The hot-electron problem in small semiconductor devices

Abstract

Decreasing device dimensions will cause an increasing internal field strength in a semiconductor device. The average carrier energy is different from the thermal equilibrium value 3/2 kT. Modification of current transport is considered on different levels of approximation. In a local approximation we derive a field-dependent carrier mobility and temperature from a more general self-consistent formulation. Numerical estimation of hot-electron effects are given for a realistic n-channel metal-oxide-semiconductor field-effect transistor of various channel lengths. It is shown that both high-field and field-gradient effects will contribute.