Hot Electron Transport in Submicron Semiconductor Devices

Hot electron transport is studied in small semiconductor structures by solving the coupled Boltzmann and Poisson equations using a simple relaxation time model and the integral formulation of the transport equation. Especially ballistic transport is investigated by calculating the electron distribution function f(x, v) in a submicron n⁺−n⁻−n⁺ diode. In the n⁻‐region f(x, v) is non‐Maxwellian and the ballistic electrons cause a dominant peak in f(x, v). The validity of the relaxation time approximation (RTA) is studied in the case of a large homogeneous electric field by calculating f(x, v) both, in RTA and using the full scattering rates for polar optical phonon scattering.