A novel SPRAM (SPin-transfer torque RAM) with a synthetic ferrimagnetic free layer for higher immunity to read disturbance and reducing write-current dispersion
- 1 June 2007
- conference paper
- Published by Institute of Electrical and Electronics Engineers (IEEE)
Abstract
A novel SPRAM (spin-transfer torque RAM) consisting of MgO-barrier-based magnetic tunnel junctions (MTJs) with a synthetic ferrimagnetic (SyF) structure in a free layer was demonstrated for both higher immunity to read disturbance and a sufficient margin between the read and write currents. Since magnetization of the free layer becomes stable against thermal fluctuation with increasing thermal-stability factor E/kBT, the SyF free layer of the MTJs realized a magnetic information retention of over 10 years due to its high E/kBT of 67. Furthermore, it was found that the SyF free layer has an advantage of reducing dispersion of write-current density Jc, which is necessary for securing an adequate margin between the read and write currents.Keywords
This publication has 7 references indexed in Scilit:
- Effect of high annealing temperature on giant tunnel magnetoresistance ratio of CoFeB∕MgO∕CoFeB magnetic tunnel junctionsApplied Physics Letters, 2006
- Right-Brain/Left-Brain Integrated Associative Processor Employing Convertible Multiple-Instruction-Stream Multiple-Data-Stream ElementsJapanese Journal of Applied Physics, 2005
- Thermal effects on the magnetic-field dependence of spin-transfer-induced magnetization reversalApplied Physics Letters, 2004
- Giant room-temperature magnetoresistance in single-crystal Fe/MgO/Fe magnetic tunnel junctionsNature Materials, 2004
- Giant tunnelling magnetoresistance at room temperature with MgO (100) tunnel barriersNature Materials, 2004
- Time-Resolved Reversal of Spin-Transfer Switching in a NanomagnetPhysical Review Letters, 2004
- Current-driven excitation of magnetic multilayersJournal of Magnetism and Magnetic Materials, 1996