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

ABSTRACT

This study examined the effects of electrical forming methods on the bipolar resistance switching (BRS) behavior in Pt/TiO(2)/Pt sandwich structures. The BRS is confined to a region near the ruptured end of conducting nanofilaments, which are composed of a Ti(n)O(2n-1) Magnéli phase formed by electroforming. The intermediate phase with an oxygen vacancy concentration between the insulating TiO(2) and the residual conducting filament that formed at the interface region was considered to be the switching layer (SL). The change in filament shape caused by a variation in the compliance current during filament formation resulted in a different filament rupture location and SL configuration. Precise control of the filament formation and rupture process resulted in SLs connected in an anti-parallel configuration. It was possible to reconfigure the SLs in the same fashion without any restraints, which allowed an unlimited memristive operation to be achieved. This paper presents a new technique in voltage sweep mode that applies a compliance current as a tool to achieve a memristor with unlimited operation.