End point detection electrode system and etch station

Abstract

An end point detection electrode system and an etch station including the electrode system are disclosed. In one embodiment, the electrode system includes: an insulative mount; a first Mu-metal electrode coupled to the insulative mount; and a second Mu-metal electrode coupled to the insulative mount, the second electrode surrounding the first electrode.

1 . An end point detection electrode system comprising:
 an insulative mount;   a first Mu-metal electrode coupled to the insulative mount; and   a second Mu-metal electrode coupled to the insulative mount, the second Mu-metal electrode surrounding the first Mu-metal electrode.   
   
   
       2 . The system of  claim 1 , wherein the insulative mount includes polyvinyl chloride (PVC). 
   
   
       3 . The system of  claim 1 , wherein the first Mu-metal electrode is substantially circular, and the second Mu-metal electrode is substantially O-shaped. 
   
   
       4 . The system of  claim 3 , wherein the first Mu-metal electrode has a diameter of approximately 1.8 inches to approximately 2.2 inches, and the second Mu-metal electrode has an inner diameter of approximately 3.8 inches to approximately 4.2 inches and an outer diameter of approximately 4.8 inches to approximately 5.2 inches. 
   
   
       5 . The system of  claim 1 , wherein the first and second Mu-metal electrodes are substantially coaxial. 
   
   
       6 . An etch station comprising:
 a wet etchant bath;   an end point detection electrode system including:
 an insulative mount, a first Mu-metal electrode coupled to the insulative mount, and a second Mu-metal electrode coupled to the insulative mount, the second electrode surrounding the first electrode; and 
   means for monitoring an electrical characteristic between the first Mu-metal electrode and the second Mu-metal electrode and controlling the etching process based on the monitoring.