Operating Mechanism of Low-Energy-Triggered Gallium Arsenide Photoconductive Semiconductor Switch
Xu Shouli1, Liu Jingliang1, Hu Long2, Ni Tao1, Xu Chunliang1
1. The 13th Research Institute China Electronics Technology Group Corporation Shijiazhuang 050050 China; 2. School of Electronic Science and Engineering Xi'an Jiaotong University Xi'an 710049 China;
Abstract：High repetitive ultrawide band pulse possesses wide application prospect to civil and military fields, whose key parameters are decided by prosperities of the pulsed power semiconductor device. Gallium arsenide (GaAs) photoconductive semiconductor switch (PCSS) in avalanche mode based on semi-insulating (SI) wafer possesses properties of low-energy triggering, high voltage and ultrafast switching. The ultrawide band generator based on GaAs PCSS can achieve miniaturization, modularization and array. For decades, there were several theories explaining the phenomena in the avalanche PCSS with consideration of field-dependent trapping of charge carriers, deep impurity ionization, double injection, avalanche injection, localized impact ionization, streamer formation, collective impact ionization, and photo-activated charge domain. However, the operation mechanism, especially the lock-on effect, of the GaAs PCSS in the avalanche mode is still unclear. Operating mechanism of low-energy-triggered GaAs PCSS was analyzed using a one-dimensional physics-based numerical simulation. The transient process of physical parameters in filament was discussed. The physics of multiple avalanche domains as the operating mechanism of the PCSS in avalanche mode was described, which leads to characteristics of low-energy triggering, ultrafast switching and voltage locking of the switch. When a 905-nm optical pulse with the power of 12 W triggered the PCSS from cathode, the switch reached a high conducting state in 147 ps after a delay time of 3.0 ns, and then turn-on voltage across the PCSS was locked at an electric field of about 3.9 kV/cm due to existing of residual avalanche domains in filament. The transient process can be divided into three stages containing delay, ultrafast switching and votage locking. In the delay stage, the intrinsic positive feedback causes formation of multiple avalanche domains and dense electron-hole plasma. In the ultrafast switching stage, the increase of plasma density leads to the increase of domain field and drastic domain shrinkage that reduces voltage across the structure very fast. Further increase of plasma density results in domains annihilation including reduction of domain width, peak field and domain number, and ultrafast switching sustainable occurs. At the last stage, the PCSS turns into voltage locking stage due to the existence of a small quantity of avalanche domains in the high conductivity structure. Moreover, the phenomenon of picosecond current oscillations was observed numerically in the avalanche GaAs PCSS, and the peak-to-peak amplitude of these current signals is about 0.04~0.25 A, and the oscillating period is about 3.8~6.1 ps.The physical reason was also discussed by evolution of avalanche domains in the filament. Based on the investigation on the switching mechanism, the experimental study of the GaAs PCSS with 4 mm gap biased at 17.5 kV was carried out using in a 50 Ω pulse forming line. When the pulse forming line was charged to 17.5 kV, the laser pulse from a laser diode module triggered the GaAs PCSS at cathode side. The PCSS turned into a conducting state, and the pulse was generated across the load resistance. The peak power of voltage pulse reaches MW level, and risetime of output pulse is only about 620 ps, and the highest repetition rate is up to 20 kHz. The numeric switching time of GaAs PCSS is significantly less than that achieved in our experiment, which is caused mainly by parasitic inductance in experimental circuit.
