Patent ID: 8747962

Claim:
A method for plasma treatment of a workpiece in the form of a hollow body, the method comprising: at least partially evacuating a treatment zone in a reactor chamber; introducing a process gas into the treatment zone; igniting a glow discharge in a space being separated from the reactor chamber and provided between the reactor chamber and a gas outlet, wherein the space in which the glow discharge is ignited is separated from the treatment zone by at least an electromagnetic shielding and is connected to an evacuation instrument, and wherein the glow discharge on its own does not yet ignite a plasma in the reactor chamber; exciting gas contained in the space by igniting the glow discharge and thereby providing excited species comprising at least one of ions, electrons and excited neutral particles, which excited species diffuse into the treatment zone; and igniting a plasma in the treatment zone by means of injected electromagnetic energy in the process gas introduced into the treatment zone; wherein the igniting of the plasma in the treatment zone by injecting the electromagnetic energy is facilitated due to free charge carriers; and wherein the process gas flows through the treatment zone between opposite ends of the zone during the plasma treatment into the space separated from the treatment zone.