Method and apparatus for measuring overlay

摘要

A method of measuring an overlay includes generating an original signal using first and second overlay measurement keys that are spaced apart from each other, generating a first spectrum signal by performing Fourier transform of the original signal, generating a second spectrum signal by filtering the first spectrum signal, and generating a corrected signal by performing inverse Fourier transform of the second spectrum signal.

主权项

1. A method of measuring an overlay, comprising:
generating an original signal using first and second overlay measurement keys which are spaced apart from each other; generating a first spectrum signal by performing Fourier transform of the original signal; generating a second spectrum signal by filtering the first spectrum signal; and generating a corrected signal by performing inverse Fourier transform of the second spectrum signal; wherein performing the Fourier transform of the original signal includes making the original signal pass through a Fourier transform lens set; and wherein the first spectrum signal is formed in a spectrum domain that includes a first axis and a second axis, which has an optical axis of the Fourier transform lens set as an original point, the first spectrum signal includes a plurality of dot signals, and a pitch of the first spectrum signal in a second-axis direction is wider than a pitch in a first-axis direction.