| CPC H01L 21/67253 (2013.01) [G01J 5/00 (2013.01)] | 5 Claims |

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1. A process monitor comprising:
a photodetector includes a plurality of light receiving units configured to separately measure intensities of radiant light from a semiconductor member being annealed, in a plurality of wavelength ranges that are different from each other; and
a processing device configured to obtain a physical quantity related to the semiconductor member that changes due to annealing by a laser beam, based on the intensities in the plurality of wavelength ranges measured by the photodetector;
a beam spot of the laser beam on a surface of the semiconductor member has a long shape that is elongated in one direction,
an imaging optical system including two lenses that forms an image of the beam spot;
the plurality of light receiving units are disposed at different positions in a longitudinal direction of the image of the beam spot; and
one light receiving unit of the plurality of light receiving units detects the radiant light emitted from a region shallower than a depth D1 and another light receiving unit of the plurality of light receiving units detects the radiant light emitted from a region shallower than a depth D2 wherein D2<D1.
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