The barrier to the copper diffusion is one of the key technologies in copper metallization. A novel barrier has been presented, which is a thin film of silicon oxynitride formed by implanting nitrogen into PECVD silicon dioxide. The method proved highly effective to block the copper diffusion after high frequency C V measurements at different BTS (Bias Thermal Stress) conditions and the XPS (X ray Photoelectron Spectroscopy) analysis. Furthermore, this method has the advantage of simplifying the damascene process of copper metallization, which has also been analyzed and discussed in detail.
Ta/NiFe film is deposited on Si substrate precoated with SiO_2 by magnetron sputtering.SiO_2/Ta interface and Ta_5Si_3 standard sample are investigated by using X-ray photoelectron spectroscopy (XPS) and peak decomposition technique.The results show that there is a thermodynamically favorable reaction at the SiO_2/Ta interface:37Ta+15SiO_2=5Ta_5Si_3+6Ta_2O_5.The more stable products Ta_5Si_3 and Ta_2O_5 may be beneficial to stop the diffusion of Cu into SiO_2.
