等离子体清洗GaAs和Al_2O_3衬底的RHEED图像分析  

RHEED images of GaAs and Al_2O_3 substrates cleaned by hydrogen or nitrogen plasma

作　　者：章家岩[1] 郎佳红[1] 秦福文[2] 顾彪[2] 

机构地区：[1]安徽工业大学电气信息学院,安徽马鞍山243002 [2]大连理工大学三束材料改性国家重点实验室,辽宁大连116024

出　　处：《华中科技大学学报（自然科学版）》2005年第5期88-91,共4页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(69976008).

摘　　要：针对GaAs和Al2O3作为外延GaN薄膜的主要衬底材料,采用电子回旋共振等离子体增强金属有机化学气相沉积(ECRPEMOCVD)工艺对其分别进行纯氢、氢氮等离子体清洗,并配备高能电子衍射仪(RHEED)实时监测清洗过程.CCD的RHEED图像分析表明,在一定条件下用纯氢等离子体对GaAs衬底清洗只需1min左右,即可得到比较平整的清洗表面,但清洗2min以上表面质量开始变坏.若在氢气中加入少量氮气,清洗时间可延长至10min左右.而Al2O3衬底对纯氢等离子体的清洗时间比较敏感,清洗2min左右就能获得平整的清洗表面,若时间延长到4min,表面质量将开始变坏.如果采用氢氮等离子体清洗,约需20min时间,而且在很宽的清洗时间范围(20～30min)内都能获得良好的清洗表面.GaAs and Al_2O_3 are important substrates for epitaxy of GaN film. The paper described hydrogen and hydrogen nitrogen plasma cleaning of substrates of GaAs and Al_2O_3 by using electron cyclotron resonance-plasma-enhanced MOCVD(ECR-PEMOCVD) equipped reflective high electronic energy diffraction (RHEED). Rheed images of cleaned GaAs and Al_2O_3 substrates indicated that GaAs substrate needs about one minute for hydrogen plasma cleaning, but the surface of substrate becomes uneven after 4?minutes. Hydrogen nitrogen plasma cleaning needs about ten minutes, Al_2O_3substrate does about 10 minutes for hydrogen plasma cleaning and is sensitive for cleaning time. But Al_2O_3 substrate needs about twenty minutes for hydrogen nitrogen plasma cleaning and has a greater scope of cleaning time.

关 键 词：电子回旋共振等离子体增强金属有机化学气相沉积 GaN 氢等离子体 氮化 

分 类 号：TN304.055[电子电信—物理电子学]