Under-cut via electrode for sub 60nm etchless MRAM devices by decoupling the via etch process
US10522741B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 14, 2018 |
| Grant date | Dec 31, 2019 |
| Priority date | — |
| Expiry date | Jun 18, 2038 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB82Y25/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method for fabricating a magnetic tunneling junction (MTJ) structure is described. A first dielectric layer is deposited on a bottom electrode and partially etched through to form a first via opening having straight sidewalls, then etched all the way through to the bottom electrode to form a second via opening having tapered sidewalls. A metal layer is deposited in the second via opening and planarized to the level of the first dielectric layer. The remaining first dielectric layer is removed leaving an electrode plug on the bottom electrode. MTJ stacks are deposited on the electrode plug and on the bottom electrode wherein the MTJ stacks are discontinuous. A second dielectric layer is deposited over the MTJ stacks and polished to expose a top surface of the MTJ stack on the electrode plug. A top electrode layer is deposited to complete the MTJ structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.