The effects of added gases in the sputter deposition of YBa/sub 2/Cu/sub 3/O/sub 7/ thin films

YBa/sub 2/Cu/sub 3/O/sub 7/ thin films have been deposited on MgO substrates by off-axis magnetron sputtering in argon, oxygen, and an additional gas. Additions of nitrogen, hydrogen, methane, air, and water vapor in amounts of up to 25% were used in this investigation. Each gas stabilized the target voltage and growth rate for the duration of the deposition. Growth rates improved by over 50% with as little as 3% hydrogen. When used with a target which had degraded after more than 150 h of use, the added gas improved T/sub c/ and J/sub c/ beyond levels attained from the new target. T/sub c/ increased from 82 K without hydrogen to 89 K with hydrogen and J/sub c/ (12 K) from 3*10/sup 4/ to >7*10/sup 6/ A/cm/sup 2/. Nitrogen yielded less dramatic effects. These improvements are attributed to the catalytic effect of these gases in maintaining elevated levels of atomic oxygen during film growth.<
>