JP5147220B2 - Method for manufacturing polycrystalline semiconductor film - Google Patents

Description

  The present invention relates to a laser annealing method and apparatus for modifying and crystallizing a semiconductor thin film formed on a substrate in the field of manufacturing liquid crystal and semiconductor devices.

  When a thin film transistor (hereinafter referred to as TFT: Thin Film Transistor) is formed on a substrate in manufacturing a liquid crystal or a semiconductor device, if an amorphous semiconductor film such as an amorphous silicon film is used as a semiconductor layer on which the TFT is formed, a carrier Because of the low mobility, high speed operation is not possible. For this reason, it is usually necessary to crystallize an amorphous semiconductor film and modify it to a polycrystalline semiconductor film (for example, a polycrystalline silicon film).

  A laser annealing apparatus is known as means for modifying an amorphous semiconductor film into a polycrystalline semiconductor film, and has already been disclosed in Patent Documents 1 and 2, for example.

The “laser processing method of a semiconductor device” in Patent Document 1 describes that thin film transistors arranged in a peripheral circuit region and a pixel region are separately formed according to necessary characteristics when annealing a semiconductor to be a liquid crystal display device. It is aimed.
As the means, in the invention of Patent Document 1, in the annealing process by laser light irradiation to the semiconductor thin film, laser light is selectively irradiated partially using a mask. For example, in manufacturing an active matrix liquid crystal display device, a laser beam is emitted at a required irradiation energy density using a mask to irradiate a peripheral circuit region and a pixel region with laser light under different conditions To obtain a crystalline silicon film selectively having the required crystallinity.

The “laser irradiation apparatus and method, and laser annealing apparatus and method” of Patent Document 2 can irradiate laser beams having the same polarization direction even when laser beams emitted from a plurality of laser oscillators are combined. Accordingly, it is an object to obtain isotropic crystal grains when applied to laser annealing of an amorphous semiconductor, and to improve the processing efficiency and productivity.
As the means, the laser irradiation apparatus of Patent Document 2 includes a plurality of laser oscillators that emit pulsed laser light, a pulse control unit that outputs a control signal to each of the pulse timings of the plurality of laser oscillators, and a plurality of laser oscillators. A polarization beam splitter that synthesizes the laser beam on the coaxial optical path, and a polarization direction that is different from the polarization direction to be aligned among the mutually orthogonal polarization components in the incident laser light that is arranged on the optical path of the synthesized laser light. And a polarization conversion optical system that aligns the polarization direction of the laser light applied to the irradiated object.

JP-A-8-227855, “Laser processing method of semiconductor device” JP 2006-253571 A, “Laser irradiation apparatus and method, and laser annealing apparatus and method”

Patent Document 1 described above proposes a method of manufacturing a transistor in a peripheral circuit portion in the same glass substrate in addition to a transistor in a pixel portion in a liquid crystal and an organic display.
In general, the transistor in the pixel portion needs to have uniform electrical characteristics, and it is necessary to improve the uniformity of the crystal grain size. On the other hand, high mobility is required for the transistor in the peripheral circuit portion, and the crystal grain size needs to be increased.

In order to achieve the above object, Patent Document 1 proposes means for irradiating the peripheral circuit portion and the pixel portion with laser with different energy, and means for adding a metal element.
However, in order to irradiate laser with different energy, a mask may be necessary, and the addition of a metal element has a problem of complicating the process and the apparatus.

  The present invention has been made in view of the above-described problems. That is, an object of the present invention is to make electrical characteristics uniform in a single glass substrate having an amorphous semiconductor film such as an amorphous silicon film, without using a mask and without complicating processes and apparatuses. An object of the present invention is to provide a laser annealing method and apparatus capable of increasing the crystal grain size in order to improve the uniformity of the crystal grain size in the pixel portion and achieve high mobility of the transistors in the peripheral circuit portion.

According to the present invention, there is provided a laser annealing method for crystallizing an amorphous semiconductor film formed on a glass substrate for liquid crystal and organic display devices by laser light irradiation,
A polarized pulse laser beam is converted into two or more types of rectangular polarized beams having a rectangular cross section that is short in the scanning direction on the glass substrate and long in the orthogonal direction, and having different polarization states, and a peripheral circuit unit and a pixel unit on the glass substrate And irradiating the rectangular polarized beam in different polarization states.

