Use of the phase-shifting mask in lithography allows substantial improvement of the resolution of commercial steppers for periodic circuit patterns, and, in certain cases, features smaller than 200 nm can be fabricated using i-line steppers ((lambda) equals 365 nm). There has therefore been much interest in developing this technology in recent years. In this paper, we examine and compare several approaches to evaluating mask designs for terminated periodic features, narrow gate lines, and contact holes, and compare the simulations with the actual results obtained when one attempts to use these designs in practice. Although we have found atomic force microscopy (AFM) to be a key tool for metrology, we conclude that there is a vital need for mask simulation, fabrication, inspection, and repair techniques to be developed further before these `imaginary' masks can be useful in the real world.

Date Published: 26 March 1993
PDF: 29 pages
Proc. SPIE 1809, 12th Annual BACUS Symposium on Photomask Technology and Management, (26 March 1993); doi: 10.1117/12.142145

Published in SPIE Proceedings Vol. 1809:
12th Annual BACUS Symposium on Photomask Technology and Management
Scott Landstrom; Richard LaFrance, Editor(s)