Low ON-Resistance and High Peak Voltage Transmission Efficiency Based on High-Purity 4H-SiC Photoconductive Semiconductor Switch

Silicon carbide (SiC) is a wide-bandgap semiconductor suitable for high-power high-voltage devices, especially the feasibility and superiority of SiC photoconductive semiconductor in microwave generation have been demonstrated via linear operating mode. Here, the photoconductive semiconductor switch (PCSS) with a channel length of 0.5 mm is fabricated as planar structures on high-purity semi-insulating 4H-SiC. The experimental results show that the voltage transmission of the elliptic morphology laser incident from the rear is larger than the circular counterpart, which is consistent with the formula calculation and the simulations of the current density distribution of a 2-D cross section. Upon the elliptic incident laser centered at ∼355 nm, the peak voltage transmission efficiency of SiC PCSS is 99.5% at the biased voltage of ∼2220 V. In addition, the output voltage waveform is observed with a half-height width of roughly 1.6 ns and rise time of less than 300 ps as well as the minimum on -state resistance of approximately 0.3 Ω at this moment.