Method for heating, at least local, a wafer comprising at least one layer to be heated and a sub-layer, at least local, adjacent to said layer to be heated, under the effect of at least one light flux pulse, comprising the following steps: Selecting a light flux - wherein the wavelength is such that the absorption coefficient of said flux by the layer to be heated is low in relation to the absorption coefficient of said flux by the sub-layer as long as the temperature of said layer to be heated is in a low temperature range and said absorption coefficient increases significantly when the temperature of the layer to be heated enters a high temperature range situated above said low temperature range, - and wherein the pulse intensity and duration are such that, in the absence of said sub-layer, the temperature of the layer to be heated remains within said low temperature range; Selecting a sub-layer - wherein the absorption coefficient of said light flux at said selected wavelength is high in relation to the absorption coefficient of said flow by the layer to be heated in said low temperature range; - and wherein the temperature enters the high temperature range when said sub-layer is subject to said light flux; And applying said light flux to said wafer, at least locally, via the face of said layer to be heated opposite said sub-layer; Such that, in a first phase, the light flux heats the sub-layer from the initial temperature thereof to a temperature at least situated in said high temperature range, that, in a second phase, the sub-layer heats, by thermal diffusion, the adjacent portion of the layer to be heated to a temperature situated in said high temperature range, and that, in a third phase, this adjacent portion thus becoming absorbent and generating, in the layer to be heated, an absorbent thermal front wherein the temperature is situated in said high temperature range and is greater than the temperature of the sub-layer, said absorbent thermal front progresses towards said front face under the combined effect of forward thermal diffusion of the thermal front and a thermal energy supply by said light flux which reaches said thermal front via the not yet absorbent remainder of the layer to be heated. Selecting a light flux - wherein the wavelength is such that the absorption coefficient of said flux by the layer to be heated is low in relation to the absorption coefficient of said flux by the sub-layer as long as the temperature of said layer to be heated is in a low temperature range and said absorption coefficient increases significantly when the temperature of the layer to be heated enters a high temperature range situated above said low temperature range, - and wherein the pulse intensity and duration are such that, in the absence of said sub-layer, the temperature of the layer to be heated remains within said low temperature range; - wherein the wavelength is such that the absorption coefficient of said flux by the layer to be heated is low in relation to the absorption coefficient of said flux by the sub-layer as long as the temperature of said layer to be heated is in a low temperature range and said absorption coefficient increases significantly when the temperature of the layer to be heated enters a high temperature range situated above said low temperature range, - and wherein the pulse intensity and duration are such that, in the absence of said sub-layer, the temperature of the layer to be heated remains within said low temperature range; Selecting a sub-layer - wherein the absorption coefficient of said light flux at said selected wavelength is high in relation to the absorption coefficient of said flow by the layer to be heated in said low temperature range; - and wherein the temperature enters the high temperature range when said sub-layer is subject to said light flux; - wherein the absorption coefficient of said light flux at said selected wavelength is high in relation to the absorption coefficient of said flow by the layer to be heated in said low temperature range; - and wherein the temperature enters the high temperature range when said sub-layer is subject to said light flux; And applying said light flux to said wafer, at least locally, via the face of said layer to be heated opposite said sub-layer; Such that, in a first phase, the light flux heats the sub-layer from the initial temperature thereof to a temperature at least situated in said high temperature range, that, in a second phase, the sub-layer heats, by thermal diffusion, the adjacent portion of the layer to be heated to a temperature situated in said high temperature range, and that, in a third phase, this adjacent portion thus becoming absorbent and generating, in the layer to be heated, an absorbent thermal front wherein the temperature is situated in said high temperature range and is greater than the temperature of the sub-layer, said absorbent thermal front progresses towards said front face under the combined effect of forward thermal diffusion of the thermal front and a thermal energy supply by said light flux which reaches said thermal front via the not yet absorbent remainder of the layer to be heated.