InAs/GaSbⅡ类超晶格长波红外探测器的表面处理研究  

Studies on the surface treatment of InAs/GaSb type-Ⅱsuper-lattice long-wave infrared detectors

作　　者：崔玉容 周易[1,2] 黄敏 王芳芳 徐志成[1] 许佳佳[1] 陈建新[1,2] 何力[1] CUI Yu-Rong;ZHOU Yi;HUANG Min;WANG Fang-Fang;XU Zhi-Cheng;XU Jia-Jia;CHEN Jian-Xin;HE Li(Key Laboratory of Infrared Imaging Materials and Detectors,Shanghai Institute of Technical Physics,Chinese Academy of Sciences,Shanghai 200083,China;University of Chinese Academy of Science,Beijing 100049,China)

机构地区：[1]中国科学院上海技术物理研究所红外成像材料与器件重点实验室,上海200083 [2]中国科学院大学,北京100049

出　　处：《红外与毫米波学报》2023年第1期8-13,共6页Journal of Infrared and Millimeter Waves

基　　金：国家自然科学基金(61974152,61904183,62222412,62004205,62104237)。

摘　　要：开展了In As/Ga SbⅡ类超晶格长波红外探测器的表面处理研究。通过对不同处理工艺形成台面器件的暗电流分析,发现N2O等离子处理结合快速热退火(RTA)的优化工艺能够显著改善长波器件电学性能。对于50%截止波长12.3μm的长波器件,在液氮温度,-0.05 V偏置下,表面处理后暗电流密度从5.88×10^(-1)A/cm^(2)降低至4.09×10^(-2)A/cm^(2),零偏下表面电阻率从17.7Ωcm提高至284.4Ωcm,有效降低侧壁漏电流。但是该表面处理后的器件在大反偏压下仍有较大的侧壁漏电,这可能是由于高浓度的表面电荷使得大反偏下侧壁存在较高的隧穿电流。通过栅控结构器件的变栅压实验,验证了长波器件存在纯并联电阻及表面隧穿两种主要漏电机制。最后,对表面处理前后的暗电流进行拟合,处理后器件表面电荷浓度为3.72×1011cm-2。In this work,the surface treatment of In As/Ga Sb type-Ⅱsuper-lattice long-wavelength infrared detectors is studied.An optimizing process of N2O plasma treatment and rapid thermal annealing was developed,which can im‐prove the performance of long-wavelength detector withλ50%cut-off=12.3μm from 5.88×10^(-1)A/cm^(2)to 4.09×10^(-2)A/cm^(2)at liquid nitrogen temperature,-0.05 V bias.Through variable area device array characterization,the sidewall leakage current was extracted.Under zero bias,the surface resistivity improved from 17.9Ωcm to 297.6Ωcm.However,the sidewall leakage couldn’t be ignored under large inverse bias after optimizing process,where surface charge might in-duce the surface tunneling current.It is verified by gate-control structure that there are two main leakage mechanisms in long-wave device:pure sidewall parallel resistance and surface tunneling.At last,the surface charge was calculated to be 3.72×1011cm-2byⅣcurve fitting after optimizing process.

关 键 词：二类超晶格 长波红外探测器 表面处理 暗电流分析 栅控结构 

分 类 号：TN304.2[电子电信—物理电子学] TN305