Laser annealing apparatus and semiconductor device manufacturing method

Abstract

This invention is intended to provide a laser annealing method by employing a laser annealer lower in running cost so as to deal with a large-sized substrate, for preventing or decreasing the generation of a concentric pattern and to provide a semiconductor device manufacturing method including a step using the laser annealing method. While moving a substrate at a constant rate between 20 and 200 cm/s, a laser beam is radiated aslant to a semiconductor film on a surface of the semiconductor substrate. Therefore, it is possible to radiate a uniform laser beam to even a semiconductor film on a large-sized substrate and to thereby manufacture a semiconductor device for which the generation of a concentric pattern is prevented or decreased. By condensing a plurality of laser beams into one flux, it is possible to prevent or decrease the generation of a concentric pattern and to thereby improve the reliability of the semiconductor device.

1 . A method of manufacturing a semiconductor device comprising:
 emitting a plurality of laser beams from a plurality of oscillators;   making the plurality of laser beams pass through a fiber array;   condensing the plurality of laser beams having passed through the fiber array to form a condensed laser beam; and   irradiating a semiconductor film with the condensed laser beam in order to increase crystallinity of the semiconductor film.   
   
   
       2 . The method of manufacturing a semiconductor device according to  claim 1 , wherein the step of irradiating the semiconductor film with the condensed laser beam includes:
 changing a relative position of the semiconductor film with respect to the condensed laser beam in a first direction;   changing the relative position of the semiconductor film in a second direction perpendicular to the first direction by a distance equal to or smaller than a length of the condensed laser beam in the second direction; and then   changing the relative position of the semiconductor film with respect to the condensed laser beam in a third direction parallel and opposite to the first direction.   
   
   
       3 . The method of manufacturing a semiconductor device according to  claim 2 , wherein the steps of changing the relative position includes a step of changing a position of the semiconductor film. 
   
   
       4 . The method of manufacturing a semiconductor device according to  claim 1 , wherein the semiconductor film is irradiated with the condensed laser beam aslant to the semiconductor film. 
   
   
       5 . The method of manufacturing a semiconductor device according to  claim 1 , wherein the semiconductor film is crystallized by the irradiation of the condensed laser beam. 
   
   
       6 . The method of manufacturing a semiconductor device according to  claim 1 , wherein the plurality of laser beams is condensed by a waveguide. 
   
   
       7 . The method of manufacturing a semiconductor device according to  claim 1 , wherein each of the plurality of oscillators is one selected from a group consisting of a Nd: YAG laser, an Nd: YLF laser, an Nd: YVO 4  laser and an Nd: YAlO 3  laser. 
   
   
       8 . The method of manufacturing a semiconductor device according to  claim 1 , wherein each of the plurality of laser beams is a CW laser beam. 
   
   
       9 . The method of manufacturing a semiconductor device according to  claim 1 , wherein each of the plurality of laser beams is a pulsed laser beam. 
   
   
       10 . A method of manufacturing a semiconductor device comprising:
 emitting a plurality of laser beams from a plurality of oscillators;   making the plurality of laser beams proximate to one another by a fiber array;   irradiating a semiconductor film with a laser beam passed through the fiber array in order to increase crystallinity of the semiconductor film while moving a laser-light irradiation position relative to the semiconductor film in a first direction;   moving the laser-light irradiation position relative to the semiconductor film in a second direction perpendicular to the first direction by a distance equal to or smaller than a length of the laser beam in the second direction;   irradiating the semiconductor film with the laser beam while moving the laser-light irradiation position relative to the semiconductor film in a third direction parallel and opposite to the first direction after moving the laser-light irradiation position relative to the semiconductor film in the second direction; and then   moving the laser-light irradiation position relative to the semiconductor film in the second direction by a distance equal to or smaller than the length of the laser beam in the second direction.   
   
   
       11 . The method of manufacturing a semiconductor device according to  claim 10 , wherein the steps of irradiating the semiconductor film with the laser beam while moving the laser-light irradiation position relative to the semiconductor film in the first direction, moving the laser-light irradiation position relative to the semiconductor film in the second direction, irradiating the semiconductor film with the laser beam while moving the laser-light irradiation position relative to the semiconductor film in the third direction, and moving the laser-light irradiation position relative to the semiconductor film in the second direction are continuously repeated. 
   
   
       12 . The method of manufacturing a semiconductor device according to  claim 10 , further comprising modulating the plurality of laser beams by a plurality of nonlinear optical elements after emitting the plurality of laser beams from the plurality of oscillators. 
   
   
       13 . The method of manufacturing a semiconductor device according to  claim 10 , wherein the semiconductor film is irradiated with the laser beam aslant to the semiconductor film. 
   
   
       14 . The method of manufacturing a semiconductor device according to  claim 10 , wherein the semiconductor film is crystallized by the irradiation of the laser beam. 
   
   
       15 . The of manufacturing a semiconductor device according to  claim 10 , wherein the plurality of laser beams is condensed by a waveguide. 
   
   
       16 . The method of manufacturing a semiconductor device according to  claim 10 , wherein each of the plurality of oscillators is one selected from a group consisting of a Nd:
 YAG laser, an Nd: YLF laser, an Nd: YVO 4  laser and an Nd: YAlO 3  laser.   
   
   
       17 . The method of manufacturing a semiconductor device according to  claim 10 , wherein each of the plurality of laser beams is a CW laser beam. 
   
   
       18 . The method of manufacturing a semiconductor device according to  claim 10 , wherein each of the plurality of laser beams is a pulsed laser beam. 
   
