Novel STT/SHE MTJ Compact Model Compatible with NGSPICE

TL;DR

This paper introduces a physics-based, simulator-independent compact model for STT/SHE Magnetic Tunnel Junctions (MTJs) compatible with NGSPICE, enabling accurate device simulation and stochastic noise analysis for next-generation computing circuits.

Contribution

It presents a novel, open-source compatible MTJ model that accurately captures device physics and thermal noise, with Monte-Carlo simulation support for hybrid circuit design.

Findings

Model accurately emulates MTJ physics and stochastic thermal noise.

Demonstrated with PCSA read/write operations and neuron MTJ implementation.

Supports hybrid MTJ/CMOS circuit simulation with Monte-Carlo capabilities.

Abstract

Ensuring high performance, while meeting the power budget is a challenging task as the world is moving towards next-generation computing. Researchers and designers are in search of new solutions for efficient computation. Spintronics devices have been viewed as a promising way to deal with the escalating difficulties of CMOS downscaling, explicitly, the Magnetic Tunnel Junction (MTJ) devices have been the focal point of investigation. They possess some essential features from the aforementioned perspective such as nonvolatility, low power, and scalability. In light of the significance of MTJ devices in next-generation computing, this paper presents a physics-based STT/SHE MTJ model for hybrid MTJ/CMOS circuit simulation, that accurately emulates the device physics and stochastic thermal noise behavior of the MTJ. It is vital to have an MTJ compact model which is compatible with the open-source NGSPICE simulation framework since previously developed models are reliant on commercial EDA tools. In addition, for developing hybrid circuits with random process fluctuations, a simulator-independent Monte-Carlo simulation capability has been incorporated Finally, the STT/SHE-MTJ model is demonstrated using PCSA read/write operation and the implementation of neuron MTJ.