Methods and apparatus for temperature measurement and control on a remote substrate surface

An apparatus for processing a substrate comprising:

• a radiation source adapted to emit a photonic beam;
• an optical system to form from the beam an image on a substrate;
• a stage adapted to scan the substrate across the beam image to heat the substrate surface;
• a temperature monitoring means for analyzing p-polarized radiation of at least three different wavelengths emitted from at least two positions along an image to determine temperatures at the at least two locations;
• an output error signal generator that makes temperature difference calculations that take into account at least one of a preset desired maximum temperature and a desired minimum temperature with the temperatures determined at the at least two locations to generate an output error signal;
• and
• a controller operably coupled to the radiation source and the stage, wherein the controller, in response to the output error signal is programmed to do at least one of alter the beam intensity and provide a change to the scanning speed between the stage and the beam in a manner so the error output signal is nulled.