宝石衬底上生长的氮化镓薄膜的表面组成和结构。用4 keV Ar+原离子收集了散射和反冲离子加快中性的TOF-SARS光谱。利用三维散射反冲成像代码（SARIC）对散射结果进行了模拟。这些数据得出结论，n端{001}-（1×1）和ga端{0001}-（1×1）表面都存在，但没有证据表明存在混合末端。虽然两个表面都表现出两个结构域，但在两个表面上都没有检测到松弛或重建。{0001}表面是有序的，包含氢原子与最外层的N原子结合。{0001}表面对碳的吸附具有高度活性。
The surface composition and structure of GaN films grown on sapphire substrates by organometallic vapor-phase epitaxy (OMVPE) have been determined through the use of time-of-flight scattering and recoiling spectrometry (TOF-SARS), classical ion trajectory simulations, and low-energy electron diffraction (LEED). TOF-SARS spectra of scattered and recoiled ions plus fast neutrals were collected using 4 keV Ar+ primary ions. The scattering results were simulated by means of the three-dimensional scattering and recoiling imaging code (SARIC). This data leads to the conclusions that both N-terminated {001}-(1×1) and Ga-terminated {0001}-(1×1) surfaces occur, however no evidence was obtained for mixed terminations. No relaxation or reconstruction was detected on either surface, although both surfaces exhibited two structural domains. The {0001} surfaces are well-ordered and contained hydrogen atoms bound to the N atoms of the outermost layer. The {0001} surfaces are highly reactive towards adsorption of carbon...