| 摘要 |
The improvement proposed relates to the dipole ring magnet in a magnetic field generator for magnetron plasma in an apparatus for plasma sputtering or plasma etching. Different from the conventional dipole ring magnet, which is an assembly of anisotropic columnar segment magnets in a circular arrangement each in an integral columnar form, each of the segment magnets according to the first aspect of the invention is divided into upper and lower halves and the gap space held between the upper and lower halves is varied from position to position so that the uniformity of the magnetic field formed inside of the dipole ring magnet is increased in the horizontal direction with consequently increased uniformity of the plasma density generated thereby. Instead of dividing each of the segment magnets into the upper and lower halves, according to the second aspect of the invention, the circular arrangement of the segment magnets is not regular and symmetrical but assymmetrical relative to the direction of the magnetic field so that similar improvements to those in the first aspect of the invention can be accomplished in the uniformity of the magnetic field and in the density of the plasma. <IMAGE> |
