The Effect of nitrogen partial pressure on Zr–Si–N diffusion barrier

Abstract

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 Si 3N 4 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.