Low-temperature method for enhancing sputter-deposited HfO2 films with complete oxidization

Chih-Tsung Tsai, Ting‐Chang Chang, Po‐Tsun Liu, Po-Yu Yang, Kon-Tsu Kin, Pei-Lin Chang, Fon-Shan Huang

Applied Physics Letters · 2007 · 36 citations · 10 references

Concepts

Abstract

A low-temperature method, supercritical CO2 fluid (SCF) technology, is proposed to improve the dielectric properties of ultrathin hafnium oxide (HfO2) film at 150°C without significant formation of parasitic oxide at the interface between HfO2 and Si substrate. In this research, the HfO2 films were deposited by dc sputter at room temperature and post-treated by SCF which is mixed with 5vol% propyl alcohol and 5vol% H2O. From high-resolution transmission electron microscopy image, the interfacial oxide of SCF-treated HfO2 film is only 5Å thick. Additionally, the enhancements in the qualities of sputter-deposited HfO2 film after SCF process are exhibited by x-ray photoelectron spectroscopy and capacitance-voltage (C-V) measurement.

References

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