A high di/dt 4H-SiC thyristor with ‘-shaped’ n-base
A high di/dt 4H-SiC thyristor with '-shaped' n-base is proposed and investigated by simulation. Unlike the conventional SiC thyristors, the proposed SiC thyristor features a lightly-highly-lightly doped ('-shaped') n-base. By modulating the concentration difference of the top p+-n emitter junction its injection efficiency increases. An extra electric field is induced by the existence of an abrupt high-low junction in n-base to force the transit of holes and therefore reduce the recombination. As a result, the turn-on time and turn-on di/dt of the new SiC thyristor are 145 ns and 948 A/cm2/μs, respectively, which are reduced by approximately 72% and increased by approximately 400% compared to conventional SiC thyristors (turn-on time is 514 ns and di/dt is 188 A/cm2/μs).