Electron Beam Writing and Direct Processing System for Nanolithography
This article describes the electron beam direct processing system developed for patterning beyond the resolution limit of conventional resists by using inorganic resists or electron beam induced surface reactions. A probe beam with the probe current of 120 pA was focused into 3nm with the newly developed optical column. An ultra high vacuum sample chamber, which can coexist with a precise stage driving mechanism and a LASER measuring system. The base pressure of the sample chamber after baking was 1x10-8 Torr and differential evacuation of the sample chamber and the mechanism chamber was demonstrated. The stabilities of the stage and the optical column were measured with a LASER measuring system and mark detection procedures. The standard deviations of stitching and overlay accuracy measured by an exposure of PMMA resists revealed that this FB system can delineate the lines with the ultimate resolution of PMMA resists.