Profiling of Y–Ba–Cu–O radio-frequency sputtering by optical emission spectroscopy

Abstract

The optical emission spectra from species excited during radio-frequency sputtering of a Y–Ba–Cu–O target were observed as a function of position. A collimated optical fiber bundle parallel to the plane of the horizontal sputter target was translated vertically and horizontally to spectroscopically profile the excited species. The Ba and Cu constant intensity contours indicate a significantly different intensity decrease with increasing distance along a line normal to the plane of the target. However, there does exist a region immediately to the side and slightly above the target surface in which the Ba and Cu contours are similar. The pronounced extension of the O contours in a direction perpendicular to the target surface is consistent with negative ion resputtering phenomena.