AVS 45th International Symposium
    Plasma Science and Technology Division Thursday Sessions
       Session PS-ThP

Paper PS-ThP1
Improvement on Lithography Pattern Profile by Plasma Treatment

Thursday, November 5, 1998, 5:30 pm, Room Hall A

Session: Plasma Science and Technology Division Poster Session
Presenter: C.P. Soo, National University of Singapore
Authors: C.P. Soo, National University of Singapore
M.H. Fan, Chartered Semiconductor Manufacturing Ltd., Singapore
A.J. Bourdillon, National University of Singapore
L.H. Chan, Chartered Semiconductor Manufacturing Ltd, Singapore
Correspondent: Click to Email
Chemically amplified (CA) resist is designed to have high sensitivity towards KrF excimer laser stepper. Unavoidably, this brings about substrate-specific effect as well. A few years recently, there are publications reported that during investigation of resist pattern profile by cross-sectional SEM micrographs, positive CA resist on nitride wafers revealed ?footing?.@footnote 1@ Various kinds of postulation had been made for degradation of resist pattern profile at resist/substrate interface by substrate poisoning. Sturtevant et al.@footnote 2@ reported that the chemical contaminants of substrate degraded the resist patterns on nitride and other substrate. A. Usujima et al.@footnote 1@ reported that substrate treatment using oxygen plasma is extremely effective in improvement on resist footing problem. However, down-stream oxygen plasma treatment needed to be optimized as excessive plasma treatment gave adverse performance because of surface damage. In this study, further optimization on oxygen plasma treatment was done. Besides using oxygen plasma, N@sub 2@O plasma treatment, was experimented to obtain repeatable straight resist profile. Besides , the substrate-specific effect was discussed from the standpoint of chemical interference from nitride substrate. The contaminants on the nitride substrate was studied by XPS and GC mass-spectrometry. XPS and GC mass-spectrometry were also used to investigate the effect of various surface treatments. The performance of each kind of surface treatment was evaluated by looking at cross-sectional profiles. @FootnoteText@ @footnote 1@ A. Usujima, K. Tago, A. Oikawa, K. Nakagawa, "Effects of substrate treatment in positive chemically-amplified resist", Proc. SPIE, vol 2438, pp529-39, 1995 @footnote 2@ J. Sturtevant, S. Holmes, S. Knight, D. Poley, P. Rabidoux, L. Somerville, T. McDevitt, E. Valentine, W. Conley, A. Katnani, J. Fahey, "Substrate contamination effects in the processing of chemically amplified DUV photoresists", Proc. SPIE, vol 2197, pp770, 1994.