多靶磁控共溅射纳米Ta-Al-N薄膜的阻挡性能研究

The Diffusion Barrier Properties of Multi-target Magnetron Co-sputtered Ta-Al-N Thin Films

采用磁控反应共溅射方法制备了纳米Ta-Al-N薄膜,并原位制备了Cu/Ta-Al-N薄膜,对薄膜进行了热处理。用四探针测试仪、X射线衍射仪(XRD)、扫描电镜(SEM)、原子力显微镜(AFM)以及台阶仪等研究了退火对薄膜结构及阻挡性能的影响。结果表明,Ta-Al-N薄膜具有优良的热稳定性,保持非晶态且能对Cu有效阻挡的温度可达800°C;同时发现在900°C退火5 min后,薄膜开始晶化,在Cu/Ta-Al-N/Si界面处生成了Cu3Si等相,表明此时Ta-Al-N薄膜阻挡层开始失效。

Nanometer Ta-Al-N thin films were prepared by RF magnetron reactive co-sputtering, and then Cu/Ta-Al-N multilayer structures were fabricated in situ. The samples were annealed at different temperatures form 400 ℃ to 900 ℃ in Nz ambience for 5 minutes. Four-point probe, X-ray diffraction （XRD）, scanning electron microscope （SEM）, atomic force microscope （AFM） and surface profilers were used to study the effects of thermal treatment to the microstrueture and diffusion barrier properties of the films. The results indicated that the thermal stability of the films was very good. After annealing at 800 ℃, the films can keep stable and Cu diffusion phenomena was not observed. With the annealing temperature increased to 900℃, the films began to crystalline, and Cu-Si compounds were formed in the Cu/Ta-Al-N/Si interface, this indicated that the Ta-Al-N diffusion barrier began to fail.