| 摘要 |
A plasma etch reactor and a related method of its operation to provide self-cleaning of its top electrode, which is subject to being coated by polymer deposits during normal operation. In one form of the invention, radio-frequency (rf) power is applied to the top electrode on a continuous basis, but at a much lower power level than that of a primary rf power source used to supply power through a lower electrode, to generate and sustain a plasma in the reactor. The small rf power applied through the top electrode is selected to be of such a level as to remove deposits from the electrode continuously, as they are formed, but without removing any significant amount of electrode material. In another form of the invention, power is applied to the top electrode periodically during cleaning periods and power supply to the lower electrode is suspended during the cleaning periods. The two cleaning approaches may also be combined, with continuous cleaning being supplemented with occasional or periodic dry cleaning while etch processing is suspended.
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