Patent ID: 6239862
Filing Date: 2001-05-29
Classification: G03F

Abstract:
A photolithographic method for imaging a mask pattern on a substrate, comprising:providing a substrate which is at least partially covered by a layer of radiation-sensitive material;providing a mask which contains a mask pattern;producing illumination radiation having a preselected intensity;projecting an image of at least part of the mask pattern onto a target area of the layer of radiation sensitive material using said illumination radiation;generating a slit-shaped illumination field from said illumination radiation produced, said slit-shaped illumination field having a variable slit width; andconcentrating substantially all the illumination radiation produced into said slit-shaped illumination field,wherein a value of energy of said illumination radiation within said slit-shaped illumination field is maintained substantially constant for all slit widths in a preselected photolithographic mode of operation.