Model for reactive sputtering Optimisation results for YBaCuO thin films deposited on polycrystalline zirconia substrates

Diagnostics of sputtering plasma variations affecting Y–Ba–Cu–O thin film growth and properties

“…Although the voltage increased, the deposition rate decreased on H 2 addition, together with the emission line intensities of the target cation constituents (Cu I, Ba I, Ba II, Y O) in a way similar to H 2 O vapour addition [5,13]. This behaviour is in accord with [10] and in contrast with [8]. The latter fact, together with the assessed decrease of T UV Ar II e suggests that the sputtering rate has diminished rather than the film resputtering rate has increased.…”

“…For the constant discharge current mode used, the voltage in our DC diode discharge depends on the gas type and pressure, and on the secondary electron emission coefficient of the target/plasma density. Voltage increase on H-containing gas addition, similar to an increase of oxygen partial pressure, has been attributed [6][7][8]10] to the better oxidation state of the target. One of the authors observed an initial decrease of the voltage for low H 2 O content [8] and attributed it to an increase in plasma density caused by the catalytic effect of the added gas.…”

“…Voltage increase on H-containing gas addition, similar to an increase of oxygen partial pressure, has been attributed [6][7][8]10] to the better oxidation state of the target. One of the authors observed an initial decrease of the voltage for low H 2 O content [8] and attributed it to an increase in plasma density caused by the catalytic effect of the added gas. One can speculate that Ba depletion of the target would contribute to an increase of the target voltage due to the high secondary electron emission coefficient of Ba.…”

“…A 50% increase in J c and a rise of T c from 88-89 to 90-91 K have been observed on 4% H 2 O addition. An optimum of 4-10% H 2 O (pertaining to the particular system) has been observed for RF on-axis magnetron sputtering in Ar/O 2 , achieving a T c increase from 50 to 85 K [8]. On the other hand, previous experiments in our high-pressure onaxis system showed a detrimental effect of small H 2 or H 2 O addition ( 1%) to the O 2 /30% Ar sputtering gas [5,[11][12][13].…”

“…Small amounts of hydrogen and water vapour have been used as an addition to the sputtering gas in order to restore used targets and reduce the deposition temperature [6][7][8]. The authors explain these results through the catalytic action of hydrogen and do not consider the incorporation of hydrogen into the growing film.…”