摘要 |
A workpiece 34 such as a semiconductor wafer is pre-heated to an intermediate temperature (Fig 4: TI) then a surface 46 of the workpiece is heated rapidly, for a time period less than the thermal conduction time of the workpiece, to a temperature (fig 4: TD) greater than the intermediate temperature. An arc lamp or filament lamp 32 may be used for pre-heating, and a flashlamp or laser 36 may be used for heating. Pre-heating and heating may be achieved using radiation sources disposed on either side of the wafer, and radiation may be transmitted though a selective filter which is cooled by a liquid flow across the surface of a quartz window 65, 71. Cooling of the workpiece may be enhanced by absorbing radiation thermally emitted by the workpiece. One heat-treating system comprises a liquid-cooled arc lamp, using water as a cooling fluid, with a pulsed discharge power supply configured to supply an electrical discharge pulse to the arc lamp to produce an irradiance flash. |