Semiconductor device and manufacturing method therefor, and chip bonding structure

Abstract

A method of manufacturing a semiconductor device includes: providing bonded first and second wafers; forming a patterned insulating layer on the second substrate, the patterned insulating layer having first holes and dummy holes both exposing the second substrate; forming a protective layer, which fills a partial depth of the dummy holes and covers side surfaces of the first holes; forming through-silicon vias (TSVs); and forming a second metal layer including an interconnect metal layer and a dummy metal layer, the interconnect metal layer filling the TSVs and electrically connected to the first metal layer, the dummy metal layer filling the dummy holes. The formation of the dummy metal layer is integrated in the TSV process and is therefore done without using any additional process or adding additional cost to enable uniform pattern density (e.g., metal density) across the surface of the second wafer and enhanced CMP uniformity.