Patent ID: 7234862
Filing Date: 2007-06-26
Classification: G01K

Abstract:
1. An apparatus for measuring temperatures of plural physically separated locations on a substrate in a plasma processing system, comprising: a substrate holder for holding a substrate to be processed in the plasma processing system, the substrate to be processed on a first side opposite to a second side of the substrate that is in contact with the substrate holder; a broad band light source for coupling plural light beams to be incident on plural discrete reflection points on the second side of the substrate, said broad band light source emitting at least a range of wavelengths for which absorption by the substrate changes from absorption of essentially all light entering the substrate to absorption of essentially no light incident on the substrate; a light collection system having a plurality of light collecting elements each for collecting from the second side of the substrate a portion of a respective one of the plural light beams reflected at the plural reflection points during plasma processing of the first side of the substrate; plural optical fibers provided within a chamber of said plasma processing system, two of such fibers passing through said substrate holder and having a terminal end adjacent to said second side of the substrate and each other, one of the two fibers having a first end coupled to the broad band light source, and the other of the two fibers having a first end coupled to the light collection system; and a computer configured to calculate two dimensional temperature of said substrate based on the plural light beams, wherein the apparatus does not include a pyrometry based temperature sensor.