Abstract: The invention is directed to a method and apparatus of projection lithography in which the contrast introduced into a radiation sensitive material caused by the proximity effect is effectively removed in a single exposure. Patterned radiation is transmitted through a lens system with at least one lens and a back focal plane filter. The back focal plane filter has at least two apertures, an image aperture and a proximity effect correction aperture. Patterned radiation is transmitted through the image aperture and introduces the desired image into the energy sensitive resist material. A portion of the inverse pattern radiation is transmitted through the proximity effect correction aperture and onto the energy sensitive resist material to effectively remove the contrast therein caused by the proximity effect.

Abstract: Fabrication of devices of micron and submicron minimum feature size is accomplished by lithographic processing involving a back focal plane filter. A particularly important fabrication approach depends upon mask patterns which produce images based on discrimination as between scattered and unscattered radiation by accelerated electrons.