JP2001319892A - Laser annealing apparatus and method for fabricating transistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make mass production practicable by enlarging the fluence margin of a line beam at the time of obtaining p-Si having a desired grain size uniformly by laser annealing a-Si. SOLUTION: A mirror 23 of an excimer laser annealing apparatus 14 is adjusted such that the widths of first and second steepnesses 27, 28 on the opposite sides of the plateau region [A-1] in the beam profile of a line beam satisfy a relation e1cosθ1<=e2cosθ2<=k.e2cosθ1 (θ1>θ2, k is not larger than 2). After θ1, θ2 of the beam profile are adjusted, respectively, to 85 deg. and 82 deg., a-Si formed on a first glass substrate 46 is annealed while being scanned in the direction from the point of θ1 toward the point of α2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to polycrystalline silicon (hereinafter abbreviated as p-Si) by annealing a semiconductor film such as amorphous silicon (hereinafter abbreviated as a-Si).
Laser irradiation apparatus for irradiating a semiconductor film with a line beam and a thin film transistor (hereinafter referred to as TF) having p-Si formed by laser annealing as a semiconductor layer.
Abbreviated as T. )).

[0002]

2. Description of the Related Art In recent years, as a switching element of a large-screen and high-definition liquid crystal display element, an electric field mobility (μFE) of 1 is known.
Since it is as high as 00 to ²⁰⁰ cm ² / Vs, high display quality can be obtained and the driving speed of the liquid crystal display element can be increased, a polycrystalline thin film transistor integrated with a driving circuit using p-Si as a semiconductor layer (hereinafter referred to as p -SiTFT) is being put to practical use.

[0003] In general, p-Si is formed by a laser annealing method in which a-Si is irradiated with a laser beam such as an excimer laser to be polycrystallized. Specifically, for example, a laser beam having an oscillation frequency of 300 Hz is formed on the a-Si surface into a line beam having a length of 250 mm and a width of 0.4 mm. -Si surface was sequentially scanned to anneal a-Si to form p-Si.

On the other hand, the electric field mobility of a p-Si TFT is determined by the size of the grain size of p-Si formed by annealing. Fluence F, irradiation energy density
Greatly depends on That is, as the fluence F increases, the particle size of p-Si formed by cooling after annealing increases. In order to obtain a high-performance p-Si TFT having an electric field mobility of 100 cm ² / Vs or more, a fluence higher than a certain fluence of F1 is required.
Here, if the fluence of the line beam used for annealing is increased from F1 in order to obtain a high electric field mobility,
Although the particle size of p-Si also increases, the p-Si becomes fine crystal grains at a certain fluence F2, and it becomes impossible to obtain TFT characteristics having a desired electric field mobility.

[0005] The particle size of p-Si, which affects the electric field mobility of the p-Si TFT, can be determined by etching p-Si with a liquid called a Seco etchant and observing it with a scanning electron microscope. Can be. Utilizing this method, the fluence of the line beam is conventionally reduced to p-
P- is selected from the range of F1 to F2, which can form the Si particle size to some extent, and exhibits a desired high electric field mobility.
SiTFT had been obtained.

[0006]

However, conventionally,
In order to obtain a p-Si TFT having high electric field mobility,
a-Si is annealed to obtain p-Si having a desired particle size.
The width (fluence margin) from F1 to F2 of the fluence of the line beam forming was very narrow. For this reason, the fluence of the line beam is likely to deviate from the fluence margin of F1 to F2 due to the fluctuation of the oscillation laser from the laser oscillation device, the a-Si cannot be favorably annealed, and the grain size of the formed p-Si is uneven. As a result, a high-performance p-SiTFT having uniform characteristics over the entire surface of the substrate cannot be obtained, resulting in a problem that the production yield at the time of mass production of the p-SiTFT is reduced.

[0007] The present invention has been made to solve the above-mentioned problems, and a-
The laser beam anneal of Si increases the fluence margin of the line beam to form p-Si with a desired crystal grain size, enabling mass production of high-performance p-Si TFTs exhibiting high electric field mobility. It is an object of the present invention to provide a laser annealing apparatus and a method of manufacturing a thin film transistor.

