Patent ID: 7359033
Filing Date: 2008-04-15
Classification: G03F

Abstract:
1. An exposure method for exposing an image of a mask pattern onto a plate via a projection optical system, said method comprising: a step of illuminating one of a binary mask and an attenuated phase shifting mask, which comprises a contact hole pattern and an auxiliary pattern by utilizing light from a light source and an illumination optical system so that the contact hole pattern can be resolved, but a resolution of the auxiliary pattern is restrained, wherein said illuminating step uses off-axis illumination that is polarized in a tangential direction when a value that is calculated by normalizing half the length of an interval between centers of the auxiliary pattern and the contact hole pattern that are adjacent to each other by λ/NA is 0.25×√{square root over (2)} or less, where λ is a wavelength of the light, and NA is a numerical aperture of the projection optical system at an image side.