High-temperature superconductor thin films: preparation, characterization, and microstructure fabrication

Abstract

High-quality thin film cuprate superconductors can be fabricated by different deposition techniques using a variety of substrates including SrTiO3, MgO, LaAlO3, and even semiconducting silicon single crystals, By means of the pulsed laser deposition technique we explore different schemes for crystallization and oxygenation of Y–Ba–Cu–O thin films, such as furnace annealing, rapid thermal annealing, and low-temperature plasma processes, and optimize the thin film quality with respect to Tc, jc surface morphology, and stability. Films on SirTiO3 and LaAlO3 show Tc of 90–92 K and critical currents jc > 106 A/cm2, while films deposited on bare silicon suffer from lower values of jc but still have Tc > 80 K. Degradation problems associated with photolithographic patterning are studied, and these can be overcome using epitaxially grown high density films.