KR20050017002A - Crystal growing method, crystal growing apparatus, beam splitter, and display - Google Patents

Abstract

Provides a crystal growth method capable of crystallization at high speed. In the crystal growth method, the mth (m is an integer of 1 or more) and the m + 1 band-like beams are irradiated toward the thin film, and the amorphous silicon film 201 is subjected to the mth and m + 1th kth crystallization regions 202a and 202b. ), An area spaced apart from the m-th kth crystallization region 202a by a distance r (r is greater than the length of one crystal growth) and part of the k-th crystallization region 202b of m + 1 Irradiating an m-th band-shaped beam to a region where s overlaps and forming an m-th k + 1th crystallization region 203a continuous to the m-th kth crystallization region 202b in the amorphous silicon film 201. It includes.

Description

Crystal Growth Method, Crystal Growth Device, Beam Branch Device and Display Device {CRYSTAL GROWING METHOD, CRYSTAL GROWING APPARATUS, BEAM SPLITTER, AND DISPLAY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crystal growth method using a beam such as a laser light, a crystal growth device and a branching device, and a display device having a thin film transistor having the polycrystalline thin film as an active layer.

The thin film transistors used in the display device employing liquid crystal or electroluminescence (EL) use amorphous or polycrystalline silicon as the active layer. Among them, the thin film transistor using polycrystalline silicon as an active layer has many advantages compared to the thin film transistor using amorphous silicon as an active layer because of high carrier (electron) mobility.

For example, the switching element may be formed in the pixel portion, and the driving circuit may be formed in the peripheral region of the pixel. Alternatively, some peripheral circuits may be formed on one substrate. As a result, it is not necessary to mount a separate driver IC (integrated circuit) or drive circuit board on the display device, so that the display device can be provided at a unit price.

In addition, as another advantage, since the size of the transistor can be reduced, the switching element formed in the pixel portion can be miniaturized and the aperture ratio can be increased. This makes it possible to provide a display device with high brightness and high precision.

In the method for producing a polycrystalline silicon thin film, an amorphous silicon thin film is formed on a glass substrate by CVD (chemical vapor deposition method) or the like, followed by a step of polycrystallizing amorphous silicon separately.

As a process of crystallizing an amorphous silicon thin film, there exists a method by the high temperature annealing method of 600 degreeC or more of temperature. In this case, since expensive glass substrates that withstand high temperatures must be used, it has been a deterrent to lowering the price of display devices. In recent years, a technique of crystallizing amorphous silicon at a low temperature of 600 ° C. or lower by using a laser has become common, and it is possible to provide a display device in which a polycrystalline silicon thin film transistor is formed on a low temperature glass substrate at low cost.

In the crystallization technique using a laser, as shown in Fig. 15, the glass substrate 505 on which the amorphous silicon thin film is formed is heated to a temperature of about 400 占 폚. Next, a method of irradiating the glass substrate 505 with a linear beam 506 having a length of 200 mm to 400 mm and a width of 0.2 mm to 1.0 mm while scanning the glass substrate 505 at a constant speed is common. By this method, crystal grains with a grain size of 0.2 µm or more and about 0.5 µm are formed. At this time, the amorphous silicon of the portion irradiated with the laser is not melted over the entire thickness direction, but is melted leaving a part of the amorphous region, so that crystal nuclei to reach are generated over the entire laser irradiation area and the outermost surface of the silicon thin film is generated. Crystals grow toward the grains to form grains of random orientation.

In addition, in order to obtain a high-performance display device, it is necessary to increase the crystal grain size of polycrystalline silicon or to control the orientation of crystals. Therefore, many researches and developments have been made in recent years for the purpose of obtaining performance close to single crystal silicon. Among them, international publication WO97 / 45827 discloses a technique called super lateral growth method. In the method described in the above publication, a slit pulsed laser is irradiated to a silicon thin film, and the silicon thin film is melted and solidified over the entire thickness direction of the laser irradiation area to determine it. Fig. 16 is a diagram illustrating a needle crystal structure formed by one pulse of irradiation. For example, the laser irradiation area 521 is melted by the slit pulse irradiation having a width of 2 μm to 3 μm, and is transverse to the boundary of the melting area, that is, the direction parallel to the glass substrate [arrow 522. The crystal grows in the direction indicated by). In the central portion of the melting region, crystals grown on both sides collide with each other to terminate growth. Crystal growth in the direction indicated by the arrow 522 is called super side growth.

Fig. 17 is a diagram for explaining the form of super side growth by a plurality of pulses of irradiation. Super side growth is completed by irradiating the pulsed laser once, as described with reference to FIG. As shown in Figs. 17 to 19, that is, the irradiation region 521a is melted by always irradiating a beam onto the amorphous thin film. And the crystal is grown in this part. Next, it is slightly changed to melt the irradiation area 521b. This is where crystals grow further. As shown in Fig. 18, the irradiation area 521c is then formed by irradiating the beam to a position slightly changed later. Further, the crystals can be further increased by slightly changing the irradiation area 521d and the irradiation area 521e. In other words, when the laser beam is irradiated in order so as to overlap a part of the needle crystals formed by one pulse irradiation, the longer crystals are grown following the already grown crystals, and the longer crystals are aligned in the direction of crystal growth. This has the characteristics obtained.

In the super lateral growth described in the above publication, the length of the crystal grown by one pulse irradiation varies depending on various conditions. For example, when the substrate temperature is 300 ° C, an excimer laser having a wavelength of 308 nm is irradiated. When it is made, it is known that the longest crystal becomes 1 μm to 1.2 μm. This is described, for example, in the Society of Applied Physics and Crystal Sciences, 112th Research Text pp.19-25, for reference.

