【摘要】 对GaAs光电导开关的电极进行刻蚀处理,可极大地分散电极处的电场强度,有效避免局部电场的过于集中,从而增大开关的耐压和通流能力,为有效应用这一技术,用有限元方法模拟分析了不同角度刻蚀方案对电极处电场分布的影响,研制了32 kV、峰值电流3.7 kA的高压纳秒GaAs光电导开关。根据实验结果分析了光电导开关在强场下的击穿机理,指出开关击穿主要由开关体负阻效应在开关阳极产生的空间电荷累积所导致的开关阳极电场剧增引起的;同时,基于转移电子效应对开关击穿电压进行了理论计算,计算结果与实验相吻合。更多还原

【Abstract】 We developed a semi-insulating(SI) GaAs photoconductive semiconductor switch(PCSS) with withstand voltage of 32 kV and peak current of 3.7 kA.By etching on the SI GaAs at the electrodes,the electric field distortion is depressed.The 1-D distribution of inside electric field between the electrodes is calculated by the method of finite element.The breakdown mechanism of the PCSS is analyzed.It is revealed that the breakdown of PCSS’s fabricated from indirect band-gap semiconductors is mainly caused by trap filled limited conduction model;however,for PCSS’s fabricated from materials that exhibit the transferred-electron effect,such as GaAs,the breakdown of the PCSS’s is mainly caused by negative resistance inducing electric field enhancement at the anode boundary.Based on Gunn effect electronics,the breakdown voltage of the PCSS is calculated,the calculation results agree with the experimental ones.更多还原