The microstructure and mechanical properties of He charged Al films fabricated by HiPIMS/DCMS co-sputtering

Although magnetron sputtering is an effective method to prepare helium (He) charged films, due to the shad-owing effect and low plasma density, the films prepared by this method are high porosity and residual stress. In order to solve this problem, the microstructure and properties of He charged aluminum (Al) thin films deposited by the direct current magnetron sputtering (DCMS) and high power impulse magnetron sputtering (HiPIMS)/ DCMS co-sputtering were investigated carefully. The results show that, even with the same concentration of He content, He charged film deposited by HiPIMS/DCMS show relatively lower hardness than that of He charged films by DCMS, which the difference is about 0.75 GPa. This is mainly because increased gain size and decreased the number of dislocation loops, due to strong migration ability on the growth surface in HiPIMS/DCMS process. A denser, less columnar structure of He charged film was prepared by the HiPIMS/DCMS co-sputtering, which might help to promote the research on the properties of metal materials containing He bubbles.