Patent ID: 7550694

Claim:
A laser anneal apparatus which irradiates a substrate to be treated with laser light to anneal the surface of the substrate, comprising: a laser source; a homogenizing optical system disposed in an optical path of the laser light emitted from the laser source to homogenize an intensity distribution of the laser light in a section which is perpendicular to the optical path; an optical device disposed in the optical path of the laser light passed through the homogenizing optical system, the optical device being configured to diffract the laser light to generate low-order diffracted light and high-order diffracted light, thus producing an intensity distribution pattern of the laser light in the section which is perpendicular to the optical path; a photoreceptor device disposed in the optical path of the laser light passed through the optical device, the photoreceptor device having a portion where the low-order diffracted light passes and another portion where the high-order diffracted light is absorbed, and being configured to measure the intensity of the absorbed high-order diffracted light; and an image-forming optical system disposed in the optical path of the laser light passed through the photoreceptor device to focus the laser light on the substrate to be treated, wherein the intensity of the low-order diffracted light passed through the photoreceptor device is derived based on the intensity of the absorbed high-order diffracted light.