Patent ID: 9607809
Date: 2017-03-28
CPC Classifications: C23C,H01J

Claim:
1. A plasma reactor, which comprises: an enclosure having a side wall, a top and a bottom to define a processing chamber; a plurality of inlets in the enclosure for injecting process gas into the chamber; an outlet in the enclosure for withdrawing gas from the chamber; a platform for supporting a wafer in the chamber above the bottom; and a plurality of planar spiral coils positioned at the top of the chamber, including a first planar spiral coil at a first height and a second planar spiral coil at a second height above the first height, wherein each respective one of the plurality of planar spiral coils is coupled to a respective radio frequency generator, wherein each radio frequency generator is configured to provide independently controlled power to the planar spiral coil to which it is coupled, wherein: each of the first and second planar spiral coils includes plural windings, each of the first and second planar spiral coils has a same inner radius, and the second planar spiral coil has more windings and a greater outer radius than the first planar spiral coil.