Chemical Reactivity at the Co/CuO interface

The chemical reactivity at the Co/CuO interface has been investigated using the technique of x-ray photoelectron spectroscopy. Thin films of hafnium have been deposited on CuO substrates at room temperature by the e-beam method. The Oxford Applied Research EGN4 was used for this purpose. The spectral data in the hafnium 4f core level and copper 2p core level were investigated by XPS. The copper oxide was observed to get reduced to elemental copper while cobalt was observed to get oxidized to CoO. The thickness of the cobalt overlayer resulting in no chemical reactivity has been determined. The investigation was also performed at substrate temperatures of 100, 200, 300, 400, 500, and 600°C. The diffusion of copper through the overlayer was observed. The interface consists of a mixture of elemental cobalt, CoO and elemental copper. The amount of these materials is governed by the processing conditions. The results of the investigation will be presented.