MTJ MRAM with stud patterning
US8772888B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 2012 |
| Grant date | Jul 8, 2014 |
| Priority date | — |
| Expiry date | Aug 10, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N50/10
Abstract
Use of a multilayer etching mask that includes a stud mask and a removable spacer sleeve for MTJ etching to form a bottom electrode that is wider than the rest of the MTJ pillar is described. The first embodiment of the invention described includes a top electrode and a stud mask. In the second and third embodiments the stud mask is a conductive material and also serves as the top electrode. In embodiments after the stud mask is formed a spacer sleeve is formed around it to initially increase the masking width for a phase of etching. The spacer is removed for further etching, to create step structures that are progressively transferred down into the layers forming the MTJ pillar. In one embodiment the spacer sleeve is formed by net polymer deposition during an etching phase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.