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The Center for X-Ray Optics is a multi-disciplined research group within Lawrence Berkeley National Laboratory's (LBNL) Materials Sciences Division (MSD). Notice to users.

The world's highest performance microscope for imaging EUV lithography masks.

The SEMATECH Berkeley Actinic Inspection Tool (AIT)

"In photolithography, a single defect ruins the chip. Our daily work with the AIT answers the semiconductor industry’s most pressing mask R&D questions. We study the unique EUV response to defects, mask architectures, and defect repair strategies."

Kenneth Goldberg,
AIT Principal Investigator

Photo of Ken Goldberg, CXRO Staff Scientist

About the AIT

In photolithography, masks carry the circuit pattern that becomes printed on a wafer (chip) one layer at a time. For EUV lithography specifically, masks are made from ultra-smooth 6-inch glass plates coated with an EUV-reflective multilayer coating, and a patterned absorbing layer on top. The behavior of the entire system, from the glass, to the coating, to the absorber, is highly wavelength specific, so measuring with EUV light is imperative. The AIT is a SEMATECH-sponsored mask-measuring EUV Fresnel zoneplate microscope that delivers high-resolution images of defects and patterns, years ahead of commercial tools.

Comparison of SEM and AIT images of an EUV photomask.

Printability studies.

The AIT operates at EUV wavelengths, enabling it to see the true aerial image with high resolution. Researchers use the AIT to study defect printability and to test the effectiveness of defect repair methods.

Defects can look very different with different inspection techniques.

Defects that appear severe to visible or ultraviolet light and to electron-beam microscopy can be transparent to EUV light, and vice-versa.

Another comparison of SEM and AIT images of an EUV photomask.

Visit the AIT homepage.

Visit ait.lbl.gov for more information.

The AIT team.

Photo of Kenneth Goldberg

Kenneth Goldberg

CXRO Deputy Director & Staff Scientist
Photo of Markus Benk

Markus Benk

Project Scientist
Photo of Antoine Wojdyla

Antoine Wojdyla

Project Scientist
Photo of David Johnson

David Johnson

Research Associate
Photo of Alex Donoghue

Alex Donoghue

Research Associate
Photo of James Macdougall

James Macdougall

Graduate Student Research Assistant