Growth, ambient stability and electrical characterisation of MgO thin films on silicon surfaces

Magnesium oxide (MgO) thin films were deposited onto silicon substrates, from an MgO target, by electron beam evaporation. The ambient stability of the MgO films and the formation of the MgO/Si interface were analysed using standard X-ray photoelectron spectroscopy (XPS) and high resolution synchrotron radiation based photoemission. Ambient exposure of the deposited films results in the growth of magnesium hydroxide and magnesium carbide species which can be desorbed by annealing at 500 °C in an inert atmosphere. Electrical characterisation has been performed on nickel silicide/MgO/Si(1 0 0) MOS structures for different dielectric thicknesses. The C– V results show no evidence of a low- k layer at the MgO/Si interface.