| 초록 |
Passivation techniques have attracted unprecedented interest for the past few decades to preserve or enhance the intrinsic properties of electronic materials, and to prevent undesired contamination or chemical reaction in high annealing temperatures during the semiconductor fabrication process which may lead to leakage and device failure. In particular, diverse techniques have been devised to protect copper (Cu), which is commonly used as interconnect, from rapid oxidation and silicidation which severely increases the resistivity and cause malfunctions in the device operation, respectively. Namely, polymers or amorphous carbon were traditionally researched as shields against oxidation and TaN or TiN were investigated as diffusion barriers of Cu, but they showed limitations in terms of poor conductivity. Moreover, with the aggressive scaling down of device dimensions, novel materials with lower dimensions are highly necessitated as barriers for the Cu interconnect. Graphene is a promising candidate for such barrier due to its one-atom-thickness, high electrical conductivity, reliable chemical stability, and impermeability. In this presentation, graphene as barriers for preventing oxidation of Cu nanoparticles and as diffusion barriers against silicidation of bulk Cu are demonstrated. It is shown that graphene layers synthesized using solid carbon source on Cu nanoparticles function as excellent shields that prevent the oxidation of Cu nanoparticles. Furthermore, we demonstrate that single to multi-layered graphene placed at the interface of Cu/Si serve as outstanding diffusion barrier even at high temperatures of 700 °C. |
