采用金属有机化合物化学气相沉积(MOCVD)方法制备了不同A1N隔离层厚度的A1GaN/A1N/GaN结构的高电子迁移率晶体管(HEMT)材料。研究了A1N隔离层对HEMT材料电学特性的影响。AIN隔离层厚度约为1.5nm的HEMT材料,二维电子气浓度和迁移率分别达到1.2×10^13cm^-2和1680cm^2/Vs、方块电阻低至310Ω,体现了HEMT材料良好的电学性能。原子力显微镜和高分辨X射线衍射测试结果显示HEMT材料具有较好的表面形貌和异质结界面,较好的异质结界面也有利于增强HEMT材料的二维电子气浓度和迁移率。
AIGaN/AIN/GaN high electron mobility transistors (HEMT) structures with AIN interfacial layer of various thicknesses are grown by metalorganic chemical vaper deposition, and their electrical properties are investigated. The HEMT sample with an AIN layer thickness of about 1. 5 nm shows a highly Hall mobility of 1680 cm2/Vs with a low sheet resistance of 310Ω, and high two-dimensional electron gas (2DEG) density of 1.2×10^13cm^-2 are obtained at room temperature, indicating good electrical properties of the HEMT material. Furthermore, the results from atomic force microscopy and high resolution X-ray diffraction measurements confirm that the samples possess well surface morphology and heterostructure interface. Thence, the well heterostructure interface enhances the 2DEG density and mobility of the HEMT materials.