Raw and analyzed data for manuscript "Dielectric barrier discharge plasma reduction of oxidized copper surfaces in an Ar/SiH4 atmosphere"

Abstract:

Native oxide layers on copper surfaces limit the performance of compounds in many industrial applications. Different plasma deoxidation techniques were developed to remove such layers. Among these, cold plasma techniques like dielectric barrier discharge (DBD) plasmas have attracted considerable interest in view of high deoxidation efficiencies as well as relative simplicity of setups. Although DBD plasma deoxidation of copper has been mainly studied in Ar/H₂ gas mixtures, there is no information on reduction performance of such methods in other promising protective atmospheres. In this study, the reduction of natively oxidized copper surfaces using a DBD plasma in an Ar/SiH₄ atmosphere at 100 hPa and 20 °C was investigated. The influence of the silane gas on the deoxidation performance of the plasma was studied by varying the SiH₄ concentration in the argon mixture from 0.0 to 0.5 vol%. The chemical structure of surfaces before and after deoxidation was analyzed by X-ray photoelectron spectroscopy (XPS). The results revealed that an addition of a SiH₄ gas to an Ar atmosphere results in the increase of the deoxidation effect of the DBD plasma, so almost all copper surface oxide was reduced to copper after ca. 10 s of treatment in 0.1 vol% silane. The morphology of the surfaces was analyzed with atomic force microscopy (AFM), showing formation of particles after Ar/SiH₄ plasma treatments, which can be cleaned from the surfaces by wiping. Additionally, optical emission spectroscopy (OES) analysis of the plasma phase showed the presence of SiH^* radicals, which likely could play a role in the deoxidation effect. Moreover, an elimination of residual oxygen and nitrogen species in an Ar gas by addition of SiH₄ was observed.