CASE Quantitative Thermal Conduction Measurement and Imaging at 200nm scale

The performance of modern electronic and optical components is dominated by thermal effects. Modern devices make extensive use of nanostructuring to obtain greatly enhanced optical and electronic properties, but this structuring comes at a significant cost since it reduces the ability of the materials used to conduct away heat. Thermal conduction at the nanoscale is significantly different to that observed at macroscopic distances, being subject to acoustic boundary reflection effects, ballistic conduction, phonon-wavelength dependent scattering and quantized thermal conduction. Since the physics of nanoscale thermal transport is so profoundly different it is necessary to develop new techniques for its measurement.
Nanoscale thermal measurements are often made using "Scanning Thermal Microscopy", a technique related to Atomic Force Microscopy (AFM) in which a thermal sensor is combined with a MEMS AFM sensor to give high resolution measurements of topography and temperature at the same time. This project is concerned with the development and validation of techniques to quantify thermal conduction at the nanoscale using custom AFM probes which have two tips, separated by a few hundred nanometres. The two tips will act as heaters and thermometers, allowing a measurement of the temperature rise from the flow of a known thermal power: Classically this would constitute a measurement of thermal conductivity. Technical objectives are the development of a measurement methodology, determination of the range of validity of the measurement and quantification of errors in measurement with reference to the characteristics of known bulk materials. The project will involve nanofabrication of the advanced sensors in the James Watt Nanofabrication Centre combined with the development of the associated instrumentation and measurement techniques.