Laser apparatus and method of manufacturing electronic device

A method of manufacturing an electronic device, the method comprising:

• generating a laser beam with a laser apparatus, the laser apparatus including
• a grating system,
• an actuator system configured to adjust a first incident angle on the grating system and a second incident angle on the grating system, the first incident angle being an angle of a first part of an optical beam incident on the grating system, the second incident angle being an angle of a second part of the optical beam incident on the grating system, and
• a processor configured to control the actuator system to periodically vary the first and second incident angles so that the first and second incident angles are different from each other in at least one of phase and variation range;
• outputting the laser beam to an exposure apparatus;
• and
• exposing a photosensitive substrate to the laser beam in the exposure apparatus to manufacture the electronic device.