Eliminating the hysteresis effect for reactive sputtering processes

Reactive sputter processes frequently exhibit stability problems. The cause of this is that these processes normally exhibit hysteresis effects in the processing curves. Eliminating the hysteresis would significantly simplify the use of reactive sputtering processes. So far the only known way of eliminating the hysteresis is to increase the pumping speed to unrealistically high values. By an increased understanding of the process we have realized a fully realistic technique to eliminate the hysteresis for reactive sputtering processes. By simply reducing the size of the target sputter erosion zone below a critical value, simulations predicted that hysteresis should be eliminated. This has been experimentally verified for reactive sputtering of Al in an $Ar∕O2$ atmosphere. The fundamental explanation to this behavior as well as the experimental verification are presented.