AVS 50th International Symposium
    High-k Gate Dielectrics and Devices Topical Conference Monday Sessions
       Session DI-MoA

Paper DI-MoA9
Hafnium Germanosilicate Thin Films for Gate and Capacitor Dielectric Applications: Thermal Stability Studies

Monday, November 3, 2003, 4:40 pm, Room 317

Session: High-k Dielectric Stability
Presenter: S. Addepalli, University of North Texas
Authors: S. Addepalli, University of North Texas
P. Sivasubramani, University of North Texas
P. Zhao, University of North Texas
M.J. Kim, University of North Texas
M. El-Bouanani, University of North Texas
B.E. Gnade, University of North Texas
R.M. Wallace, University of North Texas
Correspondent: Click to Email
The use of SiO@sub 2@-GeO@sub 2@ mixtures in gate and capacitor dielectric applications is hampered by the inherent thermodynamic instability of germanium oxide. Studies to date have confirmed that germanium oxide is readily converted to elemental germanium.@footnote 1,2@ In sharp contrast, germanium oxide is known to form stable compounds with transition metal oxides such as hafnium oxide (hafnium germanate, HfGeO@sub 4@).@footnote 3@ Thus, the incorporation of hafnium in SiO@sub 2@-GeO@sub 2@ may be expected to enhance the thermal stability of germanium oxide via Hf-O-Ge bond formation. In addition, the introduction of transition metal would simultaneously enhance the capacitance of dielectric thereby permitting a thicker dielectric, which reduces leakage current.@footnote 4@ In this study, the thermal stability and electrical properties of PVD-grown hafnium germanosilicate (HfSiGeO) films on Si(100) substrate were investigated. XPS, RBS, HR-TEM, C-V and I-V results for germanosilicate films after deposition and subsequent annealing treatments will be presented. Our results indicate that the thermal stability of the hafnium germanosilicate films is drastically affected not only by the presence or formation of elemental germanium during annealing, but also by the germanium content in the film. This work is supported by DARPA through SPAWAR Grant No. N66001-00-1-8928, and the Texas Advanced Technology Program. @FootnoteText@ @footnote 1@ W. S. Liu, J .S. Chen, M.-A. Nicolet, V. Arbet-Engels, K. L. Wang, J. Appl. Phys. 72, 4444 (1992), and, Appl. Phys. Lett. 62, 3321 (1993).@footnote 2@ W. S. Liu, M.-A. Nicolet, H.-H. Park, B.-H. Koak, J.-W. Lee, J. Appl. Phys. 78, 2631 (1995). @footnote 3@ P. M. Lambert, Inorg. Chem. 37, 1352 (1998).@footnote 4@ G. D. Wilk, R. M. Wallace and J. M. Anthony, J. Appl. Phys. 89, 5243 (2001).