Patent ID: 7144178
Filing Date: 2006-12-05
Classification: B82Y,G03F,H01J,H01L,Y10S

Abstract:
1. A method of producing a semiconductor device including the step of irradiating a charged particle beam on a photosensitive surface via a mask on which predetermined patterns are formed to transfer said patterns on said photosensitive surface, said method comprising the steps of: using a mask comprising: a support frame; a thin film formed thinner than said support frame and surrounded by said support frame; a first section comprised of one of four sections consisting of regions obtained by dividing said thin film into four by a first straight line passing through a first point consisting of one point on said thin film and extending in a first direction and a second straight line orthogonal to said first straight line at said first point and extending in a second direction; a second section adjacent to said first section in the first direction; a third section adjacent to said second section in the second direction; a fourth section adjacent to said third section in the first direction and adjacent to said first section in the second direction; a first group of struts, in each of said first to fourth sections, comprised of a plurality of struts formed from the same material as said support frame, extending in the first direction, and formed in parallel with each other at equal intervals so as to connect with said support frame on said thin film; a second group of struts, in each of said first to fourth sections, comprised of a plurality of struts formed from the same material as said support frame, extending in the second direction, and formed in parallel with each other at equal intervals so as to connect with said support frame on said thin film and intersect the first group of struts; skirts provided in parallel to said struts at said thin film at the two side parts of said struts; strut zones comprised of said struts and said skirts at the two sides where the interval between adjacent strut zones becomes a whole multiple of at least 3 of the width of the strut zones, a first strut zone including one of said first group of struts formed in said first section and contacting said first straight line, said first strut zone being connected to said second group of struts of said fourth section at different locations from said second group of struts of said first section in said first direction, a second strut zone including one of said second group of struts formed in said first section and contacting said second straight line, said second strut zone being connected to said first group of struts of said second section at different locations from said first group of struts of said first section in said second direction, a third strut zone including one of said first group of struts formed in said third section and contacting said first straight line, said third strut zone being connected to said second group of struts of said second section at different locations from said second group of struts of said third section in said first direction; a fourth strut zone including one of said second group of struts formed in said third section and contacting said second straight line, said fourth strut zone being connected to said first group of struts of said fourth section at different locations from said first group of struts of said third section in said second direction; holes provided in the part of said thin film surrounded by the strut zones and passed through by a charged particle beam, said holes being formed by complementary divided patterns comprised of different parts of the same patterns in said first to fourth sections; and four superpositioned regions of the same shapes and sizes selected from the first to fourth sections, said superpositioned regions including the first and second straight lines, wherein any point on the superpositioned regions is included in the thin film other than the strut zones in at least two sections of the first to four sections, to perform first exposure to transfer said complementary divided patterns of said superpositioned regions of said first to fourth sections to said photosensitive surface; performing second exposure on said photosensitive surface to transfer overlaid said complementary divided patterns of said superpositioned region of a different section from the first exposure; performing third exposure on said photosensitive surface to transfer overlaid said complementary divided patterns of said superpositioned region of a different section from the first and second exposures; and performing fourth exposure on said photosensitive surface to transfer overlaid said complementary divided patterns of said superpositioned region of a different section from the first to third exposures.