Patent attributes
An exposure method for exposing an image of a mask pattern onto a plate via a projection optical system. The method includes a step of illuminating one of a binary mask and an attenuated phase shifting mask, which has 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. The illuminating step uses an 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 smaller, where λ is a wavelength of the light, and NA is a numerical aperture of the projection optical system at an image side.
