Patent ID: 9638739
Date: 2017-05-02
CPC Classifications: G01R,G03F

Claim:
1. A defect coordinates measurement device configured to achieve a high stage coordinate accuracy without reliance on a temperature stabilization mechanism, the device comprising: a stage that receives a test sample; a detection unit that includes a photodetector configured to capture an image of the test sample; a driving mechanism configured to change a relative position of the detection unit and the test sample; and at least one processor configured to detect a defect of the test sample based on an image of the test sample, to detect coordinates of the defect based on a driving position of the driving mechanism and to convert the detected coordinates of the defect into a coordinate system in a reference sample, wherein the test sample has a fiducial mark, and wherein the test sample is used for a EUVL (Extreme Ultra-Violet lithograph) mask, a defect mitigation being implemented in the EUVL mask, the reference sample has at least one alignment mark and a plurality of reference marks, the plurality of reference marks are arranged in an array, each of the plurality of reference marks has a known position relative to the at least one alignment mark, the driving mechanism is configured to change a relative position of the detection unit and the test sample so that the photodetector captures a whole image of the test sample; the processor detects, as first detected coordinates, the detected coordinates of the defect on the basis of detected coordinates of the fiducial marks based on a first image included in the whole image of the test sample, the driving mechanism changes a relative position of the detection unit and the reference sample placed on the stage so that the photodetector captures a second image including the at least one alignment mark, the processor detects, as second detected coordinates, detected coordinates based on the second image; the processor extracts N reference marks nearest the first detected coordinates from the plurality of the reference marks based on the second detected coordinates, wherein N is an integer of two or more, the driving mechanism changes the relative position of the detection unit and the reference sample placed on the stage so that the photodetector captures a third image including the extracted N reference marks, the processor detects, as third detected coordinates, detected coordinates of the extracted N reference marks based on the third image, and the processor converts the first detected coordinate into the coordinates of the reference sample based on the third detected coordinates, wherein the step of converting the first detected coordinate into the coordinates of the reference sample based on the third detected coordinates is performed without construction of and reliance on a polynomial linearity model and consequent introduction of approximation error, thereby mitigating defect coordinate measurement error.