Thermal conduction in ultrathin pure and doped single-crystal silicon layers at high temperatures

Abstract

This work presents the in-plane thermal-conductivity data for pure as well as boron-doped (1.6×1021∕cm3), arsenic-doped (2.3×1020∕cm3), and phosphorus-doped (2.3×1020∕cm3) silicon layers of thickness 30nm in the temperature range of 300–450K. The steady-state Joule heating and electrical resistance thermometry are used to measure the lateral thermal conductivity of suspended silicon layers. Thermal-conductivity data for pure and doped single-crystalline thin silicon layers can be interpreted using thermal-conductivity integral in relaxation-time approximation that accounts for phonon-boundary and phonon-impurity scatterings. No additional fitting parameters are used in this work in contrast with previous studies that required an unusually large phonon-impurity scattering coefficient to fit the thermal-conductivity data for bulk doped silicon to the predictions of the thermal-conductivity integral in relaxation-time approximation.