Lam Research Corporation
Fault detection using showerhead voltage variation

Abstract:

A plasma processing system having a plurality of stations is provided. Each station has a substrate support and a showerhead for supplying process gases. A radio frequency (RF) power supply and a distribution system is provided, where the distribution system is coupled to the RF power supply. A plurality of voltage probes is provided. Each of the plurality of voltage probes is connected in-line between the distribution system and each showerhead of each of the stations. A controller is configured to receive sensed voltage values from each of the plurality of voltage probes and compare the sensed voltage values against a plurality of voltage check bands. Each voltage check band is predefined for a process operation, and the controller is configured to generate an alert when the comparing detects that a sensed voltage value is outside of a voltage check band. The alert is configured to identify a type of fault based on the voltage check band and identify a specific one of the plurality of stations having said type of fault.