Submicron scaling in indium phosphide/indium gallium arsenide single heterojunction bipolar transistors

Heterojunction bipolar transistors (HBTs) with InGaAs collectors are being developed for a number of high-speed applications. By scaling HBT lateral dimensions into the submicron regime, important improvements in HBT high-speed, low-power performance can be realized.; A unique, highly scalable submicron mesa HBT process flow has been developed. The process has been exercised on InP/InGaAs SHBTs grown by MOCVD using carbon as the p-type dopant. Devices with 0.35 μm emitter width demonstrated f_T of 180 GHz and f_MAX of 340 GHz. This is the fastest SHBT reported to date, and the state of the art performance was achieved at the modest base doping level of 2.3 × 10 19 cm−3. An essentially ideal dependence of f_MAX on the inverse square root of emitter width was shown.; Measurement-based characterization of SHBTs scaled down to 0.35 μm was performed, and detailed understanding of do and RF scaling properties was developed. Important scaling phenomena that emerge as the emitter width is scaled to the deep submicron regime were identified and analyzed. A unique small-signal model extraction procedure was developed and used to study base resistance scaling in submicron HBTs. A measurement-based analysis technique was developed to quantitatively describe the current spreading phenomenon in submicron InP HBTs for the first time. These results suggest that additional device scaling along with improvements in epitaxial materials should lead to further progress in the development of high-speed, low power electronics using InP-based HBTs.