With the inherent advantages of good Critical Dimension (CD) control and good pattern fidelity, dry etching of Chrome-on- Quartz (COG) binary masks is necessary for production of 0.18um or below technology generation masks. Chrome dry etching process, however, tends to produce more defects than the traditional wet etch processes. We have conducted in-process defect inspection studies, which have identified several defect sources and have proposed process controls that minimize the number and size of defects from the entire dry etch process. This paper discusses the design of a defect test vehicle and describes an approach and methodology of defect inspection as a means of understanding the creation mechanisms of process related defects. A Lasertec Corporation (i)-line inspection system is employed along with different microscopy and metrology tools to identify and characterize these defects that can be attributed to the various steps in this entire dry etch process. Our results demonstrate that this approach of in-process inspection is very effective at identifying defects and their sources as they become evident at different process steps.

Date Published: 22 January 2001
PDF: 10 pages
Proc. SPIE 4186, 20th Annual BACUS Symposium on Photomask Technology, (22 January 2001); doi: 10.1117/12.410692

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