TMR device with improved MgO barrier
US8202572B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 2010 |
| Grant date | Jun 19, 2012 |
| Priority date | — |
| Expiry date | Dec 30, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N50/01
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of forming a high performance magnetic tunnel junction (MTJ) is disclosed wherein the tunnel barrier includes at least three metal oxide layers. The tunnel barrier stack is partially built by depositing a first metal layer, performing a natural oxidation (NOX) process, depositing a second metal layer, and performing a second NOX process to give a MOX1/MOX2 configuration. An uppermost metal layer on the MOX2 layer is not oxidized until after the MTJ stack is completely formed and an annealing process is performed to drive unreacted oxygen in the MOX1 and MOX2 layers into the uppermost metal layer. In an alternative embodiment, a plurality of metal oxide layers is formed on the MOX1 layer before the uppermost metal layer is deposited. The resulting MTJ stack has an ultralow RA around 1 ohm-μm2 and maintains a high magnetoresistive ratio characteristic of a single metal oxide tunnel barrier layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.