Seal rings in electrochemical processors

Abstract

A seal ring for an electrochemical processor does not slip or deflect laterally when pressed against a wafer surface. The seal ring may be on a rotor of the processor, with the seal ring having an outer wall joined to a tip arc through an end. The outer wall may be a straight wall. A relatively rigid support ring may be attached to the seal ring, to provide a more precise sealing dimension. Knife edge seal rings that slip or deflect laterally on the wafer surface may also be used. In these designs, the slipping is substantially uniform and consistent, resulting in improved performance.

1 . An electrochemical processor, comprising:
 a vessel;   a rotor engageable with the vessel;   the rotor having a seal ring that does not slip when sealed against a wafer surface.   
     
     
         2 . An electrochemical processor, comprising:
 a vessel;   a rotor engageable with the vessel;   a seal ring on the rotor having an outer wall joined to a tip arc through an end.   
     
     
         3 . The electrochemical processor of  claim 2  with the outer wall comprising a straight wall. 
     
     
         4 . The electrochemical processor of  claim 2  with the end having a radius of less than 0.01 inches and the tip arc has a radius of less than 0.03 inches. 
     
     
         5 . The electrochemical processor of  claim 2  with the seal ring having an upper end for engaging a wafer, with the upper end formed via a straight wall and a radius. 
     
     
         6 . The electrochemical processor of  claim 5  further including a support ring attached to the seal ring. 
     
     
         7 . The electrochemical processor of  claim 6  with seal ring comprising a fluoroelastomer and the support ring comprising a metal. 
     
     
         8 . A seal ring for use in an electrochemical processor, comprising:
 a material having a straight vertical outer wall intersected by a curved surface to form an edge having a radius of less than 0.005 inches.   
     
     
         9 . The seal ring of  claim 8  with the material comprising a fluoroelastomer. 
     
     
         10 . The seal ring of  claim 8  with the curved surface comprising a radius of less than 0.03 inches. 
     
     
         11 . The seal ring of  claim 8  further including a slot in the material, and a metal support ring having an inner edge inserted into the slot. 
     
     
         12 . A seal ring for use in an electrochemical processor, comprising:
 a material having a first surface and a second surface forming a knife edge with the second surface, with the knife edge at an inner diameter of the material, and with the knife edge having a radius of less than 0.002 inches.   
     
     
         13 . The seal ring of  claim 12  with first and second surfaces comprising straight and flat surfaces forming an angle of 15 to 25 degrees between them. 
     
     
         14 . A seal ring for use in an electrochemical processor, comprising:
 a material having a first surface and a second surface forming a knife edge with the second surface, with the second surface forming a shielded overhang space between a wafer surface and the material, when the seal ring is engaged onto a wafer.   
     
     
         15 . The seal ring of  claim 14  with the second surface forming an angle of 90 to 130 degrees to the first surface. 
     
     
         16 . A seal ring for use in an electrochemical processor, comprising:
 a tip that contacts a workpiece;   a first section that deflects radially inwardly on the workpiece as the tip contacts the workpiece;   a second section that deflects radially outwardly on the workpiece as the tip contacts the workpiece; and with the radially inward movement of the first section substantially equal to the radially outward movement of the second section, resulting in substantially no net sliding movement of the tip on the workpiece.   
     
     
         17 . The seal ring of  claim 16  wherein the first section comprises an arc section and the second section comprises a wall section. 
     
     
         18 . The seal ring of  claim 16  wherein the net sliding movement of the tip is less than 0.5 mm.