Millimetre wave performance of carbon-doped-base AlGaAs/GaAs HBTs

AlGaAs/GaAs HBTs with f/sub T/ of 52 GHz and f/sub max/ of 85 GHz have been obtained using a heavily-carbon-doped base layer. The HBT epitaxial layers were prepared by low-pressure MOVPE using carbon tetrachloride as the carbon source. To the author's knowledge, this work reports the first carbon-doped AlGaAs/GaAs HBTs with f/sub T/ and f/sub max/ greater than 50 GHz. >