Generation of Spiral Shape Nitrogen Recombining Plasma for Atomic Nitrogen Source

Abstract

We propose a new method using a spiral shape nitrogen plasma with a long magnetic connection length to produce high density nitrogen (N) atoms for nitriding application. A high density N molecular ion plasma was generated by DC discharge and is transported along a long spiral magnetic field line. As a result, the electron temperature drops along the magnetic field to be low enough to produce dissociate recombining plasma, where dissociative recombination would occur to generate N atoms. 2D Langmuir probe measurement showed that the electron temperature and density decreased along the magnetic field. Optical emission spectroscopy showed the ratio of the atomic N and N molecular emission intensities increased with a discharge power. The ground state N atom density was estimated by analyzing the atomic line intensity.