Negative and positive tone protein patterning on e-beam/deep-UV resists

The patterning of protein features on poly[(tert-butylmethacrylate)-co-(met hyl methacrylate)] via e-beam lithography was achieved using two mechanisms which control the radiation-assisted, spatially addressable, selective att achment of the protein on the polymer surface. The hydrophobicity-controlle d adsorption on the unexposed hydrophobic polymeric surface produces negati ve tone, high-contrast, high-resolution images. The chemical linkage of the protein amino groups to the carboxylic groups generated by the e-beam radi olysis produces images with a contrast tunable by the exposure energy. The performance measures of protein patterning, that is, the contrast, resoluti on, and level of defects, were discussed in the context of the respective m echanisms. As PtBuMA is the radiation sensitive component of a class of dee p-UV resists, the study applies to the protein patterning via deep-UV litho graphy, with potential impact on the fabrication of biodevices and combinat orial chemistry.