Increasing effective resolution through surface conditioners for 1x imprint templates, and photo mask applications beyond 65nm

Abstract

The improvement in effective resolution of photo masks and templates is demonstrated by reducing pattern collapse through the use of surface conditioners. The masks were coated with a chemically amplified negative e-beam resist, FEN270, and exposed on a 50keV e-beam system. The factors investigated in this experiment included two surface conditioner (SC) formulations, SC concentration, exposure dose, post bake temperature, and resist thickness. A test pattern was designed to pinpoint the onset of resist collapse. Line sizes from 40nm to 130nm were tested with different line spacing to exert varying amounts of capillary forces on the resist walls. Surface conditioners were manually dispensed prior to the final spin dry step. The results were compared to masks processed in the same manner but with DI water as a control. OptiPattern 50% concentration surface conditioner showed the most significant resolution improvement with approximately 23nm increase from the baseline. Some adverse swelling effects were observed with some formulations.