Production of nitrogen-containing carbon plasma using shunting arc discharge for carbon nitride films preparation

Abstract

Summary form only given. Plasma-based ion implantation and deposition (PBII&D) technology is a promising method for improving surface properties of three-dimensional substrates as a workpiece without a complicated manipulation system. A shunting arc is a convenient pulsed plasma source of metals and semi-metals. In this study, a carbon-shunting arc discharge is generated in nitrogen gas circumstance and amorphous carbon nitride (a-CNx) films are prepared using the plasma. In the experiment, a self-magnetically accelerating system is employed to improve deposition rate. A carbon rod with a diameter of 2 mm and a length of 40 mm is held vertically between a pair of carbon electrodes. A 20 muF-capacitor bank is used to ignite a shunting arc. The carbon film is prepared on a disk target with 80 mm-diameter and 10 mm-thickness is positioned at 100 mm from the rod as an arc source. Silicon substrates are pasted on the disk target and a series of pulse voltage is applied to Si substrate synchronizing with ignition of the shunting arc with a peak current of 1.7 kA. The ambient nitrogen gas pressure is varied from 2times10-2 to 300 Pa. The shunting arc plasma is successfully produced and is accelerated along carbon rails. The heating energy to generate the shunting arc has minimum value for variation of the gas pressure. A spectroscopic measurement of the plasma shows that the produced plasma contains nitrogen particles in ambient nitrogen gas circumstance. X-ray photoelectron spectroscopy analysis shows that the energy at which the C (1s) peak shifts from the binding energy (BE) of C-C to that of sp2C-N and sp3C-N by injecting nitrogen gas. The peak in the N (1s) spectrum also appears around BE of N-sp3C and N-sp2C with the nitrogen injection. The N/C ratio of the film is obtained to be 0.35 at 2 Pa gas pressure.