We present a micro-electro-mechanical system-based experimental technique to measure thermal conductivity of freestanding ultra-thin films of amorphous silicon nitride (Si 3N 4) as a function of mechanical strain. Using a combination of infrared thermal micrography and multi-physics simulation, we measured thermal conductivity of 50 nm thick silicon nitride films to observe it decrease from 2.7 W (m K) 1at zero strain to 0.34 W (m K) 1at about 2.4% tensile strain. We propose that such strong strainthermal conductivity coupling is due to strain effects on fractionphonon interaction that decreases the dominant hopping mode conduction in the amorphous silicon nitride specimens.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Mechanics of Materials
- Mechanical Engineering
- Electrical and Electronic Engineering