[0008]

According to the present invention, in order to solve the above-mentioned problems, an oscillating means for oscillating a laser beam, and a trapezoidal beam profile when the laser beam is set to a horizontal axis in a scanning direction is d1 cos θ1 ≦ d2cosθ2 ≦ k · d2cosθ1
(Where d1 and d2 are the steepness of the beam profile, θ1 is the angle between d1 and the long side of the trapezoid, θ2 is the angle between d2 and the long side of the trapezoid, θ1> θ2, and the coefficient k is 1 or more and 3 or less. And a beam shaping means having a homogenizer for shaping the line beam into a line beam, and the line beam from the side having the above θ1 on the irradiation object.
And scanning means for relatively scanning on the side having 2.

According to another aspect of the present invention, there is provided an oscillation unit for oscillating a laser beam, and a trapezoidal beam profile of the laser beam when the scanning direction is represented by a horizontal axis is e1.
cosθ1 ≦ e2cosθ2 ≦ k · e2cosθ1 (however, e1, e2
Is the portion of the steepness d1, d2 of the beam profile cut out by two parallel lines arbitrarily drawn between the long side and the short side of the trapezoid, θ1 is the angle between e1 and the parallel line on the long side, θ2 is the angle between e2 and the parallel line on the long side, and θ1
> Θ2, and the coefficient k is a real number from 1 to 3. ), A beam shaping means having a homogenizer for shaping the line beam into
Scanning means for relatively scanning from the side having θ2 to the side having θ2.

According to another aspect of the present invention, there is provided a method of manufacturing a thin film transistor using polycrystalline silicon as a semiconductor layer by irradiating a non-single-crystal silicon deposited on an insulating substrate with a line beam. Depositing the non-single-crystal silicon thereon, and forming a trapezoidal beam profile on the non-single-crystal silicon when the scanning direction is the horizontal axis, d1cosθ1 ≦ d2cosθ2 ≦ k · d2cosθ1
(Where d1 and d2 are the steepness of the beam profile, θ1 is the angle between d1 and the long side of the trapezoid, θ2 is the angle between d2 and the long side of the trapezoid, θ1> θ2, and the coefficient k is 1 or more and 3 or less. The relative beam from the side having θ1 to the side having θ2 to anneal the non-single-crystal silicon to crystallize it into polycrystalline silicon. It is to be implemented.

According to another aspect of the present invention, there is provided a method of manufacturing a thin film transistor using polycrystalline silicon as a semiconductor layer by irradiating a non-single-crystal silicon deposited on an insulating substrate with a line beam. Depositing the non-single-crystal silicon thereon, and forming a trapezoidal beam profile on the non-single-crystal silicon when the scanning direction is the horizontal axis, e1cosθ1 ≦ e2cosθ2 ≦ k · e2cosθ1
(However, e1 and e2 are portions obtained by cutting out the steepness d1 and d2 of the beam profile by two parallel lines arbitrarily drawn between the long side and the short side of the trapezoid, and θ1 is the parallel line between e1 and the long side. And θ2 is the angle between e2 and the parallel line on the long side, and θ1> θ2, and the coefficient k is a real number of 1 or more and 3 or less. Scanning relatively to the side having θ2 to anneal the non-single-crystal silicon to crystallize it into polycrystalline silicon.

According to the present invention, the beam profile is adjusted from the shape of the beam profile of the line beam so that the fluence margin of the line beam irradiated on the a-Si can be widened, and then the leading end of the line beam on the a-Si is scanned. Annealing by scanning a line beam in the direction in which the irradiation intensity on the rear end side becomes stronger than that on the side, p-Si with a desired particle size can be easily obtained, and has high electric field mobility even during mass production. It is intended to obtain a high-performance p-Si TFT uniformly and at a high yield over the entire surface of a substrate.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the principle of the present invention will be described. For example, in a laser annealing method in which a-Si deposited on an insulating substrate is irradiated with a line beam to form p-Si, in order to obtain good annealing, scanning is performed on the insulating substrate in the short-axis direction of the line beam. Ideally, the beam profile, which is the intensity distribution of the line beam with the direction as the horizontal axis, is a rectangle [E] as shown by a dotted line in FIG. However, when the beam profile in the short-axis direction of the line beam 2 actually formed by the laser annealing apparatus is measured using a CCD profiler, a trapezoidal shape substantially close to a rectangle as shown by a solid line in FIG. F]. That is, on both sides of a flat plateau region [A] where the beam profile is constant,
Steepness [D1] whose strength decreases toward the hem,
[D2] is formed.

