AACVD of Cu₃N on Al₂O₃ Using CuCl₂ and NH₃

Area of Science:

• Materials Science
• Thin Film Deposition
• Semiconductor Physics

Background:

• Copper nitride (Cu3N) is a promising material for electronic applications.
• Developing scalable and controlled synthesis methods for Cu3N is essential.

Purpose of the Study:

• To investigate the synthesis of Cu3N thin films using aerosol-assisted chemical vapor deposition (AACVD).
• To characterize the structural and electrical properties of the synthesized Cu3N films.

Main Methods:

• Growth of Cu3N on m-Al2O3 via a two-step AACVD process.
• Utilizing CuCl2 precursor in ethanol with excess ammonia, followed by an NH3:O2 treatment.
• Characterization using X-ray diffraction and electrical property measurements.

Main Results:

• Successfully deposited Cu3N with an anti-ReO3 cubic crystal structure (lattice constant ~3.8 Å).
• Achieved persistently n-type conductivity with a room temperature carrier density of 2 × 10^16 cm^-3 and mobility of 32 cm^2/Vs.
• Identified surface depletion extending ~0.15 µm due to native Cu2O formation.

Conclusions:

• AACVD provides a viable route for synthesizing n-type Cu3N thin films.
• The persistent n-type nature and structural properties make Cu3N suitable for semiconductor devices.
• Understanding surface effects like Cu2O formation is key for optimizing device performance.