Three-dimensional observation of the conductive filament in nanoscaled resistive memory devices.
The basic unit of information in filamentary-based resistive switching memories is physically stored in a conductive filament. Therefore, the overall performance of the device is indissolubly related to the properties of such filament. In this Letter, we report for the first time on the three-dimensional (3D) observation of the shape of the conductive filament. The observation of the filament is done in a nanoscale conductive-bridging device, which is programmed under real operative conditions. To obtain the 3D-information we developed a dedicated tomography technique based on conductive atomic force microscopy. The shape and size of the conductive filament are obtained in three-dimensions with nanometric resolution. The observed filament presents a conical shape with the narrow part close to the inert-electrode. On the basis of this shape, we conclude that the dynamic filament-growth is limited by the cation transport. In addition, we demonstrate the role of the programming current, which clearly influences the physical-volume of the induced conductive filaments.
IMEC , Kapeldreef 75, B-3001 Heverlee (Leuven), Belgium.
Umberto
U
Celano
Ludovic
L
Goux
Attilio
A
Belmonte
Karl
K
Opsomer
Alexis
A
Franquet
Andreas
A
Schulze
Christophe
C
Detavernier
Olivier
O
Richard
Hugo
H
Bender
Malgorzata
M
Jurczak
Wilfried
W
Vandervorst