Carrier Thermal Conductivity: Analysis and Application to Submicron-Device Simulation

A Greiner,M C Vecchi,T Kuhn,L Varani,L Reggiani,P Golinelli

doi:10.1155/1998/27140

Abstract

Within a correlation-function (CF) formalism, the kinetic coefficientsof charge carriers in semiconductors are studied under different conditions. For the case of linear response in equilibrium, thetransitions from the non-degenerate to the degenerate regimes as wellas from ballistic to diffusive conditions are discussed within ananalytical model. Generalizing the method to high-field transport innondegenerate semiconductors, the CFs are determined by Monte Carlo (MC) calculations for bulk silicon from which the appropriate thermalconductivity has been obtained and included into the hydrodynamic code HEIELDS. For an n+nn+ submicron structure the temperatureand velocity profiles of the carriers have been calculated with HFIELDS.

Highlights

Thermal conductivity of charge carriers is of fundamental interest in describing transport phenomena in bulk materials as well as electronic devices
Within a correlation-function (CF) formalism, the kinetic coefficientsof charge carriers in semiconductors are studied under different conditions
Generalizing the method to high-field transport innondegenerate semiconductors, the CFs are determined by Monte Carlo n+nn (MC) calculations for bulk silicon from which the appropriate thermalconductivity has been obtained and included into the hydrodynamic code HEIELDS

Summary

INTRODUCTION

Thermal conductivity of charge carriers is of fundamental interest in describing transport phenomena in bulk materials as well as electronic devices. As a consequence of the fluctuation-dissipation theorem, the carrier transport coefficients may be determined by the spectrum of the fluctuations in the system. A weighting ofthe single relaxation time with a power of the energy yields a generalization ofthe Wiedemann-Franz law (WFL) given by. Q where c is the so called power law exponent, # is the mobility and T the electron temperature. This WFL together with the energy relaxation time is usually introduced within hydrodynamic approaches [4,5,6,7,8]. Diffusive regime under different degeneracy conditions [9], as well as the hot-carrier regime in the classical-diffusive condition [10, 11] with its applications to the simulation of an n+nn+-structure

LINEAR RESPONSE REGIME

DEVICE SIMULATIONS

CONCLUSION