基于金属催化等离子体刻蚀的MPCVD单晶金刚石生长缺陷调控

Control of Defects in MPCVD Single Crystal Diamond Growth Based on Metal Catalyzed Plasma Etching

单晶金刚石作为一种性能优异的半导体材料,在功率器件、深空探测等领域具有广阔的应用前景。然而采用微波等离子体化学气相沉积(MPCVD)法制备的单晶金刚石通常含有大量的缺陷,尤其是位错,严重限制了其电学性能的发挥。横向外延生长是半导体材料中常用的缺陷调控方法,近年也被应用于金刚石材料制备领域。本研究首先通过金属催化等离子体刻蚀在单晶金刚石籽晶上构造图形阵列,从而为同质外延单晶制备创造横向生长条件;随后通过MPCVD法在此基础上进行单晶金刚石制备,研究了横向外延生长过程并对样品进行了激光共聚焦显微镜、偏光显微镜、Raman光谱和缺陷密度测试。测试表明该方法能够稳定可控的制备图形化生长所需的阵列并降低生长层的缺陷密度。

As one kind of semiconductor material with the superiorperformance,single crystal diamond(SCD)has broad application prospects in power devices,deep space exploration and other fields.However,SCD prepared viamicrowave plasma chemical vapor deposition(MPCVD)usually contains defects,especially dislocations,seriously restrictingits electrical performance.Lateral epitaxial growth as a common defect control method in semiconductor materialsis used in SCD preparation in recent years.In this work,firstly,a pattern array was constructed on SCD seed by metal catalyzed plasma etching to create a lateral growth condition for the preparation of homogeneous epitaxial.Secondly,SCD layer was prepared by MPCVD method,and the lateral epitaxial growth process was investigated.The samples were tested by laser confocal microscopy,polarizing microscopy,Raman spectroscopyand defect density measurement.The results show that this method can stably and controllably prepare the arrays needed for patterned growth and reduce the defect density of the growth layer.