Patent ID: 6268907
Filing Date: 2001-07-31
Classification: G03F

Abstract:
A method for eliminating the standing wave effect present in a photoresist exposed to light from a light source in a pattern defined by a photomask, wherein the light travels on an optical path from the light source through the photomask to the photoresist, said optical path having a length, and said method comprising the step of varying the length of the optical path traveled by the light incident on the photoresist through a plurality of values, thereby eliminating the standing wave effect, wherein the path length is varied by passing the light through a rotating disk, saidn rotating disk having a plurality of apertures formed therein, each aperture having disposed therein a transparent medium having parallel entry and exit surfaces, and wherein the transparent medium in each aperture provides an optical path length for light passing through the transparent medium which is different from optical path length of the transparent medium in other apertures.