Berlin 2018 – wissenschaftliches Programm
KFM 26.8: Vortrag
Donnerstag, 15. März 2018, 17:50–18:10, EMH 025
GISAXS reconstruction of profiles of gratings produced by quadruple patterning — •Mika Pflüger1, Victor Soltwisch1, R. Joseph Kline2, Frank Scholze1, and Michael Krumrey1 — 1Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany — 2National Institute of Standards and Technology (NIST), Gaithersburg, United States
New approaches are needed for the fast, non-destructive dimensional measurement of complex nanostructures produced in the semiconductor industry. One technique being considered is Small-Angle X-ray Scattering (SAXS), which has already been used to reconstruct the line profile of gratings with low uncertainties. Grazing-Incidence SAXS (GISAXS) additionally provides surface sensitivity, but the interpretation of the scattering is complicated by multiple scattering effects.
To produce structures beyond the diffraction limit of a single lithographic exposure, self-aligned double patterning (SADP) can be used. In SADP, sidewalls are deposited on the original line and the original line is removed, such that the sidewalls form lines with a doubled structure density. If the sidewall width and the original linewidth do not match, an alternating pitch error is introduced, impacting the performance of the resulting structures.
We present GISAXS measurements of a sample series produced by self-aligned quadruple patterning with varying pitch errors. From the intensities of the grating diffraction orders, we quantify the pitch errors and compare our results to previous SAXS measurements of the same samples.