Conditioning Tools and Techniques for Chemical Mechanical Planarization

Abstract

Tools for conditioning chemical mechanical planarization (CMP) pads comprise a substrate with abrasive particles coupled to at least one surface. The tools can have various particle and bond configurations. For instance, abrasive particles may be bonded (e.g., brazed or other metal bond technique) to one side, or to front and back sides. Alternatively, abrasive particles are bonded to a front side, and filler particles coupled to a back side. The abrasive particles can form a pattern (e.g., hexagonal) and have particle sizes that are sufficiently small to penetrate pores of a CMP pad during conditioning, leading to fewer defects on wafers polished with the conditioned CMP pad. Grain bonding can be accomplished using brazing films, although other metal bonds may be used as well. Also, balanced bond material (e.g., braze on both sides) allows for low out-of-flatness value.

What is claimed is: 
     
         1 . A method for manufacturing a tool for conditioning a chemical mechanical planarization (CMP) pad comprising the steps of:
 providing a support member having a first side and a second side; and   coupling abrasive particles to at least one of the first and second sides of the support member with a metal bond, and at least 95% (by weight) of the abrasive particles have, independently, a particle size of less than about 85 micrometers;   wherein the tool is manufactured to have an abrasive particle concentration of greater than about 4000 abrasive particles/inch 2  (620 abrasive particles/centimeter 2 ), an inter-particle spacing so that substantially no abrasive particles are touching other abrasive particles, and a plurality of narrow slots extending along the surface of at least one of the first and second sides.   
     
     
         2 . The method of  claim 1  wherein coupling the abrasive particles to at least one of the sides of the support member with a metal bond comprises brazing the abrasive particles to at least one of the sides of the support member with a brazing alloy, the brazing comprising:
 bonding a brazing film to at least one of the sides of the support member; 
 positioning abrasive particles on at least a portion of the brazing film to form a green part; and 
 firing the green part and subsequently cooling the green part to thereby chemically bond the abrasive particles with the brazing alloy to the support member; 
 wherein the brazing film is at least one member selected from the group consisting of braze tape, braze foil, braze tape with perforations, and braze foil with perforations. 
 
     
     
         3 . The method of  claim 2  wherein positioning the abrasive particles comprises:
 applying the abrasive particles to a plurality of openings in or on at least a portion of the brazing film, wherein each opening is configured to receive one of the abrasive particles; 
 wherein the openings form a desired grain pattern and allow for out-gassing during brazing. 
 
     
     
         4 . The method of  claim 1  wherein coupling the abrasive particles to at least one of the sides of the support member comprises:
 applying a brazing alloy to both the first and second sides of the support member; and 
 brazing the abrasive particles to only the first side of the support member with the brazing alloy. 
 
     
     
         5 . The method of  claim 4  further comprising:
 brazing one or more inert filler particles to the first side of the support member with the brazing alloy. 
 
     
     
         6 . The method of  claim 1  wherein coupling the abrasive particles to at least one of the sides of the support member with a metal bond comprises:
 applying the abrasive particles to a plurality of openings on at least one of the sides of the support member, wherein each opening is configured to receive one of the abrasive particles; 
 wherein the openings form a desired grain pattern. 
 
     
     
         7 . The method of  claim 1  wherein the plurality of narrow slots extend along the entirety of the surface. 
     
     
         8 . A tool comprising:
 a chemical mechanical planarization (CMP) pad conditioner comprising:
 a support member having a first side and a second side opposite the first side; 
 a layer of braze coupled to the first side of the support member; 
 a layer of braze coupled to the second side of the support member; and 
 wherein the tool comprises an out-of-flatness of less than about 0.002 inches.