Silicon Wafer Grinding Apparatus, Retaining Assembly Used for the Same and Silicon Wafer Flatness Correcting Method

Abstract

A silicon wafer grinding apparatus, a retaining assembly used for the same, and a silicon wafer flatness correcting method are provided. More particularly, a silicon wafer grinding apparatus, a retaining assembly used for the same, and a silicon wafer flatness correcting method for correcting a wafer flatness in a final grinding process are provided. The silicon wafer grinding apparatus includes a grinding surface plate having a grinding pad attached thereon; a grinding head arranged opposite to the grinding surface plate and rotated in the same direction as that of the grinding surface plate; a backing film attached at a lower portion of the grinding head for supporting a wafer; and a retainer ring having an inner diameter (a wafer diameter+α) greater than a diameter of the wafer by as much as α and disposed on the backing film. By forming a diameter or physical properties of a part of the backing film of the wafer retaining assembly, the wafer flatness of the final grinding may be corrected.

1 .- 13 . (canceled) 
     
     
         14 . A wafer flatness correcting method comprising:
 marking a center of a grinding head;   attaching a first backing film to a grinding head, disposing a retainer ring having an inner diameter greater than a diameter of a sample wafer on the first backing film;   placing a sample wafer in the retainer ring and performing final grinding;   measuring flatness of the finally ground sample wafer;   manufacturing a heterogeneous second backing film according to the measured sample wafer flatness; and   finally grinding actual wafers of the same diameter as the sample wafer using the second backing film.   
     
     
         15 . The wafer flatness correcting method of  claim 14 , wherein the manufacturing of a heterogeneous second backing film includes sequentially forming a part of at least one of a foaming layer, a substrate layer, and a pressure sensitive adhesive layer with different materials. 
     
     
         16 . The wafer flatness correcting method of  claim 14 , wherein the manufacturing of a heterogeneous second backing film includes sequentially forming a part of at least one of a foaming layer, a substrate layer, and a pressure sensitive adhesive layer to have a different thickness. 
     
     
         17 . The wafer flatness correcting method of  claim 14 , wherein the forming the secondary backing film includes removing a portion of the first backing film corresponding to a portion to correct a flatness of the wafer, aligning and attaching the center marking of the secondary backing film to the center of the first backing film. 
     
     
         18 . The wafer flatness correcting method of  claim 14 , wherein the forming the secondary backing film includes removing or attaching at least one of the substrate layer of the first backing film and the foaming layer formed on the substrate layer. 
     
     
         19 .- 30 . (canceled)