SiC Heterojunction Bipolar Transistors with AlN/GaN Short-Period Superlattice Widegap Emitter
In this study, new SiC-based heterojunction bipolar transistors (HBT) are proposed. An n-type AlN/GaN short-period superlattice (quasi-AlGaN) layer is grown on a SiC pn junction as a widegap emitter. By using quasi-AlGaN emitter, we have demonstrated successful control of band offset of AlGaN/SiC. Quasi-AlGaN/SiC HBT with an Al content over 0.5, which has no potential barrier to electron injection from an n-AlGaN emitter to a p-SiC base, exhibited a common-emitter current gain of β ~ 2.7, whereas the HBT with an Al content below 0.5 showed β ~ 0.1.
Anton J. Bauer, Peter Friedrichs, Michael Krieger, Gerhard Pensl, Roland Rupp and Thomas Seyller
H. Miyake et al., "SiC Heterojunction Bipolar Transistors with AlN/GaN Short-Period Superlattice Widegap Emitter ", Materials Science Forum, Vols. 645-648, pp. 1029-1032, 2010