Enhancement of lithographic patterns by using serif features

Author

Fu, Chong-Cheng ; Yang, Tungsheng ; Stone, Douglas R.

Author_Institution

AT&T Bell Lab., Allentown, PA, USA

Volume

38

Issue

12

fYear

1991

fDate

12/1/1991 12:00:00 AM

Firstpage

2599

Lastpage

2603

Abstract

Serifs were designed for the thin-oxide level pattern of a CMOS SRAM cell with submicrometer design rules, using two-dimensional aerial image simulations for optimization. Results of experiments using I-line lithography showed good agreement with the simulations, and significant pattern shape improvement was observed when serifs were used. The proximity effects in the electron-beam mask-making process were found to reduce the full effectiveness of this technique due to the resulting deviations in serif sizes on the reticle. Further enhancement of pattern fidelity may be possible if this issue is resolved

Keywords

CMOS integrated circuits; SRAM chips; integrated circuit technology; photolithography; CMOS SRAM cell; I-line lithography; electron-beam mask-making process; lithographic patterns; optimization; pattern shape improvement; proximity effects; serif features; submicrometer design rules; thin-oxide level pattern; two-dimensional aerial image simulations; Design optimization; Lenses; Lithography; Optical diffraction; Optical losses; Printing; Proximity effect; Random access memory; Resists; Shape;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/16.158681

Filename

158681