梯度铝镓氮缓冲层对氮化镓外延层性质的影响

发布时间：2018-10-15 16:21

【摘要】：采用金属有机物化学气相沉积系统在硅面碳化硅衬底的(0001)面上生长氮化铝缓冲层,并通过改变3层梯度铝镓氮(Al_xGa_(1-x)N:x=0.8,0.5,0.2)缓冲层的生长温度和氨气流量,制备出了高质量的氮化镓外延层。分别采用X射线衍射、原子力显微镜、光致发光谱和拉曼光谱对氮化镓外延层进行表征。实验结果表明,随着氮化镓外延层中张应力的降低,样品的晶体质量、表面形貌和光学质量都有显著提高。在最优的梯度铝镓氮缓冲层的生长条件下,氮化镓外延层中的应力值最小,氮化镓(0002)和(1012)面的摇摆曲线半峰宽分别为191 arcsec和243 arcsec,薄膜螺位错密度和刃位错密度分别为7×10~7cm~(-2)和3.1×108cm~(-2),样品表面粗糙度为0.381 nm。这说明梯度铝镓氮缓冲层可以改变氮化镓外延层的应力状态,显著提高氮化镓外延层的晶体质量。
[Abstract]:Aluminum nitride buffer layer was grown on (0001) surface of silicon carbide substrate by metal organic chemical vapor deposition system. The growth temperature and ammonia flow rate of the buffer layer were changed by changing the Al_xGa_ _ (1-x) N _ (x) O _ (0.8) N _ (0.5) N _ (1-x) N _ (0.5) N buffer layer. High quality gallium nitride epitaxial layer was prepared. The epitaxial layers of gallium nitride were characterized by X-ray diffraction, atomic force microscopy, photoluminescence and Raman spectroscopy respectively. The experimental results show that the crystal quality, surface morphology and optical quality of the samples are improved significantly with the decrease of tensile stress in the epitaxial layer of gallium nitride. Under the optimal growth conditions of the gradient aluminum-gallium nitrogen buffer layer, the stress value of the gallium nitride epitaxial layer is the smallest. The half-width of the rocking curve of gallium nitride (0002) and (1012) is 191 arcsec and 243 arcsec, respectively. The density of screw dislocation and edge dislocation are 7 脳 10 ~ (-2) and 3.1 脳 10 ~ (-8) cm ~ (-2), respectively. The surface roughness of the sample is 0.381 nm.. The results show that the gradient aluminum-gallium nitrogen buffer layer can change the stress state of the gallium nitride epitaxial layer and improve the crystal quality of the gan epitaxial layer.
【作者单位】：集成光电子国家重点联合实验室吉林大学电子科学与工程学院;
【基金】：国家自然科学基金(61274023,61106003,61376046,61674068) 国家重点研发计划(2016YFB0400103) 吉林省科技发展计划(20130204032GX,20150519004JH,20160101309JC) 教育部新世纪人才计划(NCET13-0254)资助项目~~
【分类号】：TN304

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