Abstract: A Method (1) for Rapid Thermal Processing of a wafer (7), wherein the wafer (7) is heated by lamps (9), and the heat radiation is reflected by an optical switching device (15,17) which is in the reflecting state during the heating stage. During the cooling stage of the wafer (7), the heat is absorbed by the switching device (15,17), which is in the heat-absorbing state. The switching device includes a switching film of a trivalent metal, such as gadolinium, which is capable of forming hydrides by an exchange of hydrogen. Dependent on the hydrogen concentration of the hydrides, the film reflects or absorbs heat. The hydrogen content in the switching film can be changed by varying the partial pressure of hydrogen, or, preferably, by varying the potential of the switching film forming part of a stack of layers in an electrochemical cell.

Abstract: A description is given of an optical switching device (1) comprising a transparent substrate (3), a switching film (5) of a hydride compound of a trivalent transition or rare earth metal having a thickness of 300 nm, and a palladium capping layer (7) having a thickness of 30 nm. The capping layer is in contact with hydrogen. An electric current through the switching film (5) can be switched on and off between the terminals (9, 11). Joule heating of the switching film (5) causes a rapid transition from the transparent trihydride state to the absorbing dihydride state. By switching off the current, the switching film (5) cools down, which results in the formation of the absorbing dihydride state. The conversion between both states is reversible and can be repeated many times. The device can be used for controlling light beams, or it can be used in or for a display. Optionally, cooling of the switching film (5) is obtained with a Peltier element in thermal contact with the switching film (5).

Abstract: A furnace (1) for Rapid Thermal Processing of a wafer (7), characterized in that the wafer (7) is heated by lamps (9), and the heat radiation is reflected by an optical switching device (15,17) which is in the reflecting state during the heating stage. During the cooling stage of the wafer (7), the heat is absorbed by the switching device (15,17), which is in the heat-absorbing state. The switching device comprises a switching film of a trivalent metal, such as gadolinium, which is capable of forming hydrides by an exchange of hydrogen. Dependent on the hydrogen concentration of the hydrides, the film reflects or absorbs heat. The hydrogen content in the switching film can be changed by varying the partial pressure of hydrogen, or, preferably, by varying the potential of the switching film forming part of a stack of layers in an electrochemical cell.

Abstract: A description is given of a switching device (1) comprising a transparent substrate (3), a switching film (5) including hydrides of gadolinium or other trivalent metal, and magnesium, covered with a palladium layer (7). By exchange of hydrogen, the switching film can be reversibly switched from a transparent state to a mirror-like state with zero transmission via an intermediate black absorbing state. The conversion between both states is reversible, and this phenomenon can be used, for example, in an optical switching element or sun roof.