Surface modification and oxidation of Si wafers after low energy plasma treatment in hydrogen, helium and argon

Surface layers of the single crystalline silicon wafers subjected to low-energy hydrogen, helium and argon plasma treatments were investigated using X-ray absorption near edge structure spectroscopy (XANES) with the use of synchrotron radiation. It was shown that a surface silicon oxide layer with a thickness greater than native silicon oxide is formed as a result of such treatment. At the same time, in the investigated wafers the surface layers of a few nanometers appear to contain elemental silicon in a disordered (amorphous) state. Possible clusterization of Si in the surface layers was considered to result from the plasma treatment.