COINTEGRATION OF RESONANT-TUNNELING AND DOUBLE-HETEROJUNCTION BIPOLAR-TRANSISTORS ON INP

We report the first co-integration of resonant tunneling and heterojunction bipolar transistors. Both transistors are produced from a single epitaxial growth by metalorganic molecular beam epitaxy on InP substrates. The fabrication process yields 9-mum m2 emitter resonant tunneling bipolar transistors (RTBT's) operating at room temperature with peak-to-valley current ratios (PVR's) in the common-emitter transistor configuration exceeding 70, at a resonant peak current density of 10 kA/cm2, and a differential current gain at resonance of 19. The breakdown voltage of the In0.53Ga0.47As/InP base/collector junction, V(CBO), is 4.2 V, which is sufficient for logic function demonstrations. Co-integrated 9-mum2 emitter double heterojunction bipolar transistors (DHBT's) are also obtained with low collector/emitter offset voltage, 200 mV, and dc current gain as high as 32. On-wafer S-parameter measurements of the current gain cutoff frequency (f(T)) and the maximum frequency of oscillation (f(max)) yielded f(T) and f(max) values of 11 and 21 GHz for the RTBT and 59 and 43 GHz for the HBT, respectively. Integration of these two transistors enables the demonstration of room-temperature resonant tunneling transistor logic integrated circuits.