Internal linear inductively coupled plasma (ICP) sources for large area FPD etch process applications

A large area (830mm × 1020mm) inductively coupled plasma source with a six internal straight antennas was developed for large area FPD (Flat Panel Display) etch process applications and the effects of magnetic fields employing permanent magnets on the plasma characteristics were investigated. Using six straight antennas connected in series into plasma and though the induction of strong electric field into the plasma by the antennas, high-density plasma on the order of 10¹¹cm^-3 could be obtained by applying above 1500W power to the antennas. By employing the magnetic fields perpendicular to the antenna currents using permanent magnets, improved plasma characteristics such as increase of the ion density and decrease of both electron temperature and plasma potential could be achieved in addition to the stability of the plasma possibly due to the reduction of the electron loss. However, the application of the magnetic field decreased the plasma uniformity slightly even though the uniformity within 10% could be maintained in the 800mm processing area.