Therefore, in order to form long crystals, pulse irradiation is repeated at a feeding pitch of about 1/2 to l / 3 of the crystal length grown by one laser irradiation, that is, a very fine feeding pitch of about 0.3 μm to 0.6 μm. It is achieved by doing so. For this reason, very long time was required to crystallize over the whole substrate area.

As a method for shortening the time required for crystallization, for example, Japanese Unexamined Patent Application Publication No. 2000-306859 discloses a method of forming an image of a mask on a substrate surface using a mask having equally spaced slit type light transmitting portions. It is. In this method, the length of the crystal becomes the pitch on the slit-like light transmitting part determined from the pitch of the slit-like light transmitting part and the magnification of the imaging system. Further, Japanese Laid-Open Patent Publication No. 2000-306859 has a longer crystal length as compared with the method of irradiating one linear beam 506 shown in Fig. 15, so that polycrystalline silicon is divided into a plurality of crystallization regions. The crystallization region refers to a region in which a crystal approximately equal to the crystal length is parallel to the direction perpendicular to the crystal length direction. The mobility between crystallization zones is not so high, but the mobility within one crystallization zone is high. Therefore, when the transistors are formed in one crystallization region with the dimensions of one crystallization region as the dimensions capable of forming at least one transistor, transistors with better performance than the method shown in Fig. 15 can be obtained.

In this method, however, the laser irradiation area is crystallized, the irradiation area is moved to the next area on the substrate, and crystallization is repeated in sequence. At this time, since crystallization is not performed during the time required for moving the substrate or mask to the next irradiation area, this becomes a wasteful time.

As described above, the super lateral growth forms crystals of higher quality than the conventional laser annealing method, but the time required for crystallization is long.

1 is a schematic diagram showing an apparatus for manufacturing a semiconductor thin film according to Example 1 of the present invention.

2 is a plan view of a mask having a slit according to Embodiment 1 of the present invention.

3 is a cross-sectional view of the mask shown for explaining a method of crystallizing a thin film.

FIG. 4 is an enlarged view of the m-th kth crystallization region 202a shown in FIG. 3.

5 is a cross-sectional view of the mask shown for explaining a method of crystallizing a thin film.

FIG. 6 is an enlarged view of the m-th k + 1th crystallization region 203a shown in FIG. 5.

7 is a view for explaining the movement trajectory of the irradiation area according to the present invention.

8 is a view showing a state in which a crystallization region is formed in a band region in the forward band crystallization region.

Fig. 9 shows a layout in which nine display elements in total are formed from one glass substrate at a time.

10 is a plan view showing in detail the crystallization region crystallized in Example 2. FIG.

11 is a plain view showing the crystallization region crystallized in Example 2 in detail.

12 is a plan view showing in detail the crystallization region crystallized in Example 2. FIG.

FIG. 13 is a plan view showing in detail the crystallization region crystallized in Example 2. FIG.

14 is a plan view showing in detail the crystallization region crystallized in Example 2. FIG.

Fig. 15 is a schematic diagram showing a crystallization technique by a conventional laser.

Fig. 16 is a diagram illustrating a needle crystal structure formed by one pulse of irradiation.

Fig. 17 is a diagram for explaining the form of super side growth by a plurality of pulses of irradiation.

Fig. 18 is a diagram for explaining the form of super side growth by a plurality of pulses of irradiation.

Fig. 19 is a diagram for explaining the form of super side growth by a plurality of pulses of irradiation.

Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a crystal growth method and apparatus and a beam branching apparatus which can produce a high quality polycrystalline semiconductor thin film in a short time.

Another object of the present invention is to efficiently manufacture a high quality polycrystalline semiconductor thin film and to provide a high performance display device having a thin film transistor having the polycrystalline semiconductor thin film as an active layer.

The crystal growth method according to the present invention comprises the steps of irradiating the m-th (m is an integer greater than or equal to) and the m-th + 1 band-like beam to the thin film to form the m-th and m + 1-th k-crystallization region, The m band-shaped beam is irradiated to an area spaced apart from the kth crystallization region of m by a distance r (r is greater than the length t of one crystal growth) and partially overlapped with the kth crystallization region of m + 1. And forming a m-th k + 1th crystallization region continuous to the m-th + 1th kth crystallization region in the thin film.

According to the crystal growth method equipped with such a process, after forming the k-th crystallization region of m-th and m + 1, the crystal growth method is located in a region away from the k-th crystallization region of m-th by a distance r longer than the length t of one crystal growth. In order to form the m-th k + 1th crystallization region on the thin film, the next crystallization region may be formed at a position further away than in the prior art. As a result, as compared with the prior art, another crystallization region can be formed in a region further separated from one crystallization region, and the manufacturing time can be shortened.

Also preferably, the step of forming the k-th crystallization region includes the step of branching the beam radiated from the beam source and shaping the m-th and m + 1 band-like beams.

Also preferably, the distance r is constant regardless of the value of m, and the shape of the band-like beams of m and m + 1 is constant regardless of the value of m, and the direction in which the plurality of k-th crystallization regions are parallel to each other is k. It is constant regardless of the value of.

Also preferably, the step of forming the k-th crystallization region and the step of forming the k + 1th crystallization region include the step of irradiating the first to n-th band-like beam groups toward the thin film, and the first to n-th band-like Each beam group includes y (y is greater than 1) beams formed parallel to the direction 1 spaced by the interval p, and the distance q from the kth crystallization region of m + 1 to the kth crystallization region of m + 1 Is not less than 0.2 times but not more than 0.8 times the length t of one crystal growth.

