Patent ID: 7276714

Claim:
A pattern definition device ( 102 ) for use in a particle-beam processing apparatus ( 100 ), said device being adapted to be irradiated with a beam (lp,bp) of electrically charged particles and allow passage of the beam only through a plurality of apertures, said apertures ( 21 , 230 ) of identical shape defining the shape of beamlets (bm) permeating said apertures, wherein the apertures ( 21 ) are arranged within a pattern definition field (pf), wherein with said apertures are associated corresponding blanking openings ( 220 ) located such that each of the beamlets (bm) traverses that blanking opening which corresponds to the aperture defining the beamlet respectively, each blanking opening ( 220 ) being provided with a deflection means ( 221 ) controllable by a blanking signal ( 911 ) between two deflection states, namely, a first state (‘switched on’) when the deflection means has assumed a state in which particles radiated through the opening are allowed to travel along a desired path (pl), and a second state (‘switched off’) when the deflection means is deflecting particles radiated through the opening off said path (pl), wherein the positions of the apertures ( 21 ) in the pattern definition field (pf) taken with respect to a direction (Y) perpendicular to a scanning direction and/or a direction (X) taken with respect to a direction parallel to said scanning direction are offset to each other by not only multiple integers of the effective width (w) of an aperture taken along said direction, but also additional multiple integers of an integer fraction of said effective width (‘fractional offsets’), said scanning direction (sd) denoting a direction along which an image of the apertures formed by said beam on a target surface is moved over the target surface during an irradiation process.