Viktor Sverdlov, Siegfried Selberherr

DOI Number
First page
Last page


Miniaturization of semiconductor devices is the main driving force to achieve an outstanding performance of modern integrated circuits. As the industry is focusing on the development of the 3nm technology node, it is apparent that transistor scaling shows signs of saturation. At the same time, the critically high power consumption becomes incompatible with the global demands of sustaining and accelerating the vital industrial growth, prompting an introduction of new solutions for energy efficient computations.

Probably the only radically new option to reduce power consumption in novel integrated circuits is to introduce nonvolatility. The data retention without power sources eliminates the leakages and refresh cycles. As the necessity to waste time on initializing the data in temporarily unused parts of the circuit is not needed, nonvolatility also supports an instant-on computing paradigm.

The electron spin adds additional functionality to digital switches based on field effect transistors. SpinFETs and SpinMOSFETs are promising devices, with the nonvolatility introduced through relative magnetization orientation between the ferromagnetic source and drain. A successful demonstration of such devices requires resolving several fundamental problems including spin injection from metal ferromagnets to a semiconductor, spin propagation and relaxation, as well as spin manipulation by the gate voltage. However, increasing the spin injection efficiency to boost the magnetoresistance ratio as well as an efficient spin control represent the challenges to be resolved before these devices appear on the market. 

Magnetic tunnel junctions with large magnetoresistance ratio are perfectly suited as key elements of nonvolatile CMOS-compatible magnetoresistive embedded memory. Purely electrically manipulated spin-transfer torque and spin-orbit torque magnetoresistive memories are superior compared to flash and will potentially compete with DRAM and SRAM. All major foundries announced a near-future production of such memories.

Two-terminal magnetic tunnel junctions possess a simple structure, long retention time, high endurance, fast operation speed, and they yield a high integration density. Combining nonvolatile elements with CMOS devices allows for efficient power gating. Shifting data processing capabilities into the nonvolatile segment paves the way for a new low power and high-performance computing paradigm based on an in-memory computing architecture, where the same nonvolatile elements are used to store and to process the information.


digital spintronics, SpinFET, SpinMOSFET, spin-transfer torque, STT, spin-orbit torque, SOT, MRAM, in-memory computing

Full Text:



S.-E. Thompson, M. Armstrong, C. Auth et al., “A 90-nm Logic Technology Featuring Strained-Silicon”, IEEE Trans.Electron Devices, vol. 51, 1790, 2004.

K. Mistry, C. Allen, C. Auth et al., “A 45nm Logic Technology with High-k+Metal Gate Transistors, Strained Silicon, 9 Cu Interconnect Layers, 193nm Dry Patterning, and 100% Pb-Free Packaging”, In IEDM Techn. Digest, 2007, pp. 247-250.

S. Natarajan, M. Armstrong, M. Bost et al., “A 32nm Logic Technology Featuring 2nd-Generation High-k + Metal-Gate Transistors, Enhanced Channel Strain and 0.171μm2 SRAM Cell Size in a 291Mb Array”, In IEDM Techn. Digest, 2008, pp. 941-943.

R. Xie, P.Montanini, K.Akarvardar et al., “A 7nm FinFET Technology Featuring EUV Patterning and Dual Strained High Mobility Channels”, In IEDM Techn. Digest, 2016, pp. 47-50.

S.-Y. Wu, C.Y.Lin, M.C.Chiang et al., “7nm CMOS Platform Technology Featuring 4th Generation FinFET Transistors with a 0.027µm2 High Density 6-T SRAM cell for Mobile SoC Applications”, In IEDM Techn. Digest, 2016, pp. 43-46.

N. Loubet, T. Hook, P. Montanini et al., ”Stacked Nanosheet Gate-all-around Transistor to Enable Scaling beyond FinFET”, In Proceedings of the Symp. VLSI Technology and Circuits, 2017, T230.

