THE FABRICATION AND STUDY OF INGAASP/INP DOUBLE-COLLECTOR HETEROJUNCTION BIPOLAR-TRANSISTORS

This paper deals with a theoretical and experimental study of InGaAsP/InP double-collector heterojunction bipolar transistors (HBTs) fabricated by liquid phase epitaxy. A thin undoped n--InGaAsP layer was used as sub-collector. Good performance was achieved, e.g. high current gain (= 140 for a.c. and 120 for d.c.), low offset voltage (< 100 mV), and small emitter-size effect. Theoretically, the thermionic field-diffusion model was used to calculate the current transport of the InGaAsP/InP HBTs. A detailed analytical simulation of the characteristics of offset voltage and Gummel plot of the InGaAsP/InP HBT is presented.