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US 7,479,420 B2Granted
Laser optical apparatus
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorKoichiro Tanaka
Life of this patent
Estimating the term…
Abstract
There is provided a structure for reducing optical loss in an optical apparatus (homogenizer) for making the intensity distribution of a laser beam uniform. In a multi-cylindrical lens (a glass substrate having a multiplicity of cylindrical lenses formed thereon) used in a homogenizer, convex cylindrical lenses and concave cylindrical lenses are arranged alternately, and the boundaries between the cylindrical lenses have a smooth structure. This makes it possible to reduce scattering of beams that has occurred at the boundaries between the cylindrical lenses.
Claims25
A method for manufacturing a semiconductor device, comprising:
- forming a semiconductor film comprising an amorphous silicon over a substrate;
- emitting a laser beam from a laser oscillator;
- converting the laser beam into an uniform laser beam having a distributed energy density by using a laser system;
- and
- crystallizing the semiconductor film by irradiating the uniform laser beam, the laser system comprising:
- a homogenizer provided between the laser oscillator and the semiconductor film, the homogenizer comprising at least one multi-cylindrical lens,
- wherein the at least one multi-cylindrical lens comprises a plurality of convex cylindrical lenses and concave cylindrical lenses arranged alternately,
- wherein a convex surface of one of the convex cylindrical lenses and a concave surface of one of the concave cylindrical lenses adjacent to each other are smoothly continuous without having an angle therebetween.
5 more elements
A method for manufacturing a semiconductor device, comprising:
- forming a semiconductor film comprising an amorphous silicon over a substrate;
- emitting a laser beam from a laser oscillator;
- converting the laser beam into an uniform laser beam having a distributed energy density by using a laser system;
- and
- crystallizing the semiconductor film by irradiating the uniform laser beam, the laser system comprising:
- a homogenizer provided between the laser oscillator and the semiconductor film, the homogenizer comprising at least one multi-cylindrical lens;
- and
- a beam expander provided between the laser oscillator and the homogenizer, the beam expander comprising at least one lens,
- wherein the at least one multi-cylindrical lens comprises a plurality of convex cylindrical lenses and concave cylindrical lenses arranged alternately,
- wherein a convex surface of one of the convex cylindrical lenses and a concave surface of one of the concave cylindrical lenses adjacent to each other are smoothly continuous without having an angle therebetween, and
- wherein the at least one lens has a concave surface opposed to the laser oscillator.
8 more elements
A method for manufacturing a semiconductor device, comprising:
- forming a semiconductor film comprising an amorphous silicon over a substrate;
- emitting a laser beam from a laser oscillator;
- converting the laser beam into an uniform laser beam having a distributed energy density by using a laser system;
- and
- crystallizing the semiconductor film by irradiating the uniform laser beam, the laser system comprising:
- a homogenizer provided between the laser oscillator and the semiconductor film, the homogenizer comprising at least one multi-cylindrical lens;
- and
- a beam expander provided between the laser oscillator and the homogenizer, the beam expander comprising at least one lens,
- wherein the at least one multi-cylindrical lens comprises a plurality of convex cylindrical lenses and concave cylindrical lenses arranged alternately,
- wherein a convex surface of one of the convex cylindrical lenses and a concave surface of one of the concave cylindrical lenses adjacent to each other are smoothly continuous without having an angle therebetween, and
- wherein the at least one lens has a convex surface opposed to the homogenizer.
8 more elements
A method for manufacturing a semiconductor device, comprising:
- forming a semiconductor film comprising an amorphous silicon over a substrate;
- emitting a laser beam from a laser oscillator;
- converting the laser beam into an uniform laser beam having a distributed energy density by using a laser system;
- and
- crystallizing the semiconductor film by irradiating the uniform laser beam, the laser system comprising:
- a converging lens provided between the laser oscillator and the semiconductor film;
- and
- a homogenizer provided between the laser oscillator and the converging lens, the homogenizer comprising at least one multi-cylindrical lens,
- wherein the at least one multi-cylindrical lens comprises a plurality of convex cylindrical lenses and concave cylindrical lenses arranged alternately, and
- wherein a convex surface of one of the convex cylindrical lenses and a concave surface of one of the concave cylindrical lenses adjacent to each other are smoothly continuous without having an angle therebetween.
7 more elements
A method for manufacturing a semiconductor device, comprising:
- forming a semiconductor film comprising an amorphous silicon over a substrate;
- emitting a laser beam from a laser oscillator;
- converting the laser beam into an uniform laser beam having a distributed energy density by using a laser system;
- and
- crystallizing the semiconductor film by irradiating the uniform laser beam, the laser system comprising:
- a converging lens provided between the laser oscillator and the semiconductor film;
- a beam expander provided between the laser oscillator and the converging lens, the beam expander comprising at least one lens,
- a homogenizer provided between the beam expander and the converging lens, the homogenizer comprising at least one multi-cylindrical lens,
- wherein the at least one multi-cylindrical lens comprises a plurality of convex cylindrical lenses and concave cylindrical lenses arranged alternately, and
- wherein a convex surface of one of the convex cylindrical lenses and a concave surface of one of the concave cylindrical lenses adjacent to each other are smoothly continuous without having an angle therebetween.
7 more elements
Dependencies are inferred from the claim text.