Self-aligned line-space pattern customization with directed self-assembly graphoepitaxy at 24nm pitch

Abstract

A viable pattern customization strategy is a critical to continue fin pitch scaling. Analysis shows that a self-aligned customization scheme will be required for fin pitch scaling beyond 20nm. In this paper, we explore scaling of the Tone-Inverted Grapho-Epitaxy technique with 24nm pitch PS-b-PMMA polymer to create groups of fins with self-aligned spaces in between. We discuss material selection, self-aligned customization, and etch processes to form 24-nm-pitch fins on silicon on insulator substrates. We demonstrate two-dimensional pattern customization at 24nm pitch, confirming scalability of this approach. FinFET device integration results at both 28 and 24 nm pitches shows a promising path for continued fin pitch scaling.