n-In_(0.35)Ga_(0.65)N/p-Si异质结的制备及其电学性能研究

Preparation and Electrical Properties of n-In_(0.35)Ga_(0.65) N/p-Si Heterojunction

采用双光路双靶材脉冲激光沉积(PLD)系统在p-Si衬底上外延生长InGaN薄膜,研究了InGaN薄膜的显微组织结构和n-InGaN/p-Si异质结的电学性能。研究表明,InGaN薄膜为单晶结构,沿[0001]方向择优生长,薄膜表面光滑致密,In的原子含量为35%。霍尔(Hall)效应测试表明In 0.35 Ga 0.65 N薄膜呈n型半导体特性,具有高的载流子浓度和迁移率及低的电阻率。I-V曲线分析表明In_(0.35)Ga_(0.65) N/p-Si异质结具有良好的整流特性,在±4 V时的整流比为25,开路电压为1.32 V。In_(0.35)Ga_(0.65) N/p-Si异质结中存在热辅助载流子隧穿和复合隧穿两种电流传输机制。经拟合,得到异质结的反向饱和电流为1.05×10^(-8) A,势垒高度为0.86 eV,理想因子为6.87。

InGaN film was deposited on p-Si substrate using a self-refited pulsed laser deposition(PLD)system with double laser light paths and two-component target.The microstructure of InGaN film and the electrical properties of n-InGaN/p-Si heterojunction were investigated.The results show that InGaN film exhibits a single crystal structure with[0001]preferred orientation.The surface of the film is smooth and dense,and the atomic content of In is 35%.The Hall effect measurements show that In 0.35 Ga 0.65 N film exhibits n-type characteristics with high carrier concentration,high mobility and low resistivity.The current-voltage(I-V)analysis shows that n-In 0.35 Ga 0.65 N/p-Si heterojunction has good rectification characteristics with the rectification ratio of 25 at±4 V,and the open circuit voltage is 1.32 V.There exists two current transport mechanisms in n-In 0.35 Ga 0.65 N/p-Si heterojunction:thermally assisted carrier tunneling and recombination-tunneling mechanism.In addition,the reverse saturation current,barrier height and ideality factor of the heterojunction are 1.05×10^(-8) A,0.86 eV,and 6.87,respectively.