4H-SiC BJTs With Record Current Gains of 257 on (0001) and 335 on ( $\hbox {000}\bar{\hbox {1}}$ )

We demonstrate 4H-SiC bipolar junction transistors (BJTs) with record current gains. An improved current gain was achieved by utilizing optimized device geometry and continuous epitaxial growth of the emitter-base junction, combined with an intentional deep-level-reduction process based on thermal oxidation to improve the lifetime in p-SiC base. A current gain (β) of 257 was achieved for 4H-SiC BJTs fabricated on the (0001) Si face. A gain of 257 is twice as large as the previous record gain. We also demonstrate BJTs on the (0001̅] ) C face that showed the highest β of 335 among the SiC BJTs ever reported.