Also preferably, n is selected to satisfy the relation of n = p / q.

Also preferably, the step of forming the k + 1th crystallization region may include moving the thin film at a constant speed to irradiate the band-shaped beams of the mth and m + 1th periods at regular intervals.

Also preferably, the frequency f for irradiating the m-th and m + 1 band-like beams and the moving speed s of the thin film satisfy a relational expression of s = r × f.

The crystal growth apparatus according to the present invention includes a support means for supporting a thin film, irradiating means for irradiating and crystallizing the thin film of the mth (m is an integer of 1 or more) and the m + 1 band-like beam, and moving the supporting means relative to the irradiating means. Drive means, and control means for controlling the irradiation means and the drive means. The irradiating means irradiates the m-th and m + 1 band-like beams toward the thin film to form the m-th and m + 1th k-th crystallization regions on the thin film, and then the supporting means has a distance r (r) The driving means moves the thin film by a length t of the number of times of crystal growth, so that the m is separated from the k-th crystallization region m by a distance r and is partially overlapped with the k-th crystallization region m + 1. The control means controls the driving means and the irradiating means so that the irradiating means irradiates the band-shaped beam of to form the m-th k + 1th crystallization region continuous to the k-th crystallization region of m + 1.

In the crystal growth apparatus configured as described above, the irradiating means irradiates the band-shaped beam to form the m-th and m-th kth crystallization regions, and thereafter, the m-th th crystal is formed by a distance r longer than the length t of one crystal growth. Since the m-th k + 1th crystallization region is formed in the thin film in a region spaced from the k crystallization region, the next crystallization region can be formed at a position further away from the conventional one. As a result, compared with the prior art, another crystallization region can be formed in a region further separated from one crystallization region, and the manufacturing time can be shortened.

Also preferably, the control means controls the drive means and the irradiating means such that the drive means moves the support means with respect to the irradiating means at a constant speed, so that the irradiating means irradiates the beam with a certain period.

Also preferably, the crystal growth apparatus further includes a beam source for generating a beam.

Also preferably, the irradiating means comprises a mask having a plurality of slits. The mask diverges the light emitted from the beam source to form the m-th and m + 1 band-shaped beams.

Also preferably, the mask comprises a slit group of first to Nth (N is an integer of 2 or more) formed in parallel with direction 1, so that each of the first to Nth slit groups is parallel to direction 1 at a predetermined interval P And a plurality of slits, each of which has the same shape.

Also preferably, the number N of slit groups satisfies the relational formula of N = P / Q (Q is a distance on a mask corresponding to 0.2 to 0.8 times the length t of one crystal growth).

Also preferably, the drive means moves the support means at a constant speed relative to the irradiating means.

According to another aspect of the present invention, a beam branching apparatus includes a first to Nth region (N is an integer of 2 or more) and parallel to the first to Nth slit groups formed in each of the first to Nth regions. Equipped. Each of the first to Nth slit groups includes a plurality of slits formed side by side in the first direction at the same interval P. FIG. From the boundary portion between the S-region (S is an integer of 1 or more and Nl or less) and the S + 1 region adjacent to the S-region, to the slit located at the portion closest to the S region of the S + 1 region Is the distance on the beam branching device corresponding to 0.2 to 0.8 times the length t of the crystal growth.

In the beam branching apparatus configured as described above, the slit group of the S-th group formed in the S-th region and the slit group of the S + 1 formed in the S + l-region are shifted by the distance Q, so that the movement amount is constant. Each crystallization area | region can be formed in the position which shifted only the position.

A display device according to an aspect of the present invention includes a pixel region in which a plurality of pixels are disposed, and an outer peripheral region formed by polycrystals arranged to surround the pixel region and extending in a substantially constant direction. The width of one pixel along the direction in which the polycrystal extends is almost a natural number multiple of the length of the polycrystal of the outer peripheral region.

A display device according to another aspect of the present invention includes a pixel region in which a plurality of pixels are arranged, and an outer peripheral region formed by polycrystals arranged to surround the pixel region and extending in a substantially constant direction. The length of the polycrystal of the outer circumferential region is almost a natural multiple of the width of one pixel.

Best Mode for Carrying Out the Invention Embodiments of the present invention will be described below with reference to the drawings.

(Example 1)

1 is a schematic diagram showing an apparatus for manufacturing a semiconductor thin film according to Example 1 of the present invention. Referring to FIG. 1, the crystal growth apparatus 1 includes a beam radiating means 11, a variable attenuating means 12, a beam shaping means 13, an irradiance uniforming means 14, a mask 16, and the like as a beam source. The imaging means 17 on the mask is provided.

The beam radiating means 11 radiates a pulsed beam capable of melting silicon. For example, it is preferable to configure the beam radiating means 11 with a light source that emits light having a wavelength in the ultraviolet region, such as an excimer laser and various solid laser oscillators represented by YAG (yttrium-aluminum-garnet) lasers. . In this embodiment, an excimer laser oscillator whose wavelength emits light of 308 nm is employed as the beam radiating means 11.

The variable attenuation means 12 is a means for attenuating the irradiance of the beam irradiating the substrate surface at a predetermined ratio.

The beam shaping means 13 shapes the beam to a predetermined dimension. The irradiance uniformity means 14 is a means for making uniform irradiance of the nonuniform beam. Specifically, the beam of the Gaussian type irradiance distribution is divided once using a cylindrical lens array and a condenser lens, and then polymerized and irradiated on the surface of the mask 16 again.

