Elevated Reliability Augmentation for Avalanche GaAs Photoconductive Semiconductor Switch by Ni/Ge/Ti/Pt/W-Based Stacked Metals

How to achieve high-reliability in gallium arsenide (GaAs) photoconductive semiconductor switches (PCSSs) represents a critical research frontier. The avalanche mode of GaAs PCSS causes high current density, leading to premature electrode damage and switch failure. To address this issue, this study proposes using high-reliability Ni/Ge/Ti/Pt/W as an alternative contact configuration to the conventional Ni/Ge/Au/Ni/Au setup, improving device reliability. Under 12 kV direct current bias, 915 nm wavelength, 5 Hz repetition frequency, and $20~\mu $ J energy, after 4,000 cycles, the amplitudes of #1 PCSS (with Ni/Ge/Au/Ni/Au contacts) and #2 PCSS (with Ni/Ge/Ti/Pt/W contacts) decreased 57.33% and 23.49%, respectively, indicating that the #2 PCSS has higher reliability. This study enhances high-voltage PCSS performance through optimized contact electrodes, offering significant potential for future pulse power applications.