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

We report the first co-integration of resonant tunneling and heterojun ction bipolar transistors. Both transistors are produced from a single epitaxial growth by metalorganic molecular beam epitaxy on InP substr ates. The fabrication process yields 9-mum m2 emitter resonant tunneli ng bipolar transistors (RTBT's) operating at room temperature with pea k-to-valley current ratios (PVR's) in the common-emitter transistor co nfiguration 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-inte grated 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 G Hz for the RTBT and 59 and 43 GHz for the HBT, respectively. Integrati on of these two transistors enables the demonstration of room-temperat ure resonant tunneling transistor logic integrated circuits.