A method for heating a wafer that has at least one layer to be heated and a sub-layer. The method includes applying at least one light flux pulse to the wafer for heating the at least one layer in a manner such that the absorption coefficient of the flux by the layer is low as long as the temperature of the layer to be heated is in the low temperature range (PBT) but the absorption coefficient increases significantly when the temperature of the layer enters a high temperature range (PHT). Also, a sub-layer is selected such that the absorption coefficient of the applied light flux at the selected wavelength is high in the low temperature range (PBT) and the temperature enters the high temperature range (PHT) when the sub-layer is subjected to the light flux. The application of the light flux achieves improved heating of the wafer.