Nanoscale Nitrogen Doping in Silicon by Self-Assembled Monolayers.

Area of Science:

• Materials Science
• Semiconductor Physics
• Chemical Engineering

Background:

• Silicon is a fundamental semiconductor material.
• Doping is crucial for tuning silicon's electrical properties.
• Nitrogen doping offers potential advantages but requires efficient methods.

Purpose of the Study:

• To present a new method for nitrogen doping of silicon.
• To characterize the properties of nitrogen dopants in silicon.
• To compare nitrogen doping with traditional phosphorus doping.

Main Methods:

• Chemical formation of self-assembled monolayers for nitrogen doping.
• Van der Pauw technique for electrical characterization.
• Secondary-ion mass spectroscopy (SIMS) and low-temperature Hall effect measurements for dopant analysis.

Main Results:

• Nitrogen dopant diffusion coefficient is 3.66 × 10⁻¹⁵ cm²/s, two orders of magnitude lower than phosphorus.
• Less than 1% of nitrogen dopants exhibit electrical activity.
• The donor energy level of nitrogen is 189 meV below the conduction band.

Conclusions:

• The developed method enables controlled nitrogen doping of silicon.
• Nitrogen dopants show significantly reduced diffusion and low electrical activity in silicon.
• The characterized donor energy level aligns with existing literature values.