The mask 16 branches the beam to form an i-th slit beam group consisting of one or more slit beams. Here, i is an integer of 1 or more and n or less. In addition, in this specification, a "slit beam" means either the image of the slit-shaped beam (light) formed on the board | substrate, the beam which produces the image, or the optical path of a beam. In addition, about the shape or the dimension of a slit-shaped beam, it is talking about the shape or the dimension on it.

The mask image forming means 17 is a slit beam forming means which forms an image of a slit beam formed by the mask 16 on the substrate as an image. Specifically, a lens or the like is used.

In addition, the radial direction changing means 19 is a means for changing the radial direction of the beam, and is composed of, for example, a mirror or a lens. There is no restriction | limiting in particular in arrangement place and quantity, You may arrange | position appropriately according to the optical design of an apparatus, and mechanical design.

In addition, this apparatus only needs to be able to irradiate a slit-shaped beam of appropriate and uniform illuminance at any position on the substrate, and is not specific to the structural example of the apparatus described above.

2 is a plan view of a mask having a slit according to Embodiment 1 of the present invention. Referring to Fig. 2, the mask 16 has a first region 10lA, a second region 10lB, and a third region 10lC ... N-th region 10lN arranged side by side in the direction 1. First to Nth slit groups 102A to 102N are disposed in each of the first to Nth regions 110 to 10LN. Each of the first to Nth slit groups 102A to 102N includes a plurality of slits 102 formed side by side in the same direction 1 at the same interval P. FIG. The second region 10lC of the third region 10lC from the boundary between the second region 10lB as the S region and the third region 101C as the S + 1 region adjacent to the second region 10lB. The distance to the slit 102 located closest to 10 lB) is S x Q (2 x Q). Q is 0.2 times or more and 0.8 times or less of the distance on the mask 16 corresponding to the length t of one crystal growth. For example, if the pattern of length 100mm on the mask 16 is transferred to the amorphous silicon thin film 201 and the length of the pattern is 20mm, the imaging magnification of the mask is 1/5. In this case, letting one crystal growth length be t, Q becomes 0.2x5xt or more and 0.8x5xt or less.

The mask 16 is formed adjacent to the first slit group 110A and the first slit group 102A in which a plurality of slits 110 are formed side by side in the same direction P at the same interval P, thereby forming the first slit group 102A. The same number of slits l02 are provided with a second group of slits l02B formed at equal intervals. An interval D between the first slit group 102A and the second slit group 102B is different from the interval P.

Since the slit beam passing through the slit 102 of the mask 16 forms an image on the semiconductor thin film at a constant magnification, the shape of the slit and the shape of the beam are similar. Moreover, the dimension on a mask is shown by capital letter, and the dimension of the beam irradiated to a semiconductor thin film is shown by small letter.

2A shows the dimensions of the effective area of the mask, which is a rectangular area. The effective area is an area on the mask irradiated by one pulse beam (hereinafter referred to as "pulse beam") (hereinafter, referred to as pulse irradiation). In addition, the area | region on the semiconductor thin film corresponding to an effective area is called irradiation area.

The effective regions are equally divided into N (N is an integer of 2 or more predetermined), so that the first to Nth regions 10lA to 10lN are formed. Here, the length C of each of the first to Nth regions 10lA to 10lN is B / N. In each of the first to Nth regions 10lA to 10lN, slit groups 102A to 102N as slit type light transmitting portions composed of one or more slits 102 are formed. In this embodiment, the slit-like light transmitting portion formed in the i (i is an integer of 1 or more and N or less) region is called an i-th slit group. The slit beam group formed by the i-th slit group is referred to as the i-th slit beam group. The distance P between each slit 102 is the same. In addition, each slit-like light transmitting portion has an equal number of slits 102. The arrangement position of the S + 1 slit group with respect to the S + 1 area is not less than 0.2 times the length of the crystal formed or grown by one beam irradiation, compared with the position of the S slit group with respect to the S area. It shifts to the right by the distance Q on the mask 16 corresponding to the length q (Fig. 6) of 0.8 times or less.

Next, a method of crystallizing the thin film according to this embodiment will be described. 3 and 5 are cross-sectional views of the mask shown for explaining the method of crystallizing the thin film. Referring to FIG. 3, an amorphous silicon thin film 201 is formed on a substrate 18. The mask 16 is placed on the amorphous silicon thin film 201, and the beam 300 is irradiated to the mask 16. In addition, although the mask image forming means 17 and the radial direction changing means 19 as shown in FIG. 1 exist between the mask 16 and the amorphous silicon thin film 20l, these are omitted in FIG.

The beam 300 is divided into a plurality of band-shaped beams 301A to 30LN by the mask 16. The band beams 30lA to 30lN are irradiated onto the amorphous silicon thin film 201, and the irradiated regions are melted. By melting this region after melting, a crystallization region is formed. For example, the mth kth crystallization region 202a, the m + 1th kth crystallization region 202b, the mth + 2th kth crystallization region 202c,... The kth crystallization region 202n of m + n is formed.

FIG. 4 is an enlarged view of the m-th kth crystallization region 202a shown in FIG. 3. Referring to Fig. 4, when the strip-shaped beam 30lA is irradiated onto the amorphous silicon thin film 201, the irradiated region is melted. After melting this region solidifies in the direction shown by arrow 222. At this time, the growth length of one crystal is represented by t.

