Modeling and Data for Thermal Conductivity of Ultrathin Single-Crystal SOI Layers at High Temperature

Abstract

Simulations of the temperature field in silicon-on-insulator (SOI) and strained-Si transistors can benefit from experimental data and modeling of the thin silicon layer thermal conductivity at high temperatures. This paper develops algebraic expressions to account for the reduction in thermal conductivity due to the phonon-boundary scattering for pure and doped silicon layers and presents the experimental data for 50-nm-thick single-crystal silicon layers at high temperatures. The model applies to the temperature range of 300-1000 K for silicon layer thicknesses from 10 nm to 1 mum (and even bulk), which agrees well with the experimental data. In addition, the algebraic model has an excellent agreement with both the experimental data and predictions of thin-film thermal conductivity based on thermal conductivity integral and Boltzmann transport equation. The analytical thermal modeling and ISE-TCAD electrothermal simulations confirm that both the electrical and thermal performances of SOI transistor can be largely affected if the reduced thermal conductivity of the silicon due to phonon boundary scattering is not properly taken into consideration