InP/GaAsSb Double Heterojunction Bipolar Transistor Emitter-Fin Technology With <i>f</i> _MAX = 1.2 THz

We report a new InP/GaAsSb double heterojunction bipolar transistor (DHBT) emitter fin architecture with record ${f}_{\mathrm {MAX}} =1.2$ THz, simultaneous {T}} =475$ GHz, and notation="LaTeX">$BV_{\mathrm {CEO}} =5.4$ V. The resulting {CEO}}\,\times \,{f}_{\mathrm =6.48$ THz-V is unparalleled in semiconductor technology. Devices were realized 20-nm-thick compositionally impurity graded GaAsSb-base 125-nm InP collector. performance arises because the process allows: 1) tunable base–emitter access distance down to 10 nm; 2) use of thicker base contact metals; 3) minimization parasitic capacitances resistances via precise lateral wet etching base–collector (B/C) mesa. Perhaps more significantly, DHBTs \ge1$ THz are demonstrated lengths as long 9.4 notation="LaTeX">$\mu \text{m}$ areas high 1.645 2 . Such an area > notation="LaTeX">$6\times $ larger than previously reported terahertz (THz) DHBTs, representing breakthrough scalability. This attractive level achieved very low dissipated power density which makes well-suited for high-efficiency millimeter- submillimeter-wave applications. Furthermore, we provide first large-signal characterization 94 GHz load-pull measurements showing peak power-added-efficiency (PAE) 32.5% (40% collector efficiency) maximum saturated 6.67 mW/ or 1.17 length common-emitter configuration. operate stably under conditions, voltages nearly twice higher those small-signal performance.