GaN基p-i-n型紫外探测器钝化工艺研究  

GaN-based p-i-n Type UV Detector Passivation Process Study

作　　者：杨富城 杨帆[2,3] 许金通 YANG Fucheng;YANG Fan;XU Jintong(Shanghai University of Technology College of Science,Shanghai 200093,CHN;Shanghai Institute of Technology Physics,Chinese Academy of Sciences,Shanghai 200083,CHN;University of Chinese Academy of Sciences,Beijing 100049,CHN)

机构地区：[1]上海理工大学理学院,上海200093 [2]中国科学院上海技术物理研究所,上海200083 [3]中国科学院大学,北京100049

出　　处：《半导体光电》2023年第6期895-900,共6页Semiconductor Optoelectronics

基　　金：国家重点研发计划项目(2021YFA0715501)。

摘　　要：钝化层膜系的选择及其工艺的优化对降低GaN基紫外探测器的漏电流和提升其可靠性是至关重要的。文章采用多种钝化层:等离子体增强化学气相沉积生长的Si_(3)N_4(PECVD-Si_(3)N_4)、电感耦合等离子体化学气相沉积生长的Si_(3)N_4(ICPCVD-Si_(3)N_4)和SiO_(2)(ICPCVD-SiO_(2))以及等离子原子层沉积生长的Al_(2)O_(3)(PEALD-Al_(2)O_(3)),分别制备了GaN基金属-绝缘体-半导体(MIS)器件,并对MIS器件的电流-电压(I-V)和电容-电压(C-V)特性进行了对比研究。采用PECVD-Si_(3)N_4作为钝化层的GaN基MIS器件具有较低的漏电流;在双层PECVD-Si_(3)N_4钝化层中插入PEALD-Al_(2)O_(3)薄膜可以进一步降低界面态密度:平均界面态密度从3.94×10^(13) eV^(-1)·cm^(-2)降低到3.52×10^(11) eV^(-1)·cm^(-2)。利用这种“三明治结构”钝化膜,制作p-i-n型GaN基紫外雪崩探测器,与单层膜系的探测器相比,在113 V反向偏压下的暗电流从3.73×10^(-8) A降至3.34×10^(-8) A。In order to reduce the leakage current and improve the reliability of GaN-based UV detectors,the selection of the passivation layer film system and the optimization of its process are crucial.In this paper,GaN-based metal-insulator-semiconductor(MIS)devices were prepared using the following passivation layers:Si3N4 grown by plasma-enhanced chemical vapor deposition(PECVD),Si3N4 and SiO_(2) grown by inductively coupled plasma chemical vapor deposition(ICPCVD),and Al_(2)O_(3) grown by plasma atomic layer deposition(PEALD),respectively.The current-voltage(I-V)and capacitance-voltage(C-V)characteristics of the devices were studied comparatively.It is found that when the PECVD-grown Si3N4 was used as the passivation layer,it has a lower leakage current in GaN-based MIS devices;by introducing a layer of PEALD-grown Al_(2)O_(3) into the double-layer PECVD-grown Si3N4 passivation layer,the interfacial state density is further reduced:the average interfacial state density decreases from 3.94×10^(13)eV^(-1)·cm^(-2) to 3.52×10^(11)eV^(-1)·cm^(-2).Using this passivation film with"sandwich structure",a p-i-n type GaN-based UV avalanche detector was fabricated.The dark current at 113V reverse bias is reduced from 3.73×10^(-8) A to 3.34×10^(-8) A compared with the detector of the Si3N4 film system without PEALD-grown Al_(2)O_(3).

关 键 词：GAN 漏电流 钝化 等离子原子层沉积 界面态密度 

分 类 号：TN23[电子电信—物理电子学]