Analysis of the Effect of Temperature on Base Current Gain in Power 4H-SiC BJTs
For 1-kV, 30-A 4H-SiC epitaxial emitter npn bipolar junction transistors, the dependence of the common-emitter current gain β on the collector current IC were measured at elevated temperatures. The collector-emitter voltage was fixed (at 100 V voltage) to provide an active operation mode at all collector currents varying in a wide range from 150 mA to 40 A (current densities 24 - 6350 A/cm2). The maximum room temperature current gain was measured to be βmax = 40 (IC = 7 A) while βmax = 32 (IC = 10 A) at 250oC. The β-IC dependences were simulated using a model which takes into account the main processes affecting the current gain. Minority carrier lifetimes and surface recombination velocity were obtained by means of those considerations.
Robert P. Devaty, David J. Larkin and Stephen E. Saddow
P. A. Ivanov et al., "Analysis of the Effect of Temperature on Base Current Gain in Power 4H-SiC BJTs", Materials Science Forum, Vols. 527-529, pp. 1441-1444, 2006