A Robust and Efficient Compact Model for Phase-Change Memory Circuit Simulations

Abstract

A phase-change memory (PCM) model for robust and efficient simulations of circuits including neuromorphic ones is reported in this work. The features of a hysteretic dynamic resistance in the voltage domain, and the incubation in the crystallization, are covered in the model. The Landau-Khalatnikov (LK)-type equation for ferroelectric is used to develop the PCM hysteresis module. A voltage-controlled relaxation oscillation is successfully simulated for the Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Sb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Te <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> (GST) PCM. A technique of direct evaluation (DE) is then developed to reformulate the PCM model without any internal node. A significant enhancement of simulation efficiency is achieved compared with the traditional approach without sacrificing the accuracy. The functional correctness of the PCM device model and the acceleration effect in circuit simulations are verified.