Digital holographic microscopy allows access to the complex electric field, enabling computational propagation of light. This enables computational corrections for lens aberrations, which remove the requirement for antireflective coatings on the lens and enable imaging over a wide spectral range. This makes digital holographic microscopy an interesting candidate for overlay metrology on semiconductor wafers. We show that a single holographic image contains all data that is required for computing the overlay, by using a source with a limited coherence length and incoherently adding multiple measurements on a camera. As an additional benefit we show that such parallel acquisition improves the reproducibility of the experiment by eliminating noise sources that are common to the two measurements that typically constitute a single overlay measurement.
|Title of host publication||Optical Measurement Systems for Industrial Inspection XII|
|Editors||Peter Lehmann, Wolfgang Osten, Armando Albertazzi Goncalves|
|Publication status||Published - 2021|
|Event||Optical Measurement Systems for Industrial Inspection XII 2021 - Virtual, Online, Germany|
Duration: 21 Jun 2021 → 25 Jun 2021
|Name||Proceedings of SPIE - The International Society for Optical Engineering|
|Conference||Optical Measurement Systems for Industrial Inspection XII 2021|
|Period||21/06/21 → 25/06/21|
Bibliographical notePublisher Copyright:
© 2021 SPIE · CCC code: 0277-786X/21/$21
Copyright 2021 Elsevier B.V., All rights reserved.
- Dark-field imaging
- Digital holographic microscopy
- Overlay metrology
- Semiconductor manufacturing