Magnetic tunnel junction patterning using Ta/TaN as hard mask

US8450119B2 · kind B2 · utility

Assignee

• MagIC Technologies, Inc. · US

Inventors

• Chyu-Jiuh Torng · Pleasanton, US
• Wei Cao · Milpitas, US
• Terry Kin Ting Ko · South San Francisco, US

Key dates

• Filing date: Mar 17, 2006
• Grant date: May 28, 2013
• Expiry date: May 12, 2026

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10N50/10

Abstract

An MTJ MRAM cell is formed by using a reactive ion etch (RIE) to pattern an MTJ stack on which there has been formed a bilayer Ta/TaN hard mask. The hard mask is formed by patterning a masking layer that has been formed by depositing a layer of TaN over a layer of Ta on the MTJ stack. After the stack is patterned, the TaN layer serves at least two advantageous purposes: 1) it protects the Ta layer from oxidation during the etching of the stack and 2) it serves as a surface having excellent adhesion properties for a subsequently deposited dielectric layer.