| 摘要 |
A plasma chamber in a semiconductor fabrication system improves the uniformity of a high density plasma by optimizing a ratio of RF power from a first coil, surrounding and inductively coupled into the high density plasma, to RF power from a second coil, positioned above a central region and inductively coupled into the high density plasma. It has also been found that an increase in RF power supplied to the second coil positioned above the central region relative to RF power suppled to the first coil surrounding the high density plasma tends to increase the relative density of the plasma toward the center of the high density plasma. It is believed that RF power supplied to the second coil positioned above the central region substrate tends to add more electrons into the central region of the high density plasma to compensate for electrons recombining with plasma ions. A balance can thus be struck between RF power supplied to the first and second coils to increase plasma uniformity in the high density plasma, which may cause an increase in the uniformity of ionization of the sputtered target material atoms by the high density plasma.
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