Department of Mechanical Engineering
Kenneth E. Goodson
Pop, E., Dutton, R.W., and Goodson, K.E., 2005, "Monte Carlo simulation of Joule Heating in Bulk and Strained Silicon," Applied Physics Letters, Vol. 86, pp. 082101-082103.
This work examines the details of Joule heating in silicon with a Monte Carlo method including efficient, analytic models for the electron bands, acoustic and optical phonon dispersion. We find that a significant portion of the initially generated phonons have low group velocity, and therefore low contribution to heat transport, e.g., optical phonons or acoustic modes near the Brillouin zone edge. The generated phonon spectrum in strained silicon is different from bulk silicon at low electric fields due to band splitting and scattering selection rules which favor g-type and reduce f-type phonon emission. However, heat generation is essentially the same in strained and bulk silicon at high fields, when electrons have enough energy to emit across the entire phonon spectrum despite the strain-induced band splitting. The results of this study are important for electro-thermal analysis of future silicon nanoscale devices.