For the fabrication of CMOS/MTJ circuits, three different technological lines were developed and made accessible for HYMAGINE purposes. For simple circuits comprising only a few MTJs interconnected with CMOS transistors, the PTA 400m² upstream research clean-room located in SPINTEC building is used. A MRAM back-end process is operational at PTA and specific process steps required […]

Within HYMAGINE, circuits of increasing complexity have been conceived from simple non-volatile logic gates to microcontrollers or microprocessor. Below is an example of magnetic Look-Up-Table (MLUT) conceived within HYMAGINE and an example of hybrid CMOS/MTJmicroprocessor. Magnetic LUT for FPGA Our purpose was to develop a radiation-hardened FPGA based on MRAM. A FPGA (Field Programmable Gate […]

Thanks to their unique set of assets (non-volatility, speed, density, endurance), STT-MRAM are seen as a unique candidate for DRAM and/or Cache SRAM replacement allowing to drastically reduce the power consumption of electronic circuits thanks to new power gating strategies made possible by the non-volatility of these memories. For these applications, fast write speed (in […]

Modelling and design tools were developed in the frame of HYMAGINE to cover both the fundamental and design aspects of the project. Concerning the fundamental aspects, we developed a code allowing to calculate both the transport properties and the magnetization dynamics in systems of complex geometry wherein the current can be expected to be non-uniform […]

Olivier Fruchart,-, Bernard Diény We calculate the magnetostatic energy of synthetic ferrimagnet (SyF) elements, consisting of two thin ferromagnetic layers coupled antiferromagnetically, e.g. through RKKY coupling. Uniform magnetization is assumed in each layer. Exact formulas as well as approximate yet accurate ones are provided. These may be used to evaluate various quantities of SyF such […]

B Dieny In 2010, the International Technology Roadmap for Semiconductors (ITRS) published an assessment of the potential and maturity of selected emerging research on memory technologies. Eight different technologies of non-volatile memories were compared (ferroelectric gate field- effect transistor, nano-electro-mechanical switch, spin-transfer torque random access memories (STTRAM), various types of resistive RAM, in particular redox […]

Yue Zhang , Weisheng Zhao , Guillaume Prenat , Thibaut Devolder , Jacques-Olivier Klein , Claude Chappert , Bernard Dieny , and Dafiné Ravelosona Magnetic tunnel junctions (MTJ) are considered as one of the most promising candidates for the next generation of nonvolatile memories and programmable logic chips. Spin transfer torque (STT) in CoFeB/MgO/CoFeB MTJs […]

S. Leulmi, H. Joisten, T. Dietsch, C. Iss, M. Morcrette, S. Auffret, P. Sabon, and B. Dieny Magnetic nanoparticles are receiving an increasing interest for various biotechnological applications due to the capability that they offer to exert actuation on biological species via external magnetic fields. In this study, two types of magnetic particles recently proposed […]

We propose a model that describes current-in-plane tunneling transport in double barrier magnetic tunnel junctions in diffusive regime. Our study shows that specific features appear in double junctions that are described by introducing two typical length scales. The model may be used to measure the magnetoresistance and the resistance area product of both barriers in […]

1 Introduction 2 Magnetic Tunnel Junctions: A Route for CMOS/Magnetism Integration 3 Spin-Transfer Phenomenon 4 Magnetic Random Access Memories (MRAM) 4.1 Stoner-Wolfarth MRAM (SW-MRAM) 4.2 Toggle MRAM 4.3 Spin-Transfer Torque MRAM (STT-MRAM) 4.4 Thermally Assisted MRAM (TA-MRAM) 5 Racetrack Memories