Laser light irradiation apparatus and laser light irradiation method

A laser light irradiation apparatus comprising:

• a laser;
• a beam expander optical system which laser light oscillated from the laser enters;
• and
• a cylindrical lens disposed between the laser and the beam expander optical system, wherein
• the beam expander optical system includes a first convex lens, and
• when an emission point of the laser is a first conjugate point, a point at which an image at the first conjugate point is formed through the cylindrical lens is a second conjugate point, a distance between the cylindrical lens and the second conjugate point is b, a focal length of the first convex lens is f, and a distance between the cylindrical lens and the first convex lens is X, the X satisfies b−|f|≦X≦b+3|f|.

A laser light irradiation method comprising the steps of:

• emitting laser light from a laser;
• and
• making the laser light enter a beam expander optical system including a concave lens through a cylindrical lens, wherein
• the laser, the cylindrical lens and the concave lens are disposed so that, when an emission point of the laser is a first conjugate point, a point at which an image at the first conjugate point is formed through the cylindrical Tens is a second conjugate point, a distance between the cylindrical lens and the second conjugate point is b, a focal length of the concave lens is f, and a distance between the cylindrical lens and the concave lens is X, the X satisfies b−3|f|≦X≦b+|f|.

A laser light irradiation method comprising the steps of;

• emitting laser light from a laser;
• and
• making the laser light enter a beam expander optical system including a first convex lens through a cylindrical lens, wherein
• the laser, the cylindrical lens and the first convex lens are disposed so that, when an emission point of the laser is a first conjugate point, a point at which an image at the first conjugate point is formed through the cylindrical lens is a second conjugate point, a distance between the cylindrical lens and the second conjugate point is b, a focal length of the first convex lens is f, and a distance between the cylindrical lens and the first convex lens is X, the X satisfies b−|f|≦X≦b+3|f|.

A method for manufacturing a semiconductor device, comprising the steps of:

• forming a semiconductor film over a substrate;
• and
• irradiating the semiconductor film with laser light, wherein
• the laser light is emitted from a laser and passes through a cylindrical lens and a beam expander optical system including a concave lens which are provided in order in a traveling direction of the laser light, and
• the laser, the cylindrical lens and the concave lens are disposed so that, when an emission point of the laser is a first conjugate point, a point at which an image at the first conjugate point is formed through the cylindrical lens is a second conjugate point, a distance between the cylindrical lens and the second conjugate point is b, a focal length of the concave lens is 1, and a distance between the cylindrical lens and the concave lens is X, the X satisfies b−3|f|≦X≦b+|f|.

A method for manufacturing a semiconductor device, comprising the steps of:

• forming a semiconductor film over a substrate;
• and
• irradiating the semiconductor film with laser light, wherein
• the laser light is emitted from a laser and passes through a cylindrical lens and a beam expander optical system including a first convex lens which are provided in order in a traveling direction of the laser light, and
• the laser, the cylindrical lens and the first convex lens are disposed so that, when an emission point of the laser is a first conjugate point, a point at which an image at the first conjugate point is formed through the cylindrical lens is a second conjugate point, a distance between the cylindrical lens and the second conjugate point is b, a focal length of the first convex lens is f, and a distance between the cylindrical lens and the first convex lens is X, the X satisfies b−|f|≦X≦b+3|f|.