Novel method for intensity correction using a simple maskless lithography device

A simple, cost effective digital micromirror device (DMD) based maskless exposure device with a novel illumination correction is presented. The small scale laboratory setup with the presented construction details can be used with virtually any microscope with a suitable connector port. We demonstrate a technique for equilibration of intensity inhomogeneity which can be measured on the projection plane. The proposed technique enables pixel wise exposure dose manipulation. Consequently, unlike other systems, we are able to use the entire projected area for exposure with a feature size independent finite exposure time for a selected area. The long working distance makes it possible to expose surfaces located in a well or structures with variable heights which otherwise would not be exposable by conventional contact exposure. This simple setup is particularly helpful in fast, inexpensive prototyping of low resolution microstructures and sensor layouts. Features on silicon, glass and metal have been successfully patterned.