NpN InGaAsN-based heterojunction bipolar transistors with f/sub max/ = 60 GHz

Microwave measurements from 3x5 /spl mu/m/sup 2/ self-aligned NpN InGaAsN DHBT devices indicate that this low band gap material system can be successfully implemented in a GaAs-based HBT structure for lowering the turn-on voltage while attaining high-speed performance.