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:
Oct. 31, 2000
Filed:
May. 28, 1998
Seshu B Desu, Blacksburg, VA (US);
Carlos A Suchicital, Blacksburg, VA (US);
Dilip P Vijay, Foster City, CA (US);
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A charge storage device is resistant to degradation in reducing atmospheres for use in dynamic random access memories. The device consists of a dielectric layer that is sandwiched between two electrodes and grown on a suitable substrate such as silicon or silicon coated with silicon dioxide. The dielectric layer is either (a) a modified composition of Ba.sub.x Sr.sub.1-x TiO.sub.3, 0<x<1 (BST) doped with acceptor type dopants such as Mn, Co, Mg, Cr, Ga and Fe ions as the dielectric layer in the capacitor; the acceptor ions can occupy the titanium sites to prevent the formation of Ti.sup.3+ and inhibit the formation of conductive BST by compensating the charges of the oxygen vacancies, and by trapping the free electrons more freely than Ti.sup.4+, or (b) modified dielectric compositions with alkaline-earth ions with compositions [(Ba.sub.x M.sub.x)O].sub.y TiO.sub.2 (where M can be Ca, Sr or Mg) with the value of y slightly larger than unity.