US Patent 10283382 Plasma processing apparatus

A plasma processing apparatus including an electrostatic chuck supporting a wafer; a focus ring disposed to surround an outer circumferential surface of the wafer; an insulation ring disposed to surround an outer circumferential surface of the focus ring; and an edge ring supporting lower portions of the focus ring and the insulation ring, the edge ring being spaced apart from the electrostatic chuck and surrounding an outer circumferential surface of the electrostatic chuck; wherein the edge ring includes a flow channel containing a fluid therein.