Overlay measurement system using lock-in amplifier technique

    公开(公告)号:US12124177B2

    公开(公告)日:2024-10-22

    申请号:US17782622

    申请日:2020-11-18

    Abstract: A detection system (200) includes an illumination system (210), a first optical system (232), a phase modulator (220), a lock-in detector (255), and a function generator (230). The illumination system is configured to transmit an illumination beam (218) along an illumination path. The first optical system is configured to transmit the illumination beam toward a diffraction target (204) on a substrate (202). The first optical system is further configured to transmit a signal beam including diffraction order sub-beams (222, 224, 226) that are diffracted by the diffraction target. The phase modulator is configured to modulate the illumination beam or the signal beam based on a reference signal. The lock-in detector is configured to collect the signal beam and to measure a characteristic of the diffraction target based on the signal beam and the reference signal. The function generator is configured to generate the reference signal for the phase modulator and the lock-in detector.

    METHOD OF EVALUATING SELECTED SET OF PATTERNS

    公开(公告)号:US20240345487A1

    公开(公告)日:2024-10-17

    申请号:US18681613

    申请日:2022-08-02

    CPC classification number: G03F7/705 G03F7/70441

    Abstract: Systems and methods for evaluating selected set of patterns of a design layout. A method herein includes obtaining (i) a first pattern set resulting from a pattern selection process, (ii) first pattern data associated with the first pattern set, (iii) characteristic data associated with the first pattern data, and (iv) second pattern data associated with a second pattern set. A machine learning model is trained based on the characteristic data, where the machine learning model being configured to predict pattern data for an input pattern. The second pattern set is input to the trained machine learning model to predict second pattern data of the second pattern set. The first pattern set is evaluated by comparing the second pattern data and the predicted second pattern data. If the evaluation indicates insufficient pattern coverage, additional patterns can be included to improve the pattern coverage.

    CHARGED PARTICLE DEVICE, CHARGED PARTICLE ASSESSMENT APPARATUS, MEASURING METHOD, AND MONITORING METHOD

    公开(公告)号:US20240339292A1

    公开(公告)日:2024-10-10

    申请号:US18748758

    申请日:2024-06-20

    CPC classification number: H01J37/244 H01J37/10 H01J37/28

    Abstract: There is provided a charged particle device for a charged particle inspection apparatus for projecting an array of sub-beams towards a sample, the charged particle device comprising: a charged particle optical element and a detector. The charged particle optical element has an up-beam surface having a plurality of openings to generate an array of sub-beams from a charged particle beam. In the charged particle optical element are defined: sub-beam apertures and monitoring apertures. The sub-beam aperture extend through the charged particle element for paths of the array of sub-beams towards a sample. The monitoring aperture extends through the charged particle element. The detector is in the monitoring aperture. At least part of the detector is down-beam of the up-beam surface. The detector measures a parameter of a portion of the charged particle beam incident on the detector.

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