Negative ions in reactive magnetron sputtering

Abstract

Negative ions are present in magnetron sputtering if electronegative elements are involved. The majority of the negative ions impinging on transparent conductive oxide (TCO) films during growth is O -produced at the oxidised target surface while it is rather unimportant whether it is bulk oxide or a surface oxide formed in reactive sputtering. O -bombards the film with energies equivalent to the target voltage and by far exceed 100 eV. It is hence apt to cause radiation damage in sensitive TCO films. This is shown by the lateral distribution of the highenergy O -flux in planar magnetron sputtering that exhibits the same pattern imaging the erosion groove as the resistivity of TCO films. This lateral inhomogeneity strongly depends on the erosion groove depth. The emission of O -further depends on the sputtered material, for TiO 2 deposition it is much less than for other TCO materials. The emission probability correlates to the secondary electron emission coefficient of the oxide.

Comparative study of sputter‐deposited SnO2 films doped with antimony or tantalum

“…Compared to the best values, achieved resistivities of sputtered ITO, AZO, and FTO films are a factor 2 larger. The limited resistivity of sputter‐deposited oxide films has been linked to the formation of particles with high kinetic energy, related to the presence of oxygen (), during the deposition process. A bombardment of the growing film by these particles is expected to result in increased defect formation.…”

Origin of sputter damage during transparent conductive oxide deposition for semitransparent perovskite solar cells

“…6c shows the energy loss distribution generated from the SRIM simulations. Oxygen ions, the most abundant species in the plasma, 42 generate phonons with 46.7% of their initial kinetic energy of 85 eV, and the recoils contribute an additional 27.4%. Tin ions, the heaviest atoms in the plasma, generated phonons with 78.6% of their initial kinetic energy, and recoils contributed an additional 8.6%.…”