A wafer, and a tungsten filament radiation heating source comprising at least one lamp arranged in a ring substantially surrounding the wafer edge. The radiation heating source irradiates the semiconductor wafer with radiation directed at the edge of the wafer, so that the radiation is adapted to penetrate the wafer edge and travel between the upper and lower surfaces into a central portion of the wafer sufficient to heat the wafer. The radiation-heating source may also have a reflector for reflecting radiation into the wafer edge, and at least one radiation and/or convection heating source mounted above or below the stage for directly heating one or both of the wafer upper and lower surfaces simultaneously with the radiation heating source surrounding the wafer.