Showerhead electrode assembly with gas flow modification for extended electrode life

摘要

A showerhead electrode assembly for a plasma processing apparatus is provided. The showerhead electrode assembly includes a first member attached to a second member. The first and second members have first and second gas passages in fluid communication. When a process gas is flowed through the gas passages, a total pressure drop is generated across the first and second gas passages. A fraction of the total pressure drop across the second gas passages is greater than a fraction of the total pressure drop across the first gas passages.

主权项

1. A method of processing a semiconductor substrate in a plasma processing apparatus including a showerhead electrode assembly for a plasma processing apparatus, comprising a silicon electrode with a plasma-exposed surface, the electrode having a plurality of axially extending first gas passages; a metallic backing member attached to the electrode and having a plurality of axially extending second gas passages in fluid communication with the first gas passages; one or more first plenums formed in the metallic backing member and in fluid communication with the second gas passages; wherein when a process gas is flowed through the first and second gas passages a total pressure drop is generated across the first and second gas passages, the method comprising:
placing a substrate on a substrate support in a processing chamber of the plasma processing apparatus; introducing the process gas into the reaction chamber with the showerhead electrode assembly so as to provide a ratio of total pressure drop across the second gas passages to total pressure drop across the first gas passages of 3:1 to 5:1; generating a plasma from the process gas in the reaction chamber between the showerhead electrode assembly and the substrate; and processing the substrate with the plasma.