Patent ID: 6066853
Filing Date: 2000-05-23
Classification: B82Y,H01J

Abstract:
In an electron-optical system for an electron-beam projection-exposure apparatus that projects a mask pattern, divided into multiple fields, field-by-field onto a substrate, an improvement wherein:(a) at least one of (i) a mask-to-substrate distance and (ii) a field length-by-width dimension has an optimal value for projection exposure of the mask pattern onto the substrate, the value being determined according to a quantitative relationship of at least one geometric optical aberration exhibited by the electron-optical system with a chromatic aberration exhibited in a single field on an optical axis of the electron-optical system and a space-charge effect exhibited by the electron beam passing through the electron-optical system; and(b) the electron-optical system comprises first and second projection lenses and at least one deflector associated with each projection lens, the at least one deflector being energizable to diminish or cancel off-axis aberrations exhibited by the electron-optical system as the electron-optical system projects a field onto the substrate using the electron beam.