Microscopic fluorescent imaging of surface temperature profiles with 0.01 °C resolution

Abstract

We have exploited the temperature‐dependent fluorescence quantum efficiency in europium thenoyltrifluoroacetonate (EuTTA) to make high‐resolution, noncontact temperature measurements on the surface of an integrated circuit chip. The EuTTA is spun onto the chip in a polymer film. The chip is illuminated with long‐wave UV light, and the orange fluorescence is imaged onto a charge‐coupled‐device (CCD) camera. Digital image processing completely removes the optical features in the image, leaving a purely thermal map of the surface temperature profile with a measured temperature resolution of better than 0.01 °C and a spatial resolution of 15 μm. With a different camera and optics, 1‐μm resolution should be possible, allowing thermal imaging of the smallest high‐speed integrated circuits.