Share Email Print

Proceedings Paper

Mask transmission resonance in bi-layer masks
Author(s): Vicky Philipsen; Peter De Bisschop; Kei Mesuda
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

We report on the experimental observation of mask transmission resonances in line/space gratings on bi-layer mask stacks and on the validation by mask 3D lithographic simulations. The mask transmission resonances manifest themselves as a local enhancement in the dose-to-size curve through mask line width for a given pitch targeted to a fixed wafer CD. We observed this resonance in gratings on a bi-layer Ta/SiON 1% attenuated phase shift mask (att.PSM). We relate the finding to a local transmission loss of the propagating diffraction orders in this range of mask line widths. This resonant-type anomaly has a large impact on the imaging performance of the mask stack. The through-mask-line-width behavior of the mask error enhancement factor (MEEF) shows strong variations and even negative MEEF values around the position of this resonance, which stem from the local dose-to-size enhancement. More precisely, the behavior of the MEEF can be well predicted by the differential of the dose-to-size curve. In this study we investigate both by experiments and simulations the dependency of this mask transmission resonance on various lithographic conditions such as incidence angle and polarization state of the incoming light, grating pitch, and mask material. Based on our findings we provide an explanation of the underlying optical mechanism.

Paper Details

Date Published: 19 May 2008
PDF: 8 pages
Proc. SPIE 7028, Photomask and Next-Generation Lithography Mask Technology XV, 702815 (19 May 2008); doi: 10.1117/12.793046
Show Author Affiliations
Vicky Philipsen, IMEC (Belgium)
Peter De Bisschop, IMEC (Belgium)
Kei Mesuda, IMEC (Belgium)
Dai Nippon Printing Co., Ltd. (Japan)

Published in SPIE Proceedings Vol. 7028:
Photomask and Next-Generation Lithography Mask Technology XV
Toshiyuki Horiuchi, Editor(s)

© SPIE. Terms of Use
Back to Top