Films fabricated by
sputter deposit are extensively used in the semiconductor, optical and optoelectronic
industries. However, studies to-date have focused only on analyzing the BFO
films fabricated by sputter deposition. This paper’s research seeks to fill the
gap in understanding the sputter effect on the target in order to fully
understand the whole process of fabricating films by sputter deposition. In
this study, 3 keV argon ions were continuously sputtered onto a target of multiferroic
bismuth ferrite, BiFeO3, (BFO) with 5 mol% BaTiO3, in
increasing time intervals. X-ray Photoelectron Spectroscopy (XPS) was applied to
examine the sputtered surface after each sputter time interval. This paper
makes the following findings. First, the surface-contaminant carbon was almost
completely removed after 5120 seconds of sputtering. Second, the study observed
two-component oxygen spectra remained after sputtering. Other than the chemi-
and physic-sorbed oxygen, these two
oxygen components perhaps resulted from the short and long O-Fe bonds due to
the displacement of the Fe3+ ions. Third, sputtering resulted in a
change of the oxidation states of bismuth from dominant Bi3+ state
to equally weighted Bi3+ state and metallic Bi° state. The changes
of the bismuth’s oxidation states, i.e.,
a non-stoichiometric BFO target might alter the film compositions deposited
onto the substrate. This paper shows by introducing low pressure oxygen during
the sputtering, the metallic Bi
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