4H-SiC power bipolar transistors with common emitter current gain >50

Silicon carbide (SiC) is an attractive material for semiconductor power devices because of its superior physical and electrical properties. Prototype devices built on SiC have demonstrated performance well in excess of the best silicon devices. Among SiC power switching devices, bipolar transistors (BJTs) show excellent on-state characteristics at both room temperature and elevated temperatures (S.-H. Ryu et al., IEEE Electron Device Lett., vol. 22, pp. 124-126, 2001; Y. Tang et al, ibid., vol. 22, pp. 119-120, 2001). However, power BJTs require substantial base drive current given by J/sub ON///spl beta/. This base current can be minimized by developing high-voltage BJTs with higher /spl beta/. In this paper we report high-voltage 4H-SiC BJTs with /spl beta/ greater than 50 (the highest values reported to date for a SiC BJT).