MTJ device process/integration method with pre-patterned seed layer

US9972777B1 · kind B1 · utility

Assignee

• Headway Technologies, Inc. · US

Inventors

• Jesmin Haq · Milpitas, US
• Tom Zhong · Saratoga, US
• Zhongjian Teng · Santa Clara, US
• Dongna Shen · San Jose, US

Key dates

• Filing date: Apr 5, 2017
• Grant date: May 15, 2018
• Expiry date: Apr 5, 2037

Classification

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

Abstract

A method for etching a magnetic tunneling junction (MTJ) structure is described. A bottom electrode layer is provided on a substrate. A seed layer is deposited on the bottom electrode layer. The seed layer and bottom electrode layer are patterned. A dielectric layer is deposited over the patterned seed layer and bottom electrode layer and planarized wherein the seed layer is exposed. Thereafter, a stack of MTJ layers is deposited on the patterned seed layer comprising a pinned layer, a tunnel barrier layer, and a free layer. The MTJ stack is then patterned to form a MTJ device. Because the seed layer was patterned before the MTJ patterning step, the exposure of the device to etching plasma gases is shortened and thus, etch damage is minimized.