US 11,600,660 B2 · Bottom-pinned magnetic random access memory having a composite SOT structure

Abstract

An ultra-fast magnetic random access memory (MRAM) comprises a three terminal bottom-pinned composite SOT magnetic tunneling junction (bCSOT-MTJ) element including (counting from top to bottom) a magnetic flux guide (MFG) having a very high magnetic permeability, a spin Hall channel (SHC) having a large positive spin Hall angle, an in-plane magnetic memory (MM) layer, a tunnel barrier (TB) layer, and a magnetic pinning stack (MPS) having a synthetic antiparallel coupling pinned by an antiferromagnetic material. The magnetic writing is significantly boosted by a combined effort of enhanced spin orbit torque (SOT) and Lorentz force generated by current-flowing wire (CFW) in the SHC layer and spin transfer torque (STT) by a current flowing through the MTJ stack, and further enhanced by a magnetic close loop formed at the cross section of MFG/SHC/MM tri-layer. Such bCSOT-MTJ element will have a very fast (down to picoseconds) switching speed and consume much less power suitable level 1 or 2 cache application for SMRAM, CPU, GPU and TPU.

Claims20

Dependent claims

A bottom-pinned composite spin-orbit torque (SOT) magnetic tunneling junction (bCSOT-MTJ) element comprises

a seed layer (SL) provided on a bottom-electrode (BE) VIA substrate;
a magnetic pinning stack (MPS) provided on the top surface of said SL having magnetic anisotropy in a film plane and having an invariable magnetization direction;
a tunnel barrier (TB) layer provided on the top surface of said MPS;
a magnetic memory (MM) layer provided on the top surface of said TB and having magnetic anisotropy in a film plane and having a variable magnetization direction;
a composite SOT (CSOT) stack comprising:
a spin Hall channel (SHC) layer provided on the top surface of said MM layer;
and
a magnetic flux guiding (MFG) layer on one of the top surface of said SHC, and both the top surface and side walls of said SHC.

5 more elements

A method of manufacturing a bottom-pinned composite SOT magnetic tunneling junction (bCSOT-MTJ) element comprising:

forming a seed layer (SL) on a bottom-electrode (BE) VIA substrate;
forming a magnetic pinning stack (MPS) on the top surface of said SL having magnetic anisotropy in a film plane and having an invariable magnetization direction;
forming a tunnel barrier (TB) layer on the top surface of said MPS;
forming a magnetic memory (MM) layer on the top surface of said TB and having magnetic anisotropy in a film plane and having a variable magnetization direction;
forming a composite SOT (C SOT) stack comprising steps of:
forming a spin Hall channel (SHC) layer on the top surface of said MM layer;
and
forming a magnetic flux guiding (MFG) layer on one of the top surface of said SHC, and
both the top surface and side walls of said SHC.

6 more elements

Dependencies are inferred from the claim text.

Bottom-pinned magnetic random access memory having a composite SOT structure

Life of this patent

Bottom-pinned magnetic random access memory having a composite SOT structure

Life of this patent

Abstract

Claims20