Patent ID: 6700649
Filing Date: 2004-03-02
Classification: G03B,G03F

Abstract:
A method for exposing a semiconductor wafer for a photolithography process comprising:placing semiconductor wafer at an image plane of a second lens, said second lens having a front focal plane; placing a pupil filter at said front focal plane of said second lens, said pupil filter designed in accordance with: Pupil Filter=1âˆ’{[2(bâˆ’a)A1sinc(kp(bâˆ’a)/2)cos(kp(a+b)/2)]/2asinc(kpa)}, where A1 is the transmission amplitude of said binary mask, &lgr; is the wavelength of said exposing light, k=2&pgr;/&lgr;, a is one-half of a feature size of said binary mask, p is the pitch of said binary mask, and b=p/2; placing a first lens having a front focal pane and a pupil plane, said pupil plane substantially coincident with said pupil filter; placing a binary mask at said front focal plane of said first lens; and illuminating said binary mask with an incident light such that said incident light selectively passes through said binary mask, said first lens, said pupil filter, and said second lens onto said semiconductor wafer.