For the sub 100 nm integrated circuit generations we investigate the potential of a new lithography concept: multiple aperture pixel by pixel enhancement of resolution. The wafer is illuminated by a large number of electron beams which are triggered by an equal number of light beams. The light beams are switched on and off by an optical mask. The electron beams are focused by parallel electric and magnetic fields [P. R. Malmberg, T. W. O'Keeffe, and M. M. Sopira, J. Vac. Sci. Technol. 10, 1025 (1973); J. P. Scott, ibid. 15, 1016 (1973)]. By means of computer simulation we determine the point spread function of the electron beam at the wafer. The requirements on the magnetic field form and the alignment are evaluated. It is concluded that the resolution can be better than 1:1 image projection. For 100 nm lines and spaces there is a wide process window.