Extending the 3ω method: thermal conductivity characterization of thin films

Area of Science:

• Materials Science
• Physics
• Nanotechnology

Background:

• Accurate characterization of thermal properties in thin films is crucial for microelectronic and nanodevice performance.
• Traditional methods often face challenges with small sample sizes and complex geometries.

Purpose of the Study:

• To present a sensitive lock-in technique for measuring thermal conductivity and volumetric heat capacity of thin films.
• To adapt a heat diffusion model for bilayer systems with distinct thermal parameters.

Main Methods:

• Utilized the 3ω (three-omega) approach for generating and detecting oscillatory heat.
• Employed electrical measurements along a thin metal strip integrated with the thin film samples.
• Deposited thin films onto silicon nitride membranes, creating a bilayer structure.

Main Results:

• Successfully measured thermal conductivity and volumetric heat capacity of thin film bilayers.
• Demonstrated highest sensitivity for metallic thin films.
• Validated results through stepwise comparison with an adapted heat diffusion model.

Conclusions:

• The presented lock-in technique provides a reliable method for thin film thermal property characterization.
• The 3ω approach is effective for analyzing bilayer thermal parameters.
• The technique shows significant promise for the analysis of metallic thin films.