Growth Monitoring With Submonolayer Sensitivity Via Real-Time Thermal-Conductance Measurements

Growth monitoring during the early stages of vapor deposition is of prime importance to understand the growth process, the microstructure, and thus the overall layer properties. We demonstrate that phonons can be used as an extremely sensitive probe to monitor the real-time evolution of film microstructure during growth. For that purpose, a silicon nitride membrane-based sensor is fabricated to measure the in-plane thermal conductivity of thin film samples. Operating with the 3ω-Völklein method at low frequencies, the sensor shows an exceptional resolution down to Δ(κ⋅t)=0.065W/mKnm, enabling accurate measurements even in poor conductive samples.
Phys. Rev. Applied 12, 014007