Mg掺杂AlGaN的特性研究  

Properties of Mg-Doped AlGaN Films

作　　者：吴超[1] 谢自力[1] 张荣[1] 张曾[1] 刘斌[1] 刘启佳[1] 聂超[1] 李弋[1] 韩平[1] 陈鹏[1] 陆海[1] 郑有炓[1] 

机构地区：[1]南京大学物理学系

出　　处：《微纳电子技术》2008年第9期512-515,541,共5页Micronanoelectronic Technology

基　　金：国家重点基础研究发展规划973资助项目(2006CB6049);国家高技术研究发展规划资助项目(2006AA03A103,2006AA03A11,2006AA03A142);国家自然科学基金资助项目(60721063,60676057,60731160628,60776001);国家基础科学人才培养基金资助项目(J0630316);高等学校博士学科点专项科研基金资助项目(20050284004)

摘　　要：采用金属有机物化学气相淀积方法在Al2O3衬底上生长不同浓度Mg掺杂的AlxGa1-xN合金薄膜,并在750℃、N2气氛下对Mg进行热退火激活。用X射线衍射ω-2θ扫描计算确定样品的Al组分,发现Mg摩尔掺杂浓度和退火对Al组分均未产生明显影响。X射线衍射摇摆曲线与原子力显微镜扫描表明随Mg摩尔掺杂浓度增加,样品晶体质量下降,样品表面凹坑增加,但热退火对薄膜表面形貌有明显的改善。阴极射线发光测量发现带边峰强度随掺杂浓度增加而减弱,退火后样品的施主-受主对复合发射与导带受主的复合发射均有增强,验证了热退火对钝化受主杂质的激活作用,对实现高效AlGaN的p型掺杂具有重要意义。Mg-doped AlxGa1-xN films were grown on Al2O3 substrate by metal organic chemical vapor deposition （MOCVD） and annealed at 750℃ in the atmosphere of N2. Al content was calculated by X-ray ω - 2θ scanning, and the result indicates that neither the doping nor the annealing affects the Al content. X-ray rocking curves and AFM images show that the crystal quality becomes worse and the pits on the surface increase as the Mg molar doping concentration increases. However, the annealing improves the morphologies of the samples. Cathode-ray luminescence （CL） was employed, and the decrease of the band-gap peak intensity was observed when the doping concentration increases. After annealing, both the donor-aceeptor pair （DAP） emission and the recombination from conduction band to deep acceptor level increase significantly. The result proves that the annealing activates the acceptor impurity of Mg effectively, which is significant to the realization of high efficient p-AlGaN doping.

关 键 词：AlGaN薄膜 Mg掺杂 热退火 表面形貌 阴极射线发光 

分 类 号：TN304.26[电子电信—物理电子学] TN304.055