Spatial structures of electronegative plasma produced by internal helical antenna in a uniform magnetic field

Spatial structures of electronegative plasma were described in an inductive ly coupled discharge driven by an internal helical antenna in a uniform mag netic field. This new type of plasma source enables production of a high de nsity (similar to 10(11) cm(-3)) electronegative plasma at a low pressure ( 2 mTorr). Good uniformity was measured for the plasma density and the elect ron temperature along the central axis. These same parameters formed respec tively hill and valley profiles in the radial direction. Mode conversion of RF discharge from capacitively coupled to inductively coupled discharge th at eventually might lead to a helicon discharge was observed at various gas pressures. The space potential was found to decline with introduction of t he electronegative (SF6) gas to the electropositive (Ar) gas, while the RF oscillating amplitude and the RF excited magnetic field increased. The elec tron energy distribution functions were found to be non-Maxwellian in elect ronegative plasma unlike in electropositive plasmas.