In-Situ Temperature Measurement and Scanning Thermal Imaging Based on Micro-Nano QDs Fluorescence Near-Field Fiber Optic Probe

The localized overheat is detrimental for the performance and lifetime of devices, especially in high-power, wide-bandgap semiconductor devices. But highly precise thermal characterization methods of the micro-nano regions within electronic devices remain challenging because of limitations in spatial resolution, electromagnetic interference and other factors. To address this challenge, we present a fluorescence thermometry utilizing a near-field fiber optic probe with quantum dots. Temperature-sensitive quantum dots modified on the probe tip as the nano-sensors provide excellent fluorescence stability and superior electromagnetic compatibility. The probe exchanges heat with the micro-nano scale hot spot on the sample surface and achieves thermal imaging based on the operating principle of scanning probe microscopy. The effective sensing area is minimized to nanoscale because of an aperture on the probe tip, achieving high detection spatial resolution. Using the probe with a sensitivity of 0.11 nm/°C, we investigated temperature difference of different-sized hot spots. The probe also effectively characterized the in-situ temperature distribution of an Au bonding wires with current flow inside, demonstrating its real-time monitoring capability for electronic devices. This innovative tool provides significant promise for performance assessment and failure analysis in electronic devices.