Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-29T07:47:40.873Z Has data issue: false hasContentIssue false

MOCVD of Alkaline Earth Titanates for Integrated RF Capacitors

Published online by Cambridge University Press:  10 February 2011

G. T. Stauf
Affiliation:
Advanced Technology Materials, 7 Commerce Dr., Danbury, CT 06810, [email protected]
C. Seegel
Affiliation:
Advanced Technology Materials, 7 Commerce Dr., Danbury, CT 06810, [email protected]
R. K. Watts
Affiliation:
Bell Laboratories, Lucent Technologies, Murray Hill, NJ 07974, [email protected]
H. M. O'Bryan
Affiliation:
Bell Laboratories, Lucent Technologies, Murray Hill, NJ 07974, [email protected]
Get access

Abstract

The high permittivity of BaSrTiO3 (BST) gives it the potential to replace discrete “passive” capacitors used in portable and wireless applications with integrated capacitors. Bringing thin film devices directly onto Si and GaAs chips shortens lead length and improves overall circuit Q values by reducing inductance, important at RF frequencies. A metalorganic chemical vapor deposition (MOCVD) process has been developed for this purpose. By modifying the basic BST stoichiometry, we have demonstrated charge storage densities up to 3,000 nF/cm2 with leakages below 10−8 A/cm2 at 3 V, and second order dielectric nonlinearities below 100 ppm/V2. For stoichiometric BST, Q factors are as high as 500 at kHz frequencies, and evidence suggests that low losses can be retained up through the L and S microwave bands (1 -4 GHz) in the modified titanates. These properties make alkaline earth titanate films suitable for use in decoupling and bypass capacitors, as well as switched capacitor filters.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

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

REFERENCES

1Advanced GaAs-MMIC process technology using high-dielectric constant thin film capacitors by low-temperature RF sputtering method”, Nishitsuji, M., Tamura, A., Kunihisa, T., Yahata, K., Shibuya, M., Kitagawa, M. and Hirao, T., (Proceedings of the 15th Annual IEEE GaAs IC Symposium, San Jose, CA 1993), p. 329.Google Scholar
2 Fujii, E., Uemoto, Y., Hayashi, S., Našu, T., Shimada, Y., Matsuda, A., Kibi, M., Azuma, M., Otsuki, T., Kano, G., Scott, M., McMillan, L.D. and Paz de Araujo, C.A., (Proc. IEDM-92 1992), p. 267.Google Scholar
Also “Integration of BST Thin Film for DRAM Fabrication”, Itoh, H., Kashihara, K., Okudaira, T., Tsunemine, Y., Ohno, Y., Nishimura, T., Horikawa, T. and Shibano, T., Int. Ferr. 11(1-4), p. 101/[461] (1995).Google Scholar
3BaTi4O9/Ba2Ti9O20 Based Ceramics Resurrected for Modern Microwave Applications”, Negas, T., Yeager, G., Bell, S., Coats, N. and Minis, I., Am. Cer. Soc. Bull. 72(1), p. 80, (1993).Google Scholar
4Growth and Characterization of Thin Film Dielectrics for Microwave Applications”, O'Bryan, H.M., Watts, R.K., Hou, S. and Ma, Z.X., Int. Ferr. 15, p. 155, (1997).Google Scholar
5Nuclear Magnetic Resonance and Infrared Spectral Studies on Labile cis-Dialkoxy-bis(acetylacetonato) titanium(IV) Compounds.” Bradley, D.C. and Holloway, C.E., J. Chem. Soc. (A), p. 282, (1969).Google Scholar