On the direction of the conductive filament growth in valence change memory devices during electroforming》.pdfVIP

Solid State Ionics 276 (2015) 9–17 Contents lists available at ScienceDirect Solid State Ionics j o ur nal homepage: www.el sevier. com/l ocate/ ssi On the direction of the conductive filament growth in valence change memory devices during electroforming D. Kalaev a, E. Yalon b, I. Riess a,⁎ a Physics Department, Technion-IIT, Haifa 3200003, Israel b Electrical Engineering Department, Technion-IIT, Haifa 3200003, Israel a r t i c l e i n f o a b s t r a c t Article history: We discuss theoretically the filament growth direction in valence change memory (VCM) devices and show that Received 20 March 2014 this direction is determined by kinetic considerations. It is being fixed by the relation between the kinetics of ion Received in revised form 8 March 2015 transfer at the electrodes and that of ion transfer through the bulk. Considering a filament consisting of donors Accepted 11 March 2015 (oxygen vacancies) the direction of growth is from the cathode when the anode ion kinetics is limited in comparison Available online 8 April 2015 to fast ion kinetics in the bulk of the oxide. In the opposite case the filament grows from the anode side. The filament Keywords: may in some cases extend between the two electrodes while in others leave a narrow insulating gap under the anode. Electroforming Filament