This paper investigates proximity effect correction methodologies for alternating aperture phase-shifting masks. A simple approximation is used to investigate the proximity effects: at low sigma, the aerial image intensity on the wafer can be calculated by taking the square of the sum of the amplitudes of each pattern on the mask taken separately. Results show that proximity effects are mainly driven by low sigma illumination and that correcting chrome patterns is less efficient than modifying the diffraction of the patterns by changing the shape of the phase-shifting regions.

Date Published: 22 January 2001
PDF: 11 pages
Proc. SPIE 4186, 20th Annual BACUS Symposium on Photomask Technology, (22 January 2001); doi: 10.1117/12.410709

Published in SPIE Proceedings Vol. 4186:
20th Annual BACUS Symposium on Photomask Technology
Brian J. Grenon; Giang T. Dao, Editor(s)