Interference assisted lithography for patterning of 1D gridded design

Abstract

We present Interference Assisted Lithography (IAL) as a promising and cost-effective solution for extending lithography. IAL achieves a final pattern by combining an interference exposure with a trim exposure. The implementation of IAL requires that today's 2D random layouts be converted to highly regular 1D gridded designs. We show that an IAL-friendly 6T SRAM bitcell can be designed following 1D gridded design rules and that the electrical characteristics is comparable to today's 2D design. Lithography simulations confirm that the proposed bitcell can be successfully imaged with IAL.