日盲型AlGaN PIN紫外探测器的电容特性  

Capacitance characteristics of solar-blind AlGaN PIN UV detector

作　　者：包西昌[1,2] 李超[1,2] 张文静[1,2] 王玲[1,2] 李向阳[1,3] 

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 [2]中国科学院研究生院,北京100039 [3]中国科学院上海技术物理研究所中国科学院红外成像材料与器件重点实验室,上海200083

出　　处：《红外与激光工程》2010年第5期835-838,共4页Infrared and Laser Engineering

基　　金：国家自然科学基金资助项目(6070802860807037)

摘　　要：对采用金属有机化学气相沉积方法生长的p-Al0.43Ga0.57N/i-Al0.43Ga0.57N/n-Al0.7Ga0.3N异质结构上制备的背照射日盲型AlGaN紫外光电探测器进行了光电性能和电容特性的研究。室温下探测器零偏压时的电流密度为0.44 nA/cm2,278 nm的峰值响应率为0.042 A/W。电容频率特性表明:器件电容随着频率的增大先迅速后缓慢地降低,但在频率高于100 kHz后又加速下降。通过器件低频下的电容计算可得,其耗尽层宽度为160 nm,低于设计的本征层厚度,说明器件的本征层没有完全耗尽。因此,未耗尽本征层的高电阻是引起100 kHz附近电容又快速下降的重要原因,由不同频率下1/C2-V曲线的变化关系及其斜率计算的杂质浓度等结果进一步证实了这一结论。The fabrication and characterization of AlGaN back-illuminated solar-blind PIN UV detectors grown on double-side polished（0001） sapphire substrates by the metal organic chemical vapor deposition（MOCVD） were presented.The I-V curve showed that the dark current density was 0.44 nA/cm2 at zero bias under the room temperature.The peak responsivity of the photodetector at 278 nm reached 0.042 A/W.The C-f curve showed that the capacitance of the device droped fast and then slowly with the increase of frequency.While the frequency was higher than 100 kHz,the capacitance droped fast again.The depletion region width was calculated to be only 160 nm through the measured capacitance under 20 Hz,which was smaller than the intrinsic layer.High resistance of the intrinsic region plays an important role in the capacitance at low and high frequency,respectively.The slopes of 1/C^2-V curves and the calculated impurity concentration under different frequencies further confirm the above reason for the C-f′s changes.

关 键 词：日盲型紫外探测器 ALGAN 响应率 电容特性 

分 类 号：TN312.4[电子电信—物理电子学]