Carl Zeiss and Synopsys Collaborate on In-Die Registration Metrology for Photomask Manufacturing
Delivering Sub-nanometer Accuracy Using 193-nm Optics and 2D Measurements
Strong optical proximity correction and double patterning techniques, required to extend 193-nm lithography to the next technology nodes, demand greater photomask pattern placement accuracy. The new PROVE system meets these increased demands with its groundbreaking concept of 193-nm illumination optics. It delivers an in-die metrology capability for measurement of the smallest production features without placing registration marks, enabling mask makers to measure and analyze registration in critical areas on the mask.
The new CATS module, currently in limited customer availability and generally available in March 2011, enables a fast, efficient and fully automated flow for the setup of photomask metrology jobs. Using the industry standard open formats OASIS.MASK and XML, advanced marking capabilities and the PROVE two-dimensional (2D) correlation method, CATS offers a significant enhancement to conventional image analysis schemes. The innovative method compares 2D design clips of the mask provided by CATS with images on the mask captured by PROVE, resulting in higher measurement accuracy compared to standard methods using 1D measurements based on edges only.
"With Synopsys' long-term experience in mask data preparation and Carl Zeiss' know-how in in-die metrology, the new CATS module with its exciting capabilities will significantly help to reduce mask registration errors on arbitrary production features," said Dr. Dirk Beyer, product manager for PROVE at Carl Zeiss SMS GmbH.
Registration errors can now be quantified for each mask with no resolution limitations, giving mask manufacturers a completely new tool for reducing placement errors in double patterning and mask-to-mask overlay.
"Synopsys' collaboration with Carl Zeiss exemplifies our commitment to offering comprehensive lithography, inspection and metrology solutions to the mask manufacturing market", said Fabio Angelillis, vice president of engineering for Synopsys' Silicon Engineering Group. "By extending CATS to support PROVE, we are delivering higher quality metrology solutions to our customers at the 32-nanometer technology node and below," he added.