MPCVD单晶金刚石初始及断续生长界面的表征与分析

Characterization and Analysis of the Initial and Intermittent Growth Interfaces of MPCVD Single Crystal Diamond

采用微波等离子体化学气相沉积(MPCVD)技术制备的大尺寸、高质量单晶金刚石材料具备卓越的物理化学性能,在珠宝、电子、核与射线探测等消费品、工业和国防科技领域极具应用前景。研究发现在化学气相沉积单晶金刚石生长过程中,在衬底与外延层之间,以及生长中途停止-继续生长的生长层之间出现明显的界面区。本文采用偏光显微镜、拉曼光谱、荧光光谱(PL)等手段对界面区域进行了测试分析,界面区在偏光显微镜下表现出因应力导致的亮区,且荧光光谱(PL)及其线扫描显示该区域的NV色心含量远高于衬底及其前后外延层,表明该界面区具有较高的缺陷和杂质含量。结果表明在生长高品质单晶金刚石初期就应当采取一定手段进行品质调控,并尽量在一个生长周期内完成制备。

Large-size and high-quality single crystal diamond synthesized by microwave plasma chemical vapor deposition(MPCVD)have excellent physical and chemical properties,which makes them have great application prospects in jewelry,electronics,nuclear and ray detection and other industry fields.During CVD single crystal diamond growth,it is found that there is an obvious interface between the substrate and the epitaxial layer,as well as between the multiple growth layers which stop-continue to grow.The interface region was analyzed by polarization microscope,Raman spectra and photoluminescence spectra(PL).The bright image under polarization microscope and higher content of NV color centers compared with substrate and its epitaxial layers indicate that the interface area has high defect and impurity content.The results show that some measures should be taken to control the quality of high-quality single crystal diamond at the initial stage,and the preparation should be completed in one growth cycle as far as possible.