A semiconductor device includes a first wafer and a second wafer. The semiconductor device includes a seal ring structure comprising a first metal structure in a body of the first wafer, a second metal structure in the body of the first wafer, a third metal structure in a body of the second wafer, and a metal bonding structure including a first set of metal elements coupling the first metal structure and the third metal structure through an interface between the first wafer and the second wafer, and a second set of metal elements coupling the second metal structure and the third metal structure through the interface between the first wafer and the second wafer.