Emerging CMOS Compatible Magnetic Memories and Logic

Johannes Ender,Wolfgang Goes,Simone Fiorentini,Roberto L De Orio,Viktor Sverdlov,Siegfried Selberherr

doi:10.1109/jeds.2021.3066679

Johannes Ender, Wolfgang Goes + Show 4 more

Open Access

https://doi.org/10.1109/jeds.2021.3066679

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Abstract

As scaling of the feature size - the main driving force behind an outstanding increase of the performance of modern electronic circuits - displays signs of saturation, the main focus of engineering research in microelectronics shifts towards finding new paradigms. Any future solution must be scalable and energy efficient while delivering high performance, superior to that of CMOS-based circuits. In order to benefit from the outstanding potential of highly advanced silicon processing technology, any new solution must be CMOS compatible. Emerging nonvolatile memories, including magnetoresistive memories, satisfy the necessary requirements: purely electrical addressability, simple structure, high endurance and fast operation. In this work we present the recent developments in the research of spin-transfer torque and spin-orbit torque random access memories and give a brief overview of spin-based logic. Here, the advantages and challenges of these two main contenders in the magnetic memory field are described and the current technological trends are noted. Areas facing computational challenges due to the long-range interaction of the demagnetizing field are highlighted and an existing solution is presented. The use of reinforcement learning to optimize handling of a purely electrically controllable spin-orbit torque memory cell is introduced and first results showing the switching reliability of an optimized switching pulse sequence under thermal fluctuations are reported.

Highlights

The continuous miniaturization of metal-oxidesemiconductor field effect transistors is slowing down
Apart from stand-alone applications as well as critical program and data storage devices, nonvolatility is promising for use in the main computer memory as it eliminates the need for data refreshment cycles in conventional CMOS-based dynamic random-access memory (DRAM) [2]
In a micromagnetic simulation framework based on the open-source libraries MFEM [30] for finite element method (FEM) discretization and H2Lib [31] for basic boundary element method (BEM) functionality, we implemented an algorithm for the calculation of the demagnetizing field of disjoint magnetic domains, as they appear in magnetic tunnel junctions (MTJs)

Summary

Introduction

The continuous miniaturization of metal-oxidesemiconductor field effect transistors is slowing down. MTJ-based magnetoresistive random access memory (MRAM) is compatible with CMOS circuits. One critical aspect of the presently used STT-MRAM technology is a quite high switching current density, due to the fact that one has to overcome the energy barrier separating the two stable memory states.

Results

Conclusion