Highly Conductive Nanocrystalline Diamond Films and Electronic Metallization Scheme.

Area of Science:

• Materials Science
• Electrical Engineering
• Nanotechnology

Background:

• Achieving high electrical conductivity in nanocrystalline diamond (NCD) films is crucial for electronic applications.
• Dopant-free methods for enhancing NCD conductivity are highly desirable.
• Reducing specific contact resistance is essential for efficient device performance.

Purpose of the Study:

• To develop a dopant-free method for achieving high electrical conductivity in NCD films.
• To investigate the effect of oxygen reactive-ion etching (O-RIE) on the specific contact resistance of NCD films.
• To elucidate the relationship between diamond surface properties and contact resistance.

Main Methods:

• Hot-filament chemical vapor deposition (HFCVD) using methane and hydrogen gas mixtures.
• Oxygen reactive-ion etching (O-RIE) process.
• X-ray photoelectron spectroscopy (XPS), Atomic Force Microscopy (AFM), and surface wetting measurements.

Main Results:

• Achieved high electrical conductivity exceeding 100 S/cm in dopant-free NCD films.
• Reduced specific contact resistance by a factor of up to 16, reaching 6×10-6 Ωcm² using O-RIE.
• Confirmed that increased electron affinity of the O-RIE treated diamond surface correlates with lower specific contact resistance.

Conclusions:

• Dopant-free NCD films with high electrical conductivity can be fabricated using HFCVD.
• O-RIE is an effective method for enhancing the electron affinity of NCD surfaces.
• Improved surface electron affinity is key to significantly reducing specific contact resistance in NCD films.