Patent · US Expired

Magnetic random access memory with stacked memory cells having oppositely-directed hard-axis biasing

US7285836B2 · kind B2 · utility

41Cited by
18References
31Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 9, 2005
Grant dateOct 23, 2007
Priority date
Expiry dateFeb 22, 2026

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH10B61/22
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A magnetic random access memory (MRAM) has memory stacks arranged in the X-Y plane on the MRAM substrate, with each memory stack having two memory cells stacked along the Z axis and each memory cell having an associated biasing layer. Each biasing layer reduces the switching field of its associated cell by applying a biasing field along the hard-axis of magnetization of the free layer of its associated cell. The free layers in the two cells in each stack have their in-plane easy axes of magnetization aligned parallel to one another. Each biasing layer has its in-plane magnetization direction oriented perpendicular to the easy axis of magnetization (and thus parallel to the hard axis) of the free layer in its associated cell. The hard-axis biasing fields generated by the two biasing layers are in opposite directions.

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