Thin-film design of amorphous hafnium oxide nanocomposites enabling strong interfacial resistive switching uniformity

• A design concept of phase-separated amorphous nanocomposite thin films is presented that realizes interfacial resistive switching (RS) in hafnium oxide-based devices. The films are formed by incorporating an average of 7% Ba into hafnium oxide during pulsed laser deposition at temperatures <= 400 degrees C. The added Ba prevents the films from crystallizing and leads to similar to 20-nm-thin films consisting of an amorphous HfOx host matrix interspersed with similar to 2-nm-wide, similar to 5-to-10-nm-pitch Ba-rich amorphous nanocolumns penetrating approximately two-thirds through the films. This restricts the RS to an interfacial Schottky-like energy barrier whose magnitude is tuned by ionic migration under an applied electric field. Resulting devices achieve stable cycle-to-cycle, device-to-device, and sample-to-sample reproducibility with a measured switching endurance of >= 10(4) cycles for a memory window >= 10 at switching voltages of +/- 2 V. Each device can be set to multiple intermediate resistance states, which enables synaptic spike-timing-dependent plasticity. The presented concept unlocks additional design variables for RS devices.

Subject headings

NATURVETENSKAP  -- Fysik -- Atom- och molekylfysik och optik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Atom and Molecular Physics and Optics (hsv//eng)

Publication and Content Type

ref (subject category)

art (subject category)