Detection of arcing events in wafer plasma processing through monitoring of trace gas concentrations

Abstract

A method of detecting substrate arcing in a semiconductor plasma processing apparatus is provided. A substrate is placed on a substrate support in a reaction chamber of a plasma processing apparatus. Process gas is introduced into the reaction chamber. A plasma is generated from the process gas and the substrate is processed with the plasma. Intensities of real-time spectrometry signals of selected gas species produced in the reaction chamber during plasma processing are monitored. The selected gas species are generated by a substrate arcing event. The arcing event is detected when the intensities are above a threshold value.

1 . (canceled) 
     
     
         2 . (canceled) 
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . (canceled) 
     
     
         6 . (canceled) 
     
     
         7 . (canceled) 
     
     
         8 . (canceled) 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . A plasma processing apparatus comprising:
 a substrate holder for supporting a substrate within an interior of a reaction chamber;   a gas supply supplying process gas to the interior of the reaction chamber using a gas distribution member;   a power source supplying energy into the interior of the reaction chamber and energizing the process gas into a plasma state for processing the substrate;   a gas sensor adapted to monitor gas species in the reaction chamber during plasma processing to identify gas species produced by substrate arcing; and   an alarm to generate a warning signal when gas species produced by substrate arcing are identified.   
     
     
         12 . The plasma processing apparatus of  claim 11 , wherein the gas sensor is a residual gas analyzer (RGA) mass spectrometer, an inductively coupled plasma optical emission (ICP-OE) spectrometer, an infrared absorption spectrometer or a Fourier transform infrared (FTIR) spectrometer. 
     
     
         13 . The plasma processing apparatus of  claim 11 , wherein the gas sensor is a residual gas analyzer (RGA) mass spectrometer adapted to monitor a real-time signal from mass spectrometry of processes gases during plasma processing and the gas species produced by substrate arcing are decomposition products of an organic photoresist. 
     
     
         14 . The plasma processing apparatus of  claim 11 , wherein the plasma processing apparatus is a plasma etcher adapted to semiconductors, metals or dielectrics; or a deposition chamber adapted to deposit conductive or dielectric material. 
     
     
         15 . The plasma processing apparatus of  claim 11 , wherein the gas distribution member is a showerhead. 
     
     
         16 . The plasma processing apparatus of  claim 15 , further comprising:
 a sampling structure adapted to collect gas species from the reaction chamber during plasma processing; and   a gas line adapted to transfer gas species to the gas sensor.   
     
     
         17 . The plasma processing apparatus of  claim 16 , wherein the sampling structure is a channel in the showerhead or a tube adjacent to the substrate holder; and the gas line is heated. 
     
     
         18 . The plasma processing apparatus of  claim 11 , wherein the gas distribution member is a showerhead electrode; and the power source is a radio-frequency (RF) power source. 
     
     
         19 . The plasma processing apparatus of  claim 18 , further comprising a plasma confinement ring assembly located outwardly of the showerhead electrode and the substrate holder.