Thermal resistance of planar semiconductor structures

The heat flow across a substrate with a temperature-dependent thermal conductivity, such as is commonly encountered with planar semiconductor structures, is discussed. Analytic solutions are derived for an isothermal active-layer approximation, and numerical results are presented for a constant heat flux at the active-layer boundary. Important features of the flow of heat in the structures, such as thermal-flow spreading, temperature increases for elevated operating temperatures and other aspects, are treated.