   
       19 . A method of manufacturing a semiconductor device comprising:
 forming a semiconductor film over a substrate having an insulating surface;   emitting a plurality of laser beams from a plurality of oscillators;   making the plurality of laser beams proximate to one another by a fiber array;   irradiating the semiconductor film with a laser beam passed through the fiber array in order to increase crystallinity of the semiconductor film while moving a laser-light irradiation position relative to the semiconductor film in a first direction;   moving the laser-light irradiation position relative to the semiconductor film in a second direction perpendicular to the first direction by a distance equal to or smaller than a length of the laser beam in the second direction;   irradiating the semiconductor film with the laser beam while moving the laser-light irradiation position relative to the semiconductor film in a third direction parallel and opposite to the first direction after moving the laser-light irradiation position relative to the semiconductor film in the second direction; and then   moving the laser-light irradiation position relative to the semiconductor film in the second direction by a distance equal to or smaller than the length of the laser beam in the second direction.   
   
   
       20 . The method of manufacturing a semiconductor device according to  claim 19 , wherein the steps of irradiating the semiconductor film with the laser beam while moving the laser-light irradiation position relative to the semiconductor film in the first direction, moving the laser-light irradiation position relative to the semiconductor film in the second direction, irradiating the semiconductor film with the laser beam while moving the laser-light irradiation position relative to the semiconductor film in the third direction, and moving the laser-light irradiation position relative to the semiconductor film in the second direction are continuously repeated. 
   
   
       21 . The method of manufacturing a semiconductor device according to  claim 19 , further comprising modulating the plurality of laser beams by a plurality of nonlinear optical elements after emitting the plurality of laser beams from the plurality of oscillators. 
   
   
       22 . The method of manufacturing a semiconductor device according to  claim 19 , wherein the semiconductor film is irradiated with the laser beam aslant to the semiconductor film. 
   
   
       23 . The method of manufacturing a semiconductor device according to  claim 19 , wherein the semiconductor film is crystallized by the irradiation of the laser beam. 
   
   
       24 . The method of manufacturing a semiconductor device according to  claim 19 , wherein the plurality of laser beams is condensed by a waveguide. 
   
   
       25 . The method of manufacturing a semiconductor device according to  claim 19 , wherein each of the plurality of oscillators is one selected from a group consisting of a Nd: YAG laser, an Nd: YLF laser, an Nd: YVO 4  laser and an Nd: YAlO 3  laser. 
   
   
       26 . The method of manufacturing a semiconductor device according to  claim 19 , wherein each of the plurality of laser beams is a CW laser beam. 
   
   
       27 . The method of manufacturing a semiconductor device according to  claim 19 , wherein each of the plurality of laser beams is a pulsed laser beam. 
   
   
       28 . A method of manufacturing a semiconductor device comprising:
 emitting a plurality of laser beams from a plurality of oscillators;   making the plurality of laser beams proximate to one another by a fiber array;   irradiating a semiconductor film with a laser beam passed through the fiber array in order to increase crystallinity of the semiconductor film while moving a laser-light irradiation position relative to the semiconductor film in a first direction;   moving the laser-light irradiation position relative to the semiconductor film in a second direction perpendicular to the first direction by a distance equal to or smaller than a length of the laser beam in the second direction;   irradiating the semiconductor film with the laser beam while moving the laser-light irradiation position relative to the semiconductor film in a third direction parallel and opposite to the first direction after moving the laser-light irradiation position relative to the semiconductor film in the second direction; and then   moving the laser-light irradiation position relative to the semiconductor film in the second direction by a distance equal to or smaller than the length of the laser beam in the second direction,   wherein the laser-light irradiation position relative to the semiconductor film is moved while being accelerated before irradiating with the laser beam, and is moved at a constant rate during the irradiation, and is moved while being decelerated during the laser-light irradiation position relative to the semiconductor film being outside of the semiconductor film.   
   
   
       29 . The method of manufacturing a semiconductor device according to  claim 28 , wherein the steps of irradiating the semiconductor film with the laser beam while moving the laser-light irradiation position relative to the semiconductor film in the first direction, moving the laser-light irradiation position relative to the semiconductor film in the second direction, irradiating the semiconductor film with the laser beam while moving the laser-light irradiation position relative to the semiconductor film in the third direction, and moving the laser-light irradiation position relative to the semiconductor film in the second direction are continuously repeated. 
   
   
       30 . The method of manufacturing a semiconductor device according to  claim 28 , further comprising modulating the plurality of laser beams by a plurality of nonlinear optical elements after emitting the plurality of laser beams from the plurality of oscillators. 
   
   
       31 . The method of manufacturing a semiconductor device according to  claim 28 , wherein the semiconductor film is irradiated with the laser beam aslant to the semiconductor film. 
   
   
       32 . The method of manufacturing a semiconductor device according to  claim 28 , wherein the semiconductor film is crystallized by the irradiation of the laser beam. 
   
   
       33 . The method of manufacturing a semiconductor device according to  claim 28 , wherein the plurality of laser beams is condensed by a waveguide. 
   
   
       34 . The method of manufacturing a semiconductor device according to  claim 28 , wherein each of the plurality of oscillators is one selected from a group consisting of a Nd: YAG laser, an Nd: YLF laser, an Nd: YVO 4  laser and an Nd: YAlO 3  laser. 
   
   
       35 . The method of manufacturing a semiconductor device according to  claim 28 , wherein each of the plurality of laser beams is a CW laser beam. 
   
   
       36 . The method of manufacturing a semiconductor device according to  claim 28 , wherein each of the plurality of laser beams is a pulsed laser beam.