Novel highly scalable multi-level cell for STT-MRAM with stacked perpendicular MTJs

Author

Aoki, Masaki ; Noshiro, Hideyuki ; Tsunoda, Koji ; Iba, Yoshihisa ; Hatada, Akiyoshi ; Nakabayashi, Masaaki ; Takahashi, Asami ; Yoshida, Chikako ; Yamazaki, Yasuyuki ; Takenaga, Takashi ; Sugii, Toshihiro

Author_Institution

Low-power Electron. Assoc. & Project (LEAP), Tsukuba, Japan

fYear

2013

fDate

11-13 June 2013

Abstract

We fabricated a new scalable multi-level cell for spin transfer torque magnetoresistive random-access memory that consists of stacked perpendicular magnetic tunnel junctions (MTJs) with a diameter of 50nm using one step etching. The cell features series-connecting MTJs using perpendicular magnetic anisotropy at the CoFeB/MgO interface and a well controlled stray field from the pinned layers resulting in H_shift~0. The cell demonstrated four-level operation with low-voltage switching (<; 0.5 V).

Keywords

cobalt compounds; integrated circuit manufacture; iron compounds; magnesium compounds; magnetic tunnelling; random-access storage; CoFeB-MgO; MTJ; STT-MRAM; magnetic tunnel junctions; multi-level cell; one step etching; perpendicular magnetic anisotropy; size 50 nm; spin transfer torque magnetoresistive random-access memory; Magnetic fields; Magnetic resonance imaging; Magnetic tunneling; Perpendicular magnetic anisotropy; Resistance; Sensors; Switches; MTJ; Multi-Level Cell; STT-MRAM;

fLanguage

English

Publisher

ieee

Conference_Titel

VLSI Technology (VLSIT), 2013 Symposium on

Conference_Location

Kyoto

ISSN

0743-1562

Print_ISBN

978-1-4673-5226-0

Type

conf

Filename

6576701