0.5 THz Performance of a Type-II DHBT With a Doping-Graded and Constant-Composition GaAsSb Base

An InGaAs/InP DHBT With Simultaneous $\text{f}_{\boldsymbol \tau }/\text{f}_{\text {max}}~404/901$ GHz and 4.3 V Breakdown Voltage

“…Under different biasing conditions, f τ = 424 GHz and simultaneous f max = 831 GHz have been exhibited. Although the f max obtained here is ≈10 % below previous results [6] due to process variations (emitter end undercut, contact resistivity) and lower than [7], it exceeds that of other reported HBTs, including those of recent publications [8], [9]. The usable range of transistor operation [10] is extended by increasing the breakdown voltage BV CEO = 4.3 V by means of passivating the base/collector semiconductor with conformal PECVD SiN x prior to BCB planarization.…”

Composition- and Doping-Graded-Base InP/InGaAsSb Double Heterojunction Bipolar Transistors Exhibiting Simultaneous <inline-formula> <tex-math notation="TeX">\(f_{t}\) </tex-math></inline-formula> and <inline-formula> <tex-math notation="TeX">\(f_{\textrm {max}}\) </tex-math></inline-formula> of Over 500 GHz

“…The conduction band discontinuity at the emitter-base junction is estimated to be 4 meV, which is much smaller than that for GaAsSb-base DHBTs (150 meV) [1]. Thus, there is no need to insert a spacer, such as InGaP [4] or InAlP [5], between the InP emitter and InGaAsSb base. Fig.…”

InP DHBT test structure optimization towards 110 GHz characterization

“…To benefit from these performances, accurate characterization of these transistors is crucial in order to confirm the high cutoff frequency and to validate the associated compact model used for integrated circuit (IC) design. Transistor characterization below 110 GHz often involves off-wafer calibration and open-short de-embedding [1]- [3]. It has been shown that measurements beyond 110 GHz are particularly difficult [4].…”