The structural characteristics of Hf-silicate films and nitrogen incorporated Hf-silicate films, prepared using a NH3 annealing treatment, were investigated by various measurements. Hf-silicate films annealed in a N2 ambient at 900 °C show the evidence of crystallization in local regions, resulting in the phase separation of HfO2 and SiO2. In addition, a SiO2 overlayer is formed on the Hf-silicate films, due to the diffusion of Si by postannealing in an ambient of N2 at 900 °C. However, in nitrogen incorporated Hf-silicate films, prepared using a NH3 annealing treatment, phase separation is effectively suppressed and no SiO2 overlayer is present. The incorporated N is distributed into the film and interfacial layer, and obstructs the diffusion of Si from the substrate as well as the film. Structural changes in films affect electrical characteristics such as the dielectric constant and flatband voltage.
Bibliographical noteFunding Information:
This work was partially supported by the National Program for Tera-level Nanodevices of the Ministry of Science and Technology as one of the 21 Century Frontier Programs. The authors gratefully acknowledge the technical advice of K. Chae, C.C. Hwang, and H.-N. Hwang in PAL on beamline 7B1.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)