High Resolution Fabrication of Submicron Structures by Ion Beam Lithography

Ion beam lithography formicro fabrication in submicrometer or smaller dimension is studied. PMMA and FPM resist are used to be exposed by 50keV H + beam. Sensitivity and γ value of PMMA for a developer of MIBK: IPA=1 : 3 are 2×10 -6 C/cm 2 and 3.3, respectively. By using Au pattern-mask without substrate, fine structure (less than 0.1 µm) at the pattern edge is replicated in PMMA resist accurately. Backscattering effect is found not to affect the high resolution of ion beam lithography unlike in electron beam lithography. These features show ion beam lithography as a very useful technique for submicron pattern fabrication.