Laser irradiation apparatus

Abstract

There are disposed two homogenizers for controlling an irradiation energy density in the longitudinal direction of a laser light transformed into a linear one which is inputtted into the surface to be irradiated. Also, there is disposed one homogenizer for controlling an irradiation energy density in a width direction of the linear laser light. According to this, the uniformity of laser annealing can be improved by the minimum number of homogenizers.

What is claimed is:  
     
         1 . A laser irradiation apparatus comprising: 
 a laser for creating a laser;    at least one first homogenizer for homogenizing an energy distribution of the laser in a width direction of a cross section of the laser; and    at least two second homogenizer for homogenizing an energy distribution of the laser in a length wise direction of the cross section,    wherein a number of the first homogenizer is smaller than a number of the second homogenizers.    
     
     
         2 . An apparatus according to  claim 1 , wherein the sum of the number of the first homogenizer and the number of the second homogenizers is an odd number.  
     
     
         3 . A laser irradiation apparatus for irradiating a linear laser light, wherein the number of homogenizers for controlling an irradiation energy density in a width direction of the linear laser light is different from that of homogenizers for controlling an irradiation energy density in a longitudinal direction of the linear laser light.  
     
     
         4 . A laser irradiation apparatus for irradiating a linear laser light, wherein the total number of homogenizers is an odd number.  
     
     
         5 . An apparatus according to  claim 4 , wherein the number of homogenizers for controlling an irradiation energy density in a longitudinal direction of the linear laser light is larger than that of homogenizers for controlling an irradiation energy density in a width direction of the linear laser light.  
     
     
         6 . A laser irradiation apparatus for irradiating a linear laser light to a semiconductor, comprising: 
 a homogenizer or homogenizers, A in number, corresponding to a width direction of the linear laser light; and    homogenizers, B in number, corresponding to a longitudinal direction of the linear laser light,    wherein A<B, and    wherein the semiconductor is responsive to the irradiation of the linear laser light to the semiconductor to cause annealing of the semiconductor.    
     
     
         7 . An apparatus according to  claim 6  wherein crystallinity of the semiconductor is improved by the annealing.  
     
     
         8 . A laser irradiation apparatus for irradiating a linear laser light to a semiconductor, wherein the number of homogenizers for controlling an irradiation energy density in a width direction of the linear laser light is different from that of homogenizers for controlling an irradiation energy density in a longitudinal direction of the linear laser light, and wherein the semiconductor is responsive to the irradiation of the linear laser light to the semiconductor to cause annealing of the semiconductor.  
     
     
         9 . An apparatus according to  claim 8  wherein crystallinity of the semiconductor is improved by the annealing.