Analytical MRAM test

Magnetic Random Access Memory (MRAM) is a new technology which offers a viable alternative to other forms of nonvolatile memory, such as flash, where read access time, writing speed, and cell endurance is at a premium. Difficulties in scaling DRAM below the 32nm node may make MRAM a suitable candidate for DRAM replacement. The rigors of MRAM cell development present array designers, process engineers, and test engineers with many unique challenges. Enabling process development through test support of defect monitors makes test development particularly difficult in MRAM technology, due to the complexity of highly nonlinear magnetic materials and device behaviors. We review a number of new strategies and methodologies employed to support MRAM cell development over several MRAM generations, in a research environment. A unique test system with both advanced digital and parametric capabilities will be described. The importance of database integration within the test software and real-time data analysis will also be discussed.

[1]  K A Mkhoyan,et al.  Sidewall oxide effects on spin-torque- and magnetic-field-induced reversal characteristics of thin-film nanomagnets. , 2008, Nature materials.

[2]  Tom Zhong,et al.  A Study of Write Margin of Spin Torque Transfer Magnetic Random Access Memory Technology , 2010, IEEE Transactions on Magnetics.

[3]  W J Gallagher,et al.  Demonstration of Ultralow Bit Error Rates for Spin-Torque Magnetic Random-Access Memory With Perpendicular Magnetic Anisotropy , 2011, IEEE Magnetics Letters.

[4]  Yuri Suzuki,et al.  Thermally activated sweep-rate dependence of magnetic switching field in nanostructured current-perpendicular spin-valves , 2002 .

[5]  S. Assefa,et al.  Recent advances in MRAM technology , 2005, IEEE VLSI-TSA International Symposium on VLSI Technology, 2005. (VLSI-TSA-Tech)..

[6]  J. Nowak,et al.  Switching distributions and write reliability of perpendicular spin torque MRAM , 2010, 2010 International Electron Devices Meeting.

[7]  Jonathan Z. Sun,et al.  Spin-transfer induced switching in magnetic nanopillars , 2005, 2005 International Conference on MEMS,NANO and Smart Systems.

[8]  Jonathan Z. Sun,et al.  Spin angular momentum transfer in a current-perpendicular spin-valve nanomagnet , 2004, SPIE OPTO.

[9]  A D Kent,et al.  Current-induced excitations in single cobalt ferromagnetic layer nanopillars. , 2004, Physical review letters.

[10]  M. Sharrock,et al.  Time-dependent magnetic phenomena and particle-size effects in recording media , 1990 .

[11]  M. Gajek,et al.  Spin torque switching of 20 nm magnetic tunnel junctions with perpendicular anisotropy , 2012 .