Paper
20 March 2006 Phase-shift focus monitoring techniques
Author Affiliations +
Abstract
Depth of focus (DOF) has become a victim of its mathematical relationship with Numerical Aperture (NA). While NA is being increased towards one to maximize scanner resolution capabilities, DOF is being minimized because of its inverse relationship with NA. Moore's law continues to drive the semiconductor industry towards smaller and smaller devices the need for high NA to resolve these shrinking devices will continue to consume the usable depth of focus (UDOF). Due to the shrinking UDOF a demand has been created for a feature or technology that will give engineers the capability to monitor scanner focus. Developing and implementation of various focus monitoring techniques have been used to prevent undetected tool focus excursions. Two overlay techniques to monitor ArF Scanner focus have been evaluated; our evaluation results will be presented here.
© (2006) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Matthew McQuillan and Bill Roberts "Phase-shift focus monitoring techniques", Proc. SPIE 6154, Optical Microlithography XIX, 615430 (20 March 2006); https://doi.org/10.1117/12.663477
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CITATIONS
Cited by 3 scholarly publications.
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KEYWORDS
Calibration

Scanners

Semiconducting wafers

Overlay metrology

Phase shifts

Diffraction

Quartz

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