Wafer back metallization method and wafer back metallization structure

The invention discloses a wafer back metallization method and a wafer back metallization structure, and the method comprises the steps: taking a titanium-nickel alloy as a metal source ingot, preparing a titanium-nickel alloy layer between a titanium metal layer and a silver metal layer on the back of a wafer, and forming a Ti-Ti/Ni-Ag metal layer. According to the method for metallizing the back surface of the wafer, the titanium-nickel alloy is used as the metal source ingot to replace the conventional metal nickel, so that the possibility of source splashing in the nickel deposition process can be fundamentally avoided on the premise of meeting the thermal expansion coefficient of the back surface metal, the yield of products can be improved, and meanwhile, the production cost is reduced. And the time required for vacuumizing can be remarkably shortened through pre-melting treatment, so that the production efficiency of the product is improved, and the method has very important significance for promoting w