Using Mosaicity to Tune Thermal Transport in Polycrystalline Aluminum Nitride Thin Films

ACS Applied Materials & Interfaces
Shivkant SinghAnastassios Mavrokefalos

Abstract

The effect of controlling the c-axis alignment (mosaicity) to the cross-plane thermal transport in textured polycrystalline aluminum nitride (AlN) thin films is experimentally and theoretically investigated. We show that by controlling the sputtering conditions we are able to deposit AlN thin films with varying c-axis grain tilt (mosaicity) from 10° to 0°. Microstructural characterization shows that the films are nearly identical in thickness and grain size, and the difference in mosaicity alters the grain interface quality. This has a significant effect to thermal transport where a thermal conductivity of 4.22 vs 8.09 W/mK are measured for samples with tilt angles of 10° versus 0° respectively. The modified Callaway model was used to fit the theoretical curves to the experimental results using various phonon scattering mechanisms at the grain interface. It was found that using a non-gray model gives an overview of the phonon scattering at the grain boundaries, whereas treating the grain boundary as an array of dislocation lines with varying angle relative to the heat flow, best describes the mechanism of the thermal transport. Lastly, our results show that controlling the quality of the grain interface provides a tuning knob t...Continue Reading

References

Feb 1, 1990·Physical Review. B, Condensed Matter·D T MorelliH P Jenssen
Jan 1, 1991·Physical Review. B, Condensed Matter·M F Crommie, A Zettl
Apr 29, 2006·Angewandte Chemie·Pierre F P PoudeuMercouri G Kanatzidis
Jan 26, 2008·Nature Materials·G Jeffrey Snyder, Eric S Toberer
Mar 3, 2015·Physical Chemistry Chemical Physics : PCCP·J Jaramillo-FernandezS Volz
Oct 30, 2015·Nanoscale·Hatem BrahmiAnastassios Mavrokefalos
Feb 9, 2018·Nanoscale·Hatem BrahmiAnastassios Mavrokefalos

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