Air Leak Detection In Plasma Processing Apparatus With Separation Grid

Abstract

Plasma processing apparatus and associated methods for detecting air leak are provided. In one example implementation, the plasma processing apparatus can include a processing chamber to process a workpiece, a plasma chamber separated from the processing chamber by a separation grid, and an inductive coupling element to induce an oxygen plasma using a process gas in the plasma chamber. The plasma processing apparatus can detect afterglow emission strength from reaction between nitric oxide (NO) and oxygen radical(s) in a process space downstream to an oxygen plasma to measure nitrogen concentrations due to presence of air leak.

1 - 17 . (canceled) 
     
     
         18 . A plasma processing apparatus for detecting presence of nitrogen, comprising:
 a processing chamber having a workpiece support, the workpiece support configured to support a workpiece during plasma processing;   a plasma chamber separated from the processing chamber by a separation grid;   an inductive coupling element configured to induce a plasma using a process gas in the plasma chamber, the process gas comprising an oxygen-containing gas;   a controller configured to:
 obtain data associated with luminescence in the processing chamber, 
 wherein the luminescence is emitted from excited nitrogen dioxide molecules; 
   determine the presence of nitrogen in the plasma processing apparatus based at least in part on the data associated with the luminescence;   wherein the one or more oxygen radicals generated in the plasma pass through the separation grid for exposure to the workpiece.   
     
     
         19 . The plasma processing apparatus of  claim 18 , wherein the controller is configured to obtain the data associated with luminescence from a location between the separation grid and the workpiece. 
     
     
         20 . The plasma processing apparatus of  claim 18 , wherein the controller is configured to obtain the data associated with luminescence from a location proximate to a gas exhaust port for evacuating a gas from the processing chamber.