Localisation of heat sources in electronic circuits by microthermal laser probing

In this work we present an original method for detection and localisation of heat sources at microscopic scale upon integrated circuits. The methodology is based upon thermoreflectance and interferometry, which allows us the measurement of surface temperature and dilatation with resolution better than micrometer. The heat sources are transistors electrically activated. The optical probes we have build act as a thermal antenna sensitive to the presence of thermal wave emitted by the heat source. By a set of three measurements of the phase of the thermal wave we are able to localise the heat source which generates the wave. This methodology is applied to microelectronics to detect and localise faults in CMOS integrated circuits