Hot spot detection in integrated circuits working at up to 1 GHz

Constraints on integration densities and on operating frequencies of integrated circuits have become so important that thermal phenomena can not be neglected any longer. A high resolution thermal mapping of such circuits under operation is then needed. As we show in this paper, the thermoreflectance technique, based on the reflection coefficient variation with temperature give access to the elevation of temperature produced by the circuit after the execution of benchmarks. In this paper, the frequency of the benchmark can be as high as 1 GHz and we show that using a low repetition rate of these benchmarks makes it possible to retrieve the thermal response of the circuit working at high frequency. These measurements can be very useful to adjust thermal dissipation models and to analyse failures.