新型阶梯变掺杂SiC漂移阶跃恢复二极管

漂移阶跃恢复二极管(DSRD)一般应用于超宽带脉冲信号源,可以将纳秒级高压脉冲换向负载,这对于输出脉冲的上升前沿有很高的要求.文章提出了一种具有基区变掺杂的新型宽禁带材料漂移阶跃恢复二极管,将传统的基区掺杂变为阶梯式的浓度分布,基区内形成由浓度差导致的内建电场,该内建电场在DSRD放电回路反向泵浦阶段调节载流子分布,并...

A Novel Silicon Carbide DSRD with Variable Doping in Base Region

Drift step recovery diodes (DSRD) are generally used in ultra-wideband pulse signal sources, which can reverse nanosecond-level high-voltage pulse to the load. However, DSRD have high requirements for the rising front edge of the output pulse. A novel wide band gap material step recovery diode with variable doping in the base region was proposed in this paper, in which the doping of the traditional base region would be changed into a stepwise concentration distribution. Built-in electric field was formed by concentration gradient in base region, which would adjust the carrier distribution during the reverse pumping phase of the DSRD discharge circuit and accelerate the carrier extraction. The joint simulation of the device-circuit was performed by Sentaurus TCAD. The results showed that the maximum structure hole velocity at the end of forward injection was increased by 29% compared with the traditional structure, and the voltage rise rate was 19.7 kV/ns, which was 25% higher than the traditional structure (15.8 kV/ns). The proposed structure reduced the time of the reverse pumping stage, and the voltage rise rate of the rising front edge of the output voltage pulse was larger, while the time was shorter. As for the process, only the gas dose of the epitaxial process needed to be changed, which could be realized.