Surface Modification of Silicon Wafers by an Atmospheric Pressure Plasma Jet to Form Si–OH Layer

Atmospheric pressure plasmas generate reactive chemical species without the need for vacuum chambers and pumps [1]. Among the many applications, an atmospheric pressure plasma jet (APPJ) is a popular tool for generating plasma plumes at a low breakdown voltage using Ar or He gas, compared with air discharges [2]. This study investigates the interaction dynamics between an APPJ and silicon wafers. The ionization wave propagation and its interaction with the silicon surface were visualized and analyzed using an intensified charge-coupled device (ICCD) camera. Post-treatment surface characterization revealed a significant reduction in water contact angle, indicating enhanced hydrophilicity. The formation of a hydrophilic Si-OH layer on the plasma-treated silicon surface was confirmed via nano-infrared spectroscopy (nano-IR). Furthermore, the temporal evolution of surface properties was systematically monitored to evaluate the stability of plasma-induced modifications.