Referring to FIG. 5, in the m-th kth crystallization region 202a, a distance r (r is longer than the length t of l crystal growths) is separated and is part of the k-th crystallization region 202b of m + 1. Irradiates the band-shaped beam 30lA as the m-th band-shaped beam to a region where is overlapped with each other, thereby forming the m-th k + 1th crystallized region 203a continuous to the m-th k-th crystallized region 202b. It forms in 201. A separate crystallization region is formed so as to overlap another portion of the crystallization region formed earlier. Specifically, m + 1th k + 1th crystallization region 203b, m + 2th k + 1th crystallization region 203c, ... m + nth k + 1th crystallization region 203n ).

FIG. 6 is an enlarged view of the m-th k + 1th crystallization region 203a shown in FIG. 5. Referring to Fig. 6, when the band-shaped beam 30lA is irradiated, the irradiated portion is melted. At this time, since the band-shaped beam 301A also covers the k-th crystallization region 202b of m + 1, crystals extend from the k-th crystallization region 202b of m + l. For this reason, the crystal produced in the process shown in FIG. 4 becomes longer. By repeating this process, crystals can be grown.

That is, in the crystal growth method according to the present invention, the amorphous silicon thin film 201 is irradiated with the m-th (m is an integer greater than or equal to 1) and the band-shaped beams 30lA and 30lB of the m + 1 toward the amorphous silicon thin film 201. Forming m-th and m + 1th kth crystallization regions 202a and 202b, and a distance r (r is greater than a length t of one crystal growth) from the k-th kth crystallization region M-th continuous beams are irradiated to the m-th crystallization region 202b of m + 1 and irradiated to the k-th crystallization region 202b of m + 1. And forming the k + 1th crystallization region 203a in the amorphous silicon thin film 201.

The crystal growth apparatus 1 includes support means 21 for supporting the amorphous silicon thin film 201, and an m-th (m is an integer of 1 or more) and an m + l band-like beam 30lA, Irradiation means 10 for irradiating and crystallizing 30 lB), driving means 9 for moving the support means 21 relative to the irradiation means 10, and controlling the irradiation means 10 and the driving means 9; The control means 20 is provided. The irradiating means 10 comprises a beam shaping means 13 and an irradiance uniforming means 14. Irradiation means 10 irradiates the m-th and m + l band-like beams 30lA and 30lB toward the amorphous silicon thin film 201 so that the k-th crystallization of m-th and m + l-th of the amorphous silicon thin film 201F is performed. After the formation of the regions 202a and 202b, the driving means 9 moves the supporting means 21 by the distance r (r is greater than the length t of one crystal growth) with respect to the irradiating means l0. Irradiating means 10 to the m-th band-like beam 30lA in a region spaced apart from the m-th kth crystallization region 202a by a distance r and partially overlapping the k-th crystallization region 202b of m + 1. ) Is irradiated to form the m-th k + 1th crystallization region 203a continuous to the m-th + 1th kth crystallization region 202b in the amorphous silicon thin film 201. The control means 20 controls 10.

The process of forming the k-th crystallization regions 202a to 202n and the process of forming the k + 1th crystallization regions 203a to 203n include thin films of the band-shaped beams 30lA to 30lN constituting the first to n-th band-shaped beam groups. Including the step of irradiating toward, each of the first to n-th band-like beam groups includes y (y is greater than l) beams formed side by side in a direction 1 with an interval p therebetween, The distance q from the kth crystallization region 202b to the mth k + 1th crystallization region 203a is not less than 0.2 times but not more than 0.8 times the length t of one crystal growth.

7 is a view for explaining the movement trajectory of the irradiation area according to the present invention. Referring to Fig. 7, the steps according to this embodiment will be described.

Step l

The irradiation region 4 of the mask is disposed at the upper left end of the substrate 18. Proceed to step 2.

Step 2

If the irradiation area 4 is at the left end of the substrate 18, the step of crystallizing the band-like area in the reverse direction is performed until the irradiation area 4 reaches the right end of the substrate 18. The step of crystallizing the band-shaped region in the reverse direction is a step of crystallizing the band-shaped region of the width a of the movement trajectory of the irradiation region 4 while moving the irradiation region 4 in the right direction (direction indicated by the arrow 4a). to be. Proceed to step 3.

Step 3

If the irradiation area 4 is at the right end of the substrate 18, the step of crystallizing the band-like area in the forward direction until the irradiation area 4 reaches the left end of the substrate 18 is performed. The step of crystallizing the band-shaped region in the forward direction is a step of crystallizing the band-shaped region of the width a of the movement trace of the irradiation region 4 while moving the irradiation region to the left. Proceed to step 4.

Step 4

The irradiation area 4 is moved downward by a distance. Proceed to step 5.

Step 5

If the irradiation area 4 is below the lower end of the substrate 18, the step ends. Otherwise, return to Step 2.

As described above, the thin film formed on the entire surface of the substrate 18 can be crystallized by repeating from Step 1 to Step 5 in this order. In addition, although the structure which stopped the board | substrate 18 and moves the irradiation area 4 was demonstrated in FIG. 7, the board | substrate 18 and the irradiation area 4 may move relatively. Either or both of the substrate 18 and the irradiation area 4 may be moved.

