物理气相输运法生长AlN六方微晶柱

采用物理气相输运法(Physical Vapor Transport, PVT), 在1700 ~ 1850℃生长温度下制备出AlN六方微晶柱; 晶柱长度在1 cm左右, 宽度在200 ~ 400 μm, 光学显微镜下观察为六棱柱形状并呈透明浅黄色光泽; 扫描电子显微镜和原子力显微镜测试表明: AlN晶柱表面为整齐台阶状形貌, 台阶宽度为2 ~ 4 μm, 高度在几个纳米; 拉曼光谱测试AlN晶柱具有良好结晶质量。PVT 法生长AlN六方微晶柱主要是在偏低温度下AlN晶体生长速率较慢, Al原子和N原子有足够时间迁移到能量较低位置结晶生长, 进而沿着<0001>方向形成柱状结构。AlN六方微晶柱是对一维半导体材料领域的补充, 通过对晶柱尺寸及杂质控制的进一步研究, 有望在微型光电器件领域表现出应用价值。

Growth of Hexagonal AlN Crystalline Microrod by Physical Vapor Transport Method

Hexagonal aluminium nitride (AlN) microrods with high crystalline quality were grown by physical vapor transport (PVT) method at low growth temperature between 1700 and 1850℃. The length of as-grown microrod is around 1 cm, and the width between 200-400 μm. The microrod exhibits typical hexagonal geometrical shape with pale yellow color under optical microscopy. Scanning electron microscope (SEM) and atomic force microscope (AFM) images show each microrod with closely arranged step waviness, of which the step interval is 2-4 μm and the height several nanometers. Raman spectrum characterization showed characteristic peaks of high crystalline AlN. The rod-like structure is attributed to slow growth velocity at lower crystalline temperature, enabling Al and N atoms having enough time to move to the lower energy site and to form hexagonal microrod along <0001> direction. High quality hexagonal AlN microrod is an enrichment to one-dimensional semiconductor materials. Data from this study suggest that, by further study on size and impurity control, high performance miniaturized opto-electronic device is hopeful to be achieved.