额外HCl对HVPE生长GaN性质的影响  

Effect of Additional HCl Flow on the Surface Morphology of HVPE GaN on Sapphire

作　　者：修向前[1] 张荣[1] 卢佃清[1] 顾书林[1] 沈波[1] 施毅[1] 郑有炓[1] 

机构地区：[1]南京大学物理系固体微结构国家重点实验室,210093

出　　处：《固体电子学研究与进展》2002年第4期395-398,共4页Research & Progress of SSE

摘　　要：利用氢化物气相外延 (HVPE)生长系统 ,提出并采用在生长区添加额外 HCl的方法改变 Ga N的极化生长方向获得 Ga面极化具有平滑表面的 Ga N生长技术。该法将一定量的 HCl添加到传统 HVPE生长方法中的总氮气流中 ,引入 Ga Cl和 NH3混合生长区 ,通过改变蓝宝石衬底表现的化学反应平衡 ,抑制 N面极化 Ga N的成核 ,获得了粗糙度只有一个纳米左右的具有平滑表面的高质量 Ga极化 Ga N薄膜。由于该方法是在 HVPE装置中“原位”获得了表面光滑的 Ga N,与其他方法相比 。The polarity of GaN is known to be an important factor in determining the surface roughness and properties of the as grown material such as chemical reactivity. And precise control of the growth in polar direction is necessary to obtain low defect density materials as well as a specular surface. In this study, we obtained high quality GaN with smooth surface on sapphire by adding the additional HCl into the HVPE growth process. The result is attributed to the control of polarity of GaN films during growth. The additional HCl altered the equilibrium at the GaN growth front, and the reversible reaction decreased the nucleation density or growth rate. Further, lower growth rate promoted the surface diffusion and the coalescence over (0001) plane. Probably additional HCl improved the surface morphology by suppressing the (000 1) polarity growth in the initial stage of the growth.

关 键 词：氢化物气相外延 湿化学法腐蚀 氮化镓极性 

分 类 号：TN304.055[电子电信—物理电子学]