Augmenting mask-based lithography with direct laser writing to increase resolution and speed

Abstract

A new method of hybrid photolithography, Laser Augmented Microlithographic Patterning (LAMP), is described in which direct laser writing is used to define additional features to those made with an inexpensive transparency mask. LAMP was demonstrated with both positive- and negative-tone photoresists, S1813 and SU-8, respectively. The laser written features, which can have sub-micron linewidths, can be registered to within 2.2 µm of the mask created features. Two example structures, an interdigitated electrode and a microfluidic device that can capture an array of dozens of silica beads or living cells, are described. This combination of direct laser writing and conventional UV lithography compensates for the drawbacks of each method, and enables high resolution prototypes to be created, tested, and modified quickly.