Use of interference lithography to pattern arrays of submicron resist structures for field emission flat panel displays

We report on the fabrication of square arrays of submicron resist dots and holes using interference lithography - a relatively simple and inexpensive way of generating periodic structures over large areas. The arrays are formed by exposing a layer of resist to a two-beam interference pattern followed by a second exposure after rotating the sample by 90 degrees. Arrays with periods of 0.67-3.2 mu m were fabricated. The size of the structures is accurately controlled by varying the exposure dose. The exposure latitude for patterning arrays of dots is +/-16% for a +/-10% change in structure-width when an optimum size-to-period ratio is chosen. Compared to dots, holes are patterned with a smaller process window. We show that arrays of dots with diameters as small as 0.20 mu m, sidewall slopes of 88 degrees, and aspect ratios as high as 3:1 can be produced. These structures are well suited for the production of field emission flat panel displays. (C) 1997 American Vacuum Society.