Generalized scanning beam interference lithography system for patterning gratings with variable period progressions

We demonstrate a versatile interference lithography system that can continuously vary the pattern period and orientation during fabrication of general periodic structures in one or two dimensions. Initial experimental results, using closed-loop beam steering control and double exposures on a stationary substrate, are obtained in order to illustrate its principle of operation. A fringe-locking scheme for phase control is also demonstrated including discussion of issues related to future system developments.