Transferred-Substrate InP/GaAsSb Heterojunction Bipolar Transistor Technology With ${f}_{\text{max}}$ ~ 0.53 THz

We report on the realization mymargin of transferred-substrate InP/GaAsSb double heterostructure bipolar transistors in a terahertz monolithic integrated circuit process. Transistors with 0.4- $\mu \text{m}$ -wide single emitters reached unilateral gain cutoff frequencies of around 530 GHz with simultaneous current gain cutoff frequencies above 350 GHz. Extrinsic collector capacitance is effectively reduced in the transfer-substrate process. In combination with the high collector breakdown voltage in the InP/GaAsSb heterobipolar transistor structure of 5 V, this process is amenable to analog power applications at millimeter (mm-wave) and sub-mm-wave frequencies. We demonstrate reliable extraction procedures for unilateral gain and current gain cutoff frequencies.