Buffer (seed) layer in a high-performance magnetic tunneling junction MRAM
US7238979B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Sep 26, 2005 |
| Grant date | Jul 3, 2007 |
| Priority date | — |
| Expiry date | Jan 17, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N50/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An MTJ (magnetic tunneling junction) device particularly suitable for use as an MRAM (magnetic random access memory) or a tunneling magnetoresistive (TMR) read sensor, is formed on a seed layer which allows the tunneling barrier layer to be ultra-thin, smooth, and to have a high breakdown voltage. The seed layer is a layer of NiCr which is formed on a sputter-etched layer of Ta. The tunneling barrier layer for the MRAM is formed from a thin layer of Al which is radically oxidized (ROX), in-situ, to form the layer with characteristics described above. The tunneling barrier layer for the read sensor formed from a thin layer of Al or a HfAl bilayer which is naturally oxidized (NOX), in-situ, to form the barrier layer. The resulting device has generally improved performance characteristics in terms of GMR ratio and junction resistance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.