Pseudomorphic InGaAs base ballistic hot-electron device

We report the first successful incorporation of a pseudomorphic InGaAs base in a ballistic hot-electron device. The device, with a 28-nm-thick In0.15Ga0.85As base, had a collector-base breakdown voltage of 0.55 V and a maximum current transfer ratio of 0.89 at 4.2 K, considerably higher than the 0.75 in a comparable GaAs-base device. Electron energy spectroscopy measurements revealed that at least 30% of the injected electrons traversed the InGaAs base ballistically, causing a strong modulation in the injected currents into the quantized base. The Γ-L valley separation in the strained In0.15Ga0.85As was estimated to be about 410 meV.