Modeling of Copper Diffusion in Amorphous Aluminum Oxide in CBRAM Memory Stack

First-principles modeling techniques are used to study the diffusion of copper in amorphous alumina (a-Al2O3) for Conductive Bridging Random Access Memories (CBRAM) Pt/CuxTe(1-x)/Al2O3/Si stacks. The enthalpy of injection (Ei) of Cu(+1/+2) and Te(-2/+2) ions into a-Al2O3 have been quantified. We found that the kinetics associated to Cu+1 injection is characterized by a diffusion pre-factor of 5.8×10-4 cm2/s and an activation energy of 0.9 eV in a-Al2O3. The diffusion kinetics of the Te+2 ions is similar to the Cu+1 one.