Technology for reliable spin-torque MRAM products

Slaughter, J. M.; Nagel, K.; Whig, R.; Deshpande, S.; Aggarwal, S.; DeHerrera, M.; Janesky, J.; Lin, Mingjie; Chia, Hao-Chung; Hossain, Moinul; Ikegawa, S.; Mancoff, F. B.; Shimon, G.; Sun, J. J.; Tran, Michaël; Andre, T.; Alam, Syed Q.; Poh, F.; Lee, J. H.; Chow, Yew Tuck; Jiang, Yi; Liu, H. X.; Wang, C. C.; Noh, Sujung; Tahmasebi, T.; Ye, S. K.; Shum, D.

doi:10.1109/iedm.2016.7838467

Cited by 33 publications

(15 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Perpendicular anisotropy-based magnetic tunnel junctions (p-MTJs) have great potential for reducing power dissipation and scaling to feature sizes below 20 nm, [1][2][3][4][5][6][7] and thus have been extensively studied to develop spin-transfer torque magnetic random access memories (STT-MRAMs) and very-large-scale integrated circuits (VLSIs). [8][9][10][11][12][13] In particular, p-MTJs with a MgO/CoFeB/heavy metal (e.g., Ta, Hf) structure have attracted interest for their enhanced perpendicular anisotropy that originates from both MgO/CoFeB and CoFeB/heavy metal interfaces, [14][15][16][17][18] bringing a reasonable magnetoresistance ratio (TMR) and STT switching critical current density (JC). Furthermore, p-MTJs with a double MgO/CoFeB interface free layer, i.e., MgO/CoFeB/Ta/CoFeB/MgO, have been shown to possess a considerable thermal stability factor (Δ), and JC comparable to that of p-MTJs with a single interface.…”

mentioning

confidence: 99%

Current-induced magnetization switching in atom-thick tungsten engineered perpendicular magnetic tunnel junctions with large tunnel magnetoresistance

et al. 2018

View full text Add to dashboard Cite

Perpendicular magnetic tunnel junctions based on MgO/CoFeB structures are of particular interest for magnetic random-access memories because of their excellent thermal stability, scaling potential, and power dissipation. However, the major challenge of current-induced switching in the nanopillars with both a large tunnel magnetoresistance ratio and a low junction resistance is still to be met. Here, we report spin transfer torque switching in nano-scale perpendicular magnetic tunnel junctions with a magnetoresistance ratio up to 249% and a resistance area product as low as 7.0 Ω µm2, which consists of atom-thick W layers and double MgO/CoFeB interfaces. The efficient resonant tunnelling transmission induced by the atom-thick W layers could contribute to the larger magnetoresistance ratio than conventional structures with Ta layers, in addition to the robustness of W layers against high-temperature diffusion during annealing. The critical switching current density could be lower than 3.0 MA cm−2 for devices with a 45-nm radius.

show abstract

mentioning

confidence: 99%

Current-induced magnetization switching in atom-thick tungsten engineered perpendicular magnetic tunnel junctions with large tunnel magnetoresistance

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Perpendicular spin transfer torque random access memory (pSTT-MRAM) based on perpendicular magnetic tunnel junction (pMTJ) stack has attracted considerable interest due to their combination of assets of non-volatility, high thermal stability, low critical current for current-induced spin transfer torque (STT) magnetization switching (few tens of microamps at sub-40nm), high speed (write access time typically in the range 10ns-30ns) and high density memory array (4Gbit capacity and 1.5F pitch demonstrated). [1][2][3][4][5][6] The core component of the stack, where spin transport phenomena such as tunneling magnetoresistance (TMR) and magnetization reversal of storage layer by STT occurs is an FeCoB/MgO/FeCoB based tunnel junction. [7][8][9] Here one of the FeCoB layer is storage layer, while other has a fixed magnetization, called as reference layer.…”

mentioning

confidence: 99%

Physicochemical origin of improvement of magnetic and transport properties of STT-MRAM cells using tungsten on FeCoB storage layer

Chatterjee

Gautier

Veillerot

et al. 2019

Applied Physics Letters

View full text Add to dashboard Cite

We investigated and compared the structural and magnetic properties of MgO/FeCoB based out-of-plane magnetized tunnel junctions at thin film level as well as the magneto-transport properties of corresponding patterned STT-MRAM cells comprising either Ta 1 nm or W2 /Ta1 nm cap layers for different annealing temperatures up to 455°C. W material in the cap was found to improve the structural stiffness of the perpendicular magnetic tunnel junctions and most importantly prohibits Fe diffusion from the FeCoB storage layer to the cap layer, remarkably improving the thermal robustness and magneto-transport properties of the stacks and of the corresponding patterned memory cells. As a result, the interfacial anisotropy constant of the MgO/FeCoB interfaces is improved by 17-29% compared to Ta cap. The STT-MRAM cells fabricated from the pMTJ stacks with W/Ta cap reveal a significant improvement of tunneling magnetoresistance and thermal stability factor, which are respectively 120% and 52 as compared to 70% and 35 for the stack with Ta cap. This improvements are ascribed to the enhancement of MgO crystallinity upon higher temperature annealing (425°C) as well as prohibition Fe out-diffusion.

show abstract

“…Moreover, when memory capacity increases, strong PMA is needed to guarantee low chip failure rate. As shown in Figure , for memories with capacity of 128 Gbit, a thermal stability factor of 75 is necessary to achieve data retention time of 10 years and chip failure rate of 10 −4 , which requires the interfacial PMA of the free layer stronger than 4.7 mJ m −2 if MTJ size is smaller than 10 nm. Even though some applications, such as cache memory, demand much shorter retention time (e.g., 1 ms), an interfacial PMA value as high as 3.1 mJ m −2 is still needed.…”

Section: Modulation Of Hm/fm Interface For Strong Pmamentioning

confidence: 99%

Modulation of Heavy Metal/Ferromagnetic Metal Interface for High‐Performance Spintronic Devices

Peng

Zhu

Zhou

et al. 2019

Adv Elect Materials

View full text Add to dashboard Cite

Spintronic devices such as magnetic tunnel junctions and skyrmions have attracted considerable attention due to features such as nonvolatility, high scalability, low power, and high speed. Over the past few years, innovative materials and new structures in this field have resulted in the emergence of new phenomena and exciting device performance. It has been found that the heavy metal (HM)/ferromagnetic metal (FM) interface plays an essential role in spintronic devices. Spintronic device performance can be significantly enhanced through proper modulation of this interface. Recent progress in this blooming field is reviewed with specific emphasis on the HM/FM interface. Investigations into HM/FM-interface-related phenomena, including perpendicular magnetic anisotropy, tunnel magnetoresistance, magnetic damping, spin-orbit torque, and Dzyaloshinskii-Moriya interaction, are put into context. Guidelines for realizing high-performance spintronic devices are provided, and an outlook on their future research direction and potential applications is given.

show abstract

Technology for reliable spin-torque MRAM products

Cited by 33 publications

References 1 publication

Current-induced magnetization switching in atom-thick tungsten engineered perpendicular magnetic tunnel junctions with large tunnel magnetoresistance

Current-induced magnetization switching in atom-thick tungsten engineered perpendicular magnetic tunnel junctions with large tunnel magnetoresistance

Physicochemical origin of improvement of magnetic and transport properties of STT-MRAM cells using tungsten on FeCoB storage layer

Modulation of Heavy Metal/Ferromagnetic Metal Interface for High‐Performance Spintronic Devices

Contact Info

Product

Resources

About