Self-aligned encapsulation hard mask to separate physically under-etched MTJ cells to reduce conductive R-deposition
US11444241B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 14, 2020 |
| Grant date | Sep 13, 2022 |
| Priority date | — |
| Expiry date | Dec 14, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B61/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method for etching a magnetic tunneling junction (MTJ) structure is described. A MTJ stack is deposited on a bottom electrode wherein the MTJ stack comprises at least a pinned layer, a barrier layer on the pinned layer, and a free layer on the barrier layer, A top electrode layer is deposited on the MTJ stack. A hard mask is deposited on the top electrode layer. The top electrode layer and hard mask are etched. Thereafter, the MTJ stack not covered by the hard mask is etched, stopping at or within the pinned layer. Thereafter, an encapsulation layer is deposited over the partially etched MTJ stack and etched away on horizontal surfaces leaving a self-aligned hard mask on sidewalls of the partially etched MTJ stack. Finally, the remaining MTJ stack not covered by hard mask and self-aligned hard mask is etched to complete the MTJ structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.