Since the photomask is one of the key elements in photolithography it deserves special care and attention. The strategic business group Semiconductor Metrology Systems (SMS) of ZEISS has many years of experience in qualification, repair and verification, metrology as well as tuning of photomasks. Together with the industry we are constantly developing complete systems and providing innovative technology for all relevant nodes.
We provide unique solutions for mask making and lithography in the areas of zero defect, in-die metrology, critical dimension/registration and overlay control to achieve high mask yield improvement and mask recovery.
Even least defects in the layout of a single photomask can consign all chips on the exposed wafer resulting in enormous losses. That is why it is crucial to inspect all masks for defects, understand their impact on the photolithography process, and eliminate them before the mask is used in a stepper or scanner.
Photomasks featuring zero printable defects are essential for the manufacture of high yielding integrated circuits. As sizes continuously shrink, the demands and costs associated with these key optical elements raise exponentially and with them the necessity to repair a defective product.
With shrinking feature sizes in-die metrology is not only desirable, but essential as the measurement of test structures no longer reflects the complex interacting between patterns and illuminating light in the deep sub-wavelength regime.