Wafer-to-wafer butt joint structure and manufacturing method thereof

The invention discloses a wafer-to-wafer butt joint structure and a manufacturing method thereof. The wafer-to-wafer butt joint structure comprises a first wafer, a second wafer, a first joint layer and a second joint layer arranged between the first wafer and the second wafer, an interface arranged on the contact surface of the first joint layer and the second joint layer, multiple first metal inner connecting lines arranged in the first joint layer, multiple second metal inner connecting lines arranged in the second joint layer, a through-silicon via passing through the first wafer, the first joint layer and the interface and entering the second joint layer, wherein the through-silicon via contacts one of the first metal inner connecting lines and one of the second metal inner connecting lines.