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:
In an optical system (20) measuring sample characteristics, by reducing the amount of ambient absorbing gas or gases and moisture present in at least a portion of the illumination and detection paths experienced by vacuum ultraviolet (VUV) radiation (34) used in the measurement process, the attenuation of such wavelength components can be reduced. Such reduction can be accomplished by a process without requiring the evacuation of all gases and moisture from the measurement system (20). In one embodiment, the reduction can be accomplished by displacing at least some of the absorbing gas(es) and moisture present in at least a portion of the measuring paths so as to reduce the attenuation of VUV radiation. In this manner, the sample (42) does not need to be placed in a vacuum, thereby enhancing system throughput.
Abstract:
In an optical system measuring sample characteristics, by reducing the amount of ambient absorbing gas or gases and moisture present in at least a portion of the illumination and detection paths experienced by vacuum ultraviolet (VUV) radiation used in the measurement process, the attenuation of such wavelength components can be reduced. Such reduction can be accomplished by a process without requiring the evacuation of all gases and moisture from the measurement system. In one embodiment, the reduction can be accomplished by displacing at least some of the absorbing gas(es) and moisture present in at least a portion of the measuring paths so as to reduce the attenuation of VUV radiation. In this manner, the sample does not need to be placed in a vacuum, thereby enhancing system throughput.