Patent ID: 6858859

Claim:
An optically scanning apparatus comprising: a light source for emitting a radiation beam; a two-dimensional diffraction grating for converting said radiation beam into a two-dimensional array of light beams arranged in an m×n matrix, where m and n are natural numbers of 2 or more; an objective lens for focusing the m×n number of light beams into spots to form an array of light spots arranged in an m×n matrix on a sample to be inspected; a photosensor having an array of light receiving elements arranged in an m′×n′ (m′ and n′ being natural numbers of 2 or more) matrix, the light receiving elements separated from each other and receiving beams reflected at the sample surface; a sample stage for supporting a sample to be inspected for defects; and a stage drive system having a rotational drive device for rotating said sample stage and a rectilinear movement device for moving the sample stage along an axis perpendicular to the rotational axis and making said sample stage move relative to said light spot array; wherein the sample surface is scanned by the two-dimensional light spot array arranged in an m×n matrix by making the sample and light spot array move relative to each other, and the sample surface is spirally scanned by the two-dimensional light spot array, and said sample stage moves rectilinearly by exactly a distance corresponding to a scan width while the sample stage rotates one time.