LITHOGRAPHIC PERFORMANCE ENHANCEMENT USING DUMMY DIFFRACTION MASK

Abstract

The basic lithographic characteristics of the dummy diffraction mask which has two (dummy and main) mask layers, are investigated by simulation and experiment. The basic principle and theoretical details of the dummy diffraction mask are explained. Influences on the aerial image by the gap size and misorientation between two mask layers and by the nonideal phase grating, are simulated. Also, results of the lithographic performances for the simple patterns (line/space, isolated line, isolated space) and the complex patterns (V-shape active pattern in dynamic random access memory core cell) are presented.