120-nm lithography using off-axis TIR holography and 364 nm exposure wavelength

An extension of total internal reflection holographic lithography is presen ted that nearly doubles its resolution limit for patterns that are periodic or quasi-periodic in one direction. An off-axis object beam is employed to record the hologram from the photomask, the angle of the beam being such t hat essentially just the zero order and a first diffraction order are trans mitted by the mask. A fully automated equipment based on this method has be en developed which also implements a step-and-repeat procedure to enable a large array of patterns to be recorded in the hologram from a single patter n in the mask. Gratings and patterns with substantial deviations from the p ure grating form, with resolutions down to 120 nm, have been printed using an exposure wavelength of 364 nm. (C) 2001 Elsevier Science B.V. All rights reserved.