Patent ID: 7717617
Filing Date: 2010-05-18
Classification: G01J,G02B,H01S

Abstract:
1. Apparatus for processing a wafer, wherein the wafer has a wafer surface, comprising: a source of laser radiation, wherein the laser radiation has at least one-laser wavelength which a semiconductor material can absorb as heat; an optical element having a surface to reflect radiation at the laser wavelength and to pass radiation at a pyrometer wavelength; optics providing an optical line beam derived from the source of laser radiation, the optical line beam focused on the wafer, the optics disposed between the surface of the optical element and the wafer, the optical line beam defining a portion of the wafer surface, which is smaller than the wafer surface, within which illumination by the laser radiation is focused; line beam scanning apparatus coupled to the optics and having a fast axis transverse to the optical line beam along which the portion is translatable by the line beam scanning apparatus at a beam translation rate; a pyrometer positioned on a side of the surface of the optical element opposite said optics to receive an image of said portion through the optics, wherein the pyrometer is sensitive to the pyrometer wavelength; and a first optical filter disposed between the source of laser radiation and the surface of the optical element to block a part of the radiation spectrum from the source of laser radiation including the pyrometer wavelength.