Laser annealing method and device

Abstract

A laser annealing method for executing laser annealing by irradiating a semiconductor film formed on a surface of a substrate with a laser beam, the method including the steps of, generating a linearly polarized rectangular laser beam whose cross section perpendicular to an advancing direction is a rectangle with an electric field directed toward a long-side direction of the rectangle or an elliptically polarized rectangular laser beam having a major axis directed toward a long-side direction, causing the rectangular laser beam to be introduced to the surface of the substrate, and setting a wavelength of the rectangular laser beam to a length which is about a desired size of a crystal grain in a standing wave direction.

1 . (canceled) 
     
     
         2 . A method of manufacturing a semiconductor device comprising:
 controlling a first laser oscillator and a second laser oscillator by a pulse controller;   combining a first laser beam from the first laser oscillator and a second laser beam from the second laser oscillator to form a combined laser beam;   adjusting a shape of the combined laser beam by an optical system to form an adjusted combined laser beam; and   irradiating a semiconductor film with the adjusted combined laser beam to increase crystallinity of the semiconductor film.   
     
     
         3 . The method of manufacturing a semiconductor device according  claim 2 , wherein a step of adjusting the shape of the combined laser beam is performed by adjusting a width of the combined laser beam. 
     
     
         4 . The method of manufacturing a semiconductor device according  claim 2 , wherein the semiconductor film is included in a transistor and includes a channel portion. 
     
     
         5 . The method of manufacturing a semiconductor device according  claim 2 ,
 wherein the first laser oscillator and the second laser oscillator is controlled by the pulse controller so as to make output timings of the first laser beam and the second laser beam different.   
     
     
         6 . The method of manufacturing a semiconductor device according  claim 2 ,
 wherein the semiconductor film irradiated with the combined laser beam includes a first crystal grain and a second crystal grain adjacent to the first crystal grain,   wherein a length of the first crystal grain in a first direction is greater than a length of the first crystal grain in a second direction,   wherein a length of the second crystal grain in the first direction is greater than a length of the second crystal grain in the second direction, and   wherein a grain boundary between the first crystal grain and the second crystal grain extends in the first direction.   
     
     
         7 . The method of manufacturing a semiconductor device according  claim 2 , wherein an energy density of the adjusted combined laser beam is greater than 500 mJ/cm 2 . 
     
     
         8 . A method of manufacturing a semiconductor device comprising:
 controlling a first laser oscillator and a second laser oscillator by a pulse controller;   combining a first laser beam from the first laser oscillator and a second laser beam from the second laser oscillator to form a combined laser beam;   adjusting a shape of the combined laser beam by an optical system to form an adjusted combined laser beam; and   irradiating a semiconductor film over a substrate with the adjusted combined laser beam to increase crystallinity of the semiconductor film, wherein an advancing direction of the adjusted combined laser beam is not perpendicular to a surface of the substrate.   
     
     
         9 . The method of manufacturing a semiconductor device according  claim 8 , wherein a step of adjusting the shape of the combined laser beam is performed by adjusting a width of the combined laser beam. 
     
     
         10 . The method of manufacturing a semiconductor device according  claim 8 , wherein the semiconductor film is included in a transistor and includes a channel portion. 
     
     
         11 . The method of manufacturing a semiconductor device according  claim 8 , wherein the first laser oscillator and the second laser oscillator is controlled by the pulse controller so as to make output timings of the first laser beam and the second laser beam different. 
     
     
         12 . The method of manufacturing a semiconductor device according  claim 8 ,
 wherein the semiconductor film irradiated with the combined laser beam includes a first crystal grain and a second crystal grain adjacent to the first crystal grain,   wherein a length of the first crystal grain in a first direction is greater than a length of the first crystal grain in a second direction,   wherein a length of the second crystal grain in the first direction is greater than a length of the second crystal grain in the second direction, and   wherein a grain boundary between the first crystal grain and the second crystal grain extends in the first direction.   
     
     
         13 . The method of manufacturing a semiconductor device according  claim 8 , wherein an energy density of the adjusted combined laser beam is greater than 500 mJ/cm 2 . 
     
     
         14 . A method of manufacturing a semiconductor device comprising:
 polarizing a first laser beam from a first laser oscillator to form a first polarized laser beam polarized in a first direction;   polarizing a second laser beam from a second laser oscillator to form a second polarized laser beam polarized in a second direction;   combining the first polarized laser beam and the second polarized laser beam to form a combined laser beam whose polarization direction is alternately changed between the first direction and the second direction;   adjusting a shape of the combined laser beam by an optical system to form an adjusted combined laser beam; and   irradiating a semiconductor film with the adjusted combined laser beam to increase crystallinity of the semiconductor film.   
     
     
         15 . The method of manufacturing a semiconductor device according  claim 14 , wherein a step of adjusting the shape of the combined laser beam is performed by adjusting a width of the combined laser beam. 
     
     
         16 . The method of manufacturing a semiconductor device according  claim 14 , wherein the semiconductor film is included in a transistor and includes a channel portion. 
     
     
         17 . The method of manufacturing a semiconductor device according  claim 14 , wherein the first laser oscillator and the second laser oscillator is controlled by a pulse controller so as to make output timings of the first laser beam and the second laser beam different. 
     
     
         18 . The method of manufacturing a semiconductor device according  claim 14 , wherein the semiconductor film irradiated with the combined laser beam includes a first crystal grain and a second crystal grain adjacent to the first crystal grain,
 wherein a length of the first crystal grain in a third direction is greater than a length of the first crystal grain in a fourth direction,   wherein a length of the second crystal grain in the third direction is greater than a length of the second crystal grain in the fourth direction, and   wherein a grain boundary between the first crystal grain and the second crystal grain extends in the third direction.   
     
     
         19 . The method of manufacturing a semiconductor device according  claim 14 , wherein an energy density of the adjusted combined laser beam is greater than 500 mJ/cm 2 . 
     
     
         20 . The method of manufacturing a semiconductor device according  claim 14 , further comprising:
 generating a rectangular laser beam from the combined laser beam,   wherein the first direction is a long-side direction of the rectangular laser beam, and   wherein the second direction is a short-side direction of the rectangular laser beam.   
     
     
         21 . The method of manufacturing a semiconductor device according  claim 14 , further comprising:
 generating a rectangular laser beam from the combined laser beam,   wherein the first direction is tilted by 45 degrees from a long-side direction of the rectangular laser beam and a short side direction of the rectangular laser beam, and   wherein the second direction is tilted by 45 degrees from the long-side direction of the rectangular laser beam and the short side direction of the rectangular laser beam.