Hybrid metallic hard mask stack for MTJ etching

US9608200B2 · kind B2 · utility

Assignee

• Headway Technologies, Inc. · US

Inventors

• Dongna Shen · San Jose, US
• Yu-Jen Wang · San Jose, US
• Tom Zhong · Saratoga, US

Key dates

• Filing date: Mar 27, 2015
• Grant date: Mar 28, 2017
• Expiry date: May 11, 2035

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10N50/01

Abstract

A hard mask stack for etching a magnetic tunneling junction (MTJ) structure is described. The hard mask stack is formed on a stack of MTJ layers on a bottom electrode and comprises an electrode layer on the MTJ stack, a buffer metal layer on the electrode layer, a metal hard mask layer on the buffer metal layer, and a dielectric layer on the metal hard mask layer wherein a dielectric mask is defined in the dielectric layer by a photoresist mask, a metal hard mask is defined in the metal hard mask layer by the dielectric mask, a buffer metal mask is defined in the buffer metal layer by the metal hard mask, an electrode mask is defined in the electrode layer by the buffer metal mask, and the MTJ structure is defined by the electrode mask wherein the electrode mask remaining acts as a top electrode.