Abstract:
PROBLEM TO BE SOLVED: To provide a system and method for inspecting the surface of a specimen such as a semiconductor wafer. SOLUTION: The system contains a lighting system wherein a 1st light beam is directed at the specimen surface at a slant angle of incidence and a 2nd light beam is directed at the same with a virtually vertical angle of incidence, a collecting system for collecting at east a part of the beams reflected from the specimen surface, and a detection system wherein the collected part of the reflected beams are processed. Defects if any in presence on the specimen are detected in the collected part of the 1st and 2nd beams.
Abstract:
A system configured to scan a beam of light over a surface of a specimen, comprising a first acousto-optical deflector (44) configured to direct the beam of light at various angles along an angular scan, wherein an amplitude of the first acousto-optical deflector is modulated such that an intensity of the directed light varies over a length of the angular scan; a lens (52) configured to expand the directed beam of light and to convert the angular scan to linear scan; and a second acousto-optical deflector (54) configured as a traveling lens to focus the beam of light onto a scan line.