Ozone‐UV irradiation effects on Ba2YCu3O7xthin films

Abstract
We studied the effects of ultraviolet (UV)irradiation in an ozone atmosphere on the electrical properties of Ba2 YCu3 O7−x thin films. The ozone‐UV treatment had effects similar to plasmaoxidation; it decreased the room‐temperature resistivity and increased the zero resistancetemperature of 460 nm Ba‐Y‐Cu‐O thin films. Film resistivity decreased by about 25% in 100 min during ozone‐UV treatment. This decreasing rate is one order of magnitude lower than plasma treatment. The ozone‐UV treatment, however, resulted in a more stable film than the plasma treatment. The rate at which the room‐temperature resistivity increased, measured 35 days after the ozone‐UV treatment, was 0.06%/day, or about 1/6 that of the plasma treatment.