An Instrumentation Guide to Measuring Thermal Conductivity Using Frequency Domain Thermoreflectance (FDTR)

Published

October 14, 2024

Author(s)

Dylan Kirsch, Joshua B. Martin, Ronald Warzoha, Mark McLean, Donald Windover, Ichrio Takeuchi

Abstract

Frequency Domain Thermoreflectance (FDTR) is a versatile and rapidly developing technique used to measure the thermal properties of thin films, multilayer stacks, and interfaces that govern the performance and thermal management in semiconductor microelectronics. Reliable thermal property measurements at these length scales, where the physics of thermal transport and phonon scattering at interfaces both grow in complexity, are increasingly relevant as electronic components continue to shrink. While FDTR is a promising measurement technique, FDTR instruments are generally home built; they can be difficult to construct, align, and maintain, especially for the novice. We provide a detailed account of unpublished insights and institutional knowledge that are critical for obtaining accurate and repeatable measurements of thermal properties using FDTR. We discuss component selection and placement, alignment procedures, data collection parameters, common challenges, and our efforts to increase measurement automation. In FDTR, the unknown thermal properties of interest are fit by minimizing the error between the phase lag at each frequency and the solution to a multilayer diffusive thermal model. For data fitting and uncertainty analysis, we compare common numerical integration methods, and we compare multiple approaches for fitting and uncertainty analysis, including Monte Carlo simulation, to demonstrate their reliability and relative speed. Since the transducer thermal properties and thickness are input parameters in the thermal model, we also discuss the deposition and characterization of high-quality transducer films. The instrument is validated with substrates of known thermal properties over a wide range of isotropic thermal conductivities, including Borofloat silica, quartz, sapphire, and silicon.

Citation

Review of Scientific Instruments

Volume

95

Pub Type

Journals

Download Paper

https://doi.org/10.1063/5.0213738

Local Download

Keywords

frequency domain thermoreflectance (FDTR), thermal conductivity, thermal transport properties, films, numerical integration, Monte Carlo simulation

Citation

Kirsch, D. , Martin, J. , Warzoha, R. , McLean, M. , Windover, D. and Takeuchi, I. (2024), An Instrumentation Guide to Measuring Thermal Conductivity Using Frequency Domain Thermoreflectance (FDTR), Review of Scientific Instruments, [online], https://doi.org/10.1063/5.0213738, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=957632 (Accessed December 3, 2024)