Analyzing the surface passivity effect of germanium oxynitride:a comprehensive approach through first principles simulation and interface state density  

作　　者：Sheng-Jie Du Xiu-Xia Li Yang Tian Yuan-Yuan Liu Ke Jia Zhong-Zheng Tang Jian-Ping Cheng Zhi Deng Yu-Lan Li Zheng-Cao Li Sha-Sha Lv 

机构地区：[1]College of Nuclear Science and Technology Joint Laboratory of Jinping Ultra‑Low Radiation Background Measurement of Ministry of Ecology and Environment Key Laboratory of Beam Technology of Ministry of Education,Beijing Normal University,Beijing Normal University,Beijing 100875,China [2]Joint Research Center,Nuctech Company Limited,Beijing 100084,China [3]Department of Engineering Physics,Key Laboratory of Particle&Radiation Imaging of Ministry of Education,Tsinghua University,Beijing 100084,China [4]Key Laboratory of Advanced Materials(MOE),School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China

出　　处：《Nuclear Science and Techniques》2024年第5期74-84,共11页核技术（英文）

基　　金：supported by the National Natural Science Foundation of China(No.12005017).

摘　　要：High-purity germanium(HPGe)detectors,which are used for direct dark matter detection,have the advantages of a low threshold and excellent energy resolution.The surface passivation of HPGe has become crucial for achieving an extremely low energy threshold.In this study,first-principles simulations,passivation film preparation,and metal oxide semiconductor(MOS)capacitor characterization were combined to study surface passivation.Theoretical calculations of the energy band structure of the -H,-OH,and -NH_(2) passivation groups on the surface of Ge were performed,and the interface state density and potential with five different passivation groups with N/O atomic ratios were accurately analyzed to obtain a stable surface state.Based on the theoretical calculation results,the surface passivation layers of the Ge_(2)ON_(2) film were prepared via magnetron sputtering in accordance with the optimum atomic ratio structure.The microstructure,C-V,and I-V electrical properties of the layers,and the passivation effect of the Al/Ge_(2)ON_(2)/Ge MOS were characterized to test the interface state density.The mean interface state density obtained by the Terman method was 8.4×10^(11) cm^(-2) eV^(-1).The processing of germanium oxynitrogen passivation films is expected to be used in direct dark matter detection of the HPGe detector surface passivation technology to reduce the detector leakage currents.

关 键 词：Surface passivation High purity germanium detector Germanium nitrogen oxide Interface state density 

分 类 号：TL814[核科学技术—核技术及应用]