In order to satisfactorily anneal a-Si with a line beam having such a trapezoidal beam profile close to a substantially rectangular shape, for example, as shown in FIG. Although scanning is performed in the direction of arrow v, the plateau region may be inclined to such an extent that it cannot be detected by the CCD profiler due to adjustment of the irradiation intensity or the like.
In such a case, conventionally, using various sample substrates,
At least at the rear end side in the scanning direction of the line beam 2, adjustment was made so that a sufficient irradiation intensity was maintained. However, in a laser annealing device, the laser light from the laser oscillation device is liable to fluctuate, and also easily fluctuates due to replacement of some parts, and sometimes the emission direction is changed. It has been difficult to perform proper scanning with a good beam profile.

Therefore, according to the present invention, the beam profile in the plateau region [A] is changed to the steepness [D1],
Detected from the difference in the width of [D2] (d1cosθ1, d2cosθ2), the width of the steepness [D1], [D2] and
By controlling the scanning direction so as to satisfy a predetermined relationship, good crystallization is enabled.

That is, the line beam having the beam profile shown in FIG. 1 scans the semiconductor film in the direction of the arrow x, and d1 is the steepness [D at the rear end in the scanning direction.
1], d2 is the length of the steepness [D2] on the leading end side in the scanning direction, θ1 is the angle between the steepness [D1] on the trailing end side in the scanning direction and the long side 3 of the beam profile, and θ2 is the scanning Is the angle formed by the steepness [D2] on the tip side in the direction and the long side 3 of the beam profile, and θ1
> Θ2, and d1cosθ1 ≦ d2cosθ2 ≦ k · d2cos
By controlling and scanning a line beam having a beam profile of θ1 (where the coefficient k is a real number of 1 or more and 3 or less), a desired size for obtaining a p-Si TFT having high electric field mobility is obtained by scanning. It has been found that a fluence margin for forming p-Si having a crystal grain size can be widened.
In addition, according to experiments performed by the present inventors, it has been found that the fluence margin can be set wider as k is closer to 2.

Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 3 shows an excimer laser annealing apparatus 14 that laser-anneals a-Si, for example, as a semiconductor film on a first glass substrate 46 described later. The excimer laser annealing device 14 controls the excimer laser beam 1
An excimer laser oscillator 17 oscillating 6, a homogenizer 20 for forming the excimer laser beam 16 into a line beam 18 via a mirror 23, and the line beam 18 are condensed on a first glass substrate 46 set on the stage 21. It has a condenser lens 22. The stage 21 is movable in the horizontal direction,
The line beam 18 scan-anneals a-Si formed on the first glass substrate 46.

Next, the excimer laser annealing apparatus 14 is used to form a semiconductor film on the first glass substrate 46, for example, a-
A method for forming p-Si by annealing Si will be described. This a-Si is formed by a plasma CVD method using a silane gas (SiH ₄ ) and a hydrogen gas (H ₂ ), and is subjected to a dehydration treatment. If a new excimer laser annealing device 14 is used, or even if the excimer laser annealing device 14 that has been used in the past is replaced, the excimer laser annealing device must first be used before annealing. The device 14 is adjusted to adjust the beam profile of the line beam 18.
That is, when a beam profile of the excimer laser annealing apparatus 14 whose horizontal axis is the scanning direction, which is the short axis direction of the line beam, is measured by a CCD profiler (not shown), the beam profile shown by a dotted line in FIG. ) Is obtained. This beam profile (A) has a flat plateau region [A-1] where the beam profile is constant.
First and second steepnesses 2 having different inclinations on both sides of
It has a trapezoidal shape close to a substantially rectangular shape having 7,28.

The first and second steepnesses 27,
28 is cut by first and second cut lines 30 and 31 parallel to the upper and lower bases of the trapezoid, and the cut portion 3 cut by the first and second cut lines 30 and 31 of each steepness.
When the lengths e1 and e2 of the cutout portions 32 on the first steepness 27 side were measured, the lengths e1 and e2 of the cutout portions 32 were 1 and 1, respectively.
00, and the length e2 of the cutout portion 33 on the second steepness 28 side was 105. Also, the cutout portions 32 and 33 of each steepness and the second cutout line 3
When θ1 and θ2 were the angles formed with 1, respectively, θ1 was 85 ° and θ2 was 80 °.

