1200 V 4H-SiC BJTs with a Common Emitter Current Gain of 60 and Low On-resistance

摘要

This paper reports a 4H-SiC bipolar junction transistor (BJT) with a breakdown voltage (BV_(CEO)) of 1200 V, a maximum current gain (β) of 60 and the low on-resistance (R_(sp_on))of 5.2 mΩcm~2. The high gain is attributed to an improved surface passivation SiO_2 layer which was grown in N_2O ambient in a diffusion furnace. The SiC BJTs with passivation oxide grown in N_2O ambient show less emitter size dependence than reference SiC BJTs, with conventional SiO_2 passivation, due to a reduced surface recombination current. SiC BJT devices with an active area of 1.8 mm × 1.8 mm showed a current gain of 53 in pulsed mode and a forward voltage drop of V_(CE)=2V at I_C=15 A (J_C=460 A/cm~2).