Electrolyte-Dependent Modification of Resistive Switching in Anodic Hafnia
Sprache des Titels:
Englisch
Original Kurzfassung:
Anodic HfO2 memristors grown in phosphate, borate, or citrate electrolytes and formed
on sputtered Hf with Pt top electrodes are characterized at fundamental and device levels. The
incorporation of electrolyte species deep into anodic memristors concomitant with HfO2 crystalline
structure conservation is demonstrated by elemental analysis and atomic scale imaging. Upon
electroforming, retention and endurance tests are performed on memristors. The use of borate
results in the weakest memristive performance while the citrate demonstrates clear superior
memristive properties with multilevel switching capabilities and high read/write cycling in the
range of 106. Low temperature heating applied to memristors shows a direct influence on their
behavior mainly due to surface release of water. Citrate?based memristors show remarkable
properties independent on device operation temperatures up to 100 °C. The switching dynamic of
anodic HfO2 memristors is discussed by analyzing high resolution transmission electron
microscope images. Full and partial conductive filaments are visualized, and apart from their
modeling, a concurrency of filaments is additionally observed. This is responsible for the
multilevel switching mechanism in HfO2 and is related to device failure mechanisms.
Forschungs-