Maskless particle-beam system for exposing a pattern on a substrate

Abstract

A device ( ) for defining a pattern, for use in a particle-beam exposure apparatus ( ), said device adapted to be irradiated with a beam (lb,pb) of electrically charged particles and let pass the beam only through a plurality of apertures, comprises an aperture array means ( ) and a blanking means ( ). The aperture array means ( ) has a plurality of apertures ( ) of identical shape defining the shape of beamlets (bm). The blanking means ( ) serves to switch off the passage of selected beamlets; it has a plurality of openings ( ), each corresponding to a respective aperture ( ) of the aperture array means ( ) and being provided with a deflection means ( ) controllable to deflect particles radiated through the opening off their path (p ) to an absorbing surface within said exposure apparatus ( ). The apertures ( ) are arranged on the blanking and aperture array means ( ) within a pattern definition field (pf) being composed of a plurality of staggered lines (p ) of apertures. Each of the lines (p ) comprises alternately first segments (sf) which are free of apertures and second segments (af) which each comprise a number of apertures spaced apart by a row offset (pm), said row offset being a multiple of the width (w) of apertures, the length (A) of said first segments (sf) being greater than the row offset. In front of the blanking means ( ) as seen in the direction of the particle beam, a cover means ( ) is provided having a plurality of openings ( ), each corresponding to a respective opening ( ) of the blanking means and having a width (w1) which is smaller than the width (w2) of the openings ( ) of the blanking array means.