Field-position dependent apodization in dark-field digital holographic microscopy for semiconductor metrology

Tamar van Gardingen-Cromwijk, Manashee Adhikary, Christos Messinis, Sander Konijnenberg, Wim Coene, Stefan Witte, Johannes F. de Boer, Arie den Boef

Research output: Contribution to journalArticleAcademicpeer-review

3 Citations (Scopus)

Abstract

Measuring overlay between two layers of semiconductor devices is a crucial step during electronic chip fabrication. We present dark-field digital holographic microscopy that addresses various overlay metrology challenges that are encountered in the semiconductor industry. We present measurement results that show that the point-spread function of our microscope depends on the position in the field-of-view. We will show that this novel observation can be explained by a combination of the finite bandwidth of the light source and a wavelength-dependent focal length of the imaging lens. Moreover, we will also present additional experimental data that supports our theoretical understanding. Finally, we will propose solutions that reduce this effect to acceptable levels.
Original languageEnglish
Pages (from-to)411-425
Number of pages15
JournalOptics express
Volume31
Issue number1
Early online date21 Dec 2022
DOIs
Publication statusPublished - 2 Jan 2023

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