Dergi makalesi Açık Erişim

Fabrication of Superconducting YBa2Cu3O7-x Thin Films on Si Wafer via YSZ/CeO2 buffer layers

2017    Uzun, Y.; Kuran, O.; Avci, I.

Fabrication of reproducible superconducting YBa2Cu3O7-x (YBCO) thin films with T-c values above 85 K on Si wafers has been realized by optimizing the thin film deposition process. Prior to the deposition of YBCO thin film on (100) p-type Si wafer, YSZ and CeO2 thin films were deposited as buffer layers by RF magnetron sputtering, and subsequently, YBCO thin film was deposited by dc magnetron sputtering. The deposition parameters such as substrate temperature, process gas pressure, Ar/O-2 ratio, and power density were optimized for all layers in order to enhance the whole structure to prevent microcrack formation caused by misfits in crystal lattice parameters and thermal expansion coefficients between Si/YSZ/CeO2 and YBCO. Structural analyses were performed on YSZ and CeO2 layers, and electrical and magnetic measurements were carried out on a YBCO layer by employing XRD, SEM, resistance vs. temperature, and AC magnetic susceptibility vs. temperature measurements, respectively. The YBCO layer was also patterned as microbridges in order to test the durability of the whole Si/YSZ/CeO2/YBCO structure during the standard photolithography and wet etching process commonly used in device applications.