Patent ID: 7105102

Claim:
A method of removing material from a workpiece in a vacuum plasma processing chamber including first and second spaced plasma excitation electrodes, one of which includes a semiconductor interposed between a magnetic field that can be derived by a plasma excitation coil and gas in the chamber, comprising removing the material during a first interval by energizing the coil so it supplies an RF ionizing electromagnetic field to the gas, the RF ionizing electromagnetic field having magnetic field components that are coupled through the semiconductor to the gas and electric field components that are coupled to the gas without being diminished by the semiconductor, the electromagnetic field having sufficient power to cause a plasma resulting from the gas to be sufficiently energetic to etch the material, removing the material during a second interval by energizing the electrodes so they capacitively supply an RF ionizing field to the gas, the capacitively supplied RF ionizing field being coupled between the electrodes to the gas and material.