Nonequilibrium Electron Dynamics in Bipolar Transistors.

Experiments and calculations are used to illustrate the role of nonequilibrium electron transport in determining the performance of InP/In sub (0.53) Ga sub (0.47) As heterostructure bipolar transistors. The intrinsic small signal response of devices operated under low voltage bias conductions is subpicosecond. However, with increasing bias the intrinsic speed of devices decreases because of scattering into low velocity subsidiary X- and L-valleys.