Thirty years of rotatable magnetrons

Rotating cylindrical magnetrons differ in design from the well known planar magnetrons. The cylindrical target rotates around a stationary magnet configuration which is essentially the same as the one for a rectangular planar magnetron. This target rotation results in some advantages such as a higher stability in reactive mode, a much larger material inventory, and suitability to be operated at higher power density. Besides these important technological advantages, this magnetron type also has some unique features related to its rotation and/or target design. The I/V characteristics are more sensitive to the background pressure, the critical reactive gas flow defining the switching between metallic mode and poisoned mode depends on the rotation speed, and negative ions are emitted from the racetrack in two beams. Due to the cylindrical design, angular resolved measurements are more easily investigated. This advantage is used to compare the target behavior in DC mode and HIPIMS.