Alignment Sensor and Lithographic Apparatus

    公开(公告)号:US20170212434A1

    公开(公告)日:2017-07-27

    申请号:US15328194

    申请日:2015-07-07

    CPC classification number: G03F9/7088 G03F9/7065 G03F9/7069

    Abstract: An alignment sensor for a lithographic apparatus is arranged and constructed to measure an alignment of a movable part of the lithographic apparatus in respect of a stationary part of the lithographic apparatus. The alignment sensor comprises a light source configured to generate a pulse train at a optical wavelength and a pulse repetition frequency, a non-linear optical element, arranged in an optical propagation path of the pulse train, the non-linear optical element configured to transform the pulse train at the optical wavelength into a transformed pulse train in an optical wavelength range, an optical imaging system configured to project the transformed pulse train onto an alignment mark comprising a diffraction grating; a detector to detect a diffraction pattern as diffracted by the diffraction grating, and a data processing device configured to derive alignment data from the detected diffraction pattern as detected by the detector.

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