The invention relates to a charged particle lithography system for patterning a target. The lithography system has a beam generator for generating a plurality of charged particle beamlets, a beam stop array with a beam-blocking surface provided with an array of apertures; and a modulation device for modulating the beamlets by deflection. The modulation device has a substrate provided with a plurality of modulators arranged in arrays, each modulator being provided with electrodes extending on opposing sides of a corresponding aperture. The modulators are arranged in groups for directing a group of beamlets towards a single aperture in the beam stop array. Individual modulators within each group have an orientation such that a passing beamlet, if blocking is desired, is directed to a blocking position onto the beam stop array. Beamlet blocking positions for different beamlets are substantially homogeneously spread around the corresponding single aperture in the beam stop array.