Ultrahigh Be doping of Ga0.47In0.53As by low-temperature molecular beam epitaxy

Abstract
Layers of Ga0.47In0.53As grown on InP by a beam epitaxy method have been doped with Be to p=5×1020 cm3 by growth at substrate temperatures as low as 365 °C. The maximum doping level is strongly growth temperature dependent. Heterostructure bipolar transistors with base doping p=1×1020 cm3, current gain β=54, and unity current gain cutoff frequency fT=140 GHz are illustrated.