Important Challenge for Optical Lithography Extension utilizing Double Patterning Process

Abstract

Lithographic scaling has been driven by improvements in wavelength and numerical aperture historically. In the semiconductor industry, the H2O base 192 immersion technique has still been main exposure tool combined with various low-k1 techniques, such like off-axis illumination, phase-shift mask and so on. The focus is now on double patterning techniques (DPT) as a means to circumvent the limitations of Rayleigh′s definition. Actually, self-aligned spacer double patterning (SADP) has already been employed in high volume manufacturing of NAND flash memory devices. This paper introduces demonstration results focused on the extendibility of double patterning techniques for downward scaling and various device layouts utilizing SADP (Self-aligned Double patterning) mainly.