Interfacial chemical structure of HfO2/Si film fabricated by sputtering.

The interfacial structure for HfO2 dielectrics on Si (100) substrate was investigated using x-ray photoelectron spectroscopy. The Hf 4f binding energy changes with the depth, which confirms the presence of Hf–O–Si state. Together with the analysis of O 1s and Si 2p spectra, it is believed that the interfacial structure includes both SiOx and Hf silicates. The electrical measurement is also consistent with the above conclusions. According to the theoretical and experimental results, a cursory model of the interfacial structure was established: The main body is SiOx species, on the top of SiOx is HfSixOy species, and Hf silicides are embedded in the Hf silicates. [ABSTRACT FROM AUTHOR]