Magnetic random access memory cell with a dual junction for ternary content addressable memory applications

摘要

An MRAM cell including a first tunnel barrier layer between a soft ferromagnetic layer having a free magnetization and a first hard ferromagnetic layer having a first storage magnetization; a second tunnel barrier layer between the soft ferromagnetic layer and a second hard ferromagnetic layer having a second storage magnetization; the first storage magnetization being freely orientable at a first high predetermined temperature threshold and the second storage magnetization being freely orientable at a second predetermined high temperature threshold; the first high predetermined temperature threshold being higher than the second predetermined high temperature threshold. The MRAM cell can be used as a ternary content addressable memory (TCAM) and store up to three distinct state levels. The MRAM cell has a reduced size and can be made at low cost.

主权项

1. A method for writing up to three distinct write data to a MRAM cell including a magnetic element comprising a soft ferromagnetic layer having a magnetization that can be freely aligned; a first hard ferromagnetic layer having a first storage magnetization; a first tunnel barrier layer comprised between the soft ferromagnetic layer and the first hard ferromagnetic layer; a second hard ferromagnetic layer having a second storage magnetization; and a second tunnel barrier layer comprised between the soft ferromagnetic layer and the second hard ferromagnetic layer; the first storage magnetization being be freely orientable at a first high predetermined temperature threshold and the second storage magnetization being freely orientable at a second predetermined high temperature threshold; the first high predetermined temperature threshold being higher than the second predetermined high temperature threshold; the method comprising:
heating the magnetic element to a temperature above the first predetermined high temperature threshold; and applying a write magnetic field such as to align the first storage magnetization and the second storage magnetization in accordance with the write magnetic field.