Share Email Print

Proceedings Paper

Materials design and development of fluoropolymers for use as pellicles in 157-nm photolithography
Author(s): Roger H. French; Joseph S. Gordon; David J. Jones; M. F. Lemon; Robert C. Wheland; Xun Zhang; Fredrick C. Zumsteg; Kenneth G. Sharp; Weiming Qiu
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

The introduction of 157 nm as the next optical lithography wavelength has created a need for new soft (polymeric) or hard (quartz) pellicle materials optimized for this wavelength. Materials design and development of ultra transparent fluoropolymers suitable for 157 nm soft pellicle applications has produced a number of promising candidate materials with absorbances below 0.03/micrometer as is necessary to achieve pellicle transmissions above 95%. We have developed 12 families of experimental TeflonAFR (TAFx) materials which have sufficient transparency to produce transmissions above 95%. For the successful fabrication of 157 nm pellicles from these materials, the fluoropolymers must have appropriate physical properties to permit the spin coating of thin polymer films and their lifting and adhesive mounting to pellicle frames, the processes which produce free standing pellicle membranes of micron scale thickness. Relevant physical properties include molecular weight, glass transition temperature, and mechanical strength and toughness. We have successfully developed various of the ultra transparent TAFx polymer families with these physical properties. Upon irradiation these 157 nm pellicle polymers undergo photochemical darkening, which reduces the 157 nm transmission of the material. Measurements of the photochemical darkening rate allow the estimation of the pellicle lifetime corresponding to a 10% drop in 157 nm transmission. Increasing the 157 nm lifetime of fluoropolymers involves simultaneous optimization of the materials, the pellicle and the end use. Similar optimization was essential to achieve the desired radiation durability lifetimes for pellicles successfully developed for use with KrF (248 nm) and ArF (193 nm) lithography.

Paper Details

Date Published: 14 September 2001
PDF: 9 pages
Proc. SPIE 4346, Optical Microlithography XIV, (14 September 2001); doi: 10.1117/12.435710
Show Author Affiliations
Roger H. French, DuPont Co. (United States)
Joseph S. Gordon, DuPont Photomasks, Inc. (United States)
David J. Jones, DuPont Co. (United States)
M. F. Lemon, DuPont Co. (United States)
Robert C. Wheland, DuPont Co. (United States)
Xun Zhang, DuPont Photomasks, Inc. (United States)
Fredrick C. Zumsteg, DuPont Co. (United States)
Kenneth G. Sharp, DuPont Co. (United States)
Weiming Qiu, DuPont Co. (United States)

Published in SPIE Proceedings Vol. 4346:
Optical Microlithography XIV
Christopher J. Progler, Editor(s)

© SPIE. Terms of Use
Back to Top