Thin-Film Thermocouple Array for Time-Resolved Local Temperature Mapping

This letter reports on a technique to obtain time-resolved 2-D mapping of local temperatures on a solid substrate by employing an array of Cr-Ni thin-film thermocouples (TFTCs). Using 100-nm-thick Cr-Ni TFTCs, a stable and reproducible thermopower of 26.2 ± 1.5 μV/K with temperature resolutions better than 0.1 K was obtained. Investigation showed that the thermopower of these thermocouples had no obvious dependence on their junction area down to 3 × 3 μm2. In an array of 18 individual thermocouples, a relative standard deviation of 0.31% was measured for the thermopower. This technique may have applications in, e.g., thermal failure analysis, real-time and on-site thermal sensing for integrated circuits, and other modern electronic, optical, and thermal devices.