Pt Buffer Layer for Protecting YBCO from Al at Annealing Temperatures up to 450°C
We have studied the effectiveness of different buffer layers to protect YBa2Cu3O7-δ (YBCO) from aluminum when annealing at temperature up to 450°C. Since Al is commonly used to form ohmic contacts to Si, these results have implications for potential hybrid superconductor-semiconductor applications. Buffer layers of Ag, Au, Au/Ag, Au/Cr, Au/Pt, and Pt were examined. The critical temperature Tc of the contacted YBCO layer was measured before and after anneals at 300–450°C in 1 atmosphere of O2. Pt and Au/Pt were effective at preventing significant Al diffusion into YBCO and subsequent Tc degradation. The critical current density Jc could also be maintained when these buffer layers were employed.
KeywordsCritical Temperature Buffer Layer Ohmic Contact Critical Current Density Contact Formation
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