Substrate hot spot correction for a chemical mechanical polishing processs

Abstract

A method of processing a substrate, includes placing a front surface of a substrate disposed in a carrier head on a polishing surface of a pad. The method further includes delivering a first fluid onto the polishing surface using a first fluid delivery arm. The method further includes determining a location of a hot spot on the front surface. The method further includes determining a rotational orientation of the substrate relative to the carrier head. The method further includes treating the hot spot while polishing the front surface on the polishing surface using a second fluid delivery arm to deliver a second fluid to the polishing surface at a location that will intersect with the hot spot during polishing of the front surface of the substrate.

What is claimed is: 
     
         1 . A method of processing a substrate, comprising:
 placing a front surface of a substrate disposed in a carrier head on a polishing surface of a pad coupled to a platen;   delivering a first fluid onto the polishing surface using a first fluid delivery arm;   determining a location of a hot spot on the front surface;   determining a rotational orientation of the substrate relative to the carrier head; and   treating the hot spot while polishing the front surface on the polishing surface using a second fluid delivery arm to deliver a second fluid to the polishing surface, the treating comprising:
 determining a first radial position on the polishing surface to pulse a first amount of a second fluid such that the first amount of second fluid will at least partially pass underneath the hot spot; and 
 pulsing the first amount of the second fluid onto the polishing surface at the first radial position using the second fluid delivery arm. 
   
     
     
         2 . The method of  claim 1 , the treating further comprising:
 determining a second radial position on the polishing surface to pulse a second amount of the second fluid such that the second amount of second fluid will at least partially pass underneath the hot spot; and   pulsing the second amount of the second fluid onto the polishing surface at the second radial position.   
     
     
         3 . The method of  claim 2 , wherein the second fluid delivery arm is moved to a first position to pulse the first amount of second fluid and moved to a second position to pulse the second amount of second fluid at the second radial position. 
     
     
         4 . The method of  claim 2 , wherein the second amount of the second fluid has a different composition than the first amount of the second fluid. 
     
     
         5 . The method of  claim 1 , wherein the first radial position is determined based on at least the rotational speed of the carrier head, the rotational speed of the pad, the location of the hot spot, and the rotational orientation of the substrate relative to the carrier head. 
     
     
         6 . The method of  claim 1 , wherein the location of the hot spot is determined by a metrology station. 
     
     
         7 . A method of processing a substrate, comprising:
 polishing a front surface of a substrate on a first pad coupled to a first platen;   transferring the substrate from the first pad to a second pad coupled to a second platen with a carrier head;   delivering a first fluid onto a polishing surface of the second pad;   determining a location of a hot spot on the front surface;   determining a rotational orientation of the substrate relative to the carrier head; and   treating the hot spot while polishing the front surface on the second pad, the treating comprising:
 determining a first radial position on the polishing surface to pulse a first amount of a second fluid such that the first amount of second fluid will at least partially pass underneath the hot spot; and 
 pulsing the first amount of the second fluid onto the polishing surface at the first radial position. 
   
     
     
         8 . The method of  claim 7 , wherein the first radial position is determined based on at least the rotational speed of the carrier head, the rotational speed of the second pad, the location of the spot, and the rotational orientation of the substrate relative to the carrier head. 
     
     
         9 . The method of  claim 7 , wherein the location of the hot spot is determined by one or more endpoint sensors disposed in the second pad. 
     
     
         10 . The method of  claim 7 , wherein the treating further includes:
 obtaining a thickness of the hot spot with one or more endpoint sensors disposed in the second pad.   
     
     
         11 . The method of  claim 10 , further comprising:
 pulsing a second amount of the second fluid at a second radial position based on the thickness of the hot spot.   
     
     
         12 . The method of  claim 7 , the treating further comprising:
 determining a second radial position on the polishing surface to pulse a second amount of the second fluid such that the second amount of second fluid will at least partially pass underneath the hot spot; and   pulsing the second amount of the second fluid onto the polishing surface at the second radial position.   
     
     
         13 . The method of  claim 12 , wherein the second radial position is different than the first radial position. 
     
     
         14 . The method of  claim 12 , wherein second fluid is pulsed onto the polishing surface by a fluid delivery head, wherein the fluid delivery head is moved from a first position above the first radial position to a second position above the second radial position prior to pulsing the second amount. 
     
     
         15 . The method of  claim 12 , wherein pulsing the second amount of second fluid occurs one second after pulsing the first amount of second fluid. 
     
     
         16 . The method of  claim 12 , wherein the second amount of the second fluid has a different composition than the first amount of the second fluid. 
     
     
         17 . The method of  claim 16 , wherein the first amount of the second fluid increases the polishing rate of the hot spot and the second amount of the second fluid decreases the polishing rate of the hot spot. 
     
     
         18 . A polishing system, comprising:
 a polishing station, including:
 a platen including a polishing pad; 
 a carrier head configured to rotate a substrate including a reference mark and a front surface; 
 a first fluid delivery arm configured to deliver a first fluid onto the polishing pad; 
 a second fluid delivery arm configured to selectively deliver one or more pulses of a second fluid onto the polishing pad to treat a hot spot on the front surface, wherein the hot spot is located at a known position relative to the reference mark; 
 an orientation sensor embedded in the platen at the rotational center of the platen, wherein the orientation sensor is configured to scan an edge of a substrate that includes a reference mark; and 
 a controller in communication with the orientation sensor, the pad, the carrier head, and the second fluid delivery arm, wherein the controller is configured to analyze data obtained by the orientation sensor to identify a location of the reference mark relative to the carrier head, and wherein the controller is configured to control a position of the second fluid delivery arm relative to the pad to deliver one or more pulses at one or more radial positions on the pad to treat the hot spot. 
   
     
     
         19 . The polishing system of  claim 18 , further comprising:
 at least one of a metrology tool or a pre-alignment station configured to determine the location of the hot spot relative to the reference mark before polishing the substrate.   
     
     
         20 . The polishing system of  claim 18 , further comprising:
 a plurality of endpoint sensors embedded in the platen around the orientation sensor, each endpoint sensor configured to monitor a polishing rate of the hot spot, and wherein the controller is configured to cause a change in a composition of the second fluid based on the polishing rate of the hot spot.