Low resistance MgO capping layer for perpendicularly magnetized magnetic tunnel junctions

US10797232B2 · kind B2 · utility

Assignee

• TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD. · TW

Inventors

• Sahil Patel · Fremont, US
• Guenole Jan · San Jose, US
• Ru-Ying Tong · Los Gatos, US
• Vignesh Sundar · Fremont, US
• Dongna Shen · San Jose, US
• Yu-Jen Wang · San Jose, US
• Po-Kang Wang · San Jose, US
• Huanlong Liu · New York, US

Key dates

• Filing date: Dec 27, 2019
• Grant date: Oct 6, 2020
• Expiry date: Dec 27, 2039

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10N50/85

Abstract

A magnetic tunnel junction (MTJ) is disclosed wherein a free layer (FL) interfaces with a first metal oxide (Mox) layer and second metal oxide (tunnel barrier) to produce perpendicular magnetic anisotropy (PMA) in the FL. In some embodiments, conductive metal channels made of a noble metal are formed in the Mox that is MgO to reduce parasitic resistance. In a second embodiment, a discontinuous MgO layer with a plurality of islands is formed as the Mox layer and a non-magnetic hard mask layer is deposited to fill spaces between adjacent islands and form shorting pathways through the Mox. In another embodiment, end portions between the sides of a center Mox portion and the MTJ sidewall are reduced to form shorting pathways by depositing a reducing metal layer on Mox sidewalls, or performing a reduction process with forming gas, H2, or a reducing species.