YieldStar (YS) is an established ASML-built scatterometer that is capable of measuring wafer Critical Dimension (CD),
Overlay and Focus. In a recent work, the application range of YS was extended to measure 3D CD patterns on a reticle
(pattern CD, height, Side Wall Angle-SWA). The primary motivation for this study came from imaging studies that
indicated a need for measuring and controlling reticle 3D topography.
CD scanning electron microscope (CD-SEM), Atomic force microscope (AFM), 3D multiple detector SEM (3D-SEM)
are the preferred tools for reticle metrology. While these tools serve the industry well, the current research to the impact
of reticle 3D involves extensive costs, logistic challenges and increased reticle lead time. YS provides an attractive
alternative as it can measure pattern CD, SWA and height in a single measurement and at high throughput. This work
demonstrates the capability of YS as a reticle metrology tool.