  According to a preferred embodiment of the present invention, the peripheral circuit unit is irradiated with a polarized pulsed laser beam having an electric field oriented in the long side direction of the rectangular polarized beam, and the energy gradient of the polarized pulsed laser beam is applied in the short side direction. Increase the crystal grain.

  In addition, the pixel portion is irradiated with polarized pulsed laser light in a polarization state in which the electric field is directed to the short side direction of the rectangular polarized beam, and the standing wave generated in the short side direction suppresses the elongation of the crystal grains in the short side direction. Then, uniform crystal grains are grown.

  In addition, the pixel unit is alternately irradiated with a polarized pulsed laser beam in a polarization state in which the electric field is directed in the long side direction of the rectangular polarized beam and a polarized pulsed laser beam in the polarization state in which the electric field is directed in the short side direction of the rectangular polarized beam. However, the standing waves generated in the long-side direction and the short-side direction may make the crystal grains uniform in the long-side direction and suppress the elongation of the crystal grains in the short-side direction, thereby growing uniform crystal grains. .

According to the present invention, there is also provided a laser annealing apparatus for crystallizing an amorphous semiconductor film formed on a glass substrate for liquid crystal and organic display devices by laser light irradiation,
A laser emitting device for periodically emitting polarized pulsed laser light;
A polarization conversion optical system capable of converting the polarized pulsed laser light from the laser emitting device into a polarization state in which an electric field is directed in a direction orthogonal to a scanning direction on a glass substrate and a polarization state in which an electric field is directed in the scanning direction;
A shape conversion optical system that converts the polarized pulsed laser light from the polarization conversion optical system into a rectangular polarization beam having a rectangular cross section that is short in the scanning direction on the glass substrate and long in the orthogonal direction;
There is provided a laser annealing apparatus characterized in that a rectangular polarized beam is irradiated in different polarization states between a peripheral circuit portion and a pixel portion on a glass substrate.

According to a preferred embodiment of the present invention, the laser emitting device is a single laser resonator that periodically emits polarized pulsed laser light,
The polarization conversion optical system includes a half-wave plate disposed on the optical path between the laser resonator and the shape conversion optical system, and a drive unit that rotates the half-wave plate about the optical axis. .

According to another preferred embodiment, the laser emitting device controls each of the plurality of laser resonators that periodically emit polarized pulsed laser light and the pulse timings of the plurality of laser resonators to be shifted from each other. It consists of a pulse controller that outputs signals,
The polarization conversion optical system includes a polarization beam splitter that synthesizes a plurality of laser beams on a coaxial optical path, a half-wave plate disposed on the optical path between the polarization beam splitter and the shape conversion optical system, and the 1 / It comprises a drive unit that rotates the two-wavelength plate around the optical axis.

The shape conversion optical system includes a beam expander that converts a laser beam having a circular cross section into a rectangular polarized beam having a rectangular cross section that is short in the scanning direction on the glass substrate and long in the orthogonal direction.
A pair of cylindrical lens arrays for condensing the rectangular polarized beam in the short side direction and having a variable focal length;
It is preferable that the rectangular polarized beam that has passed through the cylindrical lens array is composed of a condenser lens that collects the light on a glass substrate.

  According to the above-described method and apparatus of the present invention, the polarized pulsed laser beam is short in the scanning direction on the glass substrate and in the orthogonal direction on the amorphous semiconductor film formed on the glass substrate for liquid crystal and organic display devices. Since it converts into two or more kinds of rectangular polarized beams having a long rectangular cross section and different polarization states, the peripheral circuit portion and the pixel portion on the glass substrate are irradiated with the rectangular polarized beams in different polarization states. Different crystallization can be performed due to the difference in polarization state between the pixel portion and the pixel portion.

  According to a preferred embodiment of the present invention, the peripheral circuit unit is irradiated with a polarized pulsed laser beam having a polarization state in which the electric field is directed in the long side direction of the rectangular polarized beam, whereby the energy gradient of the polarized pulsed laser beam causes a short side direction. The crystal grains can be increased.

