摘要 |
In a processing chamber of an etching apparatus a lower electrode and an upper electrode grounded through a processing container are disposed oppositely to each other. A first high frequency power supply section composed of a first filter, a first matching device, and a first power source, and a second high frequency power supply section composed of a second filter, a second matching device, and a second power source are connected to the lower electrode. A superimposed power of two frequencies composed of a first high frequency power component of at least 10 MHz produced from the first power source and a second high frequency power component of at least 2 MHz produced from the second power source is applied to the lower electrode. Ions in the plasma do not accelerated by changes of electric field in the processing chamber, but are accelerated by a self-bias voltage and collide only against a wafer on the lower electrode.
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