Paper Info
Title
Characterization, Modeling and Test of Synthetic Anti-Ferromagnet Flip Defect in STT-MRAMs
Abstract
Understanding the manufacturing defects in magnetic tunnel junctions (MTJs), which are the data-storing elements in STT-MRAMs, and their resultant faulty behaviors are crucial for developing high-quality test solutions. This paper introduces a new type of MTJ defect: synthetic anti-ferromagnet flip (SAFF) defect, wherein the magnetization in both the hard layer and reference layer of MTJ devices undergoes an unintended flip to the opposite direction. Both magnetic and electrical measurement data of SAFF defect in fabricated MTJ devices is presented; it shows that such a defect reverses the polarity of stray field at the free layer of MTJ, while it has no electrical impact on the single isolated device. The paper also demonstrates that using the conventional fault modeling and test approach fails to appropriately model and test such a defect. Therefore device-aware fault modeling and test approach is used. It first physically models the defect and incorporate it into a Verilog-A MTJ compact model, which is afterwards calibrated with silicon data. The model is thereafter used for fault analysis and modeling within an STT-MRAM array; simulation results show that a SAFF defect may lead to an intermittent Passive Neighborhood Pattern Sensitive Fault (PNPSF1i) when all neighboring cells are in logic `1' state. Finally, test solutions for such fault are discussed.
Year
DOI
Venue
2020
10.1109/ITC44778.2020.9325258
2020 IEEE International Test Conference (ITC)
Keywords
DocType
ISSN
synthetic anti-ferromagnet flip defect,magnetic tunnel junctions,magnetic measurement data,electrical measurement data,SAFF defect,fabricated MTJ devices,electrical impact,single isolated device,device-aware fault modeling,Verilog-A MTJ compact model,STT-MRAM array,intermittent passive neighborhood pattern sensitive fault,PNPSF1i,device-aware fault test
Conference
1089-3539
ISBN
Citations 
PageRank 
978-1-7281-9114-0
2
0.37
References 
Authors
0
6
Name
Order
Citations
PageRank
Lizhou Wu120.37
Siddharth Rao2112.23
Mottaqiallah Taouil322433.40
Erik Jan Marinissen42053170.58
G. Kar596.91
Said Hamdioui6887118.69