Polishing apparatus and method of manufacturing semiconductor device using the same

Abstract

A polishing apparatus includes: a wafer polishing unit including a polishing surface plate, an abrasive supply part supplying an abrasive to a polishing pad placed on the polishing surface plate, and a wafer holding part holding a semiconductor wafer; and a dressing unit including a dresser. The dresser has a pellet-shaped grindstone with abrasive particles fixed to a surface thereof. The pellet-shaped grindstone is divided into a first region along an outer peripheral portion thereof and a second region located inside the first region. A chipping preventing portion for the abrasive particles is provided in the first region.

1 . A polishing apparatus, comprising:
 a wafer polishing unit comprising a polishing surface plate, an abrasive supply part supplying an abrasive to a polishing pad placed on the polishing surface plate, and a wafer holding part holding a semiconductor wafer, the wafer polishing unit polishing a surface to be polished of the semiconductor wafer held on the wafer holding part by pressing the surface to be polished of the semiconductor wafer against the polishing pad; and   a dressing unit comprising a dresser having a pellet-shaped grindstone with abrasive particles fixed to a surface thereof, the dressing unit dressing a surface of the polishing pad using the pellet-shaped grindstone,   wherein the pellet-shaped grindstone has a first region along an outer peripheral portion thereof and a second region located inside the first region, and comprises a chipping preventing portion for the abrasive particles provided in the first region.   
     
     
         2 . The polishing apparatus as set forth in  claim 1 ,
 wherein the chipping preventing portion for the abrasive particles comprises a resin coating covering the abrasive particles fixed to the first region.   
     
     
         3 . The polishing apparatus as set forth in  claim 2 ,
 wherein the resin coating is formed of an acrylic resin or a fluorine based resin.   
     
     
         4 . The polishing apparatus as set forth in  claim 2 ,
 wherein the thickness of the resin coating is half or less of a projecting amount of the abrasive particles.   
     
     
         5 . The polishing apparatus as set forth in  claim 1 ,
 wherein the chipping preventing portion for the abrasive particles comprises a ceramic coating covering the abrasive particles fixed to the first region.   
     
     
         6 . The polishing apparatus as set forth in  claim 5 ,
 wherein the ceramic coating is formed of amorphous silicon carbide.   
     
     
         7 . The polishing apparatus as set forth in  claim 5 ,
 wherein the thickness of the ceramic coating is half or less of a projecting amount of the abrasive particles.   
     
     
         8 . The polishing apparatus as set forth in  claim 1 ,
 wherein the chipping preventing portion for the abrasive particles is provided in the first region where the abrasive particles are not fixed, and comprises a guide member composed of a resin material or a ceramic material.   
     
     
         9 . The polishing apparatus as set forth in  claim 8 ,
 wherein the guide member is composed of a fluorine based resin, silicon nitride or silicon carbide.   
     
     
         10 . The polishing apparatus as set forth in  claim 8 ,
 wherein a top of the guide member is located at a position lower by 20 μm or more than the highest position of a projecting height of the abrasive particles.   
     
     
         11 . The polishing apparatus as set forth in  claim 1 ,
 wherein a width of the first region from an outer edge of the pellet-shaped grindstone is not less than 1% nor more than 10% of an outer diameter of the pellet-shaped grindstone.   
     
     
         12 . The polishing apparatus as set forth in  claim 1 ,
 wherein an outer diameter of the pellet-shaped grindstone is 10 to 30 mm, and a width of the first region from an outer edge of the pellet-shaped grindstone is not less than 0.1 mm nor more than 3 mm.   
     
     
         13 . The polishing apparatus as set forth in  claim 1 ,
 wherein the dresser comprises a plurality of pellet-shaped grindstones spaced from each other.   
     
     
         14 . The polishing apparatus as set forth in  claim 1 ,
 wherein the abrasive particles comprise diamond abrasive particles and/or CBN abrasive particles.   
     
     
         15 . The polishing apparatus as set forth in  claim 1 ,
 wherein the abrasive particles comprise irregular-type diamond abrasive particles.   
     
     
         16 . The polishing apparatus as set forth in  claim 1 ,
 wherein the abrasive particles are fixed to a surface of a pellet-shaped member by electrodeposition, metal bonding, resin bonding, or brazing.   
     
     
         17 . The polishing apparatus as set forth in  claim 1 ,
 wherein the polishing apparatus is a CMP apparatus.   
     
     
         18 . A method of manufacturing a semiconductor device using a polishing apparatus, the polishing apparatus comprising: a wafer polishing unit comprising a polishing surface plate, an abrasive supply part supplying an abrasive to a polishing pad placed on the polishing surface plate, and a wafer holding part holding a semiconductor wafer, the wafer polishing unit polishing a surface to be polished of the semiconductor wafer held on the wafer holding part by pressing the surface to be polished of the semiconductor wafer against the polishing pad; and a dressing unit comprising a dresser having a pellet-shaped grindstone with abrasive particles fixed to a surface thereof, the dressing unit dressing a surface of the polishing pad using the pellet-shaped grindstone, wherein the pellet-shaped grindstone has a first region along an outer peripheral portion thereof and a second region located inside the first region, and comprises a chipping preventing portion for the abrasive particles provided in the first region, the method comprising:
 polishing the surface to be polished of the semiconductor wafer held on the wafer holding part by pressing the surface to be polished of the semiconductor wafer against the polishing pad; and   dressing the surface of the polishing pad using the pellet-shaped grindstone before, after, or during the polishing of the semiconductor wafer.   
     
     
         19 . The method of manufacturing a semiconductor device as set forth in  claim 18 ,
 wherein the dressing includes relatively moving the dresser and the polishing pad while pressing an abrasive particles surface of the pellet-shaped grindstone against the surface of the polishing pad.   
     
     
         20 . The method of manufacturing a semiconductor device as set forth in  claim 18 ,
 wherein the polishing is performed by a CMP method.