Investigation of sulfur-doped n-type diamond thin films

High-quality Sulfur doped n-type diamond thin films have been successfully synthesized via glow plasma assisted hot filament chemical vapor deposition using gas mixtures of methane, hydrogen, Argon and hydrogen sulfide. Impacts of the volume ratio of hydrogen sulfide to methane RS/Con the structural and physical properties of the films have been systematic ally studied using various techniques such as Hall effect measurement, x-ray diffraction (XRD) and atom force microscope. We found that the carrier mobility is 474 cm2V-1S-1 and the electrical conductivity is 1.45Ω-1·cm-1at RS/C=6800ppm. The sheet resistivities of the films increase with increase of RS/C, reach the maximum at RS/C of 6200ppm, and then begin to decrease. Also, with increase of RS/C, a linear increase in the conductivities of the films is found, which is believed that higher RS/Cis favorable for the increase of electrical conductivity of sulfur doped diamond thin films.