Analytical Spectroscopic Ellipsometry of Ta2O5 and TiO2 for Use as High-k Gate Dielectrics

Published

December 2, 1999

Author(s)

Curt A. Richter, Nhan Van Nguyen, G A. Alers, X Guo, Xiaorui Wang, T P. Ma, T Tamagawa

Abstract

Extended abstract on Analytical Spectroscopic Ellipsometry of Ta₂O₅ and TiO₂ for Use as High-k Gate Dielectrics. Opening paragraph of abstract: There is tremendous interest in high dielectric constant (high-k) films to use as alternates to SiO₂ to continue traditional CMOS scaling. Proper methods to interpret ellipsometry, a widely used method for process control, are needed for these new materials. Unlike SiO₂, which has well-accepted handbook values for the index of refraction, little is known about the optical properties of high-k materials on Si. We present spectroscopic ellipsometry (SE) studies of TiO₂ and Ta₂O₅, two proposed high-k gate dielectrics. We report an effective protocol to analytically characterize amorphous, high-k dielectric materials developed during studies of Ta₂O₅. This is then applied to characterize the optical properties of Jet Vapor Deposition (JVD) TiO₂/Si₃N₄ gate dielectrics which have excellent device properties as reported by Guo, et al. We also contrast the effect that increased dielectric constants have on electrical and optical measurements illustrating the complementary nature of these techniques.

Proceedings Title

Workbook of the 30th IEEE Semiconductor Interface Specialist Conference

Conference Dates

December 2-4, 1999

Conference Location

Charleston, SC, USA

Conference Title

IEEE Semiconductor Interface Specialist Conference

Pub Type

Conferences

Citation

Richter, C. , Nguyen, N. , Alers, G. , Guo, X. , Wang, X. , Ma, T. and Tamagawa, T. (1999), Analytical Spectroscopic Ellipsometry of Ta₂O₅ and TiO₂ for Use as High-k Gate Dielectrics, Workbook of the 30th IEEE Semiconductor Interface Specialist Conference, Charleston, SC, USA (Accessed October 12, 2025)