Process stabilization and increase of the deposition rate in reactive sputtering of metal oxides and oxynitrides

Reactive sputtering processes normally exhibit undesirable hysteresis effects which are more pronounced for oxide than nitride deposition. We present a method to reduce and ultimately eliminate these effects for reactive sputtering of metal oxides and oxynitrides. This is achieved by the addition of nitrogen to the oxygen process, which in addition leads to a higher deposition rate. These observations can be qualitatively explained and theoretically predicted using an extension of the Berg's model to two different reactive gases. Although the nitrogen addition leads to pronounced changes of the processing characteristics, incorporation of nitrogen into the growing film is very small.