MTJ etching with improved uniformity and profile by adding passivation step
US9887350B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 2015 |
| Grant date | Feb 6, 2018 |
| Priority date | — |
| Expiry date | May 31, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N50/01
Abstract
A hard mask stack for etching a magnetic tunneling junction (MTJ) structure is described. An electrode layer is deposited on a stack of MTJ layers on a bottom electrode. A photoresist mask is formed on the electrode layer. The electrode layer is etched away where it is not covered by the photoresist mask to form a metal hard mask. The metal hard mask is passivated during or after etching to form a smooth hard mask profile. Thereafter, the photoresist mask is removed and the MTJ structure is etched using the metal hard mask wherein the metal hard mask remaining acts as a top electrode. The resulting MTJ device has smooth sidewalls and uniform device shape.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.