Next, a step of crystallizing the band region in the forward direction will be described. 8 is a view showing a state in which a crystallization region is formed in a band region in the forward band crystallization region. Referring to Fig. 8, first, the first slit beam group is irradiated in the first crystallization step. The first slit beam group forms the crystallization region 1a. Next, the irradiation area is moved by the length on the substrate corresponding to the length C of the equal division area in the left direction indicated by 3a. In the second crystallization step, the second slit beam group is irradiated. The second slit beam group forms the crystallization region 1b. Since the crystallization region 1b is a position shifted to the right by q on the substrate with respect to the crystallization region 1a, crystal growth is carried over by the crystal grown by the first slit beam group. Thereafter, as in the second crystallization step, the third, fourth,... The crystallization region is formed by sequentially performing the nth crystallization process.

In this embodiment, N slit-like light transmitting portions from the first slit-like light transmitting portion moving from the left to the right by the distance C in the mask to the N-th slit-like light transmitting portion are formed side by side. Therefore, by using this mask, first crystallization is performed for the regions on the N substrates which are shifted by the distance c (the distance on the amorphous silicon thin film 201 corresponding to the distance C on the mask 16) and are arranged from left to right. The step to the n-th crystallization step can be carried out simultaneously. Since the irradiation area performs the nth crystallization step in the first crystallization step while moving the irradiation area from the right to the left by the distance c, as a whole, it becomes a conveyor system, and the locus-shaped area after the irradiation area passes through the first area. The crystallization step to the n-th crystallization step are performed sequentially to form a crystallization region.

Next, the process of crystallizing the band region in the reverse direction will be described. In the step of crystallizing the band-like region in the reverse direction, the moving direction of the irradiation region is from left to right, that is, n, n-1,... Crystallization is performed in the order of the second and first crystallization processes, and the crystallization of the band-like region in the forward direction is performed except that the crystal growth direction is from right to left. The same crystallization region can be formed as in the process.

Further, in the process of crystallizing the band-like region in the forward direction and the process of crystallizing the band-like region in the reverse direction, when the frequency of the pulse irradiation is constant, it corresponds to the length C of the divided first to Nth regions 10lA to 101N. The substrate or the irradiation area is relatively moved by the length c (the amount of movement between pulse irradiation) on the substrate and the constant speed c × f obtained from the frequency f of the pulse irradiation. As such, the slit beam similar to the shape of the slit transmission portion shown in FIG. 2 may be periodically pulsed at a frequency f. In this case, since the pulse irradiation can be performed while the substrate or the irradiation area is relatively moved at a constant speed, the substrate or the irradiation area can be moved in a short time rather than stopping the substrate or the irradiation area at a predetermined position. In addition, by performing pulse irradiation while changing the speed or frequency, it is possible to easily maintain the accuracy of the position where the pulse irradiation is performed, and to reduce the consumption of energy and equipment used for movement.

In addition, since the slit type light transmitting portion has a pitch of P and the length of the pitch direction of each of the first to Nth regions is C, the number of slits that can be formed in the equal division region is Y ≦ C / P = c / p. to be. Therefore, when Y is made into the largest integer which satisfies Y <= C / P, the largest crystallization area | region can be formed. In addition, Y may be determined first, and C may be obtained by the formula C = Y × P. Moreover, you may calculate B from C and N by Formula B = CxN. In this case, the constant speed s is c × f = p × Y × f.

Comparing the processing speed of the method described in Japanese Patent Laid-Open No. 2000-306859 with the method of Example 1 is as follows. After the pulse irradiation, the time until the next pulse irradiation is determined by the longer of moving the substrate or the irradiation area to the position where the next pulse irradiation is performed and the time when the beam radiating means enables the next pulse irradiation. In the method described in Japanese Patent Laid-Open No. 2000-306859, a step of moving the distance q by pulse irradiation is repeated to crystallize one irradiation area, and then a step of moving the distance b-q to the next irradiation area is performed. When the pulse irradiation is performed by moving the distance q, the moving is completed immediately because the moving distance is very short. Therefore, the time from the pulse irradiation to the next pulse irradiation is the same as the time at which the beam radiating means enables the next pulse irradiation. On the contrary, when moving to the next irradiation area, the moving distance is very long, which takes more time. In the meantime, the beam radiating means is in a standby state, i.e., does not radiate a beam.

On the other hand, in the above-described Embodiment 1, if the distance c is set shorter than the longest length that can be moved for the time when the next pulse irradiation becomes possible, the beam radiating means can emit the pulse beam at the shortest possible period. Can be. As described above, since the present invention does not need to move to the next irradiation area as in the method described in Japanese Patent Laid-Open No. 2000-306859, as a result, the processing time is reduced by the time required to move to the next irradiation area in Japanese Patent Laid-Open No. 2000-306859. Can be.

In addition, in the embodiment of the present invention, in order to make the crystal length equal to the pitch p of the slit beam, it is necessary to perform n = p / q (times) pulse irradiation on one crystallization region. For this purpose, it is preferable to set the number of slit type light transmission parts or the number of slit beam groups to n (piece).

If the length of the entire irradiation area is b, the amount of movement between the pulse irradiations is c = b / n = b × q / p, and the length C of the equal division area may be the distance on the mask corresponding to c described above. In this case, the number of slit beams included in one slit beam group is y = c / p = b × q / p2.

In addition, when pulse irradiation is carried out at the constant frequency f while moving the irradiation area or the substrate at a constant speed, the constant speed s = c x f = b x f x q / p.

(Example 2)

In the practice of the present invention, various embodiments are possible in addition to the case where the entire surface of the substrate is crystallized as in the first embodiment.

In particular, when a liquid crystal display device is formed using a polycrystalline silicon thin film on a glass substrate manufactured according to the present invention, a unique effect is obtained. The layout of the display element formed on the board | substrate is shown in FIG.

