Resistive switching control for conductive Si-nanocrystals embedded in Si/SiO₂ multilayers

Area of Science:

• Materials Science
• Nanotechnology
• Solid-State Physics

Background:

• Resistive switching memory devices offer promising non-volatile storage solutions.
• Controlling the formation and properties of conductive filaments is crucial for device performance.
• Silicon/silicon dioxide (Si/SiO2) multilayers are explored for their potential in resistive switching applications.

Purpose of the Study:

• To investigate enhanced control of resistive switching in multilayer Si/SiO2 structures.
• To analyze the impact of varying bilayer counts on device characteristics.
• To elucidate the mechanism behind resistive switching in these nanostructures.

Main Methods:

• Fabrication of Si/SiO2 multilayer structures with varying bilayer numbers (6, 8, 10).
• Characterization of silicon nanocrystal formation (size ~5.88 nm, homogeneous shape).
• Electrical measurements to determine SET/RESET voltages and ON/OFF resistance ratios.
• X-ray Photoelectron Spectroscopy (XPS) for chemical bond analysis.

Main Results:

• Successfully formed Si nanocrystals with controlled size and shape homogeneity.
• Demonstrated tunable SET/RESET voltages in negative bias ranges (4.5-10 V for 6 bilayers, 6.3-13 V for 10 bilayers).
• Achieved high ON/OFF resistance ratios (10^7-10^5) dependent on the number of bilayers.
• Identified the role of Si-Si and Si-O bonds in forming and breaking conductive pathways.

Conclusions:

• The number of Si/SiO2 bilayers effectively controls resistive switching behavior.
• Si nanocrystal formation and associated bond dynamics (Si-Si, Si-O) govern the switching mechanism.
• These findings pave the way for developing reliable Si/SiO2-based resistive switching memory devices.