Highly doped silicon nanowires by monolayer doping

Area of Science:

• Materials Science
• Nanotechnology
• Semiconductor Physics

Background:

• Controlling doping concentration in silicon nanostructures is a significant challenge.
• Silicon nanowires are promising for next-generation electronics.

Purpose of the Study:

• To investigate three distinct monolayer doping techniques for silicon nanowires.
• To achieve high doping doses in silicon nanowires using these techniques.

Main Methods:

• Investigated conventional monolayer doping, monolayer contact doping, and a combined route.
• Fabricated porous silicon nanowires using metal-assisted chemical etching.
• Measured doping doses using X-ray photoelectron spectroscopy and secondary ion mass spectrometry.

Main Results:

• Porosity of nanowires directly correlated with achievable doping dose.
• Slightly porous nanowires achieved 10^14-10^15 B/cm², significantly higher than non-porous samples (10^12 B/cm²).
• Highly porous nanowires reached up to 10^17 B/cm² via contact and combined doping routes.

Conclusions:

• Monolayer doping techniques offer effective control over doping concentration in silicon nanowires.
• Nanowire porosity is a key parameter for tuning doping levels.
• The combined and contact doping routes are particularly effective for highly porous silicon nanowires.