Ultrafast thermoreflectance microscopy

Abstract

As electronic and photonic devices shrink to the nanoscale, heat dissipation becomes the bottleneck for performance. As a result, understanding and controlling nanoscale thermal transport in thin films and across interfaces is a critical issue requiring new experimental tools. In this thesis, the development of an ultrafast thermoreflectance microscope for high resolution thermal property imaging is described. It can function as a time domain thermoreflectance (TDTR) or frequency domain thermoreflectance (FDTR) system. Design and implementation of the optical system will be introduced in detail. A thermal model derived from heat transfer theory is used to analyze the experimental data and obtain quantitative property maps for bulk and thin-film samples. The system is used to obtain temperature dependent thermal properties of single crystal diamond and thin film VO2, as well as thermal property maps of several thin film samples.