Carbon-Doped-Base AlGaAs/GaAs HBTs Grown by Gas-Source Molecular Beam Epitaxy Using Only Gaseous Sources

Abstract
We report the fabrication and electrical characteristics of carbon-doped-base AlGaAs/GaAs heterojunction bipolar transistors (HBTs) grown by gas-source molecular beam epitaxy (GSMBE) using only gaseous sources. The base of HBTs is compositionally uniform and doped with carbon to a carrier concentration of 4×1019 cm-3. A current gain of 45 was obtained at a collector current density of 4×104 A/cm2. These HBTs were electrically stable under current stress, as confirmed by current gain and Gummel plots.