Interferometric lithography—from periodic arrays to arbitrary patterns

Interferometric lithography is a simple technology for the production of very small features. Using I-line wavelength laser sources (364-nm Ar-ion or 355-nm tripled YAG lasers) dense (1:1 line:space ratio) periodic structures at 0.125-μm have been demonstrated. Mix-and-match with optical lithography has been demonstrated. Imaging interferometric lithography, a true integration between optical and interferometric lithographies, potentially provides a route to arbitrary structures with a resolution up to 130 nm (dense patterns) at I-line and 65 nm at a 193 nm exposure wavelength.