Study on oxidation processes of 4H-SiC(0001) surface by high energy-resolution XPS and supersonic molecular beam method

Takahashi, Shin*; Aruga, Tetsuya*; Teraoka, Yuden; Yoshigoe, Akitaka 

Chemical reaction dynamics for oxidation processes of 4H-SiC(0001) surface has been studied by a supersonic molecular beam method and high energy-resolution XPS. Especially, we have focused our attention to effects of vibrationally-excited states for the oxidation processes. All experiments were performed at the surface chemistry experimental station of JAEA BL23SU in the SPring-8. Oxygen uptake curves were obtained by using oxygen molecular beams with different vibrational states, which was changed by selecting nozzle temperature of 300K and 1400K with constant translational energy of 0.5 eV. With increasing nozzle temperature, adsorption probability of oxygen increased widely. And we found that O1s XPS peak was composed of several components. They were deconvoluted by the Doniach-Sunjic function. By plotting these peak intensity against the dose of molecular beam, we have discussed on diffusion processes of oxygen atoms from surface to bulk.