Sputtering apparatus and method of forming film

A method of forming a film in which a substrate to be processed and a target are disposed to lie opposite to each other inside a vacuum chamber, and by generating a plasma inside the vacuum chamber, the target is sputtered to thereby form a thin film on a surface of the substrate,

• wherein, provided that a direction inside the vacuum chamber from the substrate toward the target is defined to be upward, during film forming by means of a magnet unit disposed above the target, a leakage magnetic field in which a line passing through a position where a vertical component of the magnetic field becomes zero is closed in an endless manner, is caused to locally act on such a space below the target as is positioned between a center of the target and a periphery thereof, the method comprising:
• an information obtaining step in which by using, as the magnet unit, a plurality of segments divided on an imaginary line extending from a center of the target toward a periphery thereof, each of the plurality of the segments being driven by driving means corresponding to each of the segments for rotating each of the plurality of the segments in synchronization about the center of the target, thereby forming a thin film on the surface of the substrate, and obtaining information about an in-plane film thickness distribution of the substrate;
• an angular velocity determining step in which, based on such information about film thickness distribution as was obtained in the information obtaining step, an angular velocity of each of the plurality of the segments is respectively determined to a different angular velocity within a range in which the endless manner of the leakage magnetic field is maintained;
• and
• a film forming step in which a thin film is formed on the surface of the substrate by driving driving means corresponding to each of the segments to rotate each of the plurality of the segments of the magnet unit at a different rotational speed determined in the angular velocity determining step.