Study on the Effect of Base Pressure on Magnetron Sputtering Discharge Plasma by Optical Emission Spectroscopy

Argon plasma was generated by DC magnetron sputtering discharge at a constant input power and sputtering pressure. The emission spectra of the argon plasma, in a region of 300 nm to 800 nm, were recorded with three different base pressures (4x10-4 Pa, 13x10-4 Pa and 26x10-4 Pa). From the spectra, the Boltzmann temperature (TB) was calculated by using the atomic Boltzmann plot method. The intensity ratio of N and N2 lines provided the information on the changes in the degree of dissociation of nitrogen molecules. The obtained results showed that with the increase in base pressure the dissociation of N2 increased and the Boltzmann temperature (TB) decreased.