Ultrahigh molecular weight poly(methyl methacrylate) as an electron-beam resist

Ultrahigh molecular weight (UHMW) poly(methyl methacrylate) (PMMA) produced by plasma-initiated polymerization was investigated for its suitability as an electron-beam resist. Patterns exposed in this material at low to moderate doses (<5×10−6 C/cm2) displayed distorted features after development in a 1:1 mixture of methyl ethyl ketone and isopropanol. The distorted features are believed to originate from a combination of pattern swelling and stress relief.