Abstract
Copolymers of methyl methacrylate and methacrylic acid have been shown to have higher sensitivity and thermal stability than PMMA as electron resists. A new method is presented which allows further sensitivity improvement through the use of multiple resist layers consisting of PMMA and copolymers of PMMA or entirely copolymers with different methacrylic acid content. Such combinations allow electron resist sensitivity as high as 2×10−6C/cm2 with temperature stability of over 160°C.