Atomic scale simulation of Si/SiO2 boundary conductance
Résumé
Poor heat dissipation in Si-based nanodevices is an issue for their development. Most of these nanodevices are fabricated using SOI to benefit from the electrical isolation between devices provided by the burried oxyde (BOX). The top silicon layer is also easily processed to form the nanostructure from SOI. Silicon dioxide is known to be a poor thermal conductor. But an open question is whether the Si/SiO2 interfaces contribute significantly or not to the total resistance of the heat path. This question depends on the atomic structure of the interface. In the present work, we build an atomic model of the Si/SiO2 interface by molecular dynamics simulations. We calculated the thermal response of the interface by monitoring its approach-to-equilibrium after initial out-of-equilibrium thermalisation [1]. The interface resistance is low but the method is sensitive enough to extract its value [2]. The interface resistance is equivalent to an additional oxide thickness of a few nanometers that could be significant for most advanced technologies using ultra-thin BOX. [1] E. Lampin, P. L. Palla, P.-A- Francioso and F. Cleri, J. Appl. Phys. 114, 033525 (2013) [2] E. Lampin et al, Appl. Phys. Lett. 100, 131906 (2012)