Ab-initio Modeling of CBRAM Cells: from Ballistic Transport Properties to Electro-Thermal Effects

TL;DR

This paper uses first-principles atomistic simulations to analyze the transport and thermal effects in CBRAM cells, revealing how atomic-scale changes influence resistance and device performance.

Contribution

It introduces a detailed atomistic simulation approach combining DFT and NEGF for CBRAM, highlighting atomic-scale effects on transport and thermal behavior.

Findings

Few-atom relocation causes 6 orders of magnitude resistance change

Electron trajectories depend on filament morphology

Self-heating is negligible below 1 μA current

Abstract

We present atomistic simulations of conductive bridging random access memory (CBRAM) cells from first-principles combining density-functional theory and the Non-equilibrium Green's Function formalism. Realistic device structures with an atomic-scale filament connecting two metallic contacts have been constructed. Their transport properties have been studied in the ballistic limit and in the presence of electron-phonon scattering, showing good agreement with experimental data. It has been found that the relocation of few atoms is sufficient to change the resistance of the CBRAM by 6 orders of magnitude, that the electron trajectories strongly depend on the filament morphology, and that self-heating does not affect the device performance at currents below 1 $\mu$A.