Self-aligned top contact for MRAM fabrication
US9318696B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 3, 2014 |
| Grant date | Apr 19, 2016 |
| Priority date | — |
| Expiry date | Jul 22, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76832
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Systems and methods for forming precise and self-aligned top metal contact for a Magnetoresistive random-access memory (MRAM) device include forming a magnetic tunnel junction (MTJ) in a common interlayer metal dielectric (IMD) layer with a logic element. A low dielectric constant (K) etch stop layer is selectively retained over an exposed top surface of the MTJ. Etching is selectively performed through a top IMD layer formed over the low K etch stop layer and the common IMD layer, based on a first chemistry which prevents etching through the low K etch stop layer. By switching chemistry to a second chemistry which precisely etches through the low K etch stop layer, an opening is created for forming a self-aligned top contact to the exposed top surface of the MTJ.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.