X-ray Photoelectron/Auger Electron Spectroscopic Studies of Tin and Indium Metal Foils and Oxides

X-ray photoelectron spectroscopy (XPS or ESCA) and Auger electron spectroscopy (AES) have been applied to the surface analysis of “standards” of metal foils and oxides of two elements, tin and indium. For the metal foils, the surface was initially In an oxidized state which could be removed by argon Ion sputtering to reveal the pure metal. On the surfaces of the tin and Indium foils, the oxygen to metal atomic ratios were close to the expected values for SnO₂ and In₂O₃. These ratios changed with depth profiling until the pure metal was exposed. The energetics and the atomic ratios were also obtained for several powder samples of SnO₂, SnO, and In₂O₃ standards. Although some changes in the ratios occurred with depth profiling of these standards, beam damage with decomposition was noted only for SnO. The problems and approaches to the identification of elemental composition and to quantitation of oxygen to metal atomic ratios are discussed.