Polishing fluid recovery and reuse system for semiconductor substrate processing

Abstract

The present disclosure generally relates to methods and system used to collect and reuse polishing fluids used during a chemical mechanical polishing (CMP) process for the fabrication of electronic devices. More specifically, systems and methods provided herein include a polishing fluid collection system having a catch basin, a vacuum device, and a polishing fluid recycling module for recycling polishing fluid.

What is claimed is: 
     
         1 . A polishing system, comprising:
 a catch basin sized to surround and to abut a polishing pad secured to a platen, the catch basin comprising:
 an inner wall; 
 an outer wall disposed radially outward from the inner wall; and 
 a base portion connecting the inner wall to the outer wall, the base portion configured to couple the catch basin to the platen such that the catch basin rotates with the platen and the polishing pad, wherein:
 the outer wall, the inner wall, and the base portion collectively define a trough; and 
 a radially inward facing surface of the catch basin is further defined by an arc radius which is equal to an arc radius of the platen that the catch basin is sized to surround, the radially inward facing surface of the catch basin configured to allow for a polishing fluid to flow radially outward from the polishing pad into the trough; 
 
   a first vacuum device, the first vacuum device comprising a suction tube; wherein the suction tube is disposed within the trough of the catch basin, wherein the suction tube is stationary in relation to the catch basin when rotating; and   a polishing fluid recycle module, wherein the first vacuum device draws a polishing fluid out of the trough and sends the polishing fluid to the polishing fluid recycle module for reuse.   
     
     
         2 . The polishing system of  claim 1 , wherein the suction tube is sized to be spaced apart from the base portion of the catch basin by a gap of up to 5 mm. 
     
     
         3 . The polishing system of  claim 1 , wherein the outer wall, the inner wall, and the base portion comprise a hydrophobic material. 
     
     
         4 . The polishing system of  claim 3 , wherein the hydrophobic material is a polymeric material. 
     
     
         5 . The polishing system of  claim 1 , wherein a top portion of the inner wall comprises a beveled edge on a trough facing surface of the inner wall. 
     
     
         6 . The polishing system of  claim 1 , wherein the base portion comprises a plurality of holes, the holes being configured to receive a fastener, wherein the fastener couples the catch basin to the platen such that the catch basin rotates with the platen and the polishing pad. 
     
     
         7 . The polishing system of  claim 1 , further comprising a second vacuum device spaced apart from the first vacuum device along the trough, wherein the first vacuum device is configured to collect a polishing fluid, and wherein the second vacuum device is configured to collect waste fluids. 
     
     
         8 . A fluid reuse system, the system comprising:
 a platen;   a polishing pad secured to the platen;   a first and a second closed loop control slurry delivery system (CLCSDS), wherein the first CLCSDS delivers a first polishing fluid to the polishing pad, wherein the first polishing fluid is collected by a catch basin, the catch basin comprising:
 an inner wall; 
 an outer wall disposed radially outward from the inner wall; and 
 a base portion connecting the inner wall to the outer wall, the base portion configured to couple the catch basin to the platen such that the catch basin rotates with the platen, wherein:
 the outer wall, the inner wall, and the base portion collectively define a trough; and 
 a radially inward facing surface of the catch basin is defined by an arc radius which is equal to a radius of the platen the catch basin is sized to surround; and 
 
 a first vacuum device, the first vacuum device comprising a suction tube, wherein the suction tube is disposed within the trough of the catch basin and to be spaced apart therefrom the base portion, and wherein the suction tube is stationary in relation to the catch basin when rotating; wherein the first vacuum device collects the first polishing fluid; 
   a polishing fluid recycle module, the polishing fluid recycle module configured to recycle the first polishing fluid into a second polishing fluid, wherein the second polishing fluid is provided to the second CLCSDS; and   wherein the second CLCSDS delivers the second polishing fluid the platen and the first CLCSDS delivers the first polishing fluid to the platen to allow a polishing process to be configured to operate from the first polishing fluid from the second polishing fluid, or from a mixture of both.   
     
     
         9 . The fluid reuse system of  claim 8 , further comprising a controller, the controller comprising a CPU, a memory, and a plurality of support circuits, the controller being configured to control a flow of the first and second polishing fluids. 
     
     
         10 . The fluid reuse system of  claim 9 , wherein the controller further comprises sensors for monitoring the fluid reuse system and a fluid property of the first and second polishing fluids. 
     
     
         11 . The fluid reuse system of  claim 10 , wherein the fluid property is one of a pH, dissolved oxygen, or both. 
     
     
         12 . The fluid reuse system of  claim 10 , wherein the controller further comprises adding quantities of acid to modify the pH of the first and second polishing fluids. 
     
     
         13 . The fluid reuse system of  claim 10 , wherein the memory contains instructions for controlling a flow of the first and second polishing fluid through the fluid reuse system. 
     
     
         14 . The fluid reuse system of  claim 13 , wherein the controller further comprises machine learning capabilities. 
     
     
         15 . The fluid reuse system of  claim 8 , wherein the fluid reuse system further comprises a second vacuum device, wherein the first vacuum device collects the first polishing fluid and the second vacuum device is configured to collect a waste fluid. 
     
     
         16 . The fluid reuse system of  claim 15 , wherein the fluid reuse system further comprises a waste collection system, the waste collection system separating the waste fluid collected by the second vacuum device from the first polishing fluids in the catch basin and drain the waste fluid from the fluid reuse system. 
     
     
         17 . The fluid reuse system of  claim 8 , further comprising a plurality of polishing fluid recycle modules. 
     
     
         18 . A method of polishing a substrate, comprising:
 dispensing a polishing fluid onto a surface of a polishing pad;   urging the substrate against the surface of the polishing pad while rotating a platen, the platen having the polishing pad disposed thereon;   collecting the polishing fluid using a fluid reuse system, wherein:
 the fluid reuse system comprises a catch basin coupled to the platen, the catch basin being configured to abut the platen and to rotate with the platen; and 
 at least some of the polishing fluid dispensed onto the polishing pad being collected in a trough of the catch basin; 
 the polishing fluid being collected by a vacuum device, the vacuum device comprising a suction tube disposed within the trough; 
   filtering the polishing fluid of contaminants; and   dispensing the polishing fluid collected using the catch basin onto the surface of the polishing pad.   
     
     
         19 . The method of  claim 18 , wherein the catch basin comprises an outer wall, an inner wall disposed radially inward of the outer wall, and a base portion connecting the inner wall to the outer wall, wherein the inner wall, the outer wall, and the base portion collectively define the trough. 
     
     
         20 . The method of  claim 19 , wherein the suction tube is disposed within the trough in a spaced apart relation therefrom the base portion of the catch basin.