Dilute aqueous base developable resists for environmentally friendly and biocompatible processes

Photoresists developable in dilute aqueous bases are introduced for environmentally friendly photoresist processing and biopatterning. The proposed photoresists are of positive or negative tone, chemically amplified, based on synthesized (meth)acrylate copolymers bearing either pendant t-butyl ester group or 2-hydroxylethyl ester group for positive and negative imaging, respectively. Characteristic high-resolution lithographic results (0.13 mum lines) obtained with a positive (meth)acrylate-based chemically amplified resist formulation upon development with 13 x 10(-3) M TMAH solution are presented. On the other hand, a slightly modified resist formulation was used for biomolecule patterning under biocompatible conditions and protein microstructures (<10 mum equally spaced lines) are demonstrated. (C) 2002 Elsevier Science B.V. All rights reserved.