J G.W. Burr, R.M. Shelby, A.Sebastian et al., “Neuromorphic Computing Using Non-volatile Memory”, Advances in Physics X, vol. 2, 89, 2017.

Y. Bychkov and E. Rashba, “Properties of a 2D Electron Gas with Lifted Spectral Degeneracy”, JETP Lett. vol. 39, 78, 1984.

S. Datta and B. Das, “Electronic Analog of the Electro-Optic Modulator”, Applied Physics Letters, vol.56, 665, 1990.

S. Sugahara and J. Nitta, “Spin-Transistor Electronics: An Overview and Outlook”, In Proceedings of the IEEE, 2010, vol. 98, 2124.

I. Zutic, J. Fabian, and S. Das Sarma, “Spintronics: Fundamentals and Applications”, Rev. Mod. Phys., vol. 76, 323,2004.

J. Fabian, A. Matos-Abiaguea, C. Ertler, et al., “Semiconductor Spintronics”, Acta Phys. Slovaca, vol. 5, 565, 2007.

P. Li and H. Dery, “Spin-Orbit Symmetries of Conduction Electrons in Silicon”, Phys. Rev. Lett., vol. 107, 107203, 2011.

O. Chalaev, Y. Song, and H. Dery, “Suppressing the Spin Relaxation of Electrons in Silicon”, Phys. Rev. B, vol. 95, 035204, 2017.

V. Sverdlov and S. Selberherr, “Silicon Spintronics: Progress and Challenges”, Physics Reports, vol. 585, 1, 2015.

V. Sverdlov, “Strain-induced Effects in Advanced MOSFETs”, Springer, 2011.

V. Sverdlov, J. Ghosh, and S. Selberherr, “Universal Dependence of the Spin Lifetime in Silicon Films on the Spin Injection Direction”, In Proceedings of the Workshop on Innovative Devices and Systems (WINDS), 2016, p.7.

T. Tahara, H. Koike, M. Kameno, et al., “Room-temperature Operation of Si Spin MOSFET with High on/off Spin Signal Ratio”, Appl. Phys. Express, vol. 8, 11304, 2015.

M. Oltscher, F. Eberle, T. Kuczmik et al., “Gate-tunable Large Magnetoresistance in an All-semiconductor Spin Valve Device”, Nature Communications, vol. 8, 1897, 2017.

P. Chuang, S.-C. Ho, L.W. Smith et al., “All-electric All-semiconductor Spin Field-effect Transistors”, Nature Nanotechnology, vol. 10, 35, 2015.

E.I. Rashba, “Theory of Electrical Spin Injection: Tunnel Contacts as a Solution of the Conductivity Mismatch Problem”, Phys. Rev. B, vol. 62, R16267, 2000.

T. Tahara, Y. Ando, M. Kameno et al., “Observation of Large Spin Accumulation Voltages in Nondegenerate Si Spin Devices due to Spin Drift Effect: Experiments and Theory”, Phys. Rev. B, vol. 93, 214406, 2016.

R. Jansen, “Silicon Spintronics“, Nature Materials, vol. 11, 400, 2012.

Y. Song and H. Dery, “Magnetic-Field-Modulated Resonant Tunneling in Ferromagnetic-Insulator-Nonmagnetic Junctions”, Phys. Rev. Let. vol. 113, 047205, 2014.

Z. Yue, M.C. Prestgard, A. Tiwari, and M.E. Raikh, “Resonant Magnetotunneling between Normal and Ferromagnetic Electrodes in Relation to the Three-terminal Spin Transport”, Phys. Rev. B,

vol. 91, 195316, 2015.

V. Sverdlov and S. Selberherr, “Current and Shot Noise at Spin-dependent Hopping through Junctions with Ferromagnetic Contacts”, Solid-State Electronics, submitted, 2018.

