Integration of STT-MRAMs for Embedded Cache Memories

We report the current status of our development of spin-transfer torque magnetic RAMs (STT-MRAMs) and their integration with the back-end-of-line (BEOL) process to replace conventional embedded SRAM cache memories. Our MRAM technology features a top-pinned, perpendicular magnetic tunnel junction (MTJ) and a highly reliable MTJ for a cache memory. We could obtain a higher density cache memory than that with conventional SRAMs with our STT-MRAMs, and leakage free characteristics, as well as unlimited write and read cycling times and 10-year time-dependent dielectric breakdown (TDDB) characteristics. They were integrated into Cu interconnects with 300 mm facilities. We also discuss variations in MTJ pattern sizes that are very important for memory applications from the viewpoint of high density embedded cache memories.

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Compact Model of Dielectric Breakdown in Spin-Transfer Torque Magnetic Tunnel Junction

IEEE Transactions on Electron Devices ◽

10.1109/ted.2016.2533438 ◽

2016 ◽

Vol 63 (4) ◽

pp. 1762-1767 ◽

Cited By ~ 49

Author(s):

You Wang ◽

Hao Cai ◽

Lirida Alves de Barros Naviner ◽

Yue Zhang ◽

Xiaoxuan Zhao ◽

...

Keyword(s):

Tunnel Junction ◽

Dielectric Breakdown ◽

Magnetic Tunnel Junction ◽

Spin Transfer Torque ◽

Spin Transfer ◽

Compact Model

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Double Magnetic Tunnel Junction with switchable assistance layer for improved spin transfer torque magnetic memory performance

Nanoscale ◽

10.1039/d1nr01656c ◽

2021 ◽

Author(s):

Daniel Sanchez Hazen ◽

Stephane Auffret ◽

Isabelle Joumard ◽

Laurent Vila ◽

Liliana Buda-Prejbeanu ◽

...

Keyword(s):

Tunnel Junction ◽

Memory Performance ◽

Magnetic Tunnel Junction ◽

Spin Transfer Torque ◽

Spin Transfer ◽

Magnetic Memory ◽

Memory Cells ◽

Experimental Demonstration

This paper reports the first experimental demonstration of a new concept of double magnetic tunnel junction comprising a magnetically switchable assistance layer. These double junctions are used as memory cells...

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Tunnel magnetoresistance and spin transfer torque in magnetic tunnel junction with embedded nanoparticles

EPJ Web of Conferences ◽

10.1051/epjconf/201818501015 ◽

2018 ◽

Vol 185 ◽

pp. 01015

Author(s):

Niazbeck Useinov

Keyword(s):

Ballistic Transport ◽

Magnetic Tunnel Junction ◽

Mean Free Path ◽

Spin Transfer Torque ◽

Spin Transfer ◽

Tunnel Magnetoresistance ◽

Spin Dependent Transport ◽

Plane Component ◽

Dependent Transport ◽

Embedded Nanoparticles

The theoretical model of spin-dependent transport in magnetic tunnel junctions (MTJ) containing magnetic or non-magnetic nanoparticle is developed. The dependences of tunnel magnetoresistance (TMR) and in-plane component of spin transfer torque (STT) on the applied voltage for various sizes of nanoparticles of the order of the mean free path of the conduction electron are calculated. The calculation is performed in the approximation of the ballistic transport of conduction electrons through the insulating layers of the MTJ and the nanoparticles.

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A compact model for magnetic tunnel junction (MTJ) switched by thermally assisted Spin transfer torque (TAS + STT)

Nanoscale Research Letters ◽

10.1186/1556-276x-6-368 ◽

2011 ◽

Vol 6 (1) ◽

Cited By ~ 28

Author(s):

Weisheng Zhao ◽

Julien Duval ◽

Jacques-Olivier Klein ◽

Claude Chappert

Keyword(s):

Tunnel Junction ◽

Magnetic Tunnel Junction ◽

Spin Transfer Torque ◽

Spin Transfer ◽

Compact Model

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WRITE ERROR RATE IN SPIN TRANSFER TORQUE MAGNETIC RANDOM ACCESS MEMORY

SPIN ◽

10.1142/s2010324712400012 ◽

2012 ◽

Vol 02 (03) ◽

pp. 1240001 ◽

Cited By ~ 2

Author(s):

ZIHUI WANG ◽

YUCHEN ZHOU ◽

JING ZHANG ◽

YIMING HUAI

Keyword(s):

Error Rate ◽

Random Access ◽

Magnetic Tunnel Junction ◽

Random Access Memory ◽

Underlying Mechanism ◽

Theoretical Description ◽

Spin Transfer Torque ◽

Spin Transfer ◽

Access Memory ◽

Magnetic Random Access Memory

This paper reviews the recent progress made to realize reliable write operations in spin transfer torque magnetic random access memory. Theoretical description of write error rate (WER) based on macro-spin models are discussed with comparison to experimental data. Recent studies on the phenomena that can lead to abnormal WER behaviors which include back-hopping and low probability bifurcated switching are reviewed with emphasis on underlying mechanism. The studies on the WER in perpendicular magnetic tunnel junction (MTJ) are also reviewed. It is demonstrated that, for both in-plane and perpendicular MTJ, reliable and error-free write operations can be achieved with thorough understanding of the underlying physics and innovative design/process solutions.

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