Multiple images of a photolithography mask are produced, for simultaneously exposing a plurality of regions of a photoresist coating on a semiconductor substrate, by directing monochromatic light through the mask, collimating the light, and transmitting it through a first diffraction grating with vertical rulings and a second diffraction grating with horizontal rulings. The diffraction gratings each divide the light into a plurality of diffraction orders each containing the image to be recorded; and each of these images is imaged on the photoresist coating.