In0.53Ga0.47As/InP Type-I DHBTs w/ 100 nm collector and 491 GHz f,415 GHz fmax

In_0.53Ga_0.47As/InP double heterojunction bipolar transistors (Type-I DHBT) have been designed and fabricated having 100 nm drift collector and 30 nm highly doped base. The DHBTs have been scaled vertically for reduced electron transit time and aggressively scaled laterally to minimize the base-collector capacitance C_cb associated with thinner collectors. Devices employing a proven effective InGaAs/InAlAs superlattice base-collector grade (42 nm transition) exhibit a 491 GHz f and 415 GHz f_max and show no signs of current blocking until P>20 mW/μm² due to device self-heating. We also report devices of the same layer structure where the base-collector transition has been thinned to 25 nm exhibiting a 465 GHz f and 416 GHz f_max and show no signs of current blocking until J_e>9 mA/μm² at 2.0 V_ce associated with the base-collector grade. For both, the DC current gain >40, V_BR,CEO=3.1 V, and similar ideality factors n_c, n_b.