Perpendicular spin transfer torque memory (PSTTM) devices with enhanced perpendicular anisotropy and methods to form same

US10770651B2 · kind B2 · utility

Assignee

• Intel Corporation · US

Inventors

• MD Tofizur Rahman · Portland, US
• Christopher J. Wiegand · Portland, US
• Kaan Oguz · Beaverton, US
• Daniel G. Ouellette · Portland, US
• Brian Maertz · Lompoc, US
• Kevin P. O'Brien · Cincinnati, US
• Mark L. Doczy · Beaverton, US
• Brian S. Doyle · Portland, US
• Oleg Golonzka · Beaverton, US
• Tahir Ghani · Portland, US

Key dates

• Filing date: Dec 30, 2016
• Grant date: Sep 8, 2020
• Expiry date: Dec 30, 2036

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10N50/85
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

A material layer stack for a pSTTM device includes a fixed magnetic layer, a tunnel barrier disposed above the fixed magnetic layer and a free layer disposed on the tunnel barrier. The free layer further includes a stack of bilayers where an uppermost bilayer is capped by a magnetic layer including iron and where each of the bilayers in the free layer includes a non-magnetic layer such as Tungsten, Molybdenum disposed on the magnetic layer. In an embodiment, the non-magnetic layers have a combined thickness that is less than 15% of a combined thickness of the magnetic layers in the stack of bilayers. A stack of bilayers including non-magnetic layers in the free layer can reduce the saturation magnetization of the material layer stack for the pSTTM device and subsequently increase the perpendicular magnetic anisotropy.