Sub-lithographic magnetic tunnel junctions for magnetic random access memory devices
US9911914B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2017 |
| Grant date | Mar 6, 2018 |
| Priority date | — |
| Expiry date | Mar 28, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N50/10
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Methods of forming the MRAM generally include forming an array of MTJ having sub-lithographic dimensions. The array can be formed by providing a substrate including a MTJ material stack including a reference ferromagnetic layer, a tunnel barrier layer, and a free ferromagnetic layer on an opposite side of the tunnel barrier layer. A hardmask layer is deposited onto the MTJ material stack. A first sidewall spacer is formed on the hardmask layer in a first direction. A second sidewall spacer is formed over the first sidewall in a second direction, wherein the first direction is orthogonal to the second direction. The second sidewall spacer intersects the first sidewall spacer. The first sidewall spacer is processed using the second sidewall spacer as mask to form a pattern of oxide pillars having sub-lithographic dimensions. The pattern of oxide pillars are transferred into the MTJ stack to form the array.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.