Development of Ferrite-Enhanced Side-Type Inductively Coupled Plasma

A side-type inductively coupled plasma (ICP) reactor for large-area processing has been developed with the aid of ferromagnetic cores. A low-frequency operation with strong coupling to the plasma solved the problems occurring in conventional ICPs such as transmission line effect, capacitive coupling, low-power transfer efficiency, and inability to operate in a high-vacuum region. Using an auxiliary antenna, the additional electric field can be applied to the discharge center. The energy flux from the side sources toward the discharge center could be controlled by applying an additional electric field to the center using the auxiliary antenna on the quartz window. This result showed a drastic increase in the center density with a small amount of the auxiliary power and thus provided easy control of the spatial uniformity over 450 mm. An image of the ferrite ICP operated by single power is presented.