a-Axis-oriented superconducting EuBa2Cu3O7 films and EuBa2Cu3O7/PrBa2Cu3O7 superlattices have been grown by sputtering on SrTiO3 (100) substrates. Structural analysis by high resolution transmission electron microscopy and X-ray diffraction has been performed. Both kind of samples are well-oriented with the c-axis parallel to the substrate plane, the structure at the boundaries is highly coherent and, in the superlattices, high angle X-ray satellite peaks are observed. The presence of PrBa2Cu3O7 layers in the superlattices induces a reduction in the superconducting transition temperature that can be attributed to a charge redistribution process in the CuO2 planes, which in this a-axis orientation belong simultaneously to insulating and superconducting layers.