Laser marking techniques

Abstract

A laser marking apparatus and method for marking the surface of a semiconductor chip are described herein. A laser beam is directed to a location on the surface of the chip where a laser reactive material, such as a pigment containing epoxy, is present. The heat associated with the laser beam causes the laser reactive material to fuse to the surface of the chip, creating a visibly distinct mark in contrast to the rest of the surface of the chip. Only reactive material contacted by the laser fuses to the chip surface, and the remaining residue on the non-irradiated portion can be readily removed.

What is claimed is:  
     
         1 . A semiconductor device including a surface with a marking thereon, said marking comprising energy-reacted material on said surface without being recessed in said surface.  
     
     
         2 . The semiconductor device of  claim 1 , wherein said energy-reacted material comprises a pigment.  
     
     
         3 . The semiconductor device of  claim 1 , wherein said energy-reacted material of said marking is at least partially laterally surrounded by unreacted energy-reactive material.  
     
     
         4 . The semiconductor device of  claim 3 , wherein a color of said energy-reacted material is visibly different from a color of said unreacted energy-reactive material.  
     
     
         5 . The semiconductor device of  claim 1 , wherein regions of said surface beneath and laterally adjacent said marking are substantially free of decomposition and damage.  
     
     
         6 . The semiconductor device of  claim 1 , wherein said marking is at least one of bonded or fused to said surface.  
     
     
         7 . The semiconductor device of  claim 1 , wherein said surface on which said marking is located comprises a surface of a packaging material.  
     
     
         8 . The semiconductor device of  claim 1 , wherein said surface on which said marking is located comprises a surface of a semiconductor die.  
     
     
         9 . A semiconductor device, comprising: 
 at least one semiconductor die;    a surface; and    a marking comprising energy-reactive material bonded or fused to said surface without being recessed therein.    
     
     
         10 . The semiconductor device of  claim 9 , wherein said surface comprises at least one of a surface of said at least one semiconductor die and a surface of a substrate on which said at least one semiconductor die is formed.  
     
     
         11 . The semiconductor device of  claim 10 , wherein said energy-reactive material comprises a pigment.  
     
     
         12 . The semiconductor device of  claim 10 , wherein unreacted energy-reactive material is located laterally adjacent to at least a portion of said energy-reactive material of said marking.  
     
     
         13 . The semiconductor device of  claim 12 , wherein a color of said energy-reactive material of said marking is visibly distinct from a color of said unreacted energy-reactive material.  
     
     
         14 . The semiconductor device of  claim 12 , wherein said unreacted energy-reactive material is not bonded or fused to said surface.  
     
     
         15 . The semiconductor device of  claim 9 , further comprising: 
 an encapsulant material covering at least a portion of said at least one semiconductor die, said surface comprising a surface of said encapsulant material.    
     
     
         16 . The semiconductor device of  claim 15 , wherein said energy-reactive material comprises a pigment.  
     
     
         17 . The semiconductor device of  claim 15 , wherein unreacted energy-reactive material is located laterally adjacent to at least a portion of said energy-reactive material of said marking.  
     
     
         18 . The semiconductor device of  claim 17 , wherein a color of said energy-reactive material of said marking is visibly distinct from a color of said unreacted energy-reactive material.  
     
     
         19 . The semiconductor device of  claim 17 , wherein said unreacted energy-reactive material is not bonded or fused to said surface.  
     
     
         20 . The semiconductor device of  claim 9 , wherein regions of said surface located beneath and laterally adjacent to said marking are substantially free of decomposition and damage.