Development of TiSiN diffusion barriers for Cu/SiLK metallization schemes

Abstract

Diffusion barrier optimization and compatibility studies were undertaken with respect to the integration of Cu/TiSiN stacks on SiLK low-k dielectric films. First-pass testing optimized TiSiN film composition and evaluated process compatibility with SiLK. TiSiN/SiO/sub 2/ stacks were used for baseline comparisons. Second-pass testing evaluated thermal stability of TiSiN/Cu/TiSiN/SiLK stacks against Cu diffusion and the stability of the TiSiN/SiLK interface. At temperatures up to 450/spl deg/C no variations in stack composition or interfacial morphology were evidenced.