Non-destructive depth information by inelastic XPS/AES background analysis, application to Cu2O growth investigations

Methods for non-destructive surface analysis through studies of the peak shape of electron spectra have previously been proposed. Here these methods are applied to investigate the growth of Cu2O on polycrystalline copper at 650°C exposed to a pressure of 2 × 10−13 torr oxygen. It is found that oxidation does not proceed homogeneously over the entire surface but through the formation of islands. Initially the islands are found to grow both laterally and vertically up to a thickness of at least ∼ 100 A. For exposure ⪆ 100 A, the Langmuir, the islands continue to grow laterally. Since the method only probes depths up to ∼ 100 A, the possibility of continued vertical growth for large exposure can not be excluded.