High-Speed InGaAs/InP Double Heterostructure Bipolar Transistor with High Breakdown Voltage

e design and fabricate an InGaAs/InP double heterostructure bipolar transistor (DHBT). The spike of the conduction band discontinuity between InGaAs base and InP collector is successfully eliminated by insertion of an InGaAs layer and two InGaAsP layers. The current gain cutoff frequency and maximum oscillation frequency are as high as 155 and 144GHz. The breakdown voltage in common-emitter configuration is more than 7V. The high cutoff frequency and high breakdown voltage make high-speed andhigh-power circuits possible