Systems and methods for thermal processing and temperature measurement of a workpiece at low temperatures

A thermal processing apparatus comprising:

• a processing chamber having a workpiece support, the workpiece support configured to support a workpiece;
• a first heat source and a second heat source, each of the first and second heat source configured to emit electromagnetic radiation in a first wavelength range in a range from about 850 nanometers to about 950 nanometers to heat the workpiece to a processing temperature of from about 50° C. to about 150° C., wherein the first heat source is configured to heat a top surface of the workpiece and the second heat source is configured to heat a backside of the workpiece;
• one or more additional radiation sources configured to emit electromagnetic radiation in a second wavelength range, wherein the second wavelength range comprises a wavelength from about 7 micrometers to about 12 micrometers, wherein the workpiece is at least partially transparent to the electromagnetic radiation in the second wavelength range;
• a first sensor configured to obtain a measurement of electromagnetic radiation in the second wavelength range when the workpiece is at the processing temperature, wherein the second wavelength range does not overlap with the first wavelength range, wherein a spectral power density associated with the radiation from the heat source in the second wavelength range is less than about 5% of a peak spectral power density associated with the second wavelength range;
• and
• a first window disposed between the first heat source and the workpiece and a second window disposed between the second heat source and the workpiece, the first window and second window configured to restrict wavelengths other than the second wavelength range, the first window and second window each having a first side facing the workpiece and a second and opposite side, wherein the first window and the second window comprise quartz.