Commissioning an EUV mask microscope for lithography generations reaching 8 nm

The SEMATECH High-NA Actinic Reticle review Project (SHARP) is a synchrotron-based, EUV-wavelength microscope, dedicated to photomask imaging, now being commissioned at Lawrence Berkeley National Laboratory. In terms of throughput, resolution, coherence control, stability and ease of use, SHARP represents a significant advance over its predecessor, the SEMATECH Berkeley Actinic Inspection Tool (AIT), which was decommissioned in September 2012. SHARP utilizes several advanced technologies to achieve its design goals: including the first Fourier-synthesis illuminator on a zoneplate microscope, EUV MEMS mirrors, and high-efficiency freestanding zoneplate lenses with numerical aperture values up to 0.625 (4x). In its first week of operation, SHARP demonstrated approximately 150 times higher light throughput than AIT and a spatial resolution down to 55-nm half-pitch with 0.42 4xNA (i.e. the smallest feature size on our test mask.) This paper describes the current status of the tool commissioning and the performance metrics available at this early stage.