Method and apparatus for improving pattern fidelity in diffraction-limited imaging

Image transmission apparatus comprising a substrate having a photosensitive medium, a mask, an illumination system configured to illuminate said mask, and an imaging lens system between said mask and said substrate;

• said imaging lens system configured to reimage the illuminated mask image onto the photosensitive medium of said substrate;
• said imaging lens system having a Fourier plane with a lens opening and being further configured to allow unobstructed access to the Fourier plane to allow different pupil plane filters to be inserted into said Fourier plane;
• said imaging lens system being further configured to optimize the optical image transmitted by the lens opening;
• and
• said pupil plane filters being configured to transmit light in some regions of the Fourier plane and to block light in other regions, the transmitting regions of said pupil plane filters being determined in concert with the illumination directions of said illumination system to provide orthogonalized and selected filtering of the image transmission through the lens opening such that spectral overlap at selected frequencies is reduced, to enhance the optimized optical image transmitted by the lens opening and recorded by the photosensitive medium.

A method of transmitting an image from a mask to a substrate having a photosensitive medium, comprising the steps of

• illuminating the mask;
• providing an imaging lens system between the mask and the substrate configured to reimage the illuminated mask image onto the photosensitive medium of said substrate, said imaging lens system having a Fourier plane with a lens opening and being further configured to allow unobstructed access to the Fourier plane to allow different pupil plane filters to be inserted into said Fourier plane, and said imaging lens system being further configured to optimize the optical image transmitted by the lens opening;
• and
• inserting pupil plane filters into said Fourier plane in a scheme configured to transmit light in some regions of the Fourier plane and to block light in other regions, the transmitting regions of said pupil plane filters being determined in concert with the illumination directions of said illumination system to provide orthogonalized and selected filtering of the image transmission through the lens opening such that spectral overlap at selected frequencies is reduced, to enhance the optimized optical image transmitted by the lens opening and recorded by the photosensitive medium.