Proceedings Article | 2 April 2007
Proc. SPIE. 6519, Advances in Resist Materials and Processing Technology XXIV
KEYWORDS: Polymers, Lithography, Line edge roughness, Photoresist materials, Coating, Scanning electron microscopy, Immersion lithography, Chemically amplified resists, Optical lithography, Absorption
Recently we have developed and reported some novel non-ionic photoacid generators (PAGs) which generate a
strong acid (perfluorobutanesulfonic acid) by light irradiation and is applicable to chemically amplified ArF
photoresist, such as 2-[2,2,3,3,4,4,5,5-octafluoro-1-(nonafluorobutylsulfonyloxyimino)-pentyl]-fluorene (ONPF), 2-
[2,2,3,3,4,4,4-heptafluoro-1-(nonafluorobutylsulfonyloxyimino)-butyl]-fluorene (HNBF) and so on. Here the
lithographic property of ONPF in some ArF model formulations was evaluated under 193 nm dry and immersion
exposure comparing one of the most typical ionic PAGs, triphenylsulfonium perfluorobutanesulfonate (TPSPB), on
lithographic application-relevant properties, e.g. exposure latitude, line edge roughness (LER) and so on, by top-down
view SEM observation. 80 nm line and space (L/S) patterning was successfully conducted. Additionally we
investigated the striation issue with ONPF when the matrix polymer of resist was changed. It was revealed that ONPF
showed better coating property in a copolymer of &ggr;-butyrolactone methacrylate, 2-ethyladamantyl methacrylate and
hydroxyladamantyl methacrylate than in a copolymer of &dgr;-methacryloyloxynorbornane butyrolactone in lactone unit.
