We have developed a new mask patterning system, which can fabricate 130nm generation masks by means of a stitching exposure technique. We call this system the Photomask Repeater (PR)1,23,4. The PR is a 5x i-line stepper modified for mask manufacturing with a field size of 22x22mm in a single exposure. However, the device size on a 4x mask is larger than 22x22mm. Furthermore, excellent mask CD uniformity is required. For this purpose the exposure field size was extended with the use of “seamless stitching technology”. This is clearly the key to obtaining a practical, accurate mask patterning system. Results have been achieved on masks with this system showing CD variation of less than +/- 7nm at a stitching area by means of a “gradation filter”. Moreover, overall CD uniformity is 10.36nm (3?), while image placement accuracy is 17.8nm (3?) and 2nd alignment accuracy is 24.1nm (3?). PR is an attractive system for System on Chip mask manufacturing, and is also effective in reducing Turn Around Time.

Date Published: 22 January 2001
PDF: 12 pages
Proc. SPIE 4186, 20th Annual BACUS Symposium on Photomask Technology, (22 January 2001); doi: 10.1117/12.410713

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