Novel Ultrafast Transient Hot-Bridge Technique for Thermal Properties Measurement of Dielectric Thin Films

This article introduces an ultrafast transient hot-bridge (THB) technique for the microscale measurement of thermal properties. The system comprises microfabricated heaters and resistance thermometers, arranged in a Wheatstone bridge configuration, deposited on sample surface. These components are used in order to generate and detect electrical pulses, leading to temperature increases on micro- and nanosecond scales. The design and performance of various probes are discussed, with an evaluation of their capabilities in terms of time response, precision, and resolution. Electrical pulses are applied via metalized probes, and the resultant temperature increases are analyzed within selected time periods ranging from 10 ns to 100 mu s. By ensuring a self-balanced condition for all Wheatstone bridges, the technique facilitates the detection of rapid, time-dependent changes in thermal properties due to temperature evolution or structural transformations. This innovative method enables the measurement of thermal conductivity in very thin films and demonstrates the potential for measuring thermal properties at micrometric or even nanometric scales.