p型GaN/Al_(0·35)Ga_(0·65)N/GaN应变量子阱中二维空穴气的研究  

Research of two-dimensional hole gas in p-GaN/Al_(0.35)Ga_(0.65)N/GaN strained quantum-well

作　　者：游达[1] 许金通[1] 汤英文[1] 何政[1] 徐运华[1] 龚海梅[1] 

机构地区：[1]中国科学院上海技术物理研究所传感技术国家重点实验室,上海200083

出　　处：《物理学报》2006年第12期6600-6605,共6页Acta Physica Sinica

摘　　要：对Ga面p型GaN/Al0·35Ga0·65N/GaN应变异质结构中形成的二维空穴气(2DHG)进行了研究.首先基于半导体-绝缘体-半导体异质结构模型确定了应变异质中的临界厚度,然后自洽求解薛定谔方程和泊松方程,计算了当中间势垒层AlGaN处于完全应变状态和半应变状态两种条件下,顶层GaN及中间层AlGaN厚度的变化对2DHG分布的影响.计算结果表明,势垒层AlGaN和顶层GaN的应变状态和厚度对极化引起的2DHG面密度及分布有重要影响.在此基础上制备了p型GaN/Al0·35Ga0·65N/GaN应变量子阱结构肖特基器件,并通过器件的C-V测试证实了异质结处2DHG的存在.器件响应光谱的测试结果表明,由于p型GaN/Al0·35Ga0·65N/GaN量子阱中强烈的极化作用和Stark效应使得器件零偏压和反向偏压时的响应光谱都向短波方向移动了10nm,在零偏压下器件在280nm处的峰值响应为0·022A/W,在反向偏压为1V时,峰值响应达到0·19A/W,已经接近理论值.In this paper, the two-dimensional hole gas （2DHG） induced in the heterojunction were investigated in detail. The density of the 2DHG was calculated at first, then, based on the semiconductor-insulator-semiconductor and superlattice critical thickness model and using the self consistent Poisson-Schtǒdinger calculations, the influence of the AIGaN barrier and the top GaN layer thickness on the distribution of the 2DHG were calculated when the barrier layer is fully strained and half strained. The Schottky device with this structure was fabricated and C- V measurement was made to verify the existence of the 2DHG and the validity of calculation results. Finally, the 2DHG effects on p-GaN/AlGaN/GaN Schottky photodetector were investigated. Due to the polarization and Stark effect, the spectral responses with the 10 nm blue shift are observed. Under zero bias, the peak responsivity of the device is about 0.022 A/W, and increases to 0. 19 A/W under 1V reverse bias, which approaches the theoretical limit.

关 键 词：ALGAN 二维空穴气 极化效应 

分 类 号：O471.1[理学—半导体物理]