Published online by Cambridge University Press: 02 August 2011
The unique properties of superconductors such as radiation hardness and high microwave performances [1-3] make the integration with semiconductor conventional electronics a stimulating challenge. Many attempts have been tried to obtain good quality YBa2Cu3O7-x (YBCO) films on Si substrates, with the aim of taking advantage from the properties of both materials, but interdiffusion reactions and a poor lattice and thermal expansion coefficient matching require the use of a buffer layer at the semiconductor/superconductor interface. Yttria-stabilized zirconia (YSZ), Y2O3, MgO, SrTiO3, CeO2 and their combinations have been proposed and used as buffer layers in the case of Si/YBCO systems. In this paper we report on annealing treatments performed on Si/CeO2 bilayers. A set of optimized samples with deposition temperatures ranging from 100°C to 800°C has been radiatively heated at two different annealing temperatures, in N2 and O2 atmospheres. All the samples have been characterized by X-ray diffraction, Atomic Force Microscopy, micro-Raman spectroscopy. The preferential grain orientation, the lattice parameter, the crystals dimensions, the surface roughness have been studied. As a preliminary tentative, we report on YBCO film growth on the top of CeO2/Si optimized bi-layer before undergoing annealing treatment. This YBCO film resulted to be a-axis preferential oriented, with some contribution of c-axis oriented grains.