Si-YBaCuO intermixing and reactive patterning technique

A novel Si-YBaCuO intermixing technique has been developed for patterning YBaCuO superconducting thin films on both insulating oxide substrates (MgO) and semiconductor substrates (Si). The electrical, structural, and interfacial properties of the Si-YBaCuO intermixed system have been studied using resistivity, x-ray diffraction, scanning electron microscopy, x-ray photoelectron spectroscopy and Auger depth profiling measurements. The study showed that the reaction of Si with YBaCuO and formation of silicon oxides during a high temperature process destroyed superconductivity of the film and created an insulating film. On a MgO substrate, the patterning process was carried out by first patterning a silicon layer using photolithography or laser-direct-writing, followed by the deposition of YBaCuO film and annealing. For a silicon substrate, thin metal layers of Ag and Au were patterned as a buffer mask which defines the YBaCuO structures fabricated thereafter. Micron-sized (2-10 Μm) superconducting structures with zero resistance temperature above 77 K have been demonstrated. This technique has been used to fabricate current controlled HTS switches and interconnects.