The metal target assembly is composed of a metal target with sputtering performance and a backplane with certain strength. The backplane can play a supporting role in the assembly of the metal target assembly to the sputtering base and has the effect of conducting heat. With the continuous development of PVD technology, the demand and quality requirements for metal targets are increasing day by day. The finer the grain of the metal target, the more uniform the composition, the smaller the surface roughness, and the more uniform the film formed on the silicon wafer by PVD. In addition, the purity of the formed film is also closely related to the purity of the metal target, so the quality of the film after PVD mainly depends on the purity of the metal target, microstructure and other factors.
Tantalum(Ta) target is a relatively typical metal target, because of its good corrosion resistance, good electromagnetic shielding performance, and can be used as an energy material and other important characteristics, it is widely used in PVD. For example, tantalum can be used as a decorative and protective coating on other metal surfaces, which can be produced by vacuum sputtering on tantalum targets. The internal structure, grain size and crystal orientation of tantalum target are the key factors to determine whether the final tantalum target assembly can meet the needs of semiconductor sputtering.
Tantalum targets are obtained by corresponding processing of tantalum ingots, and at present, when tantalum ingots are used to manufacture tantalum targets, their purity requirements are above 4N(Ta content is not less than 99.99%). In the prior art, the processing technology of plastic deformation of high purity tantalum ingot to achieve high purity tantalum target for semiconductor is less and imperfect, mainly through the conventional forging and rolling production process. The internal texture of the tantalum target manufactured by this method is mainly, and there is a phenomenon of non-uniform crystal direction on the cross section. When the tantalum target is applied to the sputtering target, the resistivity of tantalum film on the silicon wafer is high and the tantalum film is not uniform after sputtering.