The cut portions 32, 33 cut by the first and second cut lines 30, 31 of each steepness.
The lengths e1 and e2 of d1cosθ1 ≦ d2cosθ2 ≦ k · d2c
osθ1 (θ1> θ2), e1cosθ1 ≦ e2cosθ2
When actually calculated as ≦ k · e2cosθ1, e1cosθ1
Is 8.716 and e2cos θ2 is 14.613. That is, in this beam profile (a), e2cos
θ2 exceeds twice e1cosθ1, which does not satisfy the desired fluence margin.

Therefore, in order to further increase the fluence margin of the line beam 18, the homogenizer 20 is used.
The angle of the mirror 23, which is closer to the excimer laser oscillator 17 and closest to the excimer laser oscillator 17, is adjusted so that the line beam 18 has a beam profile (a) indicated by a solid line in FIG. That is, by adjusting the angle of the mirror 23, the θ2 of the beam profile (a) is set to 82
°.

As a result, the length e2 of the cut-out portion 33 on the second steepness 28 side becomes 104, and e2cos
Since θ2 is 14.474, e2cosθ2 is e1c
osθ1 is twice or less. If a line beam 18 having such a beam profile (a) is used, a-Si
The desired fluence margin at the time of annealing can be satisfied. Actually, the stage 21 is moved 6 mm in the direction of the arrow y.
/ S, and the film thickness 4 deposited on the first glass substrate 46 via the undercoat layer 47 as shown in FIG.
The 7 mm a-Si has a beam profile (a), and the line beam 18 having a laser frequency of 300 Hz causes an overlap in the direction of the arrow z, which is the direction from the point θ1 to the point θ2 of the beam profile (a). 95%
When p-Si is formed by performing scanning so as to obtain p-Si, a desired crystal grain size can be obtained in a fluence of 320 to 380 mJ / cm ² , and the yield during mass production is greatly improved.

After adjusting the excimer laser annealing apparatus 14 so as to irradiate the line beam 18 having the beam profile (a) as described above, the first glass substrate 4
6 will be annealed. Adjustment of the beam profile is performed by the excimer laser annealing apparatus 14.
Any of the mirrors can be adjusted, but if the mirror closest to the excimer laser oscillator 17 is adjusted, more accurate adjustment can be performed.

Next, a p-Si TFT using p-Si as a semiconductor layer obtained by annealing a-Si with a line beam 18 having a beam profile (a) shown by a solid line in FIG. Will be described. Reference numeral 37 denotes a drive circuit integrated type p-Si active matrix type liquid crystal display element.
A liquid crystal composition 44 is sealed in the gap between the array substrate 41 for driving the pixel electrode 40 at T38 and the counter substrate 42 via the alignment films 43a and 43b.

The array substrate 41 is 400 mm × 500 m
Silicon nitride (S) is formed on a first glass substrate 46 of m size.
An active layer 48 made of p-Si via an undercoat layer 47 made of an iNx) film and a silicon oxide (SiOx) film
a, a semiconductor layer 48 having a drain region 48b and a source region 48c is patterned. On the semiconductor layer 48, a gate electrode 51 is formed via a gate insulating film 50. Further, the pixel electrode 40 is formed via the interlayer insulating film 52, the pixel electrode 40 and the source region 48c are connected by the source electrode 53, and the drain region 48b and the signal line (not shown) are connected by the drain electrode 54. Reference numeral 56 denotes a protective film. The counter substrate 42 has a counter electrode 58 on a second glass substrate 57.

The array substrate 41 includes a first glass substrate 46
After an undercoat layer 47 is formed thereon by a plasma CVD method, a-Si (not shown) is formed to a thickness of 47 nm by a plasma CVD method, and then formed at 500 ° C. in a nitrogen (N ₂ ) atmosphere at 10 ° C. The heat treatment is performed for one minute to reduce the hydrogen concentration in the film. At this time, when the film thickness of a-Si was determined by the spectral ellipsometry, the actual film thickness was 47.5 nm.

