25 normally trims blocks the tails of the gaussian distribution of the beam however if the beam exhibits significant spherical aberration at the aperture 25 then tail portions of the beam distribution pass through the aperture 25 to the reticle rather than being blocked by the aperture plate this results in deterioration of beam uniformity at the reticle an image of the illuminated region on the reticle 26 is formed on the wafer 30 by the first and second projection lenses 27 28 working in concert with each other so as to be imprinted with an image of the illuminated pattern projected from the reticle 26 the upstream facing surface of the wafer 30 includes a layer of a suitable exposure sensitive agent termed a u201c resist u201d the apertures 25 and 29 trim away scattered electrons and limit the aperture angle on the reticle and wafer respectively these various components except for configuration of the electron beam source 20 can have the same respective structures and functions as corresponding elements in a conventional microlithography apparatus in the embodiment shown in fig4 the electron beam source 20 can be similar to that shown in fig1 discussed above with such a configuration of a microlithography apparatus a comparatively large area of the reticle 26 can be illuminated uniformly hence it now is possible to transfer expose patterns having finer linewidths than conventionally possible with excellent accuracy and precision even when the per shot area of the reticle has a.