The effect of Nitrogen partial pressure on Zr-Si-N diffusion barrier

The Zr-Si-N diffusion barrier was sputtered on Si wafer with different nitrogen partial pressures by RF reactive magnetron sputtering. The Cu film was subsequently sputtered on Zr-Si-N by DC pulse magnetron sputtering. The results reveal that the Si content and resistivity of Zr-Si-N films increase with the increase of nitrogen partial pressure. There are more Si3N4 crystallites when the Zr-Si-N films are sputtered with high nitrogen partial pressure. The (111) texture of Cu films becomes strong when the Cu films are on the Zr-Si-N films that are sputtered with high nitrogen partial pressure. The thermal stability of Zr-Si-N diffusion barrier becomes good and the number of void in Cu films becomes smaller as the nitrogen partial pressure increases. The Zr-Si-N film is considered an effective diffusion barrier for potential application in ULSI.