TMR device with novel free layer structure
US9040178B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 2008 |
| Grant date | May 26, 2015 |
| Priority date | — |
| Expiry date | Dec 25, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1143
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A TMR sensor that includes a free layer having at least one B-containing (BC) layer made of CoFeB, CoFeBM, CoB, COBM, or CoBLM, and a plurality of non-B containing (NBC) layers made of CoFe, CoFeM, or CoFeLM is disclosed where L and M are one of Ni, Ta, Ti, W, Zr, Hf, Tb, or Nb. One embodiment is represented by (NBC/BC)n where n≧2. A second embodiment is represented by (NBC/BC)n/NBC where n≧1. In every embodiment, a NBC layer contacts the tunnel barrier and NBC layers each with a thickness from 2 to 8 Angstroms are formed in alternating fashion with one or more BC layers each 10 to 80 Angstroms thick. Total free layer thickness is <100 Angstroms. The free layer configuration described herein enables a significant noise reduction (SNR enhancement) while realizing a high TMR ratio, low magnetostriction, low RA, and low Hc values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.