Thereafter, the first glass substrate 46 is placed on the stage 21 of the excimer laser annealing apparatus 14, and the stage 21 is moved by scanning at a speed of 6 mm / s in the direction of the arrow y perpendicular to the long axis of the line beam 18. Consequently, the a-Si on the first glass substrate 46 is annealed by scanning with the line beam 18 indicating the beam profile (a) in the direction of the arrow z, which is the direction from the point θ1 to the point θ2. . The irradiation size of the line beam 18 is 200 mm × 0.
4 mm, the oscillation frequency from the excimer laser oscillator 17 is 300 Hz, the fluence on the first glass substrate 46 is 350 mJ / cm ² , and the overlap ratio during scanning is 95.
%, And a-Si of the first region [R] and the second region [S] are sequentially subjected to scan annealing on the first glass substrate 46 to form p-Si.

Next, using photolithography technology,
In both regions [R] and [S] of the first glass substrate 46, p-
A p-Si TFT 38 having Si as a semiconductor layer 48 and a pixel electrode 40 are formed to form an array substrate 41, which is then fixed to a counter substrate 42 with a sealant (not shown) to form a liquid crystal cell. Then, a liquid crystal composition 44 is sealed therein to complete a p-Si active matrix type liquid crystal display element 37.

The p-Si active matrix type liquid crystal display element 37 thus obtained is connected to the first glass substrate 4.
Since p-Si having a desired crystal grain size is used as the semiconductor layer 48 over the entire surface, the formed p-Si TFT 38 is formed.
Has a high electric field mobility and excellent characteristics, and has a large screen, high definition, good display quality, and high-speed driving.

With this configuration, regardless of the fluctuation of the excimer laser beam 16 from the excimer laser oscillator 17, the line beam 18 that anneals the a-Si is formed by changing the inclination angle of the steepness of the beam profile (a). , Θ1 is 85 ° and θ2 is 82 °, e1cosθ1 ≦
By adjusting e2cosθ2 ≦ k · e2cosθ1 so that k is a real number of 2 or less, and then scanning the glass substrate 46 in the direction from the point θ1 to the point θ2 of the beam profile (a), p-Si is desired. The fluence margin of the line beam 18 having a crystal grain size of the size of can be widened. Therefore, the p-Si TFT 38 exhibiting high electric field mobility
Can be mass-produced uniformly and with high yield, and a high-performance p-Si active matrix liquid crystal display element 37
Can be put to practical use.

The present invention is not limited to the above-described embodiment, but can be changed without departing from the spirit of the present invention, and the fluence margin of the line beam when annealing a-Si can be enlarged. If there is, the angles θ1 and θ2 of the beam profile are not limited. Further, the moving speed and the overlap ratio when scanning the line beam on the glass substrate are also optional as required.

[0032]

As described above, according to the present invention, a
-The laser beam anneal of Si can increase the fluence margin of the line beam when forming p-Si having the desired grain size, and the entire surface of the substrate can be irrespective of the fluctuation of the laser beam from the laser oscillator. In addition, p-Si TFTs having high electric field mobility can be mass-produced uniformly and with high yield, and a large-screen, high-definition, high-performance liquid crystal display device can be put to practical use.

[Brief description of the drawings]

FIG. 1 is a graph showing a beam profile of a line beam according to the principles of the present invention.

FIG. 2 is an explanatory view showing scanning of a line beam according to the principle of the present invention.

FIG. 3 is a schematic configuration diagram showing an excimer laser annealing apparatus according to an embodiment of the present invention.

FIG. 4 is a graph showing a beam profile of a line beam according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram showing scanning of a line beam according to the embodiment of the present invention.

FIG. 6 is a schematic sectional view showing a p-Si active matrix type liquid crystal display device according to an embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a scanning region at the time of annealing the first glass substrate according to the embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 14 excimer laser annealing apparatus 16 excimer laser beam 17 excimer laser oscillator 18 line beam 20 homogenizer 21 stage 22 condensing lens 23 mirror 27 first steepness 28 second steepness 30 First cutout line 31 Second cutout line 37 p-Si active matrix liquid crystal display element 38 p-SiTFT 40 pixel electrode 41 array substrate 42 counter substrate 44 liquid crystal composition 46 first Glass substrate 48: Semiconductor layer

Continued on the front page F term (reference) 5F052 AA02 BA07 BB07 CA04 CA07 DA02 DB01 5F110 AA01 AA30 BB02 CC02 DD02 DD13 DD14 DD17 GG02 GG13 GG25 GG45 PP03 PP05 PP06 PP35

Claims (12)

