Effect of post-nitriding on electrical properties of high-permittivity hafnium and zirconium silicate films

The effect of post-annealing in nitrogen monoxide (NO) on the electrical properties of hafnium and zirconium silicate films prepared by plasma-enhanced chemical vapor deposition was investigated. The leakage current measured in the post-annealed film decreases by two orders of magnitude as compared to the s-deposited film. From FT-IR, ESR, and XPS analyses, it is found that the post-annealing makes the structural disorder smaller and reduces the interface states by nitridation. The C-V hysteresis width, which reflects the number of interface states, also decreases. These tendencies are observed both the hafnium and zirconium silicate films. It is concluded that the NO post-annealing can effectively improve the electrical properties of the two films.