背照式AlGaN/GaN基PIN日盲型紫外探测器的研制

Research of AlGaN/GaN PIN solar-blind ultraviolet photodetector with back-illumination

利用MOCVD方法在蓝宝石（0001）衬底上生长PIN型AlGaN/GaN外延材料,研制出背照式AlGaN基PIN日盲型紫外探测器,用紫外光谱测试系统和半导体参数测试仪分别测得了器件的光谱响应和I-V特性曲线。测试结果表明,器件的响应范围为260~280 nm,峰值响应出现在270 nm处,在2.5 V偏压下的最大响应度为0.055 A/W,对应的探测率为4.6×1011cm.Hz1/2.W-1;正向开启电压为1.6 V,反向击穿电压约为16 V,在-0.3 V偏压下的暗电流约为25 pA。

The growth,fabrication and characteristics of AlGaN/GaN PIN solar-blind ultraviolet photodetectors with back-illumination are reported.The spectral responsivity and current-voltage characteristics of photodetectors were measured by the ultraviolet spectroscopy testing system and Keithley 4 200 semiconductor characterization system,respectively.The peak responsivity of photodetectors is about 0.055 A/W at 270 nm under 2.5 V reverse bias voltage.The dark current of the 1 500 μm-diameter devices is measured to be about 25 pA under-0.3 V bias voltage.Additionally,the turn-on and the breakdown voltages are about 1.6 V and 16 V,respectively.With a 2.5 V bias applied,the corresponding normalized detectivity （D） determined is 4.6×1011 cm·Hz1/2·W-1.