Two dimensional simulation and modeling of the electrical characteristics of the a-SiC/c-Si(p) based, thyristor-like, switches

E. Dimitriadis, N. Archontas, D. Girginoudi and N. Georgoulas
2015. Microelectronic Engineering, 133, 120-128. doi: 10.1016/j.mee.2014.11.006

Abstract: The electrical characteristics of the Al/a-SiC/c-Si(p)/c-Si(n+)/Al switches were successfully simulated here for the first time. Forward breakover voltage VBF, forward voltage drop VF and anode current simulated values of the device showed very good agreement with the experimental results. Electric field and impact generation rate across the switches are also simulated for different anode current conditions extending to second breakdown region of the device, showing a shifting of the phenomena caused by electric field and impact generation rate, from c-Si(p) region to a-SiC film as anode voltage values increase from VBF up to second breakdown region of the device. A both simulation and experimental based model describing the device behavior, is also presented here. Two critical facts leading to switching transition are proved to be at first a-SiC/c-Si(p) heterojunction breakdown dominated by impact generation rate and second subsequent trap filling in the amorphous film. Al/a-SiC/c-Si(p+)/c-Si(p)/c-Si(n+)/Al switches with reduced VBF and VF values, were also fabricated and successfully simulated here, enhancing the validity of our simulation procedure and making the switches candidates for ESD protection devices, also due to their advantages of high anode current value density of 5 A/mm2 before reaching second breakdown conditions in conjunction with cheap and easy fabrication procedure mainly due to r.f. sputtering technique used for a-SiC film fabrication.
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Keywords: Simulation, Amorphous SiC, Switches; ESD protection