Patent ID: 7384876
Filing Date: 2008-06-10
Classification: H01J

Abstract:
1. A method of determining the state of a gas injection system in a plasma processing device comprising: changing a process parameter in said plasma processing device to affect a change of a gas injection pressure in said gas injection system, said gas injection system comprising a gas injection assembly body configured to receive a process gas from at least one mass flow controller, a consumable gas inject plate coupled to said gas injection assembly body, said consumable gas inject plate comprising at least one orifice to distribute said process gas to said plasma processing device, a pressure sensor coupled to said gas injection system, and a controller coupled to said pressure sensor; measuring a response time corresponding to a change of said gas injection pressure using said pressure sensor, wherein said response time corresponds to a first time delay when said consumable gas inject plate exhibits a non-eroded state and said response time corresponds to a second time delay when said consumable gas inject plate exhibits an eroded state; and comparing said response time with said first time delay in order to determine said state of said gas injection system.