US Patent 7149341 Wafer inspection apparatus

A wafer inspection apparatus has a supporting means (10) for rotatably supporting a wafer (W) formed of a disk, a circumferential edge imaging means (40) for imaging a circumferential edge (S) of the wafer (W) that is supported by the supporting means for rotation, a notch imaging means (50) for imaging a notch (N), a notch illumination part (52) for illuminating the notch (N), and a control means (70) for processing image data imaged by the circumferential edge imaging means (40) and the notch imaging means (50). The circumferential edge imaging means (40) has a plurality of imaging cameras (41) for imaging a plurality of different parts in a thickness direction of the circumferential edge of the wafer (W). The different parts of the circumferential edge (S) of the wafer (W) include an apex at right angles to a surface of the wafer (W) and a front side bevel and a back side bevel inclined relative to the apex. The notch imaging means (50) for the wafer (W) having the notch (N) has a plurality of imaging cameras (51) for imaging different parts in the thickness direction of the notch (N).