摘要 |
A method and a device for transferring minute patterns (12) on the mask (11) to the substratum (17) by means of illuminating optical system (1-10) projecting beams of illuminating light onto the mask (11) and a projection aligner having a projection optical system (13) for projecting images of minute patterns (12) on the substratum (17). Beams of said illuminating light are thrown, as at least a pair of luminous fluxes slantwise facing the mask (11), through a pair of light transmitting windows (6a, 6b) of a spatial filter (6) onto the minute patterns (12), and, as a result, one of diffracted beams of the light of +/- first orders caused by minute patterns (12) of the illuminated mask (11) and diffracted beams of zero order pass portions, equidistantly spaced apart from the optical axis of the projection optical system, of or near the Fourier transform surface (14) in the projection optical system (13) for minute patterns (12) on the mask (11) so that projected images may be formed to be sharp in contrast and high in resolution on the substratum (17) at a large focal depth. <IMAGE> |