Measurement sensitivity of DUV scatterfield microscopy parameterized with partial coherence for duty ratio-varied periodic nanofeatures
Taekyung Kim, Eikhyun Cho, Yoon Sung Bae, Sang-Soo Choi, Bryan Barnes, Richard M. Silver, Martin Sohn
The deep ultraviolet (DUV) scatterfield imaging microscopy technique enables accurate dimensional measurements of periodic nanostructures with sub-nanometer sensitivity to support semiconductor device manufacturing. A parametric sensitivity analysis for targets with uneven duty ratios is essential as the duty ratios of many periodic nanostructures vary practically. This paper presents an experimental implementation to optimize illumination condition for nanoscale multiline targets on a Molybdenum Silicide (MoSi) photomask with duty ratios of 0.43 – 0.68 using a scatterfield imaging microscope with 193 nm wavelength laser designed for resolved illumination at the sample. Measurement sensitivities are analyzed using sensitivity coefficient maps parameterized with partial coherence factor, the duty ratio of the target, and the incident polarization.
, Cho, E.
, Bae, Y.
, Choi, S.
, Barnes, B.
, Silver, R.
and Sohn, M.
Measurement sensitivity of DUV scatterfield microscopy parameterized with partial coherence for duty ratio-varied periodic nanofeatures, Optics and Lasers in Engineering, [online], https://doi.org/10.1016/j.optlaseng.2022.106953, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=932950
(Accessed September 23, 2023)