Rectangular magnetron with full target erosion

The article reports bn the operation of a rectangular magnetron with three and four closed discharges simultaneously formed on the surface of sputtered target. The closed discharges, elliptically shaped with the longer axis perpendicular to the long side of the rectangular magnetron, are formed using magnetic circuits placed behind the sputtered target. By moving these magnetic circuits along the long axis of a rectangular target, it is possible to achieve almost full target erosion and therefore significantly increase the usage lifetime of the target. This principle can be used for rectangular magnetrons with arbitrary length of the target. The longer the target, the greater the number of closed discharges that are required. Experimentally, it was found that neighboring closed discharges can interact which may significantly modify the sputtering characteristics of the magnetron cathode. This interaction is described and the physical requirements to avoid its occurrence are given. The I-V characteristics' of a rectangular magnetron with one, two, and three closed discharges are given. (C) 1999 American Vacuum Society. [S0734-2101(99)03802-6].