Low switching current MTJ element for ultra-high STT-RAM and a method for making the same
US7948044B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 2008 |
| Grant date | May 24, 2011 |
| Priority date | — |
| Expiry date | Nov 18, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S977/883
Abstract
A STT-RAM MTJ that minimizes spin-transfer magnetization switching current (Jc) while achieving a high dR/R is disclosed. The MTJ has a MgO tunnel barrier formed by natural oxidation to achieve a low RA, and a CoFeB/FeSiO/CoFeB composite free layer with a middle nanocurrent channel layer to minimize Jc0. There is a thin Ru capping layer for a spin scattering effect. The reference layer has a shape anisotropy and Hc substantially greater than that of the free layer to establish a “self-pinned” state. The free layer, capping layer and hard mask are formed in an upper section of a nanopillar that has an area substantially less than a lower pedestal section which includes a bottom electrode, reference layer, seed layer, and tunnel barrier layer. The reference layer is comprised of an enhanced damping constant material that may be an insertion layer, and the free layer has a low damping constant.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.