A method of sputter coating substrates comprising • providing a target with a sputtering surface and with a back surface • providing along said back surface a magnet arrangement • pivoting or rotating said magnet arrangement about a rotational axis which is perpendicular to said back surface • wherein said magnet arrangement comprises magnet poles arranged along a pair of closed loops, an outer of said closed loops of said pair completely surrounding an inner of said closed loops of said pair and being distant from said inner of said closed loops, • the magnet poles facing said backside and arranged along one of said closed loops of said pair having opposite magnet polarity with respect to the magnet poles facing said backside and arranged along the other of said closed loops of said pair, • wherein said pair of close loops is subdivided in a first part and in a second part, said outer closed loop of said pair thereby being subdivided in a first outer section in said first part and in a second outer section in said second part and said inner closed loop of said pair being thereby subdivided in a first inner section in said first part and in a second inner section in said second part, • said first outer section being more distant from said rotational axis than said second outer section, both considered in radial direction with respect to said rotational axis, • said method comprising controllably increasing distances of at least a predominant number of magnet poles along at least one of said outer and of said inner first sections to said backside more than increasing distances to said backside of at least a predominant number of magnet poles of said outer and of said inner second sections, as operation time of said target increases. • providing a target with a sputtering surface and with a back surface • providing along said back surface a magnet arrangement • pivoting or rotating said magnet arrangement about a rotational axis which is perpendicular to said back surface • wherein said magnet arrangement comprises magnet poles arranged along a pair of closed loops, an outer of said closed loops of said pair completely surrounding an inner of said closed loops of said pair and being distant from said inner of said closed loops, • the magnet poles facing said backside and arranged along one of said closed loops of said pair having opposite magnet polarity with respect to the magnet poles facing said backside and arranged along the other of said closed loops of said pair, • wherein said pair of close loops is subdivided in a first part and in a second part, said outer closed loop of said pair thereby being subdivided in a first outer section in said first part and in a second outer section in said second part and said inner closed loop of said pair being thereby subdivided in a first inner section in said first part and in a second inner section in said second part, • said first outer section being more distant from said rotational axis than said second outer section, both considered in radial direction with respect to said rotational axis, • said method comprising controllably increasing distances of at least a predominant number of magnet poles along at least one of said outer and of said inner first sections to said backside more than increasing distances to said backside of at least a predominant number of magnet poles of said outer and of said inner second sections, as operation time of said target increases.