Voltage-Controlled Magnetic Anisotropy MeRAM Bit-Cell over Event Transient Effects

Abstract

Magnetic tunnel junction (MTJ) with a voltage-controlled magnetic anisotropy (VCMA) effect has been introduced to achieve robust non-volatile writing control with an electric field or a switching voltage. However, continuous technology scaling down makes circuits more susceptible to temporary faults. The reliability of VCMA-MTJ-based magnetoelectric random access memory (MeRAM) can be impacted by environmental disturbances because a radiation strike on the access transistor could introduce write and read failures in 1T-1MTJ MeRAM bit-cells. In this work, Single-Event Transient (SET) effects on a VCMA-MTJ-based MeRAM in 28 nm FDSOI CMOS technology are investigated. Results show the minimum SET charge Q c required to reach the access transistor associated with the striking time that can lead to an unsuccessful switch, that is, an error in the writing process (write failure). The synchronism between the fluctuations of the magnetic field in the MTJ free layer and the moment of the write pulse is also analyzed in terms of SET robustness. Moreover, results show that the minimum Q c value can vary more than 100% depending on the magnetic state of the MTJ and the width of the access transistor. In addition, the most critical time against the SET occurrence may be before or after the write pulse depending on the magnetic state of the MTJ.

Voltage-controlled magnetic anisotropy-based spintronic devices for magnetic memory applications: Challenges and perspectives

“…Typically, it involves an MTJ device characterized by a high resistance-area (RA) product. [69][70][71] As a result, the current that passes through the thin insulating barrier is extremely minimal, enhancing the energy efficiency of VCMA and making it appealing for a wide range of applications, such as MRAMs, 72,73 random number (RN) generators, [74][75][76] physically unclonable functions (PUFs), [77][78][79] neuromorphic computing, 80,81 and spintronic oscillators. [82][83][84][85][86][87] In this article, our primary focus is the VCMA-MRAM, which is discussed in Secs.…”

Random Bitstream Generation Using Voltage-Controlled Magnetic Anisotropy and Spin Orbit Torque Magnetic Tunnel Junctions

“…Here, we design an MTJ device that utilizes voltagecontrolled magnetic anisotropy (VCMA) and spin orbit torque (SOT) [17][18][19] to generate random bitstreams. While VCMA and SOT have been studied for this application, their quality,…”

Magnetic Tunnel Junction Applications

“…Even if MTJ has high tolerance to radiation [45], the MOS access transistors in MTJ-based memory structures may be impacted by radiation. Among other factors, tolerance to radiation is one important and studied field [46][47][48][49] when it is necessary to take into account performance and risks of MRAM in the integration process of MOS technology.…”