Silicon oxynitride based encapsulation layer for magnetic tunnel junctions
US10516100B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 2017 |
| Grant date | Dec 24, 2019 |
| Priority date | — |
| Expiry date | Jun 12, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N50/01
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A plasma enhanced chemical vapor deposition (PECVD) method is disclosed for forming a SiON encapsulation layer on a magnetic tunnel junction (MTJ) sidewall that minimizes attack on the MTJ sidewall during the PECVD or subsequent processes. The PECVD method provides a higher magnetoresistive ratio for the MTJ than conventional methods after a 400° C. anneal. In one embodiment, the SiON encapsulation layer is deposited using a N2O:silane flow rate ratio of at least 1:1 but less than 15:1. A N2O plasma treatment may be performed immediately following the PECVD to ensure there is no residual silane in the SiON encapsulation layer. In another embodiment, a first (lower) SiON sub-layer has a greater Si content than a second (upper) SiON sub-layer. A second encapsulation layer is formed on the SiON encapsulation layer so that the encapsulation layers completely fill the gaps between adjacent MTJs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.