학술논문

Defect and Fault Modeling Framework for STT-MRAM Testing
Document Type
Periodical
Source
IEEE Transactions on Emerging Topics in Computing IEEE Trans. Emerg. Topics Comput. Emerging Topics in Computing, IEEE Transactions on. 9(2):707-723 Jun, 2021
Subject
Computing and Processing
Magnetic tunneling
Switches
Resistors
Multiprotocol label switching
Magnetic anisotropy
Magnetization
Saturation magnetization
STT-MRAM
manufacturing defects
fault models
test development
Language
ISSN
2168-6750
2376-4562
Abstract
STT-MRAM mass production is around the corner as major foundries worldwide invest heavily on its commercialization. To ensure high-quality STT-MRAM products, effective yet cost-efficient test solutions are of great importance. This article presents a systematic device-aware defect and fault modeling framework for STT-MRAM to derive accurate fault models which reflect the physical defects appropriately, and thereafter optimal and high-quality test solutions. An overview and classification of manufacturing defects in STT-MRAMs are provided with an emphasis on those related to the fabrication of magnetic tunnel junction (MTJ) devices, i.e., the data-storing elements. Defects in MTJ devices need to be modeled by adjusting the affected technology parameters and subsequent electrical parameters to fully capture the defect impact on both the device's electrical and magnetic properties, whereas defects in interconnects can be modeled as linear resistors. In addition, a complete single-cell fault space and nomenclature are defined, and a systematic fault analysis methodology is proposed. To demonstrate the use of the proposed framework, resistive defects in interconnect and pinhole defects in MTJ devices are analyzed for a single 1T-1MTJ memory cell. Test solutions for detecting these defects are also discussed.