Patent ID: 6475684
Filing Date: 2002-11-05
Classification: G03F,Y10S

Abstract:
A method of correcting for variation in line width due to a loading effect generated when the material layer on a photomask substrate is dry-etched to have a desired pattern, the method comprising:obtaining a loading effect range &dgr; by dividing the substrate into meshes, and supposing the distribution of a loading effect frequency fL representing the degree of a loading effect at an arbitrary mesh on the substrate from each of other meshes to be a Gaussian distribution expressed according to the relationship fL&it;(r)=kÏ€&it;â€ƒ&it;Î´2&CenterDot;exp&af;[-â€ƒ&it;r2Î´2]wherein r denotes the distance between the arbitrary mesh and each of the other meshes, and k denotes a loading constant;calculating the loading density of the desired pattern, which is defined as a ratio of the area to be etched to the area of each mesh; calculating the loading effect at each of the meshes on the substrate by convolving the loading density and loading effect frequency at all of the meshes on the substrate; and correction-exposing an electron beam resist according to the loading effect calculated at each of the meshes on the substrate.