For masked ion beam lithography (MIBL) beam-induced mask heating can cause deformations and image distortion. This can be avoided by the use of a resist ten times more sensitive than PMMA. Poly(2,2,2-trifluoroethyl -chloroacrylate), PTFECA, has been shown to be about ten times more sensitive than PMMA for proton beam exposures at 100 keV, and has demonstrated sub-half-micron resolution. The etch characteristics of PTFECA, however, are not as good as PMMA.
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