JART – Jülich Aachen Resistive Switching Tools

Our laboratories provide simulation models for resistive switching devices to the scientific community. A focus on this dissemination activity are compact models to be used by circuit designers or device engineers. In the future, however, also kinetic Monte Carlo and continuum models will be provided. Please feel free to download the JART source codes. We request that you include a proper citation of either the web page or, preferentially, the corresponding papers whenever you are using it.

Contact: jart@iwe.rwth-aachen.de

JART ECM v1

Short description:

The JART ECM v1 model describes the switching dynamics of Electrochemical Metallization Cells, which are also known as Conductive Bridge RAM (CBRAM) or atomic switches. The model includes the redox-reactions at the metal insulator interfaces, ion hopping transport, and the electrocrystallization of the filament nucleus (see Figure 1). The conduction mechanism is modeled here as an electron tunneling process. The model was originally developed to model the switching dynamics of a Ag/AgI/Pt device [1]. Later it was applied to GeSx based ECM cells [2] and a Ag/SiOx based system [3].

Figure 1: Ionic and Electronic process included in the JART ECM v1 model.

The Verilog-A code of this model can be downloaded here (Verilog-A file).

  • [1] S. Menzel, S. Tappertzhofen, R. Waser and I. Valov, Switching Kinetics of Electrochemical Metallization Memory Cells, PCCP 15, 6945-6952 (2013).
  • [2] J. van den Hurk, S. Menzel, R. Waser and I. Valov, Processes and Limitations during Filament Formation and Dissolution in GeSx-based ReRAM memory cells, J. Phys. Chem. C 119, 18678-18685 (2015).
  • [3] M. Luebben, S. Menzel, S. G. Park, M. Yang, R.Waser and I. Valov, SET kinetics of electrochemical metallization cells - Influence of counter electrodes in SiO2/Ag based systems, Nanotechnology 28, 135205/1-6 (2017).

S. Menzel, C. Bengel

JART VCM v1

Short description:

The JART VCM v1 model was developed to simulate the switching characteristics of devices based on the valence change mechanism (also called OxRAM). In this model, the ionic defect concentration (oxygen vacancies) in the disc region close to the active electrode (AE) (see Figure 1) defines the resistance state. The concentration changes due to the non-isothermal drift of the ionic defects. In this model, Joule heating is considered, which significantly accelerates the switching process at high current levels.

The model was developed to study the two-step SET process of VCM cells [1] and the influence of an intrinsic series resistance on the switching characteristics [2].

Figure 1: Equivalent circuit diagram of the JART VCM v1 model.

The Verilog-A code of this model can be downloaded here (Verilog-A file). In addition, we provide a stand-alone MATLAB App (here). To use the MATLAB app the downloaded file needs to be executed. During the first installation, the MATLAB runtime environment will be downloaded from the internet.

  • [1] K. Fleck, C. La Torre, N. Aslam, S. Hoffmann-Eifert, U. Böttger and S. Menzel, Uniting Gradual and Abrupt SET Processes in Resistive Switching Oxides, Phys. Rev. Applied 6, 064015 (2016).
  • [2] A. Hardtdegen, C. La Torre, F. Cüppers, S. Menzel, R. Waser and S. Hoffmann-Eifert, Improved Switching Stability and the Effect of an Internal Series Resistor in HfO2/TiOx Bilayer ReRAM Cells, IEEE Trans. Electron Devices 65, 3229-3236 (2018).

S. Menzel, C. Bengel

JART VCM v2

Short description:

The JARV VCM v2 model is an extension of the JART VCM v1 model. It includes two different switching locations I and II (see Figure 1). Thus, the model uses two state variables. In addition, diffusion between region I and II is included in this model, enabling the simulation of retention. The model was developed to simulate complementary switching and bipolar switching in a single device [1].

Figure 1: Equivalent circuit diagram of the JART VCM v2 model.

The Verilog-A code of this model can be downloaded here (Verilog-A file). In addition, we provide a stand-alone MATLAB App (here). To use the MATLAB app the downloaded file needs to be executed. During the first installation, the MATLAB runtime environment will be downloaded from the internet.

  • [1] C. La Torre, A. F. Zurhelle, T. Breuer, R. Waser and S. Menzel, Compact Modeling of Complementary Switching in Oxide-Based ReRAM Devices, IEEE Trans. Electron Devices 66, 1268-1275 (2019).

S. Menzel, C. Bengel