Oxygen Concentration Effect on Conductive Bridge Random Access Memory of InWZnO Thin Film

Area of Science:

• Materials Science
• Electrical Engineering
• Nanotechnology

Background:

• Conductive bridge random access memory (CBRAM) is a promising non-volatile memory technology.
• The performance of CBRAM devices is highly dependent on the properties of the switching layer material.
• Indium Tungsten Zinc Oxide (IWZO) is explored as a potential switching layer material.

Purpose of the Study:

• To investigate the impact of oxygen concentration in IWZO switching layers on CBRAM device characteristics.
• To analyze the effect of oxygen vacancy distribution on electrical properties.
• To explore the potential of bilayer IWZO structures for enhanced memory performance.

Main Methods:

• Fabrication of IWZO films with varying oxygen concentrations via sputtering.
• Electrical characterization of CBRAM devices with different IWZO switching layers.
• Analysis using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS).
• Systematic investigation of bilayer stacking structures (IWZOx/IWZOy).

Main Results:

• CBRAM devices with specific bilayer IWZO (oxygen-poor/oxygen-rich) exhibited improved resistance state stability.
• Enhanced endurance exceeding 3 × 10^4 cycles was achieved with the bilayer structure.
• A stable memory window was maintained for over 10^4 seconds at 85 °C.
• Oxygen vacancy distribution was identified as a key factor influencing conductive filament formation and rupture.

Conclusions:

• A specific stacking sequence of bilayer oxygen-poor/oxygen-rich IWZO significantly enhances CBRAM performance.
• Optimized oxygen vacancy distribution in IWZO layers is crucial for stable and reliable memory operation.
• This bilayer IWZO CBRAM approach shows potential for advancing emerging memory applications.