Patent · US Expired

Multi-state magnetoresistance random access cell with improved memory storage density

US7465589B2 · kind B2 · utility

5Cited by
240References
17Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 25, 2005
Grant dateDec 16, 2008
Priority date
Expiry dateAug 25, 2025

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11C11/5607
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A multi-state magnetoresistive random access memory device having a pinned ferromagnetic region with a magnetic moment vector fixed in a preferred direction in the absence of an applied magnetic field, a non-ferromagnetic spacer layer positioned on the pinned ferromagnetic region, and a free ferromagnetic region with an anisotropy designed to provide a free magnetic moment vector within the free ferromagnetic region with N stable positions, wherein N is a whole number greater than two, positioned on the non-ferromagnetic spacer layer. The number N of stable positions can be induced by a shape anisotropy of the free ferromagnetic region wherein each N stable position has a unique resistance value.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.