Patent ID: 11862436
Assignee: TOKYO ELECTRON LIMITED
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 17:
18. A plasma processing apparatus comprising:
a plasma processing chamber;
a substrate support disposed in the plasma processing chamber and including a lower electrode;
a cover disposed on the plasma processing chamber and having an internal space;
a showerhead assembly disposed above the substrate support and including a conductive member and an upper electrode, the conductive member having a coolant passage and an upper surface exposed to the internal space of the cover;
a plasma generator configured to generate a plasma in a space between the substrate support and the showerhead assembly;
a gas supply configured to supply a gas into the internal space of the cover, the gas comprising an inert gas or dry air;
a pressure gauge configured to measure a pressure in the internal space of the cover;
a controller configured to control the gas supply based on measurements of the pressure gauge such that air containing moisture is exhausted from the internal space of the cover and the internal space of the cover is filled with the inert gas or the dry air.