Patent ID: 6262826
Filing Date: 2001-07-17
Classification: G02B,G03F,Y10S

Abstract:
A method of projecting a mask image onto a substrate using a scanning ringfield lithography apparatus, comprisingproducing extreme ultraviolet radiation of wavelengths ranging from approximately 4 to 20 nanometers;condensing the radiation and directing it generally in one direction toward a mask image;patterning the condensed radiation with the mask;reducing the patterned radiation with reflective focusing optics comprising four reflective elements which viewed from object to image are characterized as convex, concave, convex and concave;projecting a focused image on the substrate in the shape of an arcuate slit having a constant radius of curvature between approximately 30 mm and 70 mm and of a width between approximately 1.0 mm and 3.0 mm; andexposing a substrate coated with a photoresist layer to the reduced patterned radiation.