Evaluation of adhesion and barrier properties for CVD-TaN on dual damascene copper interconnects

Abstract

CVD-TaN thin films derived from a new noble precursor, tert-amylimidotrisdim-ethylamidotantalum (TAIMATA), for the diffusion barrier in Cu interconnects were studied. The effects of CVD-TaN on dual damascene interconnect (DDI) for Cu metallization were investigated on SiOC (k=2.9) dielectrics with 4 K via chains. The via resistances were measured as a function of TaN thickness (10/spl sim/45 /spl Aring/), compared to PVD TaN. Diffusion barrier properties (bias temperature stress) and delamination length (adhesion test) were studied as a function of TaN thickness. Ar and H/sub 2/ post-plasma after CVD-TaN was introduced to improve the properties of the barrier materials. After applying post-plasma, the via resistances and delamination length of CVD-TaN were investigated and compared to those without post-plasma.