Silicon carbide-based DSRD device with P type variable doped base region, and preparation method thereof

Abstract

The invention discloses a silicon carbide-based DSRD device with a P type variable doped base region and a preparation method thereof. The device comprises a substrate, an N+ buffer region, a P- baseregion, a P+ buffer region, a P+ region, a SiO2 passivation layer, a cathode and an anode, wherein the substrate, the N+ buffer region, the P- base region, the P+ buffer region and the P+ region are sequentially arranged from bottom to top, the SiO2 passivation layer covers the peripheries of the P- base region, the P+ buffer region and the P+ region, the upper end of the SiO2 passivation layer covers a part of the upper surface of the P- base region, the lower end of the SiO2 passivation layer covers an area, which is not covered by the P- base region, of the upper surface of the N+ buffer region, the cathode is arranged on the lower surface of the substrate, and the anode is arranged in a region, which is not covered by the SiO2 passivation layer, of the upper surface of the P+ region, and is in contact with the SiO2 passivation layer. The device can shorten the pulse leading edge of the silicon carbide-based DSRD, reduce the power consumption of the device, reduce the process complexity and improve the reliability of the device.

Description

technical field [0001] The invention belongs to the technical field of DSRD devices, and in particular relates to a silicon carbide-based DSRD device with a P-type variable doping base region and a preparation method thereof. Background technique [0002] DSRD (Drift Step Recovery Diodes, Drift Step Fast Recovery Diodes) is a semiconductor circuit breaker diode, which has the characteristics of high efficiency, high reliability, long continuous working time and small size, and is usually used as a key device in UWB (Ultra Wide Band, ultra-wideband) pulse signal source. [0003] Due to the theoretical limit of silicon materials, silicon-based DSRDs have been unable to meet the requirements of most pulse systems of several kilovolts or even tens of kilovolts. Silicon carbide materials have higher bandgap width, saturation drift velocity, thermal conductivity, critical breakdown electric field and radiation resistance than silicon materials, making the performance of silicon c...

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Problems solved by technology

[0004] However, due to the low carrier lifetime and mobility of current SiC materials and the impact of incomplete ionization effects of impurities, conventional SiC-based DSRDs locally deviate from electrical neutrality during the reverse pumping phase of pulse discharge, affecting the charge efficiency. The carrier extraction speed leads to long front time of voltage pulse, low peak value of voltage pulse, and high power consumption of the device. It is difficult to give full play to the advantages of silicon carbide materials, which limits the performance of DSRD devices.

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