Title :
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
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;
Conference_Titel :
Electron Devices Meeting (IEDM), 2013 IEEE International
Conference_Location :
Washington, DC
DOI :
10.1109/IEDM.2013.6724551