Fig. 9 shows a layout in which nine display elements in total are formed from one glass substrate at a time. The layout of display elements, such as active matrix liquid crystal display elements, is generally divided into pixel regions 31 and peripheral portions thereof (frame regions 32).

In the pixel region 31, a thin film transistor for driving a pixel and a liquid crystal is disposed, and a driver for pixel driving is disposed in the frame region 32. In a conventional display element, a driver was formed on a silicon wafer, and the silicon wafer cut into chips was mounted on a liquid crystal substrate and electrically connected thereto. Since this method includes a process of manufacturing a separate chip or a process of mounting a chip, not only is there a lot of processes, but also a long manufacturing time and a high manufacturing cost (paid and material costs). There existed a fault, such as a dimension becoming large.

Thus, a method has been proposed in which these driver circuits are made in advance on a liquid crystal glass substrate. At this time, not only the driver circuit but also other signal processing circuits (image processing circuits, memory circuits, controller circuits, power supply circuits, etc.) conventionally attached to the outside can be made on the liquid crystal substrate. In this case, however, it is necessary to make a high speed or high current drive or a small circuit such as a driver circuit in the frame region 32, so that the silicon thin film formed in the frame region 32 is required to have high carrier mobility. do. Specifically, the mobility of the carrier is from 100 cm ² / (Vsec) to 200 cm ² / (Vsec) or more, preferably about 50 cm ² / (Vsec).

In Embodiment 2 of the present invention, pixel driving or signal processing is accelerated by crystallizing the frame region 32 and forming a high-speed transistor made of silicon having high carrier mobility. In addition, since the pixel region 31 does not require high mobility, recrystallization due to super side growth is not performed, and the amorphous silicon or isotropic polycrystalline silicon is not formed . The mask used in this embodiment is shown in Figs. 1 and 2 as a structure similar to that of the first embodiment. However, in the second embodiment, the length a of the slit beam formed by the slit light transmitting portion of length A on the mask is set equal to or wider than the width α of the frame region 32 shown in FIG. . By setting in this way, it is possible to form a series of frame regions 32 arranged in a row by performing a forward band region crystallization process or a reverse band region crystallization process for the frame regions 32 arranged in one row.

The flow of movement of the irradiation area will be described with reference to FIG.

Step 1

The irradiation area 4 is disposed at the upper left position 420 in the drawing. Proceed to step 2.

Step 2

A reverse band region crystallization process is performed until the irradiation region 4 reaches the right end to crystallize a series of frame regions 32. Proceed to step 3.

Step 3

The irradiation area 4 is moved as indicated by the arrow 41 in the row of the frame area 32 immediately below it. Proceed to step 4.

Step 4

A forward band region crystallization process is performed until the irradiation region 4 reaches the left end to crystallize rows of the frame region 32. Proceed to step 5.

Step 5

If the lowest frame area 32 is crystallized, the process proceeds to step 7. If not, go to Step 6.

Step 6

The irradiation area 4 is moved as indicated by the arrow 42 in the row of the frame area 32 immediately below it. Proceed to step 2.

Step 7

If all of the frame area 32 is crystallized, the process ends. Otherwise, go to Step 8.

Step 8

The substrate 18 or the irradiation area 4 is rotated 90 degrees. Proceed to step 1.

By the above-described flow, the frame region 32 that requires high mobility is crystallized, and the pixel region 31 that does not require high mobility is not crystallized, so that the entire surface of the substrate 18 is crystallized. Manufacturing time can be shortened. Usually, since the area of the frame occupies only about 10 to 20% of the total substrate area, the crystallization time can be greatly shortened if the pixel area is not crystallized as in the second embodiment.

Further, this embodiment crystallizes the frame region 32 on all sides of the pixel region 31, but all or part of the frame region 32 of the four frame regions 32 on all sides is replaced. Crystallization alone has a significant effect. Therefore, it is not necessary to crystallize all the frame regions 32 on all sides of the pixel region 31.

In addition, the length a of the slit-shaped light transmitting beam is set equal to or larger than the width α of the frame region 32 shown in Fig. 9, and the unnecessary beam irradiation is avoided by utilizing the flow of the irradiation region movement of the beam irradiation. In addition, it is possible to shorten the distance for moving the irradiation area of the beam irradiation. Furthermore, crystallization can be performed in a short time and with low energy.

10 shows a detailed view of the crystallization region crystallized in Example 2. FIG. Referring to Fig. 10, when crystallization is performed in accordance with this embodiment, an elongated polycrystal 210 is obtained in which the orientation of the crystal is provided in the longitudinal direction of the frame region 32. Figs. Here, the pixel region 31 is in the pixel region of the liquid crystal, and the frame region 32 is disposed around the pixel region 31. In addition, the grid line described in the pixel region 31 represents a boundary between the pixel and the pixel.

 In Japanese Patent Laid-Open Nos. 2000-243968, 2000-243969 and 2000-243970, a technique for defining the direction of crystal anisotropy and the gate length of a transistor is disclosed. However, the technique described in these publications is characterized in that a plurality of crystals are included in the longitudinal direction of the gate.

In the present invention, the pitch p of the slit beam is equal to the pitch of the crystallization region. In this embodiment, since the band region is formed along the periphery of the pixel region, the direction of the boundary between the crystallization region and the pixel region adjacent to the crystallization region and the long crystal in the crystallization region are the same. Do. Therefore, by combining the pitch p of the slit beam and the pitch of the pixel, each pixel column and each crystallization region can be corresponded one-to-one. Fig. 10 is a detailed view showing the coincidence between the pixel and the crystallization region in the case where the pitch p of the slit beam and the pitch of the pixel are combined to crystallize. In the state of FIG. 10, since each crystallization region corresponds one-to-one with respect to each pixel column (a series of pixels continuous in the vertical direction in FIG. 10), transistors corresponding to one pixel column are assigned to one corresponding crystallization region. Can be formed.

