Laser illumination system
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsShunpei Yamazaki, Koichiro Tanaka
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Abstract
The illumination energy of an excimer laser is measured and adjusted to always effect illumination at constant energy. A laser beam output from an optics is reflected by a mirror, and applied to a sample. A beam profiler is disposed behind the mirror to measure the energy of an illumination laser beam. An energy attenuating device disposed between another mirror and the optics is operated based on the measurement value so that the energy of the laser beam applied to the sample is kept constant.
Claims24
A method for forming a thin film transistor comprising:
- forming a semiconductor film comprising silicon over a substrate;
- irradiating a laser light to said semiconductor film;
- and
- receiving at least a portion of said laser light by an energy measuring device to measure at least a portion of an energy distribution of said laser light thereby.
A method for forming a thin film transistor comprising:
- forming a semiconductor film comprising silicon over a substrate;
- irradiating a laser light to said semiconductor film while relatively scanning said semiconductor film with said laser light in order that an energy measuring device measures an energy distribution of at least a portion of said laser light.
A method for forming a thin film transistor comprising:
- forming a semiconductor film comprising silicon over a substrate;
- producing a laser light from a laser;
- attenuating said laser light by an energy attenuating device provided separately from said laser;
- and
- irradiating the attenuated laser light to said semiconductor film.
A method for forming a thin film transistor comprising:
- forming a semiconductor film comprising silicon over a substrate;
- producing a laser light from a laser;
- attenuating said laser light by changing a variable energy attenuation factor of said laser light by an energy attenuating device provided separately from said laser;
- and
- irradiating the attenuated laser light to said semiconductor film.
A method for forming a thin film transistor comprising:
- forming a semiconductor film comprising silicon over a substrate;
- producing a laser light from a laser;
- directing said laser light to an energy attenuation filter of an energy attenuating device;
- changing an energy attenuation factor of a portion of said laser light by changing an angle formed by said energy attenuation filter and said laser light to output an attenuated laser light;
- and
- irradiating the attenuated laser light to said semiconductor film.
A method for forming a thin film transistor comprising:
- forming a semiconductor film comprising silicon over a substrate;
- producing at least one shot laser light from a laser;
- measuring energy distribution of said at least one shot laser light by an energy measuring device to conduct control of said energy distribution;
- and
- irradiating said laser light to said semiconductor film with said energy distribution of said laser light determined by said control.
A method for forming a thin film transistor comprising:
- forming a semiconductor film comprising silicon over a substrate;
- producing a laser light from a laser;
- splitting said laser light into a first portion and a second portion;
- irradiating said first portion to said semiconductor film;
- and
- directing said second portion to an energy measuring device which measures an energy distribution of said second portion to determine an energy distribution of said first portion.
Dependencies are inferred from the claim text.