Carl Zeiss introduces its PROVE™ Registration and Overlay Metrology System for photomasks at SPIE Photomask Conference in Monterey / CA. PROVE™ measures image placement on photomasks with superior resolution meeting the challenging requirements of the 32nm technology node and beyond.
Further extension of 193nm lithography to the next technology nodes by introducing strong optical proximity corrections and double patterning requires new approaches for photomask registration and overlay metrology.
New PROVE Photomask Registration and Overlay Metrology System
With its diffraction limited, high resolution imaging optic working at the lithographic relevant 193nm wavelength the new PROVE™ system opens up entirely new perspectives in registration metrology. PROVE™ allows for measurement of the smallest production features without placing registration marks. “This real in-die registration metrology is a huge benefit for our customers in Mask Manufacturing. For the first time in history, mask makers are able to measure and analyse registration where it really matters. Additionally, with increasing resolution demands e.g. for EUV lithography, we can extend our tool capabilities to the upcoming technology nodes.” explains Dr. Oliver Kienzle, Managing Director of Semiconductor Metrology Systems Division of Carl Zeiss SMT.
The proprietary autofocus and calibration strategy of the new system enables a repeatability of below 0.5nm and an accuracy of below 1nm for best registration measurement performance.
Even in manufacturing of mask writers the PROVE™ system is used to tune the pattern generators to improve pattern placement results and to minimize registration errors on photomasks. Recently Carl Zeiss reported about the shipment of the first tool to NuFlare Technology Inc., the worlds leading supplier of e-beam based mask writers.
The next system to a Mask Shop customer will be delivered at the end of this month.