6H-SiC基MPS二极管正向双势垒特性研究

Investigation of forward double barrier characteristics of 6H-SiC based MPS diodes

势垒高度Φ和理想因子n是混合肖特基/PIN(MPS)二极管正向输运下的重要参数,而软度因子是MPS反向恢复能力的衡量指标之一。对6H-SiC基MPS二极管进行结构模拟仿真,验证了双势垒的存在,并研究了温度对正反向特性的影响。结果表明:正向偏压下,温度升高,势垒高度1下降,势垒高度2增大,n1和n2均随温度升高而下降。势垒1区域存在多重复合输运机制,势垒2区域主要以热电子发射输运为主。反向偏压下,反向恢复峰值电压、峰值电流均随温度的升高而增大,但软度因子逐渐趋近于1。

Barrier heightΦand ideal factor n are important parameters for forward transport of merged PIN/Schottky(MPS)diodes,and softness factor is one of the indication of MPS reverse recovery.The structure simulation of 6 H-Si C based MPS diode is carried out to verify the existence of double barrier and study the effect of temperature on the forward and reverse characteristics.Results show that in forward bias voltage,the barrier height 1 decreases and the barrier height 2 increases with increasing temperature,while both n1 and n2 decrease with increasing temperature.Because there are multiple composite transport mechanisms in the barrier region 1,and thermionic emission transport is the main transport mechanism in the barrier region 2.Under reverse bias voltage,the reverse recovery peak voltage and peak current increase with increasing temperature,but the softness factor gradually approaches 1.