EUVL resist-based aberration metrology

Autor: Sudharshanan Raghunathan, Germain Fenger, Bruce W. Smith, Obert Wood, Lei Sun
Rok vydání: 2013
Předmět:
Zdroj: Extreme Ultraviolet (EUV) Lithography IV.
ISSN: 0277-786X
Popis: Extreme Ultraviolet Lithography (EUVL) at 13.5 nm is currently the most promising technology for advanced integrated circuit (IC) manufacturing nodes. Since the wavelength for EUVL is an order of magnitude smaller than current optical lithography systems (193 nm), wavelength scaled tolerances on lens manufacturing must be tightened to avoid image distortion and contrast loss as these scale with wavelength. Therefore understanding the aberrations of an EUVL system both in idle and production conditions is paramount. This study aims to assess a photoresist based technique for capturing pupil information of EUVL systems that can be implemented during full system use. Several data sets have been collected on an ASML EUV Alpha-Demo Tool (ADT) using the latest Center for Nanoscale Science and Engineering (CNSE) baseline resist Shin-Etsu SEVR139. Various one-dimensional and two-dimensional binary structures were imaged and used for pupil extraction in conjunction with computational modeling and simulations. Results show a stable extracted aberration signature over several measurements. Results also show that the method is sensitive to sub-nm levels of aberration change.
Databáze: OpenAIRE