Silver, the most conductive room-temperature material, has drawn attention as a potential interconnect replacement material. In this study, Ag lines were self-encapsulated by annealing a Ag/Ti/SiO2/Si structure in a flowing NH3 ambient. The microstructure of this structure after the anneal was studied by the use of cross-section transmission electron microscopy (XTEM). Upon the anneal, the Ag surface was encapsulated by a TiN(O) layer, and a bilayer formed at the initial Ti/SiO2 interface. Electromigration testing shows that the self-encapsulation process improved the electromigration resistance of the Ag lines substantially by inhibition of the surface diffusion of Ag atoms.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Electrical and Electronic Engineering