SSTR can measure the thermal conductivity of thin films to isolate the conductivity effects of defect layers from high quality crystalline regimes.
The Challenge: Impact of Defects and Interfaces on Thin Film Thermal Conductivity
Thin film thermal conductivity is notoriously lower than that of bulk material due to interface and defect effects that impact phonon scattering. These defects can be spatially heterogeneous or deep under the surface. The presence of these defects leads to significant thermal boundary resistance and phonon scattering, which lower the thermal conductivity compared to ideal bulk materials.
As such, isolating the effects of these defects from high-quality regions in the film is crucial for precise thermal analysis and material testing.
The Solution: Isolating Defect Layers Using SSTR for Precise Thermal Measurements
SSTR offers a unique ability to control the depth to which thermal conductivity is measured, a capability we can leverage to measure the thermal conductivity of thin AlN films while specifically isolating the thermal conductivity in the high-quality region near the top of the film from that of the lower quality nucleation layer near the AlN/substrate interface.
In our study, we used SSTR to measure the thermal conductivity of AlN thin films and successfully distinguished the high-quality top portion of the film, which exhibits bulk-like thermal conductivity (both in-plane and cross-plane). As we shifted the measurement volume deeper into the film and sampled the defect nucleation region, the thermal conductivity significantly decreased due to the lower crystal quality in this area.
This ability to dynamically change the laser spot size and precisely control the measurement depth allows SSTR to isolate and quantify the impact of defects on thermal conductivity across different layers of the film, providing insights into the material’s heat transfer properties.
Key Insights: How SSTR Improves Thin Film Characterization and Thermal Modeling
By isolating the high-quality regions of a thin film, SSTR enables a more accurate understanding of thermal boundary resistance and conductive heat transfer within materials. This spatially resolved measurement capability is particularly useful in semiconductor testing and thermal modeling, where precise data on thermal conductivity is crucial for designing effective heat management systems.
Further Exploration: Thermal Conductivity Testing Instruments and Tools
Our thermal conductivity testing instruments powered by SSTR technology provide the accuracy and reliability needed to measure thermal conductivity across different materials. With our thermal testing services, we can support your research and development needs in fields ranging from semiconductors to academic and/or government labs.
If you’re interested in isolating thermal conductivity contributions from different layers in your thin film materials, contact us today to learn more about our thermal testing equipment and how we can help enhance your material performance.
