Microstructure Regulation and Filming Characteristics of Pure Copper Targets

The pure copper targets were prepared by vacuum induction melting, homogenization annealing, forging, warm rolling and annealing processes. The microstructure of the warm rolled and different temperature (400, 500, 600, 700 ℃) annealed pure copper targets was studied. The pure copper films were prepared by magnetron sputtering with the annealed pure copper target with the optimal structure and the warm rolled pure copper target, and then were annealed at different temperatures (300, 400, 500 ℃). The microstructure and electrical properties of deposited and annealed films were studied. The results show that the grain size distribution of the warm rolled pure copper target was not uniform. After annealing, pure copper targets underwent recovery recrystallization; with the increase of annealing temperature, the recovery recrystallization degree increased, and the grain size distribution became uniform. When the tempering temperature was 600 ℃, the grains were close to equiaxed, and the average grain size was about 39.30 μm; when the annealing temperature was 700 ℃, the grain size grew significantly, and the average grain size increased to 53.64 μm. The surface of the warm rolled and annealed copper targets presented a higher degree of (111) crystal plane preferred orientation, and the center presented a higher (220) crystal plane preferred orientation. The microstructure of the pure copper target annealed at 600 ℃ was the best. Compared with the annealed films prepared with the warm rolled pure copper target, the oxidation degree, particle size, surface roughness, and resistivity of the annealed films prepared with the annealed pure copper target were smaller, and the degree of (111) crystal plane preferred orientation was larger. With the increase of annealing temperature, the surface roughness of the film first decreased and then increased, and the resistivity decreased. When the annealing temperature was greater than 300 ℃, the film showed phenomena of particle agglomeration and oxidation. The pure copper film prepared with the 600 ℃ annealed pure copper target after annealing at 300 ℃ had the best microstructure and properties.