Highly manufacturable multi-level perpendicular MTJ with a single top-pinned layer and multiple barrier/free layers

Author

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

Author_Institution

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

fYear

2013

fDate

9-11 Dec. 2013

Abstract

In this paper, we first report a novel and highly manufacturable multi-level perpendicular magnetic tunnel junction (p-MTJ) with a single top-pinned layer and multiple barrier/free layers. In the proposed p-MTJ structure, all tunnel barriers and free layers lie under a thick pinned layer, which enables good resistance control and large coercivity due to the effect of small film roughness. We also developed a new CoFeB-based free layer and writing scheme to control the stray field and spin-transfer torque. As a result, four stable and well-separated resistance states were obtained in resistance-voltage curves with a 65-nm top-pinned p-MTJ.

Keywords

MRAM devices; cobalt compounds; iron compounds; magnetic tunnelling; magnetoelectronics; CoFeB; highly manufacturable multilevel perpendicular MTJ structure; magnetic tunnel junction; multiple barrier-free layers; resistance control; resistance-voltage curves; single top-pinned layer; size 65 nm; small film roughness; spin-transfer torque; spin-transfer torque MRAM; stray field; well-separated resistance states; writing scheme; Films; Junctions; Magnetic fields; Magnetic tunneling; Magnetization; Resistance; Writing;

fLanguage

English

Publisher

ieee

Conference_Titel

Electron Devices Meeting (IEDM), 2013 IEEE International

Conference_Location

Washington, DC

Type

conf

DOI

10.1109/IEDM.2013.6724551

Filename

6724551