Patent ID: 6528238
Filing Date: 2003-03-04
Classification: G03F

Abstract:
A method of making parallel grooves in a photoresist coating on a substrate comprising the steps of:a) providing a reticle with a pattern of parallel lines each line being opaque to electromagnetic radiation, the distance between adjacent two lines being greater than the width of the line; b) subjecting said photoresist to a first exposure of electromagnetic radiation of a selected wavelength via said reticle with a dose less than is required to fully sensitize said photoresist, wherein, by means of the width of said line and the distance between the adjacent two lines, an alternate pattern of an unexposed area and a partially exposed area is formed on the photoresisit coating; c) shifting said reticle relative to said photoresist coating or vice versa such that each line of said reticle is projected in each said partially exposed area; d) subjecting said photoresist to a second exposure of electromagnetic radiation of a selected wavelength via said shifted reticle with a dose less than is required to fully sensitize said photoresist to development such that the total dose of the two exposures is equal to or greater than the dose required to fully sensitize the photoresist, wherein part of each said partially exposed area is fully exposed; and e) developing the photoresist, wherein said fully exposed area is removed from the photoresist whereby parallel grooves can be formed in a photoresist coating.