Laser annealing apparatus, laser annealing method, and method for manufacturing semiconductor device

A laser annealing apparatus comprising:

• a laser light source configured to generate laser light;
• an annealing optical system configured to guide the laser light to a substrate so as to form, over the substrate, a linear irradiation region along a first direction in a top view;
• a moving mechanism configured to change a relative position of the irradiation region with respect to the substrate along a second direction intersecting the first direction in the top view;
• an illumination light source configured to generate illumination light for illuminating the substrate along a third direction, the third direction being a direction inclined from a vertical direction as viewed in a direction perpendicular to a plane including the first direction and the vertical direction;
• a rotating mechanism configured to rotate the illumination light source around the first direction to change an angle between the vertical direction and the third direction;
• and
• a detector configured to detect detection light reflected in a fourth direction by the substrate illuminated by the illumination light so as to photograph an annealed part of the substrate in a linear field of view along the first direction, the fourth direction being inclined from the vertical direction as viewed in the direction perpendicular to the plane including the first direction and the vertical direction.