Sub half micron structures with profile control on compound semiconductor
substrates based on conventional i-line lithography
Keywords: lithography, resolution enhancement, i-line, slant gate, resist profile, compound semiconductor
Conventional i-line lithography was used as a basis for resist profile modification. The aim was the creation of slanted passivation openings for gate contacts with gate lengths between 0.1 and 0.5 μm. It was shown that slanted profiles are possible by applying a post development bake to the Novolac photoresist. Dimension reduction was achieved by modifying the Novolac/bottom-antireflection- coating interface. A modified approach combining plasma treatment of the photoresist lines with a bake sequence was used to create slanted features below 0.1 μm in the passivation layer.