System and method for in-situ head rinse

Abstract

A carrier head and a method of cleaning the carrier head are disclosed. The carrier head may have one or more openings through a sidewall that extend into a cavity within the carrier head using a fluid passage. The openings may each have a lip. The lip may have a chamfered edge. Additionally, a fluid passage may slope generally downward from the openings to the cavity. The chamfered lips and the sloped fluid passage reduce back splashing and help ensure that sufficient rinsing fluid reaches the cavity to rinse polishing fluid and particles from the carrier head. The present invention relates to carrier heads for polishing or planarizing semiconductor substrates by chemical mechanical polishing (CMP) or electrochemical mechanical polishing (ECMP). The cavities in the carrier head are cleaned by rinsing fluid (i.e., liquid or gas) from inside the cavity towards a substrate receiving side of the carrier head.

1 . A carrier head, comprising: 
 a backing assembly;    a retaining ring, wherein a cavity is present between the retaining ring and the backing assembly; and    a fluid rinsing system for rinsing the cavity.    
     
     
         2 . The carrier head of  claim 1 , wherein the fluid rinsing system supplies fluid to at least one opening in the head extending to the cavity.  
     
     
         3 . The carrier head of  claim 2 , wherein the at least one opening is positioned substantially perpendicular to a substrate receiving surface of the carrier head.  
     
     
         4 . The carrier head of  claim 2 , wherein the at least one opening has a top wall that has a higher elevation on the carrier head than a top wall of the cavity.  
     
     
         5 . The carrier head of  claim 2 , wherein the at least one opening comprises a lip portion having at least one chamfered edge.  
     
     
         6 . The carrier head of  claim 1 , wherein the cavity is coupled with a plurality of openings.  
     
     
         7 . A carrier head, comprising: 
 a top surface; and    a side surface substantially perpendicular to the top surface, wherein a fluid passage extends through the carrier head from the side surface to a cavity.    
     
     
         8 . The carrier head of  claim 7 , wherein the fluid passage has a lip portion coupled with the side surface, the lip portion having at least one surface positioned at an angle relative to the side surface such that the lip portion slopes into the fluid passage.  
     
     
         9 . The carrier head of  claim 8 , wherein the fluid passage comprises an upper surface and a lower surface, wherein the upper surface and the lower surface each slope downward from the lip portion to a cavity positioned opposite the lip portion.  
     
     
         10 . The carrier head of  claim 8 , wherein the fluid passage comprises side surfaces, wherein the side surfaces converge toward the cavity positioned opposite the lip portion.  
     
     
         11 . The carrier head of  claim 10 , wherein the cavity is coupled with a plurality of fluid passages.  
     
     
         12 . The carrier head of  claim 10 , wherein an upper edge of the lip portion is at a higher elevation than a top wall of the cavity.  
     
     
         13 . The carrier head of  claim 7 , further comprising: 
 a retaining ring; and    a backing assembly, wherein the cavity is present between the retaining ring and the backing assembly.    
     
     
         14 . A carrier head cleaning method, comprising: 
 flowing a cleaning fluid through at least one opening in a carrier head, the cleaning fluid flowing to a cavity within the carrier head, wherein the opening and the cavity are coupled together by a fluid passageway having sidewalls, and at least one sidewall of the fluid passageway is sloped from the opening toward the cavity.    
     
     
         15 . The method of  claim 14 , wherein the flowing is performed in a load cup.  
     
     
         16 . The method of  claim 14 , wherein the flowing is performed over a platen.  
     
     
         17 . The method of  claim 14 , further comprising: 
 rotating the carrier head during the flowing.    
     
     
         18 . The method of  claim 17 , further comprising: 
 polishing a substrate at a first platen, wherein said flowing is performed over the first platen.    
     
     
         19 . The method of  claim 17 , further comprising: 
 polishing a substrate at a first platen, wherein said flowing is performed over a platen different from said first platen.    
     
     
         20 . The method of  claim 14 , wherein the at least one opening is substantially perpendicular to a substrate receiving surface of the carrier head.