【摘要】 本文研究了利用金属有机物化学汽相淀积系统(MOCVD)生长高质量不同A l组分A lxGa1-xN薄膜(0.13<x<0.8)。扫面电子显微镜(SEM)照片表明生长的A lN插入层有效地调节了A lGaN层与GaN支撑层的应力,使A lGaN表面平整无裂纹,原子力显微镜(AFM)测量得到所有A lGaN薄膜粗糙度均小于1nm。通过原位干涉谱发现,A lGaN薄膜生长速率主要由Ga流量大小控制,随A l组分升高逐渐降低。利用X射线衍射和卢瑟福背散射(RBS)两种方法确定A lGaN薄膜的A l组分,发现A l组分与摩尔比TMA l/(TMGa+TMA l)关系为线性,说明在优化的生长条件下,A l原子与NH3的寄生反应得到了有效的抑制。更多还原

【Abstract】 Variational Al composition AlxGa1-xN(0.13<x<0.8) films on(0001) sapphire grown by metalorganic chemical vapor deposition was investigated.The AlN interlayers between AlGaN and GaN template are shown to effectively reduce biaxial tensile strain in AlGaN films,thus avoiding cracks.The roughness of all AlGaN films is less than 1nm probed by atomic force microscopy.Basing on the in-situ interference spectra,the growth rate of AlGaN is dominated by TMGa flux and decreasing with elevatory Al composition.The nominal Al content of AlxGa1-xN is determined by X-ray diffraction and Rutherford backscattering,which is linear with(TMAl/TMGa+TMAl).It proves that the parasitic reaction of TMAl and NH3 is suppressed under optimized growth conditions.更多还原