Development of TaSiN diffusion barriers for Cu/SiLK metallization schemes

The development of TaSiN diffusion barriers for Cu/SiLK metallization schemes is reported. First-pass studies optimized the TaSiN deposition process and evaluated process compatibility with SiLK. TaSiN/SiO/sub 2/ stacks were used for baseline comparisons. Second-pass studies evaluated thermal stability of TaSiN/Cu/TaSiN/SiLK stacks against Cu diffusion and the stability of the TaSiN/SiLK interface. At temperatures up to 450/spl deg/C no variations in stack composition or interfacial morphology were observed. Subsequently, electrochemical deposition (ECD) of highly [111] textured Cu on TaSiN/SiLK stacks was also demonstrated with a 30 nm sputtered Cu seed layer.