Modified Valence Force Field Approach for Phonon Dispersion: from Zinc-Blende Bulk to Nanowires

Abhijeet Paul, Purdue University
Mathieu Luisier, Purdue University
Gerhard Klimeck, Purdue University

Abstract

The correct estimation of the thermal properties of ultra-scaled CMOS and thermoelectric semiconductor devices demands for accurate phonon modeling in such structures. This work provides a detailed description of the modified valence force field (MVFF) method to obtain the phonon dispersion in zinc-blende semiconductors. The model is extended from bulk to nanowires after incorpo- rating proper boundary conditions. The computational de- mands by the phonon calculation increase rapidly as the wire cross-section size increases. It is shown that nanowire phonon spectra differ considerably from the bulk disper- sions. This manifests itself in the form of different physi- cal and thermal properties in these wires. We believe that this model and approach will prove beneficial in the under- standing of the lattice dynamics in the next generation ultra- scaled semiconductor devices.

Discipline(s)

Electronic Devices and Semiconductor Manufacturing