A method involves increasing a temperature of a workpiece over a first time period
to an intermediate temperature, and heating a surface of the workpiece to a desired
temperature greater than the intermediate temperature, the heating commencing within
less time following the first time period than the first time period. Another method
involves pre-heating the workpiece from an initial temperature to an intermediate
temperature, and heating a surface of the workpiece to a desired temperature greater
than the intermediate temperature by an amount less than or equal to about one-fifth
of a difference between the intermediate and initial temperatures. Another method
involves irradiating a first side of the workpiece to pre-heat the workpiece to
an intermediate temperature, and irradiating a second side of the workpiece to
heat the second side to a desired temperature greater than the intermediate temperature.