Although it is preferable to arrange a driver transistor for driving a pixel or a transistor for other uses in the frame region 32, in such a case, the capability required for the transistor is various. A transistor requiring high speed is required to have a small device size, but a transistor having a large current driving capability for use in pixel driving or the like is required to have a wide channel width.

The pixel pitch varies depending on the liquid crystal substrate, but is designed in the range of approximately 100 µm to 100 µm. On the other hand, the width of the transistor to be molded is required to be several tens to hundreds of microns, and the transistor must be arranged for each pixel column.

According to the second embodiment, even in the transistor having a channel width, the transistor having an arbitrary channel width can be easily formed by setting the channel direction (the direction in which the current flows) in the longitudinal direction of the frame region 32. In addition, since the transistor has the same channel direction (direction of current flow) as that in which the mobility is high, a transistor having a high processing speed can be obtained. The two transistors 25 shown in Fig. 10 each have a narrow channel width and a wide channel width.

As another example, as shown in Fig. 11, it is also possible to set the width of the crystallization region formed in the frame region 32 to twice the pixel pitch. Also in this case, the same effects as in the example shown in FIG. 10 described above can be obtained. In the transistor shown in Fig. 11, the arrangement of the transistors can be arranged in a set of two pixel columns and one crystallization region, and a high-speed transistor can be formed in the crystallization region corresponding to the two pixel columns. Therefore, the design can be made more freely than in FIG.

Further, as shown in Fig. 12, it is also possible to set the crystallization region in the width of three pixel columns. In this case, the same effects as in the case where the width of the crystallization region in which the frame region 32 is formed are set to twice the pixel pitch can be obtained, and the design can be made more freely.

Further, as shown in Figs. 13 and 14, it is also possible to set a plurality of crystallization regions in the width of one pixel column, and to form a transistor having a high speed and an arbitrary channel width for each pixel column. That is, if the crystallization region is formed such that the pitch of the crystallization region is at least an integer multiple of the pixel pitch or an integer fraction, the transistor having a high speed and an arbitrary channel width corresponding to each pixel column can be easily formed.

The display device 600 of FIGS. 13 and 14 includes a pixel region 31 serving as a pixel region in which a plurality of pixels 31a are disposed, and a polycrystal 210 provided to surround the pixel region 31 and extending in a substantially constant direction. Frame region 32 as an outer circumferential region constituted by (). The width G of one pixel along the direction in which the polycrystal 210 extends is almost a natural multiple of the length J of the polycrystal 210 of the frame region 32.

The display device 600 of FIGS. 10 to 12 includes a pixel region 3 l in which a plurality of pixels 31 a are disposed, and a poly crystal 210 disposed to surround the pixel region 31 and extending in a substantially constant direction. The frame area 32 is formed as an outer circumferential area. The length J of the polycrystal 210 of the frame region 32 is almost a natural multiple of the width G of one pixel 31a.

Next, the crystallization time in the conventional crystallization method and the crystallization method according to the present invention will be described in detail.

As the precondition, the manufacturing conditions common to various manufacturing methods are unified as follows.

Board dimensions: 320 mm × 400 mm

Irradiation frequency f of the beam in the beam irradiation means: 300 Hz

Feed pitch q per pulse irradiation due to super side growth q: 0.5 μm

First, the time required for crystallizing the entire surface of the substrate using one slit beam is calculated.

Fig. 15 is a view for explaining a method for manufacturing a polycrystalline semiconductor thin film by a conventional single slit beam. FIG. 15 is a configuration in which the substrate moves at a constant speed while pulse-irradiating one slit beam capable of collectively irradiating short sides of the substrate.

(Feed rate s) of substrate = (feed pitch q) x (beam irradiation frequency f)

= 0.0005 × 300

= 0.51 mm / sec. therefore,

(Time required to crystallize the front of the substrate)

= (Substrate length / feed rate s) = 400 / 0.15 = 2667 seconds.

Next, the time required for crystallizing the entire surface of the substrate is calculated by the crystallization method described in Japanese Patent Laid-Open No. 2000-306859. In this publication, a mask in which slits are formed at the same pitch is used. In this case, as described in the above publication, after the crystallization is completed for each beam irradiation area on the entire surface of the substrate, the irradiation area is moved to the next irradiation. Various manufacturing conditions are determined as follows.

Length of needle-like crystals due to super side growth p: 50 μm

(= Pitch of slit beam on substrate surface)

Mask phase imaging magnification: 1/5

Area of irradiation area: 20mm × 20mm

Area of Effective Area on Mask Surface: 100mm × 100mm

In the prior art, the number of pulse irradiation times n required for one irradiation area is

(Number of pulse irradiation n for one irradiation area) = (length p of needle crystal) /

(Feed pitch q) = 0.05 / 0.0005

= 10O (times)

The time t required for crystallization of one irradiation area is

(Time to Crystallize One Irradiation Area)

= (Number of pulse irradiation n for one irradiation time) / (beam irradiation frequency f)

= l00 / 300 = 0.333 (sec)

Although movement to the adjacent irradiation area is performed by moving a board | substrate, for example, time required for movement and a stop of a board | substrate is required about