Abstract: A magnetron sputter reactor for sputtering deposition materials such as nickel and cobalt, for example, and its method of use, in which self-ionized plasma (SIP) sputtering is promoted. SIP is promoted by a small magnetron having poles of unequal magnetic strength and a high power applied to the target during sputtering. One embodiment of the present inventions is directed to sputter depositing a metal layer by biasing a sputter target with pulsed power in which the power applied to the target alternates between low and high levels. The high levels are, in one embodiment, sufficiently high to maintain a plasma for ionizing deposition material. The low levels are, in one embodiment, sufficiently low such that the power applied to the target during the high and low levels is, on average, low enough to facilitate deposition of thin layers if desired.