Effect of a photo-crosslinkable chemisorbed monolayer on thermal nanoimprinting of a poly(styrene) thin film on a gold substrate

摘要

A positive-type photoresist is used preferably for preparing a metal wiring circuit board in a subtractive method, because of facile removal of its residual layer from a metal surface by multiple rinses with an organic solvent after aqueous wet etching of metal. The photoresist is basically composed of a photodegradable polymer with polar functional groups. Therefore, a thin layer of the photoresist easily swells on its immersion in an aqueous etchant. The swell often causes the aqueous etchant to spread into an interface between metal and photoresist surfaces. The situation prevents us from fabricating reliably a metal pattern with a smaller width than 1μm by wet etching. Even if a non-polar hydrophobic polymer layer is used as an alternate resist layer, poor adhesion to a metal surface prevents from its pattern formation by thermal nanoimprinting.