Fiber amplifier based light source for semiconductor inspection

摘要

The invention relates to a laser illuminator for use in an inspection system, such as a semiconductor wafer inspection system or photomask inspection system comprising a laser arrangement comprising a laser oscillator (1101) configured to produce coherent laser light; and a fiber laser amplifier (1102) arrangement comprising a plurality of fiber laser amplifiers (1102) connected in parallel and configured to amplify said coherent light produced by said laser oscillator (1101) and transmit said amplified coherent light toward a specimen for purposes of inspecting the specimen, wherein said laser arrangement employs mode-locking (1103) to selectively produce energy bursts having desired properties for inspecting the specimen in a selected imaging mode. According to the invention a method for inspecting a specimen, comprising: pumping a laser oscillator (1101) within a laser arrangement to generate coherent light; amplifying said coherent light using at least one fiber laser amplifier (1102); and transmitting amplified coherent light from the fiber laser amplifier (1102) toward the specimen for purposes of inspecting the specimen, wherein said laser arrangement employs mode-locking (1103) to selectively produce energy burst having desired properties for inspecting the specimen in a selected imaging mode and wherein said amplifying and transmitting occurs free of supercontinuum processing, is also provided.