Defects in the emitter region of Ga0.51In0.49P/GaAs heterojunction bipolar transistors were investigated by means of deep-level transient spectroscopy. Both annealed (635C, 300s) and as grown metal-organic chemical vapor deposition epitaxial wafers were investigated in this study, with an electron trap observed in the heterojunction bipolar transistor emitter space-charge region from both wafers. The deep-level activation energy was determined to be 0.87eV below the conduction band, the capture cross-section was 3 x 10–14cm2 and the defect density was of the order of 1014/cm3. This defect was also found to be localized at the emitter/base interface.

Defect Study of GaInP/GaAs Based Heterojunction Bipolar Transistor Emitter Layer. K.Cherkaoui, M.E.Murtagh, P.V.Kelly, G.M.Crean, S.Cassette, S.L.Delage, S.W.Bland: Journal of Applied Physics, 2002, 92[5], 2803-6