Plasma cleaning and activation of silicon surface in Dielectric Coplanar Surface Barrier Discharge

Surface of crystalline silicon (c-Si) wafers was treated in dielectric barrier discharge and the cleaning effect, wettability and adhesion of gold nanoparticles were investigated. Treatment of c-Si was realised in air plasma at atmospheric pressure in Diffuse Coplanar Surface Barrier Discharge (DCSBD). Plasma cleaning and gold nanoparticle adhesion were investigated by means of Laser Desorption Ionisation Time of Flight Mass Spectrometry (LDI TOF MS) and X-ray photoelectron spectroscopy (XPS). Wettability and surface morphology were studied by contact angle measurement and atomic force microscopy, respectively. By laser desorption in positive ion mode, Cn+ and Na+, K+, etc. ions were detected on the industrially cleaned surface of silicon wafers. After plasma treatment the substantial decrease of such ions was observed. Plasma treatment of the surface increased also its hydrophilicity and adsorption of gold nanoparticles on the Si surface significantly increased after 5 s cleaning in plasma. Intensity of gold clusters Aun+ absorbed on the plasma treated Si surface was in order of magnitude higher than intensity of clusters absorbed on the untreated surface.