AlAsSb的外延再生长对InAs/GaSb红外探测器暗电流抑制效果研究  

Surface passivation of InAs/GaSb infrared detectors using epitaxial regrowth of AlAsSb

作　　者：严定钰 沈祥 王庶民[4] 石张勇 张焱超 张凡 YAN Dingyu;SHEN Xiang;WANG Shumin;SHI Zhangyong;ZHANG Yanchao;ZHANG Fan(Advanced Technology Research Institute,Ningbo University,Ningbo 315211,China;Key Laboratory of Photoelectric Materials and Devices of Zhejiang Province,Ningbo 315211,China;Zhejiang SuperMat Sen-Ray Optoelectronics Co.,Ltd.,Ningbo 315400,China;College of Micro-technology and Nano-science,Chalmers University of Technology,Gothenburg 41296,Sweden)

机构地区：[1]宁波大学高等技术研究院,浙江宁波315211 [2]浙江省光电探测材料及器件重点实验室,浙江宁波315211 [3]浙江超晶晟锐光电有限公司,浙江宁波315400 [4]查尔姆斯理工大学微米技术与纳米科学学院,瑞典哥德堡41296

出　　处：《宁波大学学报（理工版）》2023年第3期87-93,共7页Journal of Ningbo University：Natural Science and Engineering Edition

基　　金：国家自然科学基金联合项目(U21A2056);浙江省重点研发计划(2021C01025);宁波市“科技创新2025”重大专项(2020Z009)。

摘　　要：采用分子束外延(MBE)技术外延再生长AlAsSb,对InAs/GaSb Ⅱ类超晶格(T2SLs)长波红外探测器的表面缺陷进行钝化,实现了暗电流的显著降低.首先,研究了湿法腐蚀浅台面的最佳腐蚀液配比,获得了低横向腐蚀、光滑的侧壁以及均匀的腐蚀界面.随后,使用AlAsSb/AlAs/GaAs、AlAsSb/GaSb两种不同的外延再生长组合和单一的SiO_(2)薄层分别对刻蚀后的台面进行钝化,同时保留一个没有钝化的样品作为对照,最后对4种不同钝化条件下探测器的暗电流特性进行了测量.结果发现,使用AlAsSb/GaSb外延再生长钝化层的器件暗电流得到了进一步降低,使用SiO_(2)钝化层的效果次之,而使用AlAsSb/AlAs/GaAs外延再生长钝化层的性能相对较差.上述结果表明,外延再生长钝化技术是降低长波红外探测器暗电流的一种有效方法.Passivation of InAs/GaSb type-Ⅱ superlattice(T2SLs)infrared detectors by epitaxial regrowth of AlAsSb using molecular beam epitaxy(MBE)technology has achieved a significant reduction of dark current.Firstly,the optimal etching recipe for wet etching shallow mesa surfaces is investigated to obtain low lateral corrosion,smooth etching mesa sidewall,and a uniform corrosion interface.Thereafter,the post-etched mesa is passivated using two different epitaxial regrowth combinations of AlAsSb/AlAs/GaAs and AlAsSb/GaSb and a single SiO_(2) thin layer,respectively.A control sample without any passivation layer is also kept for comparison,and the dark current characteristics of the four different passivations are investigated.It turns out that the passivation layer prepared with the epitaxial regrowth of AlAsSb/GaSb further reduces the dark current of the device,whereas the SiO_(2) passivation shows relatively less satisfying performance,and the epitaxial regrowth passivation of AlAsSb/AlAs/GaAs is the least effective.Therefore,epitaxial regrowth passivation technology proves to be an effective method to reduce the dark current of long wavelength infrared detectors.

关 键 词：外延再生长 表面钝化 InAs/GaSbⅡ类超晶格 长波红外探测器 湿法刻蚀 

分 类 号：TN215[电子电信—物理电子学]