SOME ASPECTS OF SELF-ALIGNED MULTIPATTERNING IN IMMERSION LITHOGRAPHY
Multipatterning has enabled continued scaling of chip technology at the 28 nm node and beyond. Self-aligned double patterning (SADP) and self-aligned quadruple patterning (SAQP) as well as LithoEtch / Litho-Etch (LELE) iterations are widely used in the semiconductor industry to enable patterning at sub 193 immersion lithography resolutions for layers such as FIN, Gate and critical Metal lines [1]. However, multipatterning increases process complexity as well as EPE variations, which depend on overlay including.In this paper we review multipatterning methods for line / space and contact holes formation, their advantages and disadvantages and also ways to decrease EPE variation, self-aligned techniques including.