Perpendicular magnetic random-access memory (MRAM) formation by direct self-assembly method
US10497860B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 8, 2016 |
| Grant date | Dec 3, 2019 |
| Priority date | — |
| Expiry date | Jan 8, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C11/161
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Some embodiments of the present disclosure relate to a method that achieves a substantially uniform pattern of magnetic random access memory (MRAM) cells with a minimum dimension below the lower resolution limit of some optical lithography techniques. A copolymer solution comprising first and second polymer species is spin-coated over a heterostructure which resides over a surface of a substrate. The heterostructure comprises first and second ferromagnetic layers which are separated by an insulating layer. The copolymer solution is subjected to self-assembly into a phase-separated material comprising a pattern of micro-domains of the second polymer species within a polymer matrix comprising the first polymer species. The first polymer species is then removed, leaving a pattern of micro-domains of the second polymer species. A pattern of magnetic memory cells within the heterostructure is formed by etching through the heterostructure while utilizing the pattern of micro-domains as a hardmask.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.