V. Sverdlov and S. Selberherr, “Spin Correlations at Hopping in Magnetic Structures: from Tunneling Magnetoresistance to Single-spin Transistor”, In Proceedings of the SPIE Conference Nanoscience+Engineering, 2018,

W. Yan, O. Txoperena, R. Llopis et al., “A Two-dimensional Spin Field-effect Switch”, Nature Communications, vol. 7, 13372, 2016.

A. Fert, “Nobel Lecture: Origin, Development, and Future of Spintronics”, Rev.Modern Phys., vol. 80, 1517, 2008; P. A. Grunberg, “Nobel Lecture: From Spin Waves to Giant Magnetoresistance and Beyond”, Rev. Modern Phys., vol. 80, 1531, 2008.

S. Ikeda, J. Hayakawa, Y. Ashizawa et al., “Tunnel Magnetoresistance of 604% at 300 K by Suppression of Ta Diffusion in CoFeB/MgO/CoFeB Pseudo-spin-valves Annealed at High Temperature”, Appl. Phys. Lett., vol. 93, 082508, 2008.

J. Slonczewski, “Current-driven Excitation of Magnetic Multilayers”, J. Magnetism and Magnetic Materials, vol. 159, L1, 1996.

L. Berger, “Emission of Spin Waves by a Magnetic Multilayer Traversed by a Current”, Phys. Rev. B, vol. 54, 9353, 1996.

Z. Diao, D. Apalkov, M. Pakala et al., “Spin Transfer Switching and Spin Polarization in Magnetic Tunnel Junctions with MgO and AlOx Barriers”, Appl. Phys. Lett., vol. 87, 232502, 2005.

A. Makarov, V. Sverdlov, D. Osintsev, and S. Selberherr, “Reduction of Switching Time in Pentalayer Magnetic Tunnel Junctions with a Composite-Free Layer”, Phys. Stat. Solidi (RRL – Rapid Research Letters), vol. 5, pp. 420-422, 2011.

A. Makarov, T. Windbacher, V. Sverdlov, and S. Selberherr, “CMOS-Compatible Spintronic Devices: A Review”, Semiconductor Science and Technology, vol. 31, 113006, 2016.

S.-W. Chung, T. Kishi, J.W. Park et al., “4Gbit Density STT-MRAM Using Perpendicular MTJ Realized with Compact Cell Structure”, in IEDM Techn. Digest, 2016, pp. 659-662.

S. Ikeda, K. Miura, H. Yamamoto et al., “A Perpendicular-anisotropy CoFeB–MgO Magnetic Tunnel Junction”, Nature Materials, vol. 9, 721, 2010.

K. Watanabe, B. Jinnai, S. Fukami et al., “Shape Anisotropy Revisited in Single-digit Nanometer Magnetic Tunnel Junctions”, Nature Communications, vol. 9, 663, 2018.

D. Apalkov, B. Dieny, and J.M. Slaughter, “Magnetoresistive Random Access Memory”, Proceedings of the IEEE, vol. 104, 1796, 2016.

Y.J. Song, J.H. Lee, H.C. Shin et al., “Highly Functional and Reliable 8Mb STT-MRAM Embedded in 28nm Logic”, in IEDM Techn. Digest, 2016, pp. 663-666.

H. Sato, M. Yamanouchi, S. Ikeda et al., “MgO/CoFeB/Ta/CoFeB/MgO Recording Structure in Magnetic Tunnel Junctions with Perpendicular Easy Axis”, IEEE Trans. Magnetics, vol. 49, 4437, 2013.

J. Swerts, E. Liu, S. Couet et al., “Solving the BEOL Compatibility Challenge of Top-pinned Magnetic Tunnel Junction Stacks”, In IEDM Techn. Digest, 2017, pp. 866-859.

G. Jan, L. Thomas, S. Le et al., “Achieving Sub‐ns Switching of STT‐MRAM for Future Embedded LLC Applications through Improvement of Nucleation and Propagation Switching Mechanisms”, In Proceedings of the Symp. VLSI Technology and Circuits, 2016, p.18.

