ATMOSPHERIC PRESSURE GLOW DISCHARGE (APGD) PLASMA GENERATION AND SURFACE MODIFICATION OF ALUMINUM AND SILICON Si (100)

Atmospheric pressure glow discharge was generated by AC 50 Hz power source. Argon used as the main plasma gas was electrically excited to give the APGD plasma inside a stainless steel chamber. The plasma was characterized by optical emission spectroscopy in the range 350-1050 nm with 1.5 nm resolution. Availability of oxygen in the emission spectrum was confirmed by the presence of atomic oxygen spectral lines at 777.2, 844.6 and 926.6 nm. The oxygen activated well characterized plasma was exposed to Si (100) and Al for 11-60 min. Incorporation of oxygen in Si and Al surfaces was verified by the emergence of a strong peak of oxygen in the energy dispersive x-rays spectrum of the substrate. Thus oxidation of Si and Al to give SiO2 and Al2O3 was successfully achieved. It was critically noted that presence of nitrogen is a major part of atmosphere, but nitrogen was neither excited nor incorporated in the Si and Al substrates. So no evidence of formation of silicon nitride or aluminum nitride was found. All measurements were taken at normal temperature and pressure.