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:
Aug. 27, 2002
Filed:
Mar. 16, 2001
Rainer Bruchhaus, München, DE;
Dana Pitzer, Unterschleissheim, DE;
Robert Primig, München, DE;
Matthias Schreiter, München, DE;
Siemens Aktiengesellschaft, Munich, DE;
Abstract
A method for producing self-polarized ferroelectric layers, in particular PZT layers, with a rhombohedral crystal structure includes providing a substrate and heating it to a temperature T Afterward the layer with a rhombohedral crystal structure is applied to the substrate by means of a sputtering method. This layer includes a Zr-deficient layer with a Curie temperature TC and a Zr-abundant layer with a Curie temperature TC wherein TC TC T After the ending of the application process, the heating of the substrate is also discontinued so that the substrate cools. As a result of the cooling the Zr-deficient layer and then the Zr-abundant layer reach their Curie temperature, and change into the ferroelectric phase and become self-polarized in the process. The polarization already present in the Zr-deficient layer induces the polarization in the Zr-abundant layer, with the result that both layers are self-polarized after the cooling process.