[1] 荀涛, 孙晓亮, 樊玉伟, 等. 重频吉瓦级高功率微波源硬管化技术研究[J]. 电子科技大学学报, 2020, 49(1): 87-91. Xun Tao, Sun Xiaoliang, Fan Yuwei, et al.Progress in a hard-tube, gigawatt-class, repetitively operated high-power microwave source[J]. Journal of University of Electronic Science and Technology of China, 2020, 49(1): 87-91. [2] 王宁, 金雪雁. 高功率微波国外发展现状以及与电子战的关系[J]. 航天电子对抗, 2018, 34(2): 61-64. Wang Ning, Jin Xueyan.The present situation of high power microwave abroad and its relationship with electronic warfare[J]. Aerospace Electronic Warfare, 2018, 34(2): 61-64. [3] 薛明, 杨庆新, 章鹏程, 等. 无线电能传输技术应用研究现状与关键问题[J]. 电工技术学报, 2021, 36(8): 1547-1568. Xue Ming, Yang Qingxin, Zhang Pengcheng, et al.Application status and key issues of wireless power transmission technology[J]. Transactions of China Electrotechnical Society, 2021, 36(8): 1547-1568. [4] 何映江, 余亮, 马剑豪, 等. 一种升压模式的可调极性高频Blumlein脉冲形成线功率调制模块[J]. 电工技术学报, 2021, 36(2): 425-434. He Yingjiang, Yu Liang, Ma Jianhao, et al.An adjustable polarity high frequency Blumlein pulse forming line power modulation module with boost mode[J]. Transactions of China Electrotechnical Society, 2021, 36(2): 425-434. [5] Wu Ping, Sun Jun, Chen Changhua.Lifetime experimental study of graphite cathode for relativistic backward wave oscillator[J]. Journal of Applied Physics, 2016, 120(3): 033301. [6] 石磊, 樊亚军, 周金山, 等. 双路输出超宽谱高功率微波驱动源Tesla变压器[J]. 强激光与粒子束, 2013, 25(7): 1751-1754. Shi Lei, Fan Yajun, Zhou Jinshan, et al.Tesla transformer for dual-output ultra-wide spectrum HPM pulse generator[J]. High Power Laser and Particle Beams, 2013, 25(7): 1751-1754. [7] 何东欣, 张涛, 陈晓光, 等. 脉冲电压下电力电子装备绝缘电荷特性研究综述[J]. 电工技术学报, 2021, 36(22): 4795-4808. He Dongxin, Zhang Tao, Chen Xiaoguang, et al.Research overview on charge characteristics of power electronic equipment insulation under the pulse voltage[J]. Transactions of China Electrotechnical Society, 2021, 36(22): 4795-4808. [8] 霍群海, 李梦菲, 粟梦涵, 等. 柔性多状态开关应用场景分析[J]. 电力系统自动化, 2021, 45(8): 13-21. Huo Qunhai, Li Mengfei, Su Menghan, et al.Analysis on application scenarios of flexible multi-state switch[J]. Automation of Electric Power Systems, 2021, 45(8): 13-21. [9] 童军, 吴伟东, 李发成, 等. 基于GaN器件的高频高效LLC谐振变换器[J]. 电工技术学报, 2021, 36(增刊2): 635-643. Tong Jun, Wu Weidong, Li Facheng, et al.High frequency and high efficiency LLC resonant converter based on GaN device[J]. Transactions of China Electrotechnical Society, 2021, 36(S2): 635-643. [10] Xu Ming, Liu Chun, Luo Wei, et al.Pulse compression characteristics of an opposed-electrode nonlinear GaAs photoconductive semiconductor switch at 2 μJ excitation[J]. IEEE Electron Device Letters, 2022, 43(5): 753-756. [11] 党鑫, 杨向红, 孙岳, 等. GaAs光导开关电极制备工艺及性能测试[J]. 西安交通大学学报, 2022, 56(2): 184-190. Dang Xin, Yang Xianghong, Sun Yue, et al.Preparation technology and performance test of GaAs photoconductive semiconductor switch electrodes[J]. Journal of Xi’an Jiaotong University, 2022, 56(2): 184-190. [12] Brinkmann R P, Schoenbach K H, Mazzola M S, et al.Analysis of time-dependent current transport in an optically controlled Cu-compensated GaAs switch[C]// OE/LASE '92, Proc SPIE 1632, Optically Activated Switching II, Los Angeles, CA, USA. 1992, 1632: 262-273. [13] Yee J H, Khanaka G H, Druce R L, et al.Modeling the effect of deep impurity ionization on GaAs