Apparatus for plasma etching having rotating coil responsive to slide valve rotation

An apparatus for plasma etching, comprising:

• a chamber;
• a gas inlet port provided in said chamber to introduce etching gas into said chamber;
• a sample stage provided within said chamber;
• a spiral coil disposed externally of said chamber in opposing relation to said sample stage, said spiral coil generating a high-frequency induction field and thereby changing said etching gas into a plasma;
• a gas outlet port provided in a bottom portion of said chamber to exhaust gas from said chamber;
• a slide valve having a valve element rotating relative to a valve seat and adjusting an amount of gas exhausted from said gas outlet port with the rotation of said valve element;
• coil holding means for rotatably holding said spiral coil;
• and
• rotative driving means for rotating said spiral coil in response to the rotation of the valve element of said slide valve such that a higher-voltage region of said spiral coil coincides with an exhaust-side region of said slide valve.