Patent ID: 7564544

Claim:
A system for inspecting a surface of a substrate, the system comprising: a line scan sensor; an imaging lens; and an illumination source including a number of light sources at different wavelengths, output lights of the light sources collimated respectively and then combined by at least one dichroic beam splitters, each of the light sources being adjustable to optimize for defect detection sensitivity on the surface of the substrate, the combined light being provided via at least two lenses to illuminate the surface of the substrate being inspected, wherein the two lenses include: a cylindrical lens and a spherical lens to produce first and second illumination lines from the combined light, the first illumination line projected on the surface and the second illumination line projected in a perpendicular direction at a pupil plane of the imaging lens to achieve both intensity uniformity and angular uniformity across a field of view of the line scan sensor, wherein an image of the surface is focused onto the line scan sensor by the imaging lens.