非极性a面n-AlGaN外延层的生长与表征

Growth and Characterization of Nonpolar a-plane n-AlGaN Epitaxial Layer

摘要:

采用金属有机化学气相沉积技术,在半极性蓝宝石衬底上成功生长了具有高电子浓度和良好表面形貌的Si掺杂的非极性a面n-AlGaN外延层。深入研究了铟(In)表面活性剂和无掺杂的AlGaN缓冲层对n-AlGaN的结构特征和电学性能的影响。表征结果表明,利用In表面活性剂和无掺杂的AlGaN缓冲层,非极性a面n-AlGaN外延层的晶体质量的各向异性被有效地抑制,同时显著改善了其表面形貌和电学性能。测得非极性a面n-AlGaN的电子浓度及电子迁移率分别为-4.8×10¹⁷cm-3和3.42cm²/(V·s)。

Abstract:

The Si-doped nonpolar a-plane n-AlGaN epitaxial layer with high electron concentration and good surface morphology was successfully grown on semipolar sapphire substrate by metal organic chemical vapor deposition. The effects of indium (In) surfactant and undoped AlGaN buffer layer on the structural and electrical properties of the n-AlGaN epitaxial layer were intensively studied. The characterization results show that the anisotropy in crystalline quality of the nonpolar a-plane n-AlGaN epitaxial layer is effectively suppressed by using In surfactant and undoped AlGaN buffer layer, and its surface morphology and electrical properties are significantly improved. In fact, the electron concentration and electron mobility are determined to be -4.8×10¹⁷cm-3 and 3.42cm²/(V·s), respectively.