Thermal imaging characterization for high frequency and high power devices

We present the thermoreflectance thermal imaging method and the equipment for transient thermal characterization with a time resolution of 100 ns and a sub-micron spatial resolution for high speed RF and communication devices. Thermoreflectance is a non-invasive and non-contact imaging method. Our unique approach interlocks the timing of image acquisition and the device biasing such that a high speed thermal response is captured both in a temperature profile and a 2D image. Following the description of the thermoreflectance technology, some examples are shown from recent transient thermal characterizations of RF devices including: gallium nitride (GaN) or gallium Arsenide (GaAs) multi finger high electron mobility transistors (HEMT), GaN heterojunction bipolar transistors (HBT) and transistor arrays on a chip. Features of these devices are in the sub-micron range.