A New Phase Shifting Technique for Deep UV Excimer Laser Based Lithography

This paper reports simulation and experimental details of a novel phase shifting technique based on laser interferomeiry. Phase shifting is one of the most promising techniques L 2 for the fabrication ofhigh density DRAM's. In recent years many kinds of phase shifting methods have been proposed to extend the resolution limit and contrast of image patterns . These techniques however, have several problems that result from the phase shift elements on the mask, especially when applied to UV excimer laser illumination