A TEM study of D+-implanted Cu following Ar+-ion milling: Microstructure and epitaxial Cu2O formation

In examining the microstructure of TEM specimens prepared from D+-implanted Cu for the presence of bubbles it was found that cuprous oxide (Cu2O) layers had formed over large areas of the specimen surfaces. The Cu was irradiated at normal incidence with 200 keV D+ ions at a temperature of 120 K to a dose of ≅ 2x1021 D+/m2. Ar+ ion milling at 330 K was used to erode irradiated surfaces to various depths prior to chemical back-thinning in a jet electropolishing bath. There was no evidence for the formation in the Cu of bubbles of either deuterium or argon, but dislocations at high density and planar defects were evident. Lattice fringes from {110}, {111} and {200} planes in Cu2O and moire patterns formed by double diffraction in the Cu and overlaid Cu2O film were obvious features in bright-field micrographs. The moire patterns include examples of magnified images of lattice defects. (orig.)