High-injection barrier effects in SiGe HBTs operating at cryogenic temperatures J.D. Cressler, D.M. Richey, R.C. Jaeger, E.F. Crabbé, J.H. Comfort et J.M.C. Stork J. Phys. IV France, 04 C6 (1994) C6-117-C6-122 DOI: 10.1051/jp4:1994618