I.M. Miron, K. Garello, G. Gaudin et al., “Perpendicular Switching of a Single Ferromagnetic Layer Induced by In-plane Current Injection”, Nature, vol. 476, 189, 2011.

L. Liu, J. Lee, T.J. Gudmundsen et al., “Current-induced Switching of Perpendicularly Magnetized Magnetic Layers Using Spin Torque from the Spin Hall Effect”, Phys. Rev. Lett., vol. 109, 096602, 2012.

L. Liu, C.-F. Pai, Y. Li et al., “Spin-torque Switching with the Giant Spin Hall Effect of Tantalum”, Science, vol. 336, 555, 2012.

A. Brataas and K.M.D. Hals, “Spin–orbit Torques in Action”, Nature Nanotechnology, vol. 9, 86, 2014.

T. Taniguchi, J. Grollier, and M.D. Stiles, “Spin-transfer Torques Generated by the Anomalous Hall Effect and Anisotropic Magnetoresistance”, Phys. Rev. Appl., vol. 3, 044001, 2015.

D. MacNeil, G.M. Stiehl, M.H.D. Guimaraes et al., “Control of Spin–orbit Torques through Crystal Symmetry in WTe2/Ferromagnet Bilayers”, Nature Physics, vol. 13, 300, 2017.

S.-W. Lee and K.-J. Lee, “Emerging Three-terminal Magnetic Memory Devices”, In Proceedings of the IEEE, vol. 104, 1831, 2016.

K.U. Demasius, T. Phung, W. Zhang et al., “Enhanced Spin–orbit Torques by Oxygen Incorporation in Tungsten Films”, Nature Communications, vol. 7, 10644, 2016.

J. Han, A. Richardella, S.A. Siddiqui et al., “Room-temperature Spin-orbit Torque Switching induced by a Topological Insulator”, Phys. Rev. Lett., vol. 119, 077702, 2017.

Y. Wang, D. Zhu, Y. Wu et al., “Room Temperature Magnetization Switching in Topological Insulator-ferromagnet Heterostructures by Spin-orbit Torques”, Nature Communications, vol. 8, 1364, 2018.

D.C. Mahendr, R. Grassi, J.-Y. Chen et al., “Room-temperature High Spin–orbit Torque due to Quantum Confinement in Sputtered BixSe(1–x) Films”, Nature Materials, vol. 17, 800, 2018.

N. Huynh, D. Khang, Y. Ueda, and P.N. Hai, “A Conductive Topological Insulator with Large Spin Hall Effect for Ultralow Power Spin–orbit Torque Switching”, Nature Materials, vol. 17, 808 2018.

S. Fukami, T. Anekawa, C. Zhan, and H. Ohno, “A Spin–orbit Torque Switching Scheme with Collinear Magnetic Easy Axis and Current Configuration”, Nature Nanotechnology, vol. 11, 621, 2016.

G. Yu, P. Upadhyaya, Y. Fanet et al., “Switching of Perpendicular Magnetization by Spin-orbit Torques in the Absence of External Magnetic Fields”, Nature Nanotechnology, vol. 9, 548, 2014.

G. Yu, L.-T. Chang, M. Akyol et al., “Current-driven Perpendicular Magnetization Switching in Ta/CoFeB/[TaOx or MgO/TaOx] Films with Lateral Structural Asymmetry”, Appl. Phys. Lett., vol. 105, 102411, 2014.

S. Fukami, C. Zhang, S. DuttaGupta et al., “Magnetization Switching by Spin–orbit Torque in an Antiferromagnet–ferromagnet Bilayer System”, Nature Materials, vol. 15, 535, 2016.

A. van den Brink, G. Vermijs, A. Solignac et al., “Field-free Magnetization Reversal by Spin-Hall Effect and Exchange Bias”, Nature Communications, vol. 7, 10854, 2016.

