Magnetic tunnel junction (MTJ) bilayer hard mask to prevent redeposition

US10770652B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Nathan P. Marchack · White Plains, US
• Bruce B. Doris · Brewster, US
• Pouya Hashemi · White Plains, US

Key dates

• Filing date: Jan 3, 2019
• Grant date: Sep 8, 2020
• Expiry date: Jan 3, 2039

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10N50/80

Abstract

A semiconductor structure and fabrication method of forming a semiconductor structure. The method first provides an electrically conductive structure embedded in an interconnect dielectric material layer of a magnetoresistive random access memory device. A conductive landing pad is located on a surface of the electrically conductive structure. A multilayered magnetic tunnel junction (MTJ) structure and an MTJ cap layer is formed on the landing pad. Then there is formed a first conductive layer on top the MTJ cap layer and a second conductive metal layer formed on top the first conductive layer. A pillar mask structure is then patterned and formed on the second conductive layer. The resulting structure is subject to lithographic patterning and etching to form a patterned bilayer metal hardmask pillar structure on top the MTJ cap layer. Subsequent etch processing forms an MTJ stack having sidewalls aligned to the patterned bilayer metal hardmask pillar.