Measurement of In-Plane Thermal Conductivity of Ultrathin Films Using Micro-Raman Spectroscopy

Zhe Luo, Purdue University, Birck Nanotechnology Center
Han Liu, Purdue University, Birck Nanotechnology Center
Bryan T. Spann, Purdue University, Birck Nanotechnology Center
Yanhui Feng, University of Science and Technology Beijing
Peide D. Ye, Purdue University, Birck Nanotechnology Center
Yong P. Chen, Purdue University, Birck Nanotechnology Center
Xianfan Xu, Purdue University, Birck Nanotechnology Center

Date of this Version

4-3-2014

Citation

10.1080/15567265.2014.892553

Abstract

We report a micro-Raman-based optical method to measure in-plane thermal conductivity of ultrathin films. With the use of 20-nm-thick SiO2 substrates that assure in-plane heat transfer, sub-100-nm Bi films and Al2O3 films as thin as 5 nm were successfully measured. The results of Bi films reveal that phonon boundary scattering, both at the surface/interface and at the grain boundaries, reduces in-plane lattice thermal conductivity. The measurements of amorphous Al2O3 films were accomplished using thin Bi film as a Raman temperature sensor, and the results agree with the minimum thermal conductivity models for dielectrics. Our work demonstrates that the micro-Raman method is promising for characterization of in-plane thermal conductivity and phonon behaviors of thin-film structures if the Raman temperature sensor material and substrate material are carefully selected.

Discipline(s)

Nanoscience and Nanotechnology

 

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