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XPS sputter depth profiling of the chemical states for SrTiO 3 /Si interface by O 2 + ion beams
Author(s) -
Kim K. J.,
Moon D. W.,
Nam S. H.,
Lee W. J.,
Kim H. G.
Publication year - 1995
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.740231302
Subject(s) - x ray photoelectron spectroscopy , sputtering , ion , chemical state , profiling (computer programming) , materials science , analytical chemistry (journal) , atomic physics , chemistry , physics , nanotechnology , thin film , nuclear magnetic resonance , environmental chemistry , computer science , operating system , organic chemistry
Because the chemical states of the elements in SrTiO 3 thin film on Si are reduced by argon ion beam bombardment, it was impossible to sputter depth profile the chemical states of SrTiO 3 thin film by argon ion beams. In this paper, it is reported that the undistorted chemical states of Ti and Si at the SrTiO 3 /Si interface can be determined with oxygen ion beams at the appropriate 70° angle of incidence, with which either metallic Ti is not oxidized or Ti in SrTiO 3 is not reduced. Under the sputter depth profiling conditions, the chemical state of Ti at the SrTiO 3 /Si interface could be successfully characterized and the effects of post‐annealing at high temperature on the chemical state of Ti were studied. A significant number of Ti atoms in the metallic state were observed at the SrTiO 3 /Si interface without any post‐annealing but all of them were oxidized to the Ti 4+ chemical state after 2 h post‐annealing at the temperatures above 600°C under oxygen flow. The dielectric properties of SrTiO 3 thin films on Si were well correlated to the oxidation state of Ti and the broadening of the interface SiO 2 layer induced by post‐annealing at high temperature.