Patent ID: 8452166

Claim:
A chamber for processing a substrate, comprising: a chamber enclosure defining a processing volume; an energy source that directs radiant energy toward the processing volume; a spectral device that marks the radiant energy from the energy source towards the processing volume; a substrate support that supports the substrate in the processing volume; a reference sensor positioned in the processing volume to receive radiant energy from both the energy source and the substrate and measure the received radiant energy near a reference wavelength; a target sensor positioned in the processing volume to receive radiant energy from both the energy source and the substrate and measure the received radiant energy at a measuring wavelength, wherein the measuring wavelength and the reference wavelength are different; and a controller that determines a characteristic of the radiant energy from the energy source using measurement of the reference sensor and to determine a temperature of the substrate using measurement of the target sensor and the characteristic of the radiant energy of the energy source.