Investigation of the surface modification for Ru and RuOx films using a post-treatment method for high-dielectric applications

초록

The effect of post-treatment on the surface modification for Ru and RuO<inf>x</inf> films was investigated. The surface morphology of Ru film oxidized by N<inf>2</inf>O plasma was observed to be much smoother than that by rapid thermal oxidation. In particular, the leakage current property of the Ru film oxidized by N<inf>2</inf>O plasma was significantly improved due to suppression of heterogeneous grain growth and the Ru-O bonds formed. After post-treatment, otherwise, oxygen is fully diffused through the RuO<inf>x</inf> layer, producing a porous amorphous microstructure. In addition, the barrier properties for the Ru/TiN/poly-Si/Si contact system are better than that for the RuO<inf>x</inf>/TiN/poly-Si/Si contact system. Therefore, N<inf>2</inf> plasma oxidation can be suggested as a post-treatment method and the Ru film can be proposed as a bottom electrode to improve the electrical properties of dielectric film at the dielectric film/Ru bottom electrode interface.