Electronics Letters · 1992 · 18 citations · 0 references
EngineeringElectrical EngineeringMaterials ScienceMicroelectronicsSemiconductor DevicesSemiconductor MaterialsHigh-frequency Semiconductor DevicesMicrowave OscillatorsMicrowave Semiconductor DevicesSemiconductor Device MaterialsSemiconductor HeterostructuresSemiconductor PhysicsCurrent GainCutoff FrequencyGaas OscillatorsHigh-frequency ElectronicsMicrowave DevicesRadio-frequency DevicesSheet ResistanceTerahertz Semiconductor Devices
High performance selfaligned InGaP/GaAs HBTs are reported. SIMS and TEM analysis indicate the presence of clean and abrupt InGaP/GaAs interfaces which are reflected in excellent DC performance. Using a base layer with a sheet resistance of 135 Ω/□, a DC current gain of 25 was obtained for 2×5 μm2 devices. Both cutoff frequency ft and maximum frequency of oscillation fmax are measured above 70 GHz. These are the highest values yet reported for HBTs containing InGaP.