photoconductive switches[C]//OE/LASE '92, Proc SPIE 1632, Optically Activated Switching II, Los Angeles, CA, USA. 1992, 1632: 21-31. [14] Zhao Hanmin, Hadizad P, Hur J H, et al.Avalanche injection model for the lock‐on effect in III‐V power photoconductive switches[J]. Journal of Applied Physics, 1993, 73(4): 1807-1812. [15] Capps C D, Falk R A, Adams J C.Time-dependent model of an optically triggered GaAs switch[J]. Journal of Applied Physics, 1993, 74(11): 6645-6654. [16] Bailey D W, Dougal R A, Hudgins J L.Streamer propagation model for high-gain photoconductive switching[C]//OE/LASE'93: Optics, Electro-Optics, and Laser Applications in Scienceand Engineering, Proc SPIE 1873, Optically Activated Switching III, Los Angeles, CA, USA. 1993, 1873: 185-191. [17] Hudgins J L, Bailey D W, Dougal R A, et al.Streamer model for ionization growth in a photoconductive power switch[J]. IEEE Transactions on Power Electronics, 1995, 10(5): 615-620. [18] K. Kambour, H. P. Hjalmarson, C. W. Myles.A collective impact ionization theory of lock-on in PCSS's[C]//14th IEEE International Pulsed Power Conference, Texas, USA, 2003:345-348. [19] Hjalmarson H P, Kambour K, Myles C W, et al.Continuum models for electrical breakdown in photoconductive semiconductor switches[C]//2007 16th IEEE International Pulsed Power Conference, Albuquerque, NM, USA, 2008: 446-450. [20] Shi Wei, Dai Huiying, Sun Xiaowei.Photon-activated charge domain in high-gain photoconductive switches[J]. Chinese Optics Letters, 2003, 1(9): 553-555. [21] Hu Long, Su Jiancang, Ding Zhenjie, et al.Investigation on properties of ultrafast switching in a bulk gallium arsenide avalanche semiconductor switch[J]. Journal of Applied Physics, 2014, 115(9): 094503. [22] Smith P M, Inoue M, Frey J.Electron velocity in Si and GaAs at very high electric fields[J]. Applied Physics Letters, 1980, 37(9): 797-798. [23] Vainshtein S N, Yuferev V S, Kostamovaara J T.Ultrahigh field multiple Gunn domains as the physical reason for superfast (picosecond range) switching of a bipolar GaAs transistor[J]. Journal of Applied Physics, 2004, 97(2): 024502. [24] Hui K, Hu C, George P, et al.Impact ionization in GaAs MESFETs[J]. IEEE Electron Device Letters, 1990, 11(3): 113-115. [25] Haug A.Auger recombination in direct-gap semiconductors: band-structure effects[J]. Journal of Physics C: Solid State Physics, 1983, 16(21): 4159-4172. [26] Ghadimi-Mahani A, Goodarzi A, Farsad E, et al.Performance and reliability improvement of 905nm high power laser diode by design, fabrication and characterization of high damage threshold mirrors[J]. Microelectronics Reliability, 2021, 119: 114070. [27] Wight D R, Keir A M, Pryce G J, et al.Limits of electro-absorption in high purity GaAs, and the optimisation of waveguide devices[J]. IEE Proceedings J Optoelectronics, 1988, 135(1): 39. [28] Mikhnev V A, Vainshtein S N, Kostamovaara J T.Time-domain terahertz imaging of layered dielectric structures with interferometry-enhanced sensitivity[J]. IEEE Transactions on Terahertz Science and Technology, 2020, 10(5): 531-539. [29] Vainshtein S N, Duan Guoyong, Yuferev V S, et al.Collapsing-field-domain-based 200 GHz solid-state source[J]. Applied Physics Letters, 2019, 115(12): 123501.
2023, Vol. 38 
