Fabrication and characterization of a micromachined 5 mm inductively coupled plasma generator

The electron temperature and ion density produced by a microfabricated plasma generator are characterized in both argon gas and air. The plasma generator sustains a discharge by inductively coupling 450 MHz rf power into a small (10 mm diameter) vacuum chamber. The inductively coupled plasma source is surface micromachined on a glass wafer by electroplating a planar spiral inductor and two interdigitated capacitors. A plasma can be sustained using gas pressures between 0.1 and 10 Torr and rf powers between 0.3 and 3 W. The ion density increases from 1010 to 1011 cm−3 over this range of power. The electron temperature decreases from 4 to 2 eV as the pressure increases from 0.1 to 1 Torr.