The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 11, 1995
Filed:
Dec. 31, 1992
Seshu B Desu, Blacksburg, VA (US);
Chien-Hsiung Peng, Blacksburg, VA (US);
Sharp Kabushiki Kaisha, Osaka, JP;
Virginia Polytechnic Institute and State University, Blacksburg, VA (US);
Ceram, Inc., Colorado Springs, CO (US);
Abstract
A method to produce high quality doped and undoped lead zirconate titanate (PZT) thin films by metalorganic chemical vapor deposition is disclosed. The PZT thin films with the perovskite structure were deposited on sapphire disks, Pt/Ti/SiO.sub.2 /Si wafers, and RuO.sub.x /SiO.sub.2 /Si wafers by both hot-wall and cold-wall CVD reactors at deposition temperature as low as 550.degree. C. and a reduced pressure 6 torr. The source materials include metalorganic precursors and oxidizing agent. The metalorganic precursors can be metal alkoxides, metal acetylacetonates, or metal .beta.-diketonates. Preferably, the precursors are lead tetramethylheptadione for Pb component, zirconium tetramethylheptadione for Zr component, and titanium ethoxide for Ti component and the oxidizing agent is oxygen. The stoichiometry of the films can be easily controlled by varying the individual precursor temperature and/or the flow rate of the carrier gas. The Pb(Zr.sub.0.82 Ti.sub.0.18)O.sub.3 film produced by the present invention shows a spontaneous polarization of 23.3 .mu.C/cm.sup.2, a remanent polarization of 12.3 .mu.C/cm.sup.2, and coercive field of 64.5 kV/cm.