Chemical-mechanical polishing machine for polishing a wafer of material, and an abrasive delivery device fitted to such a machine

Abstract

The invention provides a chemical-mechanical polishing machine for polishing a wafer of a material, the machine comprising a rotary polishing turntable, a polishing head comprising a non-rotary portion and a rotary portion, and means for delivering an abrasive to the surface of the polishing turntable. The machine is remarkable in the means for distributing the abrasive comprise a hollow abrasive delivery ring fitted with abrasive feed means, with a plurality of abrasive delivery orifices distributed over its bottom face, and fixing means enabling it to be secured to the non-rotary portion of the polishing head, the ring being disposed around the rotary portion in a plane that is substantially parallel to the plane of the polishing turntable, but that is spaced apart therefrom. The invention is applicable to polishing wafers of semiconductor material.

What is claimed is:  
     
         1 . A machine for polishing a wafer for use in fabricating substrates comprising: 
 a rotatable turntable;    a polishing head for holding a wafer and being movable relative to the turntable, the polishing head comprising a non-rotary portion and a rotary portion for rotating the wafer while maintaining a surface of the wafer in contact with the turntable; and    means for delivering an abrasive to the surface of the turntable.    
     
     
         2 . The machine of  claim 1 , wherein the polishing head is movable with reciprocating motion in a plane parallel to that of the turntable.  
     
     
         3 . The machine of  claim 1 , wherein the means for delivering the abrasive comprises a tubular ring connected to a supply of abrasive, with the ring having a plurality of abrasive delivery orifices and being secured to the non-rotary portion of the polishing head.  
     
     
         4 . The machine of  claim 3 , wherein the ring is made of thermoplastic resin and includes between about six and twenty delivery orifices.  
     
     
         5 . The machine of  claim 3  wherein the ring is disposed around the rotary portion of the polishing head in a plane that is substantially parallel to the plane of the turntable but is spaced apart therefrom, with the delivery orifices opening out so as to face the turntable.  
     
     
         6 . The machine of  claim 5 , where in the abrasive delivery orifices are spaced equidistantly from the wafer periphery.  
     
     
         7 . The machine of  claim 5 , further comprising plugs for closing the abrasive delivery orifices.  
     
     
         8 . The machine of  claim 5 , wherein the abrasive is delivered to the turntable under pressure or by gravity.  
     
     
         9 . The machine of  claim 1 , further comprising means for pressing the wafer into the polishing head.  
     
     
         10 . The machine of  claim 9 , wherein the means for pressing the wafer comprises an actuator for applying pressure to the polishing head.  
     
     
         11 . The machine of  claim 9 , wherein the means for pressing the wafer comprises a diaphragm for applying pressure to the wafer.  
     
     
         12 . A device for delivering an abrasive to the surface of a turntable of a polishing machine for polishing a wafer, comprising a non-rotatable tubular ring having means for receiving an abrasive from a supply, the ring having a plurality of abrasive delivery orifices distributed over a bottom surface of the ring, wherein the ring is to be secured to a non-rotatable portion of the polishing machine.  
     
     
         13 . The device of  claim 12 , wherein the ring is made of thermoplastic resin and includes between about six and twenty delivery orifices.  
     
     
         14 . The device of  claim 12 , wherein the ring is disposed in a plane that is substantially parallel to that of the turntable but is spaced apart therefrom, with the delivery orifices opening out so as to face the turntable.  
     
     
         15 . The device of  claim 12 , further comprising plugs for closing the abrasive delivery orifices.  
     
     
         16 . A method for polishing a wafer, which comprises positioning a wafer in contact with a polishing head while feeding an abrasive onto the polishing head from a non-rotatable tubular ring having orifices for delivering the abrasive, and rotating the wafer against the polishing head to polish the wafer.  
     
     
         17 . The method of  claim 16 , wherein the polishing head is movable with reciprocating motion in a plane parallel to that of the wafer.  
     
     
         18 . The method of  claim 16 , wherein the ring is made of thermoplastic resin, includes between about six and twenty abrasive delivery orifices, and is disposed in a plane that is substantially parallel to the wafer but is spaced apart therefrom, with the abrasive delivery orifices opening out so as to face the wafer.  
     
     
         19 . The method of  claim 16 , wherein the abrasive delivery orifices are spaced equidistantly from the wafer periphery and the abrasive is delivered to the turntable under pressure or by gravity.  
     
     
         20 . The method of  claim 16 , which further comprises providing plugs for closing the abrasive delivery orifices.