Projection exposure method

A projection exposure method that projects the shape of a hole onto a wafer by projecting a diffracted light, which is produced by applying light to a mask having a pattern for forming a hole pattern, onto the wafer through a projection optical system for exposure,

• wherein, in a plane substantially perpendicular to an optical axis, the light applied to the mask has a first intensity distribution in which the intensity is higher in the vicinity of eight apexes of an octagon centered at the optical axis than in other areas,
• the mask has a plurality of first opening patterns and a plurality of second opening patterns formed therein, a first auxiliary pattern is arranged on at least part of a straight line that is parallel with a first diagonal line of the octagon passing through the optical axis and passes through the center of a first opening pattern, and a second auxiliary pattern is arranged on at least part of a straight line that is parallel with a second diagonal line of the octagon passing through the optical axis and passes through the center of a second opening pattern,
• directly opposite two apexes of the octagon lie on the same straight line passing through the optical axis and are opposite to each other at equal distances from the optical axis, and two straight lines passing through adjacent apexes of the octagon intersect with each other at the optical axis at an angle of 45 degrees, and
• the first diagonal line and the second diagonal line intersect with each other at the optical axis at an angle of 45 degrees.