论文部分内容阅读
利用低压金属有机化学气相淀积(LP-MOCVD)系统,在(0001)蓝宝石衬底上采用预淀积In纳米点技术低温合成制备了立方相的InN薄膜。首先以TM In作源在蓝宝石衬底表面预淀积了一层金属In纳米点,然后在一定条件下合成生长InN薄膜。X射线衍射谱(XRD)和X射线光电子发射谱(XPS)显示适当的预淀积In不仅能够促进InN的生长,同时还能够抑制金属In在InN薄膜中的聚集。原子力显微镜(AFM)观察表明,金属In纳米点不仅增强了成核密度,而且促进了InN岛的兼并。自由能计算表明预淀积的In优先和NH3分解得到的NH与N基反应生成InN。我们认为这种优先生成的InN为接下来InN的生长提供了成核位,从而促进了InN的生长。
The low-pressure metal-organic chemical vapor deposition (LP-MOCVD) system was used to fabricate a cubic phase InN thin film on a (0001) sapphire substrate by using the pre-deposited In nanodots technique. Firstly, a layer of metal In nanodots is pre-deposited on the sapphire substrate by using TM In as a source, and then the InN film is synthesized and grown under certain conditions. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) showed that proper pre-deposited In not only promoted the growth of InN, but also inhibited the aggregation of In in InN films. Atomic force microscopy (AFM) observation shows that metal In nanodots not only enhance the nucleation density, but also promote the merger of InN islands. The free energy calculations show that the pre-deposited In preferentially reacts with the N groups resulting from NH3 decomposition to form InN. We believe that this preferential formation of InN provides nucleation sites for the subsequent growth of InN, thereby promoting the growth of InN.