Submicrometer Resolution Hyperspectral Quantum Rod Thermal Imaging of Microelectronic Devices

The trend of electronic device miniaturization, from the microscale to the nanoscale, presents a temperature measurement challenge. The available techniques have limitations in terms of either resolution, calibration, acquisition time, or equipment cost. Here we demonstrate a thermography technique called hyperspectral quantum rod thermal imaging (HQTI), which exploits temperature-dependent photoluminescence (PL) emission of quantum rods to obtain the surface temperature map of a biased electronic device, with a straightforward calibration. This method uses relatively simple, low-cost equipment, while achieving submicrometer spatial resolution. This technique is demonstrated by measuring the thermal map of a direct current (dc) operated gallium nitride (GaN) high electron mobility transistor (HEMT), achieving a temperature precision of ∼4 °C and an ∼700–800 nm estimated lateral optical resolution. This is a versatile method for measurement both in submicrometer scale regions of interest and of larger areas in the hundreds of micrometers range.