Apparatus for laser annealing and operating method thereof

An apparatus for laser annealing comprising:

• a light source configured to generate a plurality of laser beams;
• a time division superimposing device comprising at least one beam splitter configured to temporally branch the plurality of laser beams, respectively, to propagate branched beams onto different optical paths, and wherein the time division superimposing device is configured to superimpose beams emitted from the same laser, from the branched beams propagated onto different optical paths;
• a space split superimposing device comprising
• at least one beam splitter configured to spatially branch superimposed beams from the time division superimposing device, respectively, and
• at least one reflector configured to propagate beams emitted from different lasers onto the same path, to superimpose the propagated beams emitted from the plurality of lasers beams;
• an optical illumination system comprising a plurality of lenses configured to form flat-top beams homogenizing intensities of superimposed beams from the space split superimposing device;
• a mask configured to pass homogenized beams from the flat-top beams formed by passing through the optical illumination system;
• and
• an optical imaging system comprising a plurality of lenses configured to image each of the homogenized beams passing through the mask onto a wafer.