Recently, in Critical Dimension (CD) measurement on high-end masks, Optical Proximity Correction (OPC) pattern measurement is on increase and it has become important to measure angled lines. In CD searching on a CAD layout viewer, the exact CD values can be detected for the OPC patterns because they consist of a lot of rectangles. While, the CD values for angled lines have not been detected in it. Meanwhile the mask Critical Dimension Scanning Electron Microscope (CD-SEM) can measure angled lines, but measurement accuracy cannot be verified because there is no reference standard sample available for calibration of the CD values. In this study, we made the prototype of a standard sample for CD measurement with 0 degree and 45 degree angled lines by using VLSI Standards Inc. Nano Lattice Standard. The shape is the same as 6025 mask. We measured CDs of angled lines of the above sample using Holon EMU-260 and examined the calibration method. We are going to discuss the CD marking method on a CAD layout viewer in order to automate measurement of angled lines in near future.

Date Published: 8 November 2005
PDF: 10 pages
Proc. SPIE 5992, 25th Annual BACUS Symposium on Photomask Technology, 59924H (8 November 2005); doi: 10.1117/12.632016

Published in SPIE Proceedings Vol. 5992:
25th Annual BACUS Symposium on Photomask Technology
J. Tracy Weed; Patrick M. Martin, Editor(s)