DIFFUSION BARRIERS

The integration of copper metals into the integrated circuit architectures requires ultrathin diffusion barriers between the silicon, SiO2 and the metal interconnects and metal vias. Since most of these structures are inside narrow trenches and deep vias, conformality of deposition is essential. ALD is excellent for this application and specific metals and metal nitrides with good adhesion, thickness control and low temperature deposition have been developed. Examples include WN, TaN, Co.