US Patent 11791241 Front-to-back bonding with through-substrate via (TSV)

Methods for forming a semiconductor device structure are provided. The method includes forming a conductive feature in a first wafer, and forming a first bonding layer over the conductive feature. The method includes forming a second bonding layer over a second wafer, and bonding the first wafer and the second wafer by bonding the first bonding layer and the second bonding layer. The method also includes forming a second transistor in a front-side of the second wafer, and after forming the second transistor in the front-side of the second wafer, forming a first TSV through the second wafer, wherein the first TSV stops at the conductive feature.