低温缓冲层对金刚石衬底上GaN的沉积作用

Effect of low temperature buffer layer of GaN films deposited on diamond substrate

采用电子回旋共振等离子体增强金属有机物化学气相沉积技术,以自支撑金刚石厚膜作为衬底,改变缓冲层参数条件,低温沉积氮化镓(Ga N)薄膜材料。实验结束之后,利用反射高能电子衍射、X射线衍射和原子力显微镜系统性对实验制备的薄膜样品进行测试分析,探究引入低温缓冲层与无缓冲层以及改变缓冲层沉积温度对Ga N薄膜质量的影响。结果表明,低温缓冲层的制备,对后续的薄膜样品沉积制备起到减小晶格失配的作用,而且低温缓冲层沉积温度在100℃时,沉积制备的薄膜样品呈高度c轴择优取向,结晶性较好;薄膜表面平整。

Ga N films were deposited on freestanding diamond substrate by electron cyclotron resonance plasma enhanced metal organic chemical vapor deposition（ECR-PEMOCVD） technique with various buffer layer deposition temperature. The effect of buffer layer deposition temperature on the quality of Ga N flim was studied using reflection high energy electron diffraction（RHEED）, X-ray diffraction（XRD） and atomic force microscope（AFM）. The results show that Ga N film deposited with buffer layer is very important, and as-grown Ga N films is of high c-axis preferred orientation and highly crystallined with the buffer layer temperature deposited at 100 ℃, and the Ga N fims have the smooth surface.