Suppression of Precipitate Formation in Heteroepitaxial Growth of YBa2Cu3O7-δ Film on Misoriented SrTiO3 Substrates

We have investigated the effect of misoriented substrates on precipitate formation in c-axis-oriented YBa2Cu3O7-δ films grown by the pulsed laser deposition technique. The films grown on exact SrTiO3(100) substrates had precipitate densities as high as 107–108/cm2, whereas the films on substrates with surfaces misoriented from (100) by 0.5°–1° had fewer precipitates by two to three orders of magnitude. A film surface of 105/cm2 precipitates can give 90% probability of a precipitate-free practical device size area (10 µ m×10 µ m), providing a high possibility of successful fabrication of a Josephson tunnel junction.