Y.-C. Lau, D. Betto, K. Rode et al., “Spin–orbit Torque Switching without an External Field using Interlayer Exchange Coupling”, Nature Nanotechnology, vol. 11, 758, 2016.

Y.-W. Oh, S.-H.C. Baek, Y.M. Kim et al., “Field-free Switching of Perpendicular Magnetization through Spin–orbit Torque in Antiferromagnet/Ferromagnet/Oxide Structures”, Nature Nanotechnology, vol. 11, 878, 2016.

C.K. Safeer, E. Jué, A. Lopez et al., “Spin-orbit Torque Magnetization Switching Controlled by Geometry”, Nature Nanotechnology, vol. 11, 143, 2016.

A. Makarov, T. Windbacher, V. Sverdlov, and S. Selberherr, “Concept of a SOT-MRAM based on 1Transistor-1MTJ-Cell Structure”, In Proceedings of the Conference Solid State Devices and Materials (SSDM), 2015, pp. 140-141.

V. Sverdlov, A. Makarov, and S. Selberherr, “Two-pulse Sub-ns Switching Scheme for Advanced Spin-Orbit Torque MRAM”, Solid-State Electronics, submitted, 2018.

K. Garello, F.Yasin, S Couet et al., “SOT‐MRAM 300mm Integration for Low Power and Ultrafast Embedded Memories”, In Proceedinghs of the Symp. VLSI Technology and Circuits, 2018, p.C8-2.

T. Hany, T. Endoh, D. Suzuki et al., “Standby-Power-Free Integrated Circuits Using MTJ-Based VLSI Computing”, In Proceedings of the IEEE, 2016, vol. 104, 1844.

H. Mahmoudi, T. Windbacher, V. Sverdlov, and S. Selberherr, “RRAM Implication Logic Gates”, Patent: International, No. Wo 2014/079747 A1; Patent priority number EP 12193826.0; submitted: 2013-11-13.

H. Mahmoudi, V. Sverdlov, and S. Selberherr, “MTJ-based Implication Logic Gates and Circuit Architecture for Large-Scale Spintronic Stateful Logic Systems”, In Proceedings of the European Solid-State Device Research Conference (ESSDERC), 2012, pp. 254-257.

A. Jaiswal, A. Agrawal, and K. Roy, “In-situ, In-Memory Stateful Vector Logic Operations Based on Voltage Controlled Magnetic Anisotropy”, Scientific Reports, vol.8, 5738, 2018.

B. Behin-Aein, D. Datta, S. Salahuddin, and S. Datta, “Proposal for an All-spin Logic Device with Built-in Memory”, Nature Nanotechnology, vol. 5, 266, 2010.

T. Windbacher, H. Mahmoudi, V. Sverdlov, and S. Selberherr, “Spin Torque Magnetic Integrated Circuit”, Patent: International, No. Wo 2014/154497 A1; Patent priority number EP 13161375.4; submitted: 2014-03-13, granted: 2014-10-02.

T. Windbacher, A. Makarov, V. Sverdlov, and S. Selberherr, “A Universal Nonvolatile Processing Environment”, in "Future Trends in Microelectronics - Journey into the Unknown", S. Luryi, J. Xu, A. Zaslavsky (ed); J. Wiley&Sons, 2016.

D. Ielmini and H.-S.P. Wong, “In-memory Computing with Resistive Switching Devices”, Nature Electronics, vol. 1, 333, 2018.

L.O. Chua, (1971), “Memristor—The Missing Circuit Element”, IEEE Trans. Circuit Theory, vol. CT-18, 507, 1971.

Y. Ma and T. Endoh, “A Novel Neuron Circuit with Nonvolatile Synapses Based on Magnetic-tunnel-junction for High-speed Pattern Learning and Recognition”, In Proceedings of the Asia-Pacific Workshop Fundam. Appl. Adv. Semicond. Devices, vol. 4B-1, 2015, pp. 273-278.,


  • There are currently no refbacks.

ISSN: 0353-3670