Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-29T09:05:07.165Z Has data issue: false hasContentIssue false

Deposition, Structural Characterization, and Broadband (1KHz-40GHz) Dielectric Behavior of BaxTi2-xOy Thin Films

Published online by Cambridge University Press:  21 February 2011

W.-T. Liu
Affiliation:
Center for Integrated Electronics, Also with Chemistry Department, Rensselaer Polytechnic Institute, Troy NY 12180-3590
S. Cochrane
Affiliation:
Center for Integrated Electronics, Electrical, Computer, and Systems Engineering Department, Rensselaer Polytechnic Institute, Troy NY 12180-3590
P. Beckage
Affiliation:
Center for Integrated Electronics, Materials Engineering Department, Rensselaer Polytechnic Institute, Troy NY 12180-3590
D. B. Knorr
Affiliation:
Center for Integrated Electronics, Materials Engineering Department, Rensselaer Polytechnic Institute, Troy NY 12180-3590
T.-M. Lu
Affiliation:
Center for Integrated Electronics, Physics Department, Rensselaer Polytechnic Institute, Troy NY 12180-3590
J. M. Borrego
Affiliation:
Center for Integrated Electronics, Electrical, Computer, and Systems Engineering Department, Rensselaer Polytechnic Institute, Troy NY 12180-3590
E. J. Rymaszewski
Affiliation:
Center for Integrated Electronics, Materials Engineering Department, Rensselaer Polytechnic Institute, Troy NY 12180-3590
Get access

Abstract

An ion assisted deposition technique, called Reactive Partially Ionized Beam (RPIB) deposition, was used to prepare amorphous BaxTi2-xOy thin films at a low substrate temperature (<60°C). The stoichiometry of the films varied from ×=l.0 for BaTiO3 to ×=0.2 for Ti-rich films. The optical, thermal, and broadband electrical properties of this class of thin film dielectrics were systematically studied. A lμm BaxTi2-xOy film is optically transparent with a band gap of 4.6eV. Both transmittance and bandgap decrease when the films are increasingly enriched with Ti. The Ti rich films remain amorphous at 600°C while the stoichiometric BaTiO3 crystallizes into the perovskite structure. Annealed Ti rich films are thermally stable (>700°C) with low leakage (<0.lμ/cm2 at 0.5MV/cm) and moderately high dielectric constant (εr = 15-35). Polycrystalline BaTiO 3 deposited at 600°C on a Pt/Ta/SiO2/Si substrate has an εr = 400. Capacitor structures with various metallizations were used to evaluate the dielectric properties, such as breakdown strength, leakage, εr and tanδ from DC to 600MHz. A generic test vehicle was designed and fabricated to extend the frequency domain characterization of the dielectrics up to 40GHz. No dispersion of εr was observed in this frequency range for amorphous BaxTi2-xOy.

Type
Research Article
Copyright
Copyright © Materials Research Society 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Ferroelectric Thin Films, edited by Myyers, E. R. and Kingon, A. I., (Mater. Res. Soc. Proc. 200, 1990).Google Scholar
2. Li, P. and Lu, T.-M., Appl. Phys. Lett., 57, 2336 (1990).CrossRefGoogle Scholar
3. Lu, W.-T., Cochrane, S., Lakshmikumar, S. T., Knorr, D. B., Rymaszewski, E. J., Borrego, J. M., and Lu, T.-M., IEEE Electron Device Letters, (to be published in July, 1993).Google Scholar
4. Wohlecke, M., Marello, V., and Onton, A., J. Appl. Phys., 48, 1748 (1977).CrossRefGoogle Scholar
5. Takagi, T., Ionized-Cluster Beam Deposition and Epitaxy, (Noyes Publications, Park Ridge, New Jersey, 1988).Google Scholar
6. Onton, A. and Marello, V., in Structure and Excitation of A morphous Solids, (AlP Conf. Proc. 31, New York, 1976), p.320.Google Scholar
7. Kittel, C., Phys. Rev., 83, 458 (1951).CrossRefGoogle Scholar