  The reason why the crystal grains extend in the short side direction when the electric field faces in the long side direction is that there is an energy distribution that the laser originally has in the short side direction. That is, if it is a solid-state laser, the energy profile is close to a Gaussian shape.

  Further, by irradiating the pixel portion with polarized pulsed laser light in a polarization state in which the electric field is directed to the short side direction of the rectangular polarized beam, the standing wave generated in the short side direction causes the crystal grains to extend in the short side direction. It is possible to suppress and grow uniform crystal grains.

  This characteristic is also due to the fact that a standing wave is generated on the semiconductor film in the direction of the short side, which is the polarization direction, and a temperature gradient corresponding to the periodic energy of the standing wave is generated. That is, crystal nuclei are generated at the positions of the periodic energy valleys, and each crystal nucleus grows in a higher temperature direction, and a portion where the crystal nuclei collide with each other becomes a crystal grain boundary. However, since the irradiation range in the short side direction is narrow and the temperature change is large, the growth of crystal grains in the short side direction is suppressed by this temperature distribution. Therefore, crystal growth in both the long side direction and the short side direction is restricted, and uniform crystal grains can be grown as a whole.

  In addition, the pixel unit is alternately irradiated with a polarized pulsed laser beam in a polarization state in which the electric field is directed in the long side direction of the rectangular polarized beam and a polarized pulsed laser beam in the polarization state in which the electric field is directed in the short side direction of the rectangular polarized beam. By using standing waves generated in the long side direction and the short side direction, the crystal grains are elongated in the long side direction and the elongation of the crystal grains in the short side direction is suppressed, and uniform crystal grains can be grown. it can.

  This characteristic is due to the fact that standing waves are alternately generated in the long-side direction and the short-side direction, which are polarization directions, on the semiconductor film, and a temperature gradient corresponding to the periodic energy of the standing wave is generated. That is, crystal nuclei are generated at the positions of the periodic energy valleys, and each crystal nucleus grows in a higher temperature direction, and a portion where the crystal nuclei collide with each other becomes a crystal grain boundary. Therefore, crystal nuclei generated at periodic positions grow under the influence of the same temperature gradient in the long-side direction and the short-side direction, so that many nuclei consisting of crystal grains having uniform dimensions in the long-side direction and the short-side direction are formed. A crystalline semiconductor film can be formed.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a top view of a glass substrate 1 for a liquid crystal and organic display device which is a processing target of the present invention. An amorphous semiconductor film such as an amorphous silicon film is uniformly formed on the entire surface of the substrate as a semiconductor layer. On the glass substrate 1, a rectangular pixel portion 2 for displaying an image and an “L” -shaped peripheral circuit portion 3 for driving the pixel are provided in a later process.

The laser annealing apparatus of the present invention is an apparatus for crystallizing an amorphous semiconductor film formed on the glass substrate 1 of FIG. 1 by laser light irradiation. As this laser light, a rectangular polarized beam 9 having a rectangular cross section which is short in the scanning direction 4 on the glass substrate and long in the orthogonal direction is used.
As shown in this figure, the scanning direction 4 may be scanned in the longitudinal direction of the substrate or in the lateral direction.

FIG. 2 is a diagram showing a first embodiment of a laser annealing apparatus according to the present invention.
In this figure, the laser annealing apparatus of the present invention includes a laser emitting device 10, a polarization conversion optical system 20, and a shape conversion optical system 30.

The laser emitting device 10 is a device that periodically emits the polarized pulsed laser light 5a, and is a single laser resonator 12 in this example.
The polarization direction of the polarized pulsed laser beam 5a is a polarization state 6 in which the electric field is directed in a direction orthogonal to the scanning direction 4 on the glass substrate (a direction parallel to the paper surface in this figure), and a scanning direction 4 (perpendicular to the paper surface in this figure). The polarization state 7 in which the electric field is directed in the direction of
In this figure, the polarization state 6 is indicated by a vertical arrow, and the polarization state 7 is indicated by a double circle.
In FIG. 1, the polarization state 6 is a polarization state in which the electric field is directed to the long side direction of the rectangular polarized beam 9, and the polarization state 7 is a polarization state in which the electric field is directed to the short side direction of the rectangular polarized beam 9.

