Electrografted P4VP for High Aspect Ratio Copper TSV Insulation in Via-Last Process Flow

Abstract

© The Author(s) 2016. revised manuscript received. Via-Last metallization of High Aspect Ratio Through Silicon Via (HAR TSV) for 3D integration is challenging. Indeed, the formation of a uniform and conformal dielectric to insulate HAR TSVs in Via-Last process flow is difficult to achieve for any physical deposition process. In this study, we present the first reported HAR copper TSVs, insulated by highly conformal electrografted poly-4-vinylpyridine (P4VP) in Via-Last process-flow. As a demonstration, this allowed the metallization of HAR copper TSVs for die-to-die 3D integration of a 22 × 22 photodiode array tier onto a CMOS control electronics ASIC.