Semiconductor wafer, method of manufacturing the same and semiconductor device

Abstract

The object of the present invention is to provide a semiconductor wafer in which a diffusion of Cu generated by a thermal treatment such as a Cu wiring formation step into silicon is prevented, and variations of transistor characteristics are lessened. The object of the present invention is to provide a method of manufacturing the same and a semiconductor device formed from the same. In the present invention, a protection insulating film for preventing Cu from diffusing into the inside of the wafer is formed on a peripheral portion of a principal plane, a external side plane and a rear plane of the wafer. With this protection insulating film, the diffusion of Cu that is a wiring material into a chip formation region of the wafer is prevented, so that the variations of the transistor characteristic.

What is claimed is:  
     
         1 . A semiconductor wafer comprising: 
 a semiconductor wafer having a first plane in which an integrated circuit is going to be formed, a second plane opposite the first plane and a peripheral region between the first and the second planes; and 
 a protection film formed on said second plane and said peripheral region.  
   
     
     
         2 . The semiconductor wafer according to  claim 1 , wherein said protection film is a silicon nitride film.  
     
     
         3 . The semiconductor wafer according to  claim 1 , wherein said protection film prevents a diffusion of copper into a semiconductor substrate.  
     
     
         4 . A method of manufacturing a semiconductor wafer, comprising the steps of: 
 forming a protection film on substantially the entire outside surface of a semiconductor wafer; and    removing the protection film on a region of said first plane in which an integrated circuit will be formed.    
     
     
         5 . The method according to  claim 4 , wherein the protection film is a silicon nitride film.  
     
     
         6 . The method according to  claim 4 , wherein the protection film prevents a diffusion of copper into a semiconductor substrate.  
     
     
         7 . The method according to  claim 4 , wherein the protection film also forms gate insulation saidewalls of an integrated circuit.  
     
     
         8 . A method for manufacturing a semiconductor wafer, comprising the steps of: 
 growing a cylindrical single crystal semiconductor ingot;    forming a protection insulating film on a surface of said single crystal semiconductor ingot, the protection insulating film preventing a diffusion of copper into said single crystal semiconductor ingot; and    slicing said single crystal semiconductor ingot into a plurality of semiconductor wafers, each semiconductor wafer having an external peripheral plane on which said protection insulating film is formed.    
     
     
         9 . The method according to  claim 8 , further comprising the step of: 
 forming a protection insulating film also on a peripheral portion of a principal plane and a rear plane of said semiconductor wafer, the protection insulating film preventing a diffusion of copper into said semiconductor wafer and extending to said external peripheral plane.    
     
     
         10 . A semiconductor device comprising: 
 a semiconductor chip having a first plane in which an integrated circuit is going to be formed and a second plane opposite the first plane; and a protection insulating film formed on said second plane.    
     
     
         11 . The semiconductor device according to  claim 10 , wherein a copper ion or a copper composition is on a surface of said protection insulating film or within said protection insulating film.  
     
     
         12 . The semiconductor device according to  claim 10 , wherein a copper ion or a copper composition is contained in a surface between said protection insulating film and said semiconductor chip.  
     
     
         13 . The semiconductor device according to  claim 10 , wherein said protection insulating film prevents a diffusion of copper into a semiconductor substrate.  
     
     
         14 . The semiconductor device according to  claim 10 , wherein said protection insulating film is formed of silicon nitride.  
     
     
         15 . The semiconductor device according to  claim 10 , where the integrated circuit includes at least one element or layer formed of copper.  
     
     
         16 . A method of manufacturing a semiconductor device, comprising the steps of: 
 forming a protection film on substantially the entire outside surface of a semiconductor wafer;    removing the protection film from a region of the semiconductor wafer, and    forming a integrated circuit in the region, the integrated circuit including a copper wiring.