New calibration procedure for absolute temperature measurement on electronic devices, by means of thermoreflectance technique

Temperature monitoring of electronic devices is essential, both to check co mputing simulations and also to analyze the failure mechanisms. In this res pect thermoreflectance is a very useful tool. But to get an absolute measur ement, a calibration procedure is necessary. Due to the fact that the therm oreflectance temperature coefficient depends both on the probed material an d the experimental conditions, it should not been taken from the literature , but rather determined in situ, on the probed sample itself. We propose he re a new calibration procedure, based on the transient temperature response analysis for large values of time. This method has been applied successful ly on ridge high-power 980nm GaAs laser diodes. We could determine the temp erature distribution on the front facet, in the vicinity of the laser emiss ion spot, for an injected current lower and higher than the laser emission threshold current.