US Patent 7144682 Near-field exposure method

A method for exposing a workpiece on the basis of near-field light escaping from an exposure mask having a light blocking film with a plurality of rectangular openings. The method includes protecting non-polarized near-field exposure light from a light source through the openings of the exposure mask to perform exposure of a pattern on the workpiece. The widths of the rectangular openings are smaller than that at a cross-point between a first curve on a coordinate of widths of the openings versus a near-field light intensity for an incident-light electric-field direction perpendicular to a lengthwise direction of a small-opening pattern and a second curve on the same coordinate for an incident-light electric-field direction parallel to the lengthwise direction of the small-opening pattern.