[Claims] An oscillation means for oscillating a laser beam, wherein a trapezoidal beam profile of the laser beam when the scanning direction is a horizontal axis is d1cosθ1 ≦ d2cosθ2 ≦ k · d
2 cos θ1 (where d1 and d2 are the steepness of the beam profile, θ1 is the angle between d1 and the long side of the trapezoid, θ2
Is the angle between d2 and the long side of the trapezoid, θ1> θ2, and the coefficient k is a real number of 1 or more and 3 or less. And a scanning unit that relatively scans the line beam from the side having θ1 to the side having θ2 on the irradiation object. A laser annealing apparatus characterized by the above-mentioned. 2. An oscillating means for oscillating a laser beam, wherein a trapezoidal beam profile of the laser beam when the scanning direction is a horizontal axis is e1cosθ1 ≦ e2cosθ2 ≦ k · e
2cos θ1 (where e1 and e2 are portions obtained by cutting out the steepness d1 and d2 of the beam profile by two parallel lines arbitrarily drawn between the long side and the short side of the trapezoid, and θ1 is parallel to e1 and the long side. Θ2 is the angle between e2 and the parallel line on the long side, and θ1> θ2, and the coefficient k is a real number of 1 or more and 3 or less.) A laser annealing apparatus, comprising: a shaping unit; and a scanning unit that relatively scans the line beam from the side having the θ1 to the side having the θ2 on the irradiation object. 3. The laser annealing apparatus according to claim 1, wherein the coefficient k is set based on the shape of the beam profile. 4. The laser annealing apparatus according to claim 3, wherein the coefficient k is close to 2. 5. The beam adjusting means changes the inclination of a mirror on the oscillation means side of the homogenizer to change the angle θ of the line beam.
The laser annealing apparatus according to claim 3, wherein 1 and / or θ2 is adjusted. 6. The laser annealing apparatus according to claim 5, wherein the mirror is a mirror closest to the oscillation unit. 7. A method of manufacturing a thin film transistor using polycrystalline silicon as a semiconductor layer by irradiating non-single-crystal silicon deposited on an insulating substrate with a line beam, wherein the non-single-crystal silicon is deposited on the insulating substrate. And the trapezoidal beam profile on the non-single-crystal silicon when the scanning direction is the horizontal axis is d1cosθ1 ≦ d2cos
θ2 ≦ k · d2cos θ1 (where d1 and d2 are the steepness of the beam profile, θ1 is the angle between d1 and the long side of the trapezoid, θ2 is the angle between d2 and the long side of the trapezoid and θ1>
θ2 and the coefficient k are real numbers of 1 or more and 3 or less. A) relatively scanning the line beam from the side having the θ1 to the side having the θ2 to anneal the non-single-crystal silicon to crystallize it into polycrystalline silicon. A method for manufacturing a thin film transistor. 8. A method of manufacturing a thin film transistor using polycrystalline silicon as a semiconductor layer by irradiating non-single-crystal silicon deposited on an insulating substrate with a line beam, wherein the non-single-crystal silicon is deposited on the insulating substrate. And the trapezoidal beam profile on the non-single-crystal silicon when the scanning direction is the horizontal axis is e1cosθ1 ≦ e2cos
θ2 ≦ k · e2 cos θ1 (where e1 and e2 are portions obtained by arbitrarily drawing two steepnesses d1 and d2 of the beam profile between the long side and the short side of the trapezoid, θ
1 is the angle between e1 and the parallel line on the long side, θ2 is the angle between e2 and the parallel line on the long side, and θ1> θ2, and the coefficient k is 1
It is a real number of 3 or more and 3 or less. A) relatively scanning the line beam from the side having the θ1 to the side having the θ2 to anneal the non-single-crystal silicon to crystallize it into polycrystalline silicon. A method for manufacturing a thin film transistor. 9. The method according to claim 7, wherein the coefficient k is set based on the shape of the beam profile. 10. The method according to claim 9, wherein the coefficient k is close to 2. 11. A laser annealing apparatus for forming a laser beam from an oscillating means into a line beam with a homogenizer.
The inclination of the mirror on the oscillation means side from the homogenizer is changed to change the beam profile of the line beam by θ.
11. The method for manufacturing a thin film transistor according to claim 9, wherein morphous silicon is annealed after adjusting 1 and θ2. 12. The method according to claim 11, wherein the mirror is a mirror closest to the oscillating means.