Laser annealing apparatus and method of fabricating thin film transistor

Abstract

In a method of fabricating a thin film transistor through conversion of an amorphous silicon film into a polysilicon film to be an active layer of the thin film transistor by a laser annealing treatment, a laser annealing apparatus comprising a plurality of semiconductor laser devices arranged performs the laser annealing treatment by irradiating the surface of the amorphous silicon film with laser light uniformized in the light intensity of the laser light radiated onto the surface of the amorphous silicon film, whereby the crystal grain diameter of the polysilicon film obtained through recrystallization is uniformized, and it is possible to obtain a thin film transistor with transistor characteristics enhanced by using the polysilicon film as the active layer.

1 . A laser annealing apparatus for subjecting a material to an annealing treatment by irradiating the surface of said material with laser light, comprising: 
 a plurality of semiconductor laser devices for emitting said laser light towards said material, and    uniformizing means for uniformizing the light intensity of said laser light emitted from said plurality of semiconductor laser devices and radiated onto said surface of said material.    
     
     
         2 . A laser annealing apparatus as set forth in  claim 1 , wherein said uniformizing means arranges said plurality of semiconductor laser devices on the upper side of said surface of said material so that emitting portions for emitting said laser light of said plurality of semiconductor laser devices and said surface of said material are opposed to each other.  
     
     
         3 . A laser annealing apparatus as set forth in  claim 1 , wherein 
 said uniformizing means comprises an optical device which guides said laser light emitted from said plurality of semiconductor laser devices and which has an emitting port portion for emitting said guided laser light in a predetermined direction, and    said optical device is so disposed that said emitting port portion and said surface of said material are opposed to each other.    
     
     
         4 . A laser annealing apparatus as set forth in  claim 1 , wherein 
 said uniformizing means comprises an optical device which transmits therethrough said laser light emitted from said plurality of semiconductor laser devices to thereby form the beam shape of said laser light into a predetermined shape and which has an emitting port portion for emitting said laser light with said predetermined beam shape in a predetermined direction, and    said optical device is so disposed that said emitting port portion and said surface of said material are opposed to each other.    
     
     
         5 . A laser annealing apparatus as set forth in  claim 1 , wherein 
 said uniformizing means comprises an optical device for reflecting said laser light emitted from said plurality of semiconductor laser devices to a predetermined direction, and    said optical device is disposed on the upper side of said surface of said material.    
     
     
         6 - 10 . (Canceled)