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Title: Binary pseudo-random patterned structures for modulation transfer function calibration and resolution characterization of a full-field transmission soft x-ray microscope

We present a modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) one-dimensional sequences and two-dimensional arrays as an effective method for spectral characterization in the spatial frequency domain of a broad variety of metrology instrumentation, including interferometric microscopes, scatterometers, phase shifting Fizeau interferometers, scanning and transmission electron microscopes, and at this time, x-ray microscopes. The inherent power spectral density of BPR gratings and arrays, which has a deterministic white-noise-like character, allows a direct determination of the MTF with a uniform sensitivity over the entire spatial frequency range and field of view of an instrument. We demonstrate the MTF calibration and resolution characterization over the full field of a transmission soft x-ray microscope using a BPR multilayer (ML) test sample with 2.8 nm fundamental layer thickness. We show that beyond providing a direct measurement of the microscope’s MTF, tests with the BPRML sample can be used to fine tune the instrument’s focal distance. Our results confirm the universality of the method that makes it applicable to a large variety of metrology instrumentation with spatial wavelength bandwidths from a few nanometers to hundreds of millimeters.
Authors:
; ;  [1] ;  [2] ;  [3] ;  [4] ;  [3] ;  [5] ;  [6] ;  [7] ;  [8] ; ; ;  [9]
  1. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
  2. Center for X-Ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
  3. (United States)
  4. Advance Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
  5. Diablo Valley College, 321 Golf Club Road, Pleasant Hill, California 94523 (United States)
  6. KLA-Tencor Corp., 1 Technology Drive, Milpitas, California 95035 (United States)
  7. National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973 (United States)
  8. Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
  9. aBeam Technologies, Inc., Hayward, California 94541 (United States)
Publication Date:
OSTI Identifier:
22482650
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 86; Journal Issue: 12; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; CALIBRATION; INTERFEROMETERS; MICROSCOPES; MODULATION; NOISE; RANDOMNESS; RESOLUTION; SENSITIVITY; SOFT X RADIATION; SPECTRAL DENSITY; TRANSFER FUNCTIONS; TRANSMISSION ELECTRON MICROSCOPY