Electrically configurable electroforming and bipolar resistive switching in Pt/TiO2/Pt structures

Area of Science:

• Materials Science
• Electrical Engineering
• Nanotechnology

Background:

• Bipolar resistance switching (BRS) is crucial for memristor devices.
• Conducting nanofilaments, typically a Magnéli phase Ti(n)O(2n-1), drive BRS in Pt/TiO(2)/Pt structures.
• The switching layer (SL) is an intermediate oxygen vacancy phase between TiO(2) and the filament.

Purpose of the Study:

• To investigate how electrical forming methods influence BRS behavior in Pt/TiO(2)/Pt sandwich structures.
• To understand the role of filament shape and switching layer configuration in BRS.
• To develop a technique for achieving unlimited memristive operation.

Main Methods:

• Fabrication of Pt/TiO(2)/Pt sandwich structures.
• Electrical forming using voltage sweeps with controlled compliance current.
• Analysis of bipolar resistance switching behavior.
• Characterization of filament formation and rupture dynamics.

Main Results:

• BRS behavior is localized near the ruptured end of electroformed Ti(n)O(2n-1) nanofilaments.
• Variations in compliance current alter filament shape, rupture location, and SL configuration.
• Precise control enables anti-parallel SL configurations.
• Unlimited memristive operation was achieved through controlled filament reconfiguration.

Conclusions:

• Electrical forming methods significantly impact BRS behavior by controlling filament morphology and SL characteristics.
• A novel voltage sweep technique using compliance current allows for unlimited memristor operation.
• This method offers a pathway to robust and repeatable memristive devices.