论文部分内容阅读
采用物理气相传输法在自制[0001]偏8°晶向6H-SiC衬底上制备了直径42 mm、厚度320μm的连续AlN单晶层,c轴方向生长速率为32μm/h。AlN单晶层具有明显鱼鳞状宏台阶流生长表面特征。裂纹完全单向平行分布,且与台阶走向一致,其成因与台阶对热应力的吸收作用有关。未发现明显的穿线缺陷。发现AlN-SiC界面存在双角锥空腔,其起因是生长初期界面处未被AlN完全密实覆盖的微小区域,在生长过程中因内部温差不断发生的升华和凝华的自我调制过程。喇曼光谱和X射线衍射测试显示该层结晶性较好,(0002)面X射线摇摆曲线半高宽为76 arcsec,喇曼光谱E1(TO)模的半高宽为7.5 cm-1。
A continuous AlN single crystal layer with a diameter of 42 mm and a thickness of 320 μm was prepared on the 6H-SiC substrate by self-made [0001] physical vapor deposition. The growth rate in the c-axis direction was 32 μm / h. AlN single crystal layer has obvious fish-scale macro-step flow growth surface characteristics. Cracks completely unidirectional parallel distribution, and with the step to the same, its cause and step on the absorption of thermal stress. No obvious threading defect was found. It is found that there is a double-cone cavity in the interface of AlN-SiC, which is caused by the subtle self-modulation of sublimation and sublimation during the growth due to the internal temperature difference. Raman spectroscopy and X-ray diffraction tests show that the layer has good crystallinity. The full width at half maximum of X-ray rocking curve of (0002) plane is 76 arcsec and the full-width of Raman spectrum E1 (TO) is 7.5 cm-1.