【摘要】 研究了GaN/AlGaN异质结背照式p-i-n结构可见盲紫外探测器的制备与性能。GaN/AlGaN外延材料采用金属有机化学气相沉积(MOCVD)方法生长,衬底为双面抛光的蓝宝石,缓冲层为AlN,n型层采用厚度为0.8μm的Si掺杂Al0.3Ga0.7N形成窗口层,i型层为0.18μm的非故意掺杂的GaN,p型层为0.15μm的Mg掺杂GaN。采用Cl2、Ar和BCl3感应耦合等离子体刻蚀定义台面,光敏面面积为1.96×10-3 cm2。可见盲紫外探测器展示了窄的紫外响应波段,响应区域为310～365 nm,在360 nm处响应率最大,为0.21 A/W,在考虑表面反射时,内量子效率达到82%;优质因子R0A为2.00×108Ω.cm2,对应的探测率D=2.31×1013 cm.Hz1/2.W-1;且零偏压下的暗电流为5.20×10-13 A。更多还原

【Abstract】 A back-illuminated visible-blind UV detector based on a GaN/AlGaN p-i-n heterostructure has been successfully fabricated and tested.The p-i-n photodiode structure consists of a 0.8 μm n-type Al0.3Ga0.7N:Si layer grown by MOCVD onto a low temperature AlN buffer layer on a polished sapphire substrate.On top of this layer is a 0.18 μm undoped GaN active layer and a 0.15 μm p-type GaN:Mg top layer.Square mesas of area A=1.96×10-3 cm2 are obtained by inductively coupled plasma etching using BCl3,Ar,and Cl2.The visible blind photodiode exhibits a narrow UV spectral responsivity 310～365 nm with band peaked at 360 nm,maximum responsivity R=0.21 A/W,corresponding to an internal quantum efficiency of 82%.R0A values up to 2.00×108 Ω·cm2 are obtained corresponding to D*=2.31×1013 cm·Hz1/2·W-1.The leakage current at zero bias is 5.20×10-13 A.更多还原