Title :
A novel MTJ for STT-MRAM with a dummy free layer and dual tunnel junctions
Author :
Tsunoda, Koji ; Noshiro, Hideyuki ; Yoshida, Chikako ; Yamazaki, Yasuyuki ; Takahashi, Asami ; Iba, Yoshihisa ; Hatada, Akiyoshi ; Nakabayashi, Masaaki ; Takenaga, Takashi ; Aoki, Masaki ; Sugii, Toshihiro
Author_Institution :
Low-power Electron. Assoc. & Project (LEAP), Tsukuba, Japan
Abstract :
A novel magnetic tunnel junction (MTJ) for embedded memory applications such as spin transfer torque magneto-resistive random access memory (STT-MRAM) is proposed. It consists of a dummy free layer and dual tunnel junctions using perpendicular magnetic anisotropy at the CoFeB/MgO interface. A fabricated MTJ with 53 nm diameter exhibited a high thermal stability factor Δ = 52 and a small switching current Ic0 = 57 μA, resulting in an Δ/Ic0 ratio of 0.91, which is more than twice that of the reference MTJ. This MTJ simultaneously provides an excellent Δ/Ic0 ratio, low-voltage switching (0.34 V at 100 ns), and good manufacturability.
Keywords :
MRAM devices; cobalt compounds; iron compounds; magnesium compounds; magnetic tunnelling; CoFeB-MgO; MTJ; STT-MRAM; current 57 muA; dual tunnel junctions; dummy free layer; embedded memory applications; magnetic tunnel junction; perpendicular magnetic anisotropy; spin transfer torque magneto-resistive random access memory; thermal stability factor; time 100 ns; voltage 0.34 V; Junctions; Magnetic tunneling; Perpendicular magnetic anisotropy; Resistance; Switches; Thermal factors; Thermal stability;
Conference_Titel :
Electron Devices Meeting (IEDM), 2012 IEEE International
Conference_Location :
San Francisco, CA
Print_ISBN :
978-1-4673-4872-0
Electronic_ISBN :
0163-1918
DOI :
10.1109/IEDM.2012.6479126
