Automated interference lithography systems for generation of sub-micron feature size patterns

Interferometric lithography is a maturing technology for patterning sub-micron structures in arrays covering large areas. The interference of two or more coherent optical waves is recorded in photoresist to produce a variety of structures including gratings, holes, posts, cones, and grids. This lithographic technique allows maskless patterning of large area substrates using short exposure times. Applications for periodic patterns include distributed feedback (DFB) lasers, field emission displays (FED), liquid crystal displays (LCD), advanced data storage applications, optical gratings, metrology standards, and motheye or sub-wavelength structures (SWS). Our work, is motivated by interest in bringing interferometric patterning out of research laboratories and into mainstream production facilities where hi,oh volume applications require automation and simplification of the exposure process. The concept and operational principles of two automated interference lithography systems, the HLS System 1000, and the HLS Model PC2, are introduced.