Patent ID: 6511048
Filing Date: 2003-01-28
Classification: B82Y,H01J

Abstract:
A pattern forming method using a cell projection electron beam lithography system, comprising the steps of:irradiating an electron beam emitted from an electron gun onto a first mask having a first rectangular aperture, for forming said electron beam into a rectangular cross-sectional electron beam; irradiating said rectangular cross-sectional electron beam from said first mask onto a second mask having a second rectangular aperture arranged on the central portion of said second mask, and first and second cell aperture exposure areas arranged around said second rectangular aperture, each of said first and second cell aperture exposure areas containing a plurality of cell apertures, for forming said rectangular cross-sectional electron beam respectively into an electron beam having a cell figure determined by said respective cell apertures; and projecting said electron beams having said cell figures onto a target surface to be pattern-formed, through a cell projection system having a demagnification lens and an objective lens, for writing said cell figures on said target surface; wherein said first cell aperture exposure areas are located on a peripheral portion of said second mask and said cell apertures contained in said first cell aperture exposure areas have a lower aperture area rate than that of said cell apertures contained in said second cell aperture exposure areas, and said second cell aperture exposure areas are located closer to the central portion of said second mask than said first cell aperture exposure areas.