Method of refurbishing a magnet assembly for plasma process chamber

Abstract

A method of refurbishing a wall of a plasma process chamber which has a surface with a magnet assembly fitted thereon. The magnet assembly has an expandable hollow collar with a plurality of magnets inside. In the method, the diameter of the hollow collar of the magnet assembly is expanded to remove the hollow collar from the wall. The surface of the wall is cleaned. The hollow collar of the original magnet assembly, or of another magnet assembly, is then snap fitted back onto the surface of the wall.

1 . A method of refurbishing a wall of a plasma process chamber, the wall comprising a surface having a magnet assembly fitted thereon, and the magnet assembly comprising an expandable hollow collar with a plurality of magnets therein, the method comprising: 
 (a) expanding the diameter of the hollow collar of the magnet assembly to remove the hollow collar from the wall;    (b) cleaning the surface of the wall; and    (c) snap fitting the hollow collar of the magnet assembly, or another magnet assembly, back onto the surface of the wall.    
   
   
       2 . A method according to  claim 1  wherein the hollow collar of the magnet assembly comprises a radially internal surface and an external surface, and a gap extending from the radially internal surface to the external surface, and wherein (a) comprises expanding the diameter of the hollow collar of the magnet assembly by expanding the gap.  
   
   
       3 . A method according to  claim 1  wherein the magnet assembly comprises a plurality of hollow collars that each comprises a segment of a ring sized to fit around the wall of the chamber, and wherein (a) comprises expanding the diameter of each hollow collar segment.  
   
   
       4 . A method according to  claim 1  wherein (c) comprises expanding the diameter of the hollow collar prior to snap fitting the hollow collar on the wall.  
   
   
       5 . A method according to  claim 4  wherein the hollow collar of the magnet assembly comprises a radially internal surface, and wherein (c) comprises snap fitting the hollow collar on the wall so that the radially internal surface of the magnet assembly directly contacts the wall.  
   
   
       6 . A method according to  claim 1  wherein the wall comprises a groove, and wherein (c) comprises snap fitting the magnet assembly onto the groove on the wall.  
   
   
       7 . A method according to  claim 6  further comprising fitting a retaining ring to retain the hollow collar in the groove of the wall.  
   
   
       8 . A method according to  claim 1  wherein the wall comprises a slot, wherein the hollow collar comprises an external surface with a key, and wherein (c) comprises aligning the key on the external surface of the hollow collar to couple to the slot on the wall.  
   
   
       9 . A method according to  claim 1  wherein the hollow collar of the magnet assembly comprises a radially internal surface and an external surface, and a gap extending from the radially internal surface to the external surface, the gap defining opposing faces with at least one face having an open end, and wherein the method comprises, initially, inserting a plurality of magnets in the hollow collar through the open end face.  
   
   
       10 . A method according to  claim 9  wherein the magnets comprise a south pole and a north pole, and comprising positioning the magnets in the hollow collar such that the south poles are directed upward and the north poles are directed downward.  
   
   
       11 . A method according to  claim 9  comprising positioning the magnets in the hollow collar such that the magnetic axes of the magnets are oriented perpendicular to the wall.  
   
   
       12 . A method according to  claim 9  comprising positioning the magnets in the hollow collar such that a first set of magnets have their magnetic axis oriented in one direction, and a second set of magnets have their magnetic axis oriented in the opposite direction.  
   
   
       13 . A method according to  claim 12  further comprising placing one or more pole pieces in the hollow collar to couple the first and second set of magnets.  
   
   
       14 . A method according to  claim 9  further comprising sealing the open end face with a cap.  
   
   
       15 . A method according to  claim 1  wherein the wall comprises a liner.  
   
   
       16 . A method of refurbishing a wall of a plasma process chamber, the wall comprising a surface having a magnet assembly fitted thereon, and the magnet assembly comprising an expandable hollow collar comprising (i) a radially internal surface and an external surface, (ii) a gap extending from the radially internal surface to the external surface, and (iii) a plurality of magnets therein, 
 the method comprising: 
 (a) expanding a diameter of the hollow collar of the magnet assembly by expanding the gap;  
 (b) removing the expanded hollow collar from the wall;  
 (c) cleaning the surface of the wall; and  
 (d) snap fitting the hollow collar of the magnet assembly, or another magnet assembly, back onto the surface of the wall.  
   
   
   
       17 . A method according to  claim 16  wherein the magnet assembly comprises a plurality of hollow collars that each comprises a segment of a ring sized to fit around the wall of the chamber, and wherein (a) comprises expanding the diameter of each hollow collar segment.  
   
   
       18 . A method according to  claim 16  wherein (c) comprises expanding the diameter of the hollow collar prior to snap fitting the hollow collar on the wall.  
   
   
       19 . A method according to  claim 16  wherein the wall comprises a groove, and wherein (d) comprises snap fitting the magnet assembly onto the groove on the wall.  
   
   
       20 . A method of refurbishing a wall of a plasma process chamber, the wall comprising a surface having a groove with a magnet assembly fitted thereon, the method comprising: 
 (a) removing a retaining ring which retains the magnet assembly in the groove of the wall;    (b) expanding a diameter of the magnet assembly by expanding the gap;    (c) removing the expanded magnet assembly from the groove on the surface of the wall;    (d) cleaning the surface of the wall; and    (e) snap fitting the magnet assembly, or another magnet assembly, back onto the groove of the surface of the wall.