Patent ID: 7382446
Filing Date: 2008-06-03
Classification: G03F

Abstract:
1. A method of measuring aberration of a projection optical system, comprising: an illuminating step for illuminating a reticle by use of light from an effective light source and through an illumination optical system; a projecting step for projecting an image of a test pattern formed on the reticle, upon a substrate through the projection optical system; a measuring step for measuring a positional deviation amount of the image of the test pattern formed on the substrate through the projection optical system; and a determining step for determining the aberration of the projection optical system on the basis of the positional deviation amount measured at said measuring step; wherein said illuminating step includes a shaping step for shaping the light from the effective light source by use of shaping means disposed in the illumination optical system, and by use of a light blocking pattern formed on a first surface of the reticle, remote from a second surface of the reticle where the test pattern is formed, wherein, in said shaping step, the light from the effective light source is shaped by the shaping means and the light blocking pattern so that the positional deviation amount of the image of the test pattern depends on a predetermined Zernike coefficient, and wherein a central portion of the effective light source is blocked by the shaping means.