Previous study on the invasiveness of the CW 1340 nm laser source used in failure analysis, pinpointed silicide diffusions issue and experimentally defined a safe experimental area. In this paper the area of interaction between the laser and the device has been measured more finely by frequency mapping. Then a simulation is used to predict the threshold of degradation. To reinforce the correlation between the simulation and the experiments, we also make a comparison with the area defined in the previous study. Finally, we give the areas of interaction in function of the temperature and show how it can change in function of the device (geometry and metal layers).