High quality crystalline YBa2Cu3O7−δ films on thin silicon substrates

YBa2Cu3O7−δ(001) (YBCO) films with near perfect crystallinity have been grown epitaxially on Si(100) using two intermediate buffer layers: Yttrium-stabilized zirconia (YSZ) and CeO2. All layers were grown by an in situ pulsed laser deposition process. The new films have Rutherford backscattering spectroscopy minimum yields as low as 5%, compared to 12% for YBCO films deposited directly on YSZ. The superconducting onset is above 90 K with a transition width ΔT of 1 K. After film deposition the Si substrate could be etched from the back to give a circular, 2-mm- diam, 4000 Å uniformly thick Si membrane with 300 Å YSZ, 80 Å CeO2, and 1500–3000 Å YBCO on top.