Spacer assisted ion beam etching of spin torque magnetic random access memory
US9871195B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 2017 |
| Grant date | Jan 16, 2018 |
| Priority date | — |
| Expiry date | Mar 22, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N50/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A stack of MTJ layers is provided on a substrate comprising a bottom electrode, a pinned layer, a tunnel barrier layer, a free layer, and a top electrode. The MTJ stack is patterned to form a MTJ device wherein sidewall damage is formed on its sidewalls. A dielectric spacer is formed on the MTJ device. The dielectric spacer is etched away on horizontal surfaces wherein the dielectric spacer on the sidewalls is partially etched away. The remaining dielectric spacer covers the pinned layer and bottom electrode. The dielectric spacer is removed from the free layer or is thinner on the free layer than on the pinned layer and bottom electrode. Sidewall damage is thereafter removed from the free layer by applying a horizontal etching to the MTJ device wherein the pinned layer and bottom electrode are protected from etching by the dielectric spacer layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.