Heat transport across metal–semiconductor (dielectric) structure under steady state conditions

Abstract

With continued size reduction in microelectronic devices, the thermal boundary conductance between two materials becomes the main channel on thermal dissipation. In this work, we present a theoretical work on heat transport in two-layered systems consisting in metal and a semiconductor (dielectric) and considering the role of the interface thermal conductivity between them.In a metal because the electrons are preferentially scattered by phonons with phonon momentum smaller than the average electron momentum (electron Fermi momentum), the electron–phonon collisions are more efficient in terms of energy relaxation than the phonon–phonon relaxation frequency and, in this case the phonon system can be described by the same temperature as the electron gas. Therefore the heat diffusion equation in a metal is solved in one temperature approximation with appropriate boundary conditions at the surface and at the interface. On the other hand, in the semiconductor the heat diffusion transport is described by the two-temperature approximation model.