Method for forming mixed crystal layer of integrated circuit by using epitaxy principle

The invention discloses a method for forming a mixed crystal layer of an integrated circuit by using an epitaxy principle in the technical field of mixed crystal layer formation. The method comprises the following steps: S1, performing crystal grain coalescence and pause; s2, filling an Au thin film; s3, secondary deposition of a TiW layer is carried out; s4, forming an eutectic layer; and S5, electroplating the bump. According to the method, the area of the eutectic layer between TiW and Au is increased by introducing the step of filling the gap with the Au film in the TiW layer deposition process, so that the adhesive force between the films is remarkably improved, due to enhancement of the eutectic layer, the mechanical shear strength of Bump is improved, better performance is shown in a Shear shear force test, the risks of TiW layer leakage and Bump falling are reduced, and the performance of the film is improved. By forming the more stable eutectic layer, the overall reliability of the integrated circuit