金属有机物化学气相沉积同质外延GaN薄膜表面形貌的改善

发布时间：2018-03-01 05:26

本文关键词： 金属有机物化学气相沉积同质外延GaN 插入层生长模式　出处：《物理学报》2017年10期 　论文类型：期刊论文

【摘要】：为了获得高质量的GaN薄膜材料,研究了金属有机物气相沉积系统中GaN插入层对GaN衬底同质外延层表面宏观缺陷和晶体质量的影响.研究发现,插入层生长温度是影响GaN同质外延膜表面形貌和晶体质量的关键因素.由于生长模式与插入层生长温度相关,随着插入层生长温度的降低,外延膜生长模式由准台阶流模式转变为层状模式,GaN同质外延膜表面丘壑状宏观缺陷逐渐减少,但微观位错密度逐渐增大.通过对插入层温度和厚度的优化,进一步调控外延层的生长模式,最终有效降低了外延层表面的宏观缺陷,获得了表面原子级光滑平整、位错密度极低的GaN同质外延膜,其X射线衍射摇摆曲线(002),(102)晶面半峰宽分别为125arcsec和85arcsec,表面粗糙度均方根大小为0.23nm.
[Abstract]:In order to obtain high quality GaN thin film materials, the effect of GaN intercalation layer on the surface defects and crystal quality of homogeneous epitaxial layer on GaN substrate was studied in the metal-organic vapor deposition system. The growth temperature of the intercalation layer is the key factor affecting the surface morphology and crystal quality of the GaN homoepitaxial film. Because the growth mode is related to the growth temperature of the intercalated layer, the growth temperature of the intercalated layer decreases with the decrease of the growth temperature. The growth mode of the epitaxial film changed from the quasi-step flow mode to the layered mode. The hilly macroscopic defects on the surface of the homoepitaxial film gradually decreased, but the microcosmic dislocation density gradually increased. By optimizing the temperature and thickness of the intercalation layer, the growth pattern of the epitaxial film was studied. By further regulating the growth mode of the epitaxial layer, the macroscopic defects on the surface of the epitaxial layer are effectively reduced, and the GaN homogeneous epitaxial film with a smooth and smooth surface with very low dislocation density is obtained. The X-ray diffraction rocking curve is 002 / 102) the width of the half peak is 125 arcsec and 85 arcsec.The mean square root size of the surface roughness is 0.23 nm.
【作者单位】：南京电子器件研究所微波毫米波单片集成和模块电路重点实验室;
【基金】：国家自然科学基金(批准号:61505181,61474101,61504125) 国家高技术研究发展计划(批准号:2015AA016800,2015AA033300) 国家重点研发计划(批准号:2016YFB0400902)资助的课题~~
【分类号】：TN304.055

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