Three dimensional chip stacking using a wafer-to-wafer integration

Abstract

A three-dimensional (3D) wafer-to-wafer integration technology has been developed using face-to-face dielectric wafer bonding, followed by wafer thinning and backside interconnect formation. The key technologies required for this integration include: reliable defect free direct dielectric wafer bonding, precise wafer-to-wafer alignment, backside thinning, deep inter-strata via (ISV) formation, and wafer patterning alignment across strata. Electrical measurements indicate continuity of ISV chains for all but the smallest vias.