基于Pt/GaN/AlGaN异质结高响应度双波段紫外探测器  

Dual-Band and High-Responsivity Ultraviolet Detector Based on Pt/GaN/AlGaN Heterojunction

作　　者：吴刚 唐利斌[1,2,3] 郝群 邓功荣[2] 张逸韵[4] 秦强[2] 袁绶章[2] 王静宇[2] 魏红[2] 严顺英[2] 谭英 孔金丞[2] Wu Gang;Tang Libin;Hao Qun;Deng Gongrong;Zhang Yiyun;Qin Qiang;Yuan Shouzhang;Wang Jingyu;Wei Hong;Yan Shunying;Tan Ying;Kong Jincheng(School of Optics and Photonics,Beijing Institute of Technology,Beijing 100081,China;Kunming Institute of Physics,Kunming 650223,Yunnan,China;Yunnan Key Laboratory of Advanced Photoelectronic Materials&Devices,Kunming 650223,Yunnan,China;Research and Development Center for SolidState Lighting,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100090,China)

机构地区：[1]北京理工大学光电学院,北京100081 [2]昆明物理研究所,云南昆明650223 [3]云南省先进光电子材料与器件重点实验室,云南昆明650223 [4]中国科学院半导体研究所固体照明研究开发中心,北京100090

出　　处：《光学学报》2023年第3期7-13,共7页Acta Optica Sinica

基　　金：国家重点研究开发计划(2019YFB2203404);云南省创新团队项目(2018HC020)。

摘　　要：提出一种在AlGaN基PIN器件的pGaN表面上沉积Pt,形成肖特基势垒(SB)-PIN异质结器件,器件的能带和载流子的输运发生了变化,这种新型光电探测器实现了双波段紫外探测,可分别工作在光伏和光电导模式下。器件在275 nm波长的紫外光照射的负偏置电压下,工作模式为光伏探测,当入射光功率密度为100μW/cm^(2),偏置电压为-10 V时,器件得到最大响应度(0.12 A/W);当偏置电压为-0.5 V时,器件得到最大探测率(1.0×10^(13) cm·Hz^(1/2)·W^(-1))。器件在正偏置电压工作模式下可作为高响应、高增益的光电导探测器,当偏置电压为+10 V时,用275 nm和365 nm波长的紫外光照射(光功率密度为100μW/cm^(2)),器件的响应度分别为10 A/W和14 A/W,外量子效率分别为4500%和4890%。所设计的双波段多功能器件将极大地扩展基于AlGaN的紫外探测器的用途。Objective Solar blind ultraviolet(UV)detectors based on AlGaN ternary compound semiconductors have attracted much attention due to their great application potential in fields such as precision guidance,missile warning,spacecraft tracking,open flame monitoring,bioimaging,and UV secure communication.In increasingly complex target environments and shortrange nonlineofsight optical communication systems,UV detectors with high sensitivity and wide working bandwidth are required.At the same time,new material structure designs and device structure research make the UV detectors have higher performance and wider application.In this work,metal Pt with a work function of 5.36 eV is deposited on the surface of a pGaN layer with a work function of 7.5 eV on the upper surface of GaN/AlGaN material without annealing.The Schottky contact is formed to replace the Ohmic contact formed by the traditional deposition of Ni/Au,Ti/Pt/Au,and other multilayer metals in an AlGaNbased PIN device and annealed at a high temperature.The pGaN material forms a Schottky barrier with an energy band bending downward on the side contacting with Pt and combined with the PIN structure of the AlGaN material itself.An SBPIN heterojunction structure is formed in the device,which changes the energy band,the builtin electric field,and the carrier transport mechanism of the device compared with PIN and SBD devices and results in a new operating mechanism and photoelectric characteristics of the device.The device has a high responsivity under a positive bias voltage and realizes dualband detection(275 nm and 365 nm).Methods The fabrication process of the device proposed in this work is as follows:After the wafer cleaning,a device mesa with a diameter of 700µm is defined by reactive ion etching(RIE).Ti/Al/Ni/Au metal layers are deposited on the n+-AlGaN layer by an ebeam evaporator,and the sample is then annealed at 550℃to form an ohmic contact.Then,SiO_(2)/SiNx composite dielectric film is grown to passivate the side wall of the device and the n+-AlGaN

关 键 词：探测器 双波段紫外探测器 ALGAN 异质结 响应度 

分 类 号：O472[理学—半导体物理]