Interference method to fabricate phase shifter of alternate phase shifting mask

Abstract

It has been proposed that phase shifting mask (PSM) will be applied as a convenient and effective means of optical enhancement for IC lithography. Practical materials are needed for PSM at different wavelength lithography if these theoretical improvements are to be realized. Our goal is to create an alternating (Levenson) phase shifting mask (altPSM) with single-layer interference fringes structure of birefringent effect, corresponding to the patterns of enhance resolution being transferred into the wafer.