High-frequency performance of lattice-strained heterojunction GaInAs/GaAs bipolar transistors

The performance of bipolar devices and circuits in the novel lattice-strained GaInAs/GaAs materials system show an improving trend with increased In composition in the base. An fT of 8 GHz has been measured using an 8 μm emitter stripe width and 8% In. A small-signal model is presented.