Direct Write Optical Lithography (DW-OL)
In conventional optical lithography, a resist is exposed with UV light that is projected through a specially prepared mask to emboss the desired pattern. The masks are often very expensive and made for a specific application. Therefore, any design change requires a new mask which quickly increases costs of process development. Direct write optical lithography on the other hand uses a computer controlled, high precision scanning system (either the sample or the light) where a design file dictates the pattern to be written. This is very advantageous in research and development for prototyping purposes or new types of structures are developed constantly. We use the micro-structuring laboratory in our department to do DW-OL for fabricating structures that does not need the precision of the FIB or simply too large for FIB processing. The structures can be either used as masks for subsequent RIE process or can be utilized on their own.