Abstract: A multi-wafer stacking structure and a fabrication method thereof are disclosed. A first dielectric layer and a second dielectric layer are bonded to each other, a first interconnection layer is electrically connected with a second metal layer and a first metal layer via a first opening; a third dielectric layer and an insulating layer are bonded to each other, and a second interconnection layer is electrically connected with a third metal layer and the first interconnection layer via a second opening. Reservation of a pressure welding lead space among wafers is not needed, a silicon substrate is omitted, multi-wafer stacking thickness is reduced while interconnection of multiple pieces of wafers is realized, and therefore, the overall thickness of the device after multi-wafer stacking and packaging is reduced, packaging density is increased, and the requirement of thinning of the semiconductor products is met.

Abstract: A semiconductor device and a manufacturing method thereof are disclosed. In which a uniform metal layer is formed above the second metal layer of the second wafer, the uniform metal layer is electrically connected to the second metal layer, and the uniform metal layer and the first metal layer are made of the same material. The uniform metal layer and the first metal layer simultaneously exposed by the subsequently formed TSV hole are made of the same material, the degree of over-etching is relatively easy to control in the etching process, and cross contamination of cleaning agents in the cleaning process can be avoided. In addition, when the interconnection layer is electrically connected to the first metal layer and the uniform metal layer, since the uniform metal layer and the first metal layer are made of the same material, the interconnection layer has better contact performance with the two.