Masked ion beam lithography with highly charged ions

Masked ion beam lithography using highly charged ions is demonstrated for t he first time by producing an array of hundreds of ordered micrometer wide dots using Xe44+ on poly(methylmethacrylate) resist. At low dose, exposure of the resist is incomplete and isolated single-ion impact sites can be see n within the exposed areas. Atomic force microscope images of the single-io n impact sites show Craters with a width of 24 nm. At high dose, the exposu re is complete and the dot morphology is consistent with limitations from t he mask. Scanning electron microscope images indicate that the sidewall slo pe is steeper than four. (C) 1998 American Vacuum Society. [S0734-211X(98)1 3006-8].