MANUFACTURE OF HOLOGRAPHIC GRATING

摘要

PURPOSE:To efficiently form a grating in a photoresist layer laid on a substrate by combinedly applying holography and ion etching in an oblique direction. CONSTITUTION:A photoresist layer 2 is laid on a substrate 1, and parallel lattice grooves 6 with a sine wave-shaped section are cut in the layer 2 by holography. The layer 2 is then irradiated with ion beams 4 at the angle of a direction which is obliquely upward to the grooves 6 and does not make a component projected on the lattice parallel to the grooves 6, e.g. at about 30 deg. angle of incidence to the substrate surface. The etching speed is maximized at about 60 deg. angle of incidence. Thus, the layer 2 is etched to form a grating (theta is a blaze angle) having lattice grooves 5 with an almost saw-toothed section.