The polarization conversion optical system 20 has a function of alternately converting the polarized pulsed laser light 5 a from the laser resonator 12 into a polarization state 6 and a polarization state 7.
In this example, the polarization conversion optical system 20 is a half-wave plate 22 disposed on the optical path between the laser resonator 12 and the shape conversion optical system 30, and the half-wave plate 22 is rotated about the optical axis. Alternatively, the driving unit 24 is configured to swing.
With this configuration, by rotating or swinging the half-wave plate 22 by the drive unit 24, the polarization pulse laser beam 5 a that passes through the half-wave plate 22 is changed into the polarization state 6 and the polarization state every 45 degrees. The state 7 can be alternately converted. Therefore, by stopping the half-wave plate 22 at either position, the passed polarized pulsed laser beam 5b can always be converted into the polarization state 6 or the polarization state 7.

  The shape conversion optical system 30 has a function of converting the polarized pulsed laser light 5b that has passed through the polarization conversion optical system 20 into a rectangular polarization beam 9 having a rectangular cross section that is short in the scanning direction on the glass substrate and long in the orthogonal direction.

  In this example, the shape conversion optical system 30 includes a beam expander 32, a pair of cylindrical lens arrays 34, and a condenser lens 36.

In this example, the beam expander 32 includes an aspherical concave lens 32a and a convex lens 32b. The circular pulsed polarized laser beam 5b is converted into a rectangular polarized beam 8a having a rectangular cross section that is short in the scanning direction 4 on the glass substrate and long in the orthogonal direction. Convert. The rectangular polarized beam 8a is preferably parallel light.
The beam expander 32 may be an optical system having a configuration other than that described above.

  The pair of cylindrical lens arrays 34 includes an upstream side cylindrical lens array 34a and a downstream side cylindrical lens array 34b, and the interval Δ can be changed by an actuator (not shown). By changing the interval Δ, the focal length of the pair of cylindrical lens arrays 34 can be changed, and the length of the rectangular polarized beam 8b in the long side direction can be changed.

That is, if the focal lengths of the upstream cylindrical lens array 34a and the downstream cylindrical lens array 34b are f ₁ and f ₂ , respectively, the focal length f of the pair of cylindrical lens arrays 34 can be expressed by Expression (1). .

1 / f = 1 / f ₁ + 1 / f ₂ −Δ / (f ₁ · f ₂ ) (1)

From this equation (1), it is possible to change the focal length f by changing Δ. As a result, the condensing angle in the direction orthogonal to the scanning direction 4 changes, and the long side direction of the rectangular polarized light beam 8b changes. It can be seen that the length of can be changed.
Note that the pair of cylindrical lens arrays 34 may be an optical system having a configuration other than those described above.

The condenser lens 36 condenses the rectangular polarized beam 8b that has passed through the cylindrical lens array 34 on a glass substrate. The condenser lens 36 is an aspherical convex lens, condenses the rectangular polarized beam 8b in the scanning direction 4 on the glass substrate, and the rectangular polarized beam 9 having a rectangular cross section which is short in the scanning direction 4 and long in the orthogonal direction on the glass substrate. Irradiate.
The condenser lens 36 may be an optical system having a configuration other than that described above.

  With the above-described configuration, the polarization pulse laser beam 5a is converted into the polarization state 6 or the polarization state 7 by appropriately rotating or swinging the half-wave plate 22 by the driving unit 24, and the peripheral circuit unit on the glass substrate. 3 and the pixel unit 2 can irradiate the rectangular polarized beam 9 in different polarization states.

FIG. 3 is a diagram showing a second embodiment of the laser annealing apparatus according to the present invention.
In this figure, the laser annealing apparatus of the present invention includes a laser emitting device 10, a polarization conversion optical system 20, and a shape conversion optical system 30.

The laser emitting apparatus 10 controls each of the plurality of (two in this figure) laser resonators 12A and 12B that periodically emit the polarized pulsed laser light 5a and the pulse timings of the plurality of laser resonators so that the pulse timing is shifted. And a pulse control unit 14 for outputting.
Laser resonators 12A and 12B periodically emit polarization state 7 and polarization state 6, respectively. Further, the polarization state 7 and the polarization state 6 have different pulse timings emitted by the pulse control unit 14 and are emitted alternately.

The polarization conversion optical system 20 includes a reflection mirror 26 and a polarization beam splitter 28 in addition to the half-wave plate 22 and the drive unit 24 described above.
The reflection mirror 26 totally reflects the polarization state 7 in a direction orthogonal to the polarization state 6 and causes the polarization state 7 to enter the polarization beam splitter 28.
The polarization beam splitter 28 has a function of synthesizing two polarization pulse laser beams 5a (polarization state 7 and polarization state 6) on a coaxial optical path.

With this configuration, the polarization beam splitter 28 synthesizes two polarized pulsed laser beams 5a (polarization state 7 and polarization state 6) on a coaxial optical path, and the polarization state 7 and the polarization state 6 are alternately incident on the shape conversion optical system 30. Can be made.
In addition, by appropriately rotating or swinging the half-wave plate 22 by the driving unit 24, the polarized pulsed laser light 5 incident on the shape conversion optical system 30 can be (1) only in the polarization state 6 or (2) in the polarization state. 7 or (3) It is possible to irradiate the peripheral circuit unit 3 and the pixel unit 2 on the glass substrate by alternately converting into the polarization state 7 and the polarization state 6.

  Also, with this configuration, two laser resonators 12A and 12B can be used simultaneously, so that the scanning speed of the laser light on the substrate can be increased, the processing efficiency of laser annealing can be increased, and the productivity can be improved. .

  In the laser annealing method of the present invention, using the above-described apparatus, the polarized pulsed laser beam 5a is converted into a rectangular polarized beam 9 having a rectangular cross section that is short in the scanning direction on the glass substrate and long in the orthogonal direction. The circuit unit 3 and the pixel unit 2 irradiate the rectangular polarized beam 9 in different polarization states.

  That is, in the first method of the present invention, the peripheral circuit unit 3 is irradiated with the polarized pulsed laser beam 9 in the polarization state 6 in which the electric field is directed in the long side direction of the rectangular polarized beam, and the energy gradient of the polarized pulsed laser beam 9 is obtained. Thus, the crystal grains are increased in the short side direction.

  Further, in the second method of the present invention, the pixel unit 2 is irradiated with the polarized pulsed laser light 9 in the polarization state 7 in which the electric field is directed in the short side direction of the rectangular polarized beam, and the standing wave generated in the short side direction. Thus, the elongation of the crystal grains in the short side direction is suppressed, and uniform crystal grains are grown.

  Further, according to the third method of the present invention, the pixel unit 2 has the polarization pulse laser light 9 in the polarization state 6 in which the electric field is directed in the long side direction of the rectangular polarized beam and the polarized light in which the electric field is directed in the short side direction of the rectangular polarized beam. By alternately irradiating the polarized pulsed laser light 9 in the state 7 and standing waves generated in the long side direction and the short side direction, the crystal grains are elongated in the long side direction and the elongation of the crystal grains in the short side direction is suppressed. Then, uniform crystal grains are grown.

FIG. 4 is a phase diagram of the crystal grain size obtained when the polarized pulsed laser light in the polarization state in which the electric field is directed in the long side direction of the rectangular polarized beam 9 is irradiated by the first method of the present invention. This figure shows that in the polycrystalline silicon obtained by vertically irradiating an amorphous silicon film with a rectangular laser beam having a long side direction and a wavelength of 532 nm and an energy density of 450 to 500 mJ / cm ² . Crystal grains are shown.
From this figure, the crystal grain size in the short side direction is about 1.5 μm, and it was confirmed that the crystal grain can be increased in the short side direction by the first method of the present invention.

  The reason why the crystal grains extend in the short side direction when the electric field faces in the long side direction is that there is an energy distribution that the laser originally has in the short side direction. That is, if it is a solid-state laser, the energy profile is close to a Gaussian shape. In this figure, the direction in which the crystal grains extend is the short side direction.

FIG. 5 is a state diagram of the crystal grain size obtained when the polarized pulsed laser light in the polarization state in which the electric field is directed to the short side direction of the rectangular polarized beam 9 is irradiated by the second method of the present invention. The wavelength, energy density, and irradiation angle of the laser light are the same as those in the first embodiment.
From this figure, the crystal grain size in the long side direction and the short side direction is about 0.3 μm, and it was confirmed that uniform crystal grains can be grown by the second method of the present invention.

  This characteristic is due to the fact that a standing wave is generated on the semiconductor film in the short side direction, which is the polarization direction, and a temperature gradient corresponding to the periodic energy of the standing wave is generated. That is, crystal nuclei are generated at the positions of the periodic energy valleys, and each crystal nucleus grows in a higher temperature direction, and a portion where the crystal nuclei collide with each other becomes a crystal grain boundary. However, since the irradiation range in the short side direction is narrow and the temperature change is large, the growth of crystal grains in the short side direction is suppressed by this temperature distribution. Therefore, crystal growth in both the long side direction and the short side direction is restricted, and uniform crystal grains can be grown as a whole.

FIG. 6 shows a polarization pulse laser beam in a polarization state in which the electric field is directed to the long side direction of the rectangular polarization beam and a polarization pulse laser in a polarization state in which the electric field is directed to the short side direction of the rectangular polarization beam by the third method of the present invention. It is a phase diagram of a crystal grain size obtained when light and light are alternately irradiated. The wavelength, energy density, and irradiation angle of the laser light are the same as those in the first embodiment.
From this figure, the crystal grain size in the long side direction and the short side direction is about 0.3 μm, and it was confirmed that uniform crystal grains can be grown by the third method of the present invention.

  This characteristic is due to the fact that standing waves are alternately generated in the long-side direction and the short-side direction, which are polarization directions, on the semiconductor film, and a temperature gradient corresponding to the periodic energy of the standing wave is generated. That is, crystal nuclei are generated at the positions of the periodic energy valleys, and each crystal nucleus grows in a higher temperature direction, and a portion where the crystal nuclei collide with each other becomes a crystal grain boundary. Therefore, crystal nuclei generated at periodic positions grow under the influence of the same temperature gradient in the long-side direction and the short-side direction, so that many nuclei consisting of crystal grains having uniform dimensions in the long-side direction and the short-side direction are formed. A crystalline semiconductor film can be formed.

  As described above, according to the method and apparatus of the present invention, the polarized pulsed laser beam 5a is shortened in the scanning direction 4 on the glass substrate and perpendicular to the amorphous semiconductor film on the glass substrate for liquid crystal and organic display devices. It is converted into two or more types of rectangular polarized beams 9 having a rectangular section that is long in the direction and having different polarization states, and the rectangular polarized beams 9 are irradiated with different polarization states in the peripheral circuit section 3 and the pixel section 2 on the glass substrate. Therefore, different crystallization can be performed by the difference in polarization state between the peripheral circuit unit 3 and the pixel unit 2.

  The peripheral circuit unit 3 is irradiated with the polarized pulsed laser beam 9 in the polarization state 6 in which the electric field is directed in the long-side direction of the rectangular polarized beam using the above-described device, so that the energy gradient of the polarized pulsed laser beam 9 is shortened. Crystal grains can be increased in the side direction.

  The pixel unit 2 is irradiated with the polarized pulsed laser light 9 in the polarization state 7 in which the electric field is directed in the short side direction of the rectangular polarized light beam using the above-described device, and thereby the standing wave generated in the short side direction. Thus, it is possible to suppress the elongation of the crystal grains in the short side direction and to grow uniform crystal grains.

  In addition, using the above-described device for the pixel unit 2, the polarization pulse laser light 9 in the polarization state 6 in which the electric field is directed in the long side direction of the rectangular polarized beam and the polarization state 7 in which the electric field is directed in the short side direction of the rectangular polarized beam. By alternately irradiating the polarized pulsed laser beam 9 with a standing wave generated in the long side direction and the short side direction, the crystal grains are made uniform in the long side direction and the crystal grains are elongated in the short side direction. It is possible to suppress and grow uniform crystal grains.

In general, the area required on the glass substrate is different between the peripheral circuit unit 3 and the pixel unit 2, so that it is not efficient to irradiate with the same length laser in the long side direction in the same substrate.
Therefore, in the present invention, by using the above-described apparatus, for example, by changing the distance Δ between the upstream cylindrical lens array 34a and the downstream cylindrical lens array 34b of the pair of cylindrical lens arrays 34, the pair of cylindrical lens arrays The focal length 34 is changed to change the length of the rectangular polarized beam 8 in the long side direction.
Thereby, the rectangular polarized light beam 9 is irradiated with different polarization states in the peripheral circuit portion 3 and the pixel portion 2 in the same glass substrate having an amorphous semiconductor film such as an amorphous silicon film without using a mask. Can do.

  Further, as means for obtaining different polarization states, circularly polarized light or non-polarized light may be used to make the crystal grain size uniform.

  In addition, this invention is not limited to embodiment mentioned above, Of course, a various change can be added in the range which does not deviate from the summary of this invention.

It is a top view of the glass substrate 1 for the liquid crystal and organic display apparatus which are the process target of this invention. 1 is a diagram showing a laser annealing apparatus according to a first embodiment of the present invention. It is 2nd Embodiment figure of the laser annealing apparatus by this invention. It is a phase diagram of the crystal grain size obtained by the 1st method of the present invention. It is a phase diagram of the crystal grain size obtained by the 2nd method of the present invention. It is a phase diagram of the crystal grain size obtained by the 3rd method of this invention.

Explanation of symbols

1 glass substrate, 2 pixel section, 3 peripheral circuit section, 4 scanning direction,
5 polarized pulsed laser light, 6, 7 polarization state,
8a, 8b Rectangular polarized beam, 9 Rectangular polarized beam,
10 laser emitting device, 12, 12A, 12B laser resonator,
14 Pulse controller,
20 polarization conversion optical system, 22 1/2 wavelength plate, 24 drive unit,
26 reflection mirror, 28 polarizing beam splitter,
30 shape conversion optics, 32 beam expander,
34 Cylindrical lens array, 36 condenser lens

Claims (2)

A method for producing a polycrystalline semiconductor film, wherein an amorphous semiconductor film formed on a glass substrate for liquid crystal and organic display devices is crystallized by laser light irradiation,
A polarized pulse laser beam is converted into two or more types of rectangular polarized beams having a rectangular cross section that is short in the scanning direction on the glass substrate and long in the orthogonal direction, and having different polarization states, and a peripheral circuit unit and a pixel unit on the glass substrate And irradiating the rectangular polarized beam in different polarization states,
The peripheral circuit portion is irradiated with a polarized pulse laser beam in a polarization state in which an electric field is directed in the long side direction of the rectangular polarized beam, and the crystal grains are increased in the short side direction by the energy gradient of the polarized pulse laser beam,
The pixel portion is irradiated with a polarized pulsed laser beam in which the electric field is directed to the short side direction of the rectangular polarized beam, and the standing wave generated in the short side direction is used to suppress the elongation of the crystal grains in the short side direction, A method for manufacturing a polycrystalline semiconductor film, characterized in that uniform crystal grains are grown. A method for producing a polycrystalline semiconductor film, wherein an amorphous semiconductor film formed on a glass substrate for liquid crystal and organic display devices is crystallized by laser light irradiation,
A polarized pulse laser beam is converted into two or more types of rectangular polarized beams having a rectangular cross section that is short in the scanning direction on the glass substrate and long in the orthogonal direction, and having different polarization states, and a peripheral circuit unit and a pixel unit on the glass substrate And irradiating the rectangular polarized beam in different polarization states,
The peripheral circuit portion is irradiated with a polarized pulse laser beam in a polarization state in which an electric field is directed in the long side direction of the rectangular polarized beam, and the crystal grains are increased in the short side direction by the energy gradient of the polarized pulse laser beam,
The pixel unit is alternately irradiated with a polarized pulsed laser beam in a polarization state in which the electric field is directed in the long side direction of the rectangular polarized beam and a polarized pulsed laser beam in the polarization state in which the electric field is directed in the short side direction of the rectangular polarized beam, By standing waves generated in the long-side direction and the short-side direction, the crystal grains are made uniform in the long-side direction and the elongation of the crystal grains in the short-side direction is suppressed, and uniform crystal grains are grown. A method for manufacturing a polycrystalline semiconductor film.

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