Fix the glassivation layer's micro crack point precisely by using electroplating method

Abstract

A cathode-anode apparatus is constructed whereby the wafer under test, connected to a conducting wire, forms the cathode terminal and a copper plate, also connected to a conducting wire, forms the anode terminal. The wafer under test and the copper plate are immersed in a CuSO 4 —H 2 O solution. A positive dc voltage is applied to the copper plate, the dc current ionizes the CUSO 4 solution and forms Cu 2+ ions. These Cu 2+ ions will diffuse to the wafer surface. Defects in the glassification surface will absorb most of the Cu 2+ ions, concentrations of Cu 2 ions will therefore from around these defects.

What is claimed is:  
     
         1 . A method for determining defects on the surface of a glassification layer, comprising the steps of: 
 Providing a wafer to be tested for said defects said wafer containing a glassification layer;    Providing a copper plate;    Providing a container said container containing a copper-sulfate solution;    Positioning said wafer to be tested within said container;    Positioning said copper plate within said container; and    Applying a voltage between said wafer to be tested and said copper plate.    
     
     
         2 . The method of    claim 1    wherein said container has a cross section in the horizontal plane that essentially resembles the shape of a geometric rectangle said container further has a height essentially equal to the diameter of the largest wafer to be tested whereby further the sides of said container have a first and a second small surface area and a first and a second large surface area whereby the planes of the first and second small areas are parallel whereby further the planes of the first and second large areas are parallel.  
     
     
         3 . The method of    claim 1    wherein said copper-sulfate solution is CUSO 4  mixed with H 2 O.  
     
     
         4 . The method of    claim 1    wherein said providing a wafer to be tested is: 
 mounting said wafer inside said container with the plane of said wafer being parallel to the plane of said first small surface area of said container thereby forming the cathode of a two electrode apparatus said wafer being attached to a conducting wire;  
 mounting said wafer such that the surface that is to be tested is submerged within said copper-sulfate solution;  
 mounting said wafer in relatively close proximity to said first small surface area of said container; and  
 facing said surface that is to be tested toward said second small surface area of said container.  
 
     
     
         5 . The method of    claim 1    wherein said providing said copper plate within said container is: 
 mounting said copper plate inside said container with the plane of said copper plate being parallel to the plane of said second small surface area of said container thereby forming the anode of a two electrode apparatus said copper plate being attached to a conducting wire;  
 mounting said copper such that said copper plate is at least partially submerged within said copper-sulfate solution; and  
 mounting said copper plate in relatively close proximity to said second small surface area of said container.  
 
     
     
         6 . The method of    claim 2    whereby applying a voltage between said wafer to be tested and said copper plate is applying direct current e.m.f. between said wafer and said copper plate for a selected period of time thereby causing the creation of Cu 2+  ions within said copper-sulfate solution whereby said Cu 2+  ions are forced to diffuse to the surface of said wafer thereby causing electroplating of the surface of said wafer thereby further causing electrodeposition of said Cu 2+  ions on unprotected parts of the surface of said wafer.  
     
     
         7 . An apparatus for determining defects in the surface of a glassification layer of a wafer that is tested for said defects, comprising: 
 a copper plate;    a container;    a copper-sulfate solution; and    a voltage to be applied between said wafer to be tested and said copper plate.    
     
     
         8 . The apparatus of    claim 7    wherein said container has a cross section in the horizontal plane that essentially resembles the shape of a geometric rectangle said container further has a height essentially equal to the diameter of the largest wafer to be tested whereby further the sides of said container have a first and a second small surface area and a first and a second large surface area whereby the planes of the first and second small areas are parallel whereby further the planes of the first and second large areas are parallel.  
     
     
         9 . The apparatus of    claim 7    wherein said copper-sulfate solution is CuS 04  mixed with H 20 .  
     
     
         10 . The apparatus of    claim 7    whereby said wafer to be tested is positioned within said container whereby: 
 said wafer is mounted inside said container with the plane of said wafer being parallel to the plane of said first small surface area of said container thereby forming the cathode of a two electrode apparatus said wafer being attached to a conducting wire;  
 said wafer is mounted such that the surface that is to be tested is submerged within said copper-sulfate solution; said wafer is mounted in relatively close proximity to said first small surface area of said container; and  
 said surface that is to be tested is facing toward said second small surface area of said container.  
 
     
     
         11 . The apparatus of    claim 7    wherein said copper plate is positioned within said container whereby: 
 said copper plate is mounted inside said container with the plane of said copper plate being parallel to the plane of said second small surface area of said container thereby forming the anode of a two electrode apparatus said copper plate being attached to a conducting wire;  
 said copper plate is mounted such that said copper plate is at least partially submerged within said copper-sulfate solution; and  
 said copper plate is mounted in relatively close proximity to said second small surface area of said container.  
 
     
     
         12 . The apparatus of    claim 7    whereby applying a voltage between said wafer to be tested and said copper plate is applying direct current e.m.f. between said wafer and said copper plate for a selected period of time thereby causing the creation of Cu 2+  ions within said copper-sulfate solution whereby said Cu 2+  ions are forced to diffuse to the surface of said wafer thereby causing electroplating of said the surface of said wafer to be tested further causing electrodeposition of said Cu 2+  ions on unprotected parts of said wafer surface.