Comprehensive thermal property measurement of semiconductor heterostructures using the square-pulsed source (SPS) method

Accurate thermal property measurements of multilayer heterostructures, especially in wide-bandgap semiconductor devices, are essential for optimizing device performance. While traditional methods, such as Time-Domain Thermoreflectance (TDTR) and Frequency-Domain Thermoreflectance (FDTR), are effective for thin films and interfaces, they encounter challenges with complex multilayer heterostructures. This paper presents an optical Square-Pulsed Source (SPS) method for comprehensive thermal property measurements of heterostructures. By combining the advantages of TDTR and FDTR, the SPS technique enables time-resolved signal observation and offers an adjustable heating frequency range from 1 Hz to 10 MHz. This allows for the simultaneous determination of multiple parameters, including the thermal conductivity and the heat capacity of each layer and the substrate, and interfacial thermal conductance between layers. Applied to epitaxially grown GaN/Si and ɛ-Ga2O3/SiC heterostructures, the SPS method demonstrates its simplicity, robustness, and precision for comprehensive thermal property analysis, essential for effective thermal management in advanced electronic devices.