Optical Spectroscopy of Surfaces Plasmas Treatments

Abstract

Surface plasmas treatments have been studied in Ar - gas mixtures (H₂, N₂) as film depositions in fields like microelectronics with amorphous a-SiH, iron nitriding and hard coatings with TiN deposition. At the University of Mons, magnetron discharges amplified by an RF coil were studied to determine the efficiency of this process regarding the ionization of the sputtered metal atoms. Several plasmas setups are considered: sputtering plasmas for a-SiH and TiN deposition. To control the process, diagnostics by optical spectroscopy have been developed, in particular the resonant absorption method with adapted optical sources. Densities of species such as rare gas (He, Ar) metastable atoms, Al and Ti sputtered target atoms have been determined. The control of surface layers was performed by emission and absorption spectroscopy, by measurements of rare gases (He, Ar) and metal atoms (Al, Ti, Ti+) metastable densities. 

The densities of Ti and Ti+ ground and metastable states have been specifically obtained. The behavior of these active species by varying the plasma parameters has been related to the quality of the deposited films.