Abrasive article having a window system for polishing wafers, and methods

Abstract

A process for planarizing, polishing, or providing other modification of a wafer surface or other workpiece. The process includes using an abrasive article having a textured abrasive coating affixed to a backing. The abrasive article includes a monitoring element, such as a window, to allow transmission of radiation therethrough. The radiation level is monitored throughout the planarization process to determine the approach of the desired endpoint. The window in the abrasive coating can be an area devoid of abrasive coating or having minimal or a thinned abrasive coating.

We claim:  
     
         1 . A method of modifying a workpiece surface comprising: 
 (a) contacting the workpiece surface with an abrasive article, the abrasive article comprising: 
 (i) a textured abrasive coating having a plurality of abrasive particles dispersed in a binder, the textured abrasive coating adhered to a backing;  
 (ii) a monitoring element for passage of radiation therethrough;  
   (b) moving the abrasive article in relation to the workpiece surface to modify the workpiece surface; and    (c) determining a degree of surface modification by: 
 (i) measuring a first radiation level from the workpiece surface through the monitoring element.  
   
     
     
         2 . The method according to  claim 1 , wherein the step of contacting the workpiece surface with an abrasive article comprises: 
 (a) contacting the workpiece surface with an abrasive article, the abrasive article comprising: 
 (i) a plurality of abrasive composites comprising abrasive particles dispersed in a binder, the abrasive composites adhered to a backing.  
   
     
     
         3 . The method according to  claim 2 , wherein the step of contacting the workpiece surface with an abrasive article comprises: 
 (a) contacting the workpiece surface with an abrasive article, the abrasive article comprising: 
 (i) a monitoring element for passage of radiation therethrough, the monitoring element being an area devoid of abrasive composites.  
   
     
     
         4 . The method according to  claim 2 , wherein the step of contacting the workpiece surface with an abrasive article comprises: 
 (a) contacting the workpiece surface with an abrasive article, the abrasive article comprising: 
 (i) a monitoring element for passage of radiation therethrough, the monitoring element being an area having a thinned abrasive coating.  
   
     
     
         5 . The method according to  claim 1 , wherein the step of contacting the workpiece surface with an abrasive article comprises: 
 (a) contacting the workpiece surface with an abrasive article, the abrasive article comprising: 
 (i) a textured abrasive coating having a plurality of abrasive particles dispersed in a binder, the textured abrasive coating adhered to a backing; and  
 (ii) a monitoring element for passage of radiation therethrough, the monitoring element extending from a first edge of the abrasive article to a second opposite edge of the abrasive article.  
   
     
     
         6 . The method according to  claim 5 , wherein the step of contacting the workpiece surface with an abrasive article comprises: 
 (a) contacting the workpiece surface with an abrasive article, the abrasive article comprising: 
 (i) a monitoring element for passage of radiation therethrough, the monitoring element oscillating between the first edge of the abrasive article and the second opposite edge of the abrasive article.  
   
     
     
         7 . The method according to  claim 5 , wherein the step of contacting the workpiece surface with an abrasive article comprises: 
 (a) contacting the workpiece surface with an abrasive article, the abrasive article comprising: 
 (i) an extended length of abrasive article having a longitudinal length; and  
 (ii) a monitoring element for passage of radiation therethrough, the monitoring element extending along the longitudinal length of the abrasive article.  
   
     
     
         8 . The method according to  claim 1 , wherein the step of contacting the workpiece surface with an abrasive article comprises: 
 (a) contacting the workpiece surface with an abrasive article, the abrasive article comprising: 
 (i) a monitoring element for passage of radiation therethrough, the monitoring element being a discrete area in the abrasive coating of the abrasive article.  
   
     
     
         9 . The method according to  claim 8 , wherein the step of contacting the workpiece surface with an abrasive article comprises: 
 (a) contacting the workpiece surface with an abrasive article, the abrasive article comprising: 
 (i) a monitoring element for passage of radiation therethrough, the discrete area having a shape selected from a square, rectangle, circle, or ellipse.  
   
     
     
         10 . The method according to  claim 1 , wherein the step of determining a degree of surface modification comprises: 
 (i) measuring a first radiation level from the workpiece surface;    (ii) measuring a second radiation level from the workpiece surface; and    (iii) comparing the first radiation level and the second radiation level.    
     
     
         11 . The method according to  claim 1 , wherein the step of determining a degree of surface modification comprises: 
 (i) measuring a first radiation level with a first sensor through a first monitoring element; and    (ii) measuring a second radiation level with a second sensor through a second monitoring element.    
     
     
         12 . The method according to  claim 1 , wherein the step of determining a degree of surface modification comprises: 
 (i) measuring a thermal radiation level from the workpiece surface.    
     
     
         13 . The method according to  claim 1 , wherein the step of determining a degree of surface modification comprises: 
 (i) measuring a visible light level from the workpiece surface.    
     
     
         14 . The method according to  claim 1 , wherein the step of determining a degree of surface modification comprises: 
 (i) measuring an ultraviolet light level from the workpiece surface.    
     
     
         15 . The method according to  claim 1 , wherein the step of determining a degree of surface modification comprises: 
 (i) measuring a first radiation level emitted from the workpiece surface.    
     
     
         16 . The method according to  claim 1 , wherein the step of determining a degree of surface modification comprises: 
 (i) measuring a first radiation level reflected by the workpiece surface.    
     
     
         17 . The method according to  claim 1 , wherein the step of determining a degree of surface modification comprises: 
 (i) measuring a first radiation level passing through the workpiece.    
     
     
         18 . The method according to  claim 1 , wherein the step of contacting the workpiece surface with an abrasive article comprises: 
 (a) contacting the workpiece surface with an elongate abrasive article.    
     
     
         19 . The method according to  claim 1 , wherein the step of contacting the workpiece surface with an abrasive article comprises: 
 (a) contacting the workpiece surface with an abrasive article having a shape selected from a disc, square, rectangle, daisy, pentagon, hexagon, octagon, and ellipse.    
     
     
         20 . A method of making an abrasive article for wafer planarization, the method comprising: 
 (a) providing an abrasive coating composition;    (b) bringing a backing into contact with the abrasive coating composition, so that the abrasive coating composition contacts a first portion of the backing, leaving a second portion of the backing free of abrasive coating composition; and    (c) at least partially curing the abrasive coating composition.    
     
     
         21 . The method according to  claim 20 , wherein the step of bringing a backing into contact with the abrasive coating composition, so that the abrasive coating composition contacts a first portion of the backing, leaving a second portion of the backing free of abrasive coating composition comprises: 
 (a) bringing a backing into contact with the abrasive coating composition, so that the abrasive coating composition contacts a first portion of the backing, leaving a second portion of the backing free of abrasive coating composition, wherein the second portion of the backing free of abrasive coating composition extends a length of the backing.    
     
     
         22 . The method according to  claim 20 , wherein: 
 (a) the step of providing an abrasive coating composition comprises: 
 (i) applying the abrasive coating composition into a plurality of cavities in a production tool; and wherein the method further comprises:  
   (b) removing the abrasive coating composition from the plurality of cavities.    
     
     
         23 . The method according to  claim 22 , wherein the step of applying the abrasive coating composition into a plurality of cavities in a production tool comprises: 
 (a) applying the abrasive coating composition into a plurality of cavities in a production tool, the production tool further comprising an area devoid of cavities.    
     
     
         24 . The method according to  claim 23 , wherein the step of applying the abrasive coating composition into a plurality of cavities in a production tool, the production tool further comprising an area devoid of cavities comprises: 
 (a) applying the abrasive coating composition into a plurality of cavities in a production tool, the production tool further comprising a length of the production tool devoid of cavities.    
     
     
         25 . The method according to  claim 23 , wherein the step of applying an abrasive coating composition into a plurality of cavities in a production tool, the production tool further comprising an area devoid of cavities comprises: 
 (a) applying an abrasive coating composition into a plurality of cavities in a production tool, the production tool further comprising discrete areas of the production tool devoid of cavities.    
     
     
         26 . The method according to  claim 20 , wherein the step of bringing a backing into contact with the abrasive coating composition comprises: 
 (a) bringing an extended length of backing into contact with the abrasive coating composition.    
     
     
         27 . The method according to  claim 20 , wherein the step of bringing a backing into contact with the abrasive coating composition comprises: 
 (a) providing a backing comprising a primer in the first portion of the backing and no primer in the second portion of the backing.    
     
     
         28 . The method according to  claim 20 , wherein the step of bringing a backing into contact with the abrasive coating composition comprises: 
 (a) providing a backing comprising a release element in the second portion of the backing.    
     
     
         29 . The method according to  claim 28 , wherein the step of providing a backing comprising a release element in the second portion of the backing comprises: 
 (a) providing a backing comprising a removable strip in the second portion of the backing.    
     
     
         30 . The method according to  claim 20 , wherein the step of providing an abrasive coating composition comprises: 
 (a) providing an abrasive coating composition via a gravure roll.