Presentation
13 November 2024 Sub-angstrom critical dimension metrology with EUV scatterometry
Stuart Sherwin, Matt Hettermann, Dave Houser, Luke Long, Patrick Naulleau
Author Affiliations +
Abstract
Critical Dimensions (CDs) on EUV photomasks are rapidly shrinking to print higher resolution features, enhance contrast with sub-resolution assist features, and control the stitching black border with sub-resolution gratings. Reducing mask CDs to 10s of nm necessitates single-nm CD process control and CD metrology with single-angstrom accuracy or better. Furthermore, the ideal probe for an EUV photomask is EUV radiation, due to its short wavelength and sensitivity to any and all optical effects that could potentially impact the EUV aerial image. In this work we present actinic CD metrology using EUV scatterometry performed on the EUV Tech ENK tool, capable of delivering sub-nm or even sub-angstrom CD accuracy. Furthermore, we explore extending the technique to measure more complicated dimensions such as the sidewall angle (SWA) of the absorber. We present experimental demonstrations on the ENK tool of CD and SWA metrology on EUV photomasks.
Conference Presentation
© (2024) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Stuart Sherwin, Matt Hettermann, Dave Houser, Luke Long, and Patrick Naulleau "Sub-angstrom critical dimension metrology with EUV scatterometry", Proc. SPIE 13216, Photomask Technology 2024, 132160V (13 November 2024); https://doi.org/10.1117/12.3035715
Advertisement
Advertisement
KEYWORDS
Critical dimension metrology

Extreme ultraviolet

Scatterometry

Photomasks

Metrology

Scanning electron microscopy

SRAF

Back to Top