Patent ID: 6991896

Claim:
An exposure method comprising the steps of: providing a mask that arranges a contact-hole pattern and a pattern smaller than the contact-hole pattern; and illuminating the mask by using an effective light source so as to resolve the contact-hole pattern and restrain the smaller pattern from resolving on an object to be exposed via a projection optical system, wherein the following conditions are met: A =−1.7 k 1 +C 1, 1.2 ≦C 1≦1.3 0.5 ≦B ≦0.55 and B≦A −0.1 0.80≦σ≦0.9 and σ≧ A +0.1 k 1 =( L /λ) NA, where k 1 is resolving power, L is a hole diameter of the contact-hole pattern, λ is a wavelength for exposure, NA is a numerical aperture of the projection optical system, σ is a ratio of a numerical aperture of an illumination optical system to the numerical aperture of the projection optical system, A and B are distances from two orthogonal axes to a boarder of a light-shielding part in said effective light source, the light-shielding part being symmetrical with respect to the two orthogonal axes.