Investigating Size-Dependent Conductive Properties on Individual Si Nanowires

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Vertically aligned silicon nanowires (Si NWs) are crucial for nanoelectronic devices.
• Controlling Si NWs' properties is essential for optimizing performance.
• Understanding the relationship between Si NW dimensions and conductivity is key.

Purpose of the Study:

• To fabricate ordered arrays of vertically aligned Si NWs.
• To investigate the size-dependent conductive properties of individual Si NWs.
• To elucidate the mechanism behind the observed conductivity variations.

Main Methods:

• Nanosphere lithography and metal-assisted chemical etching for Si NW fabrication.
• Conductive atomic force microscopy (CAFM) for individual Si NW electrical characterization.
• Electrostatic force microscopy (EFM) for Schottky barrier height verification.

Main Results:

• Successfully fabricated periodically ordered arrays of vertically aligned Si NWs.
• Demonstrated that Si NW conductance is highly dependent on diameter and length.
• Observed that smaller diameter and shorter length Si NWs exhibit superior conductivity.
• Identified size-dependent Schottky barrier height as the underlying mechanism.

Conclusions:

• Si NW fabrication via nanosphere lithography and etching allows for precise dimensional control.
• Conductive atomic force microscopy is an effective tool for analyzing nanostructure properties.
• Optimized Si NW dimensions and understanding Schottky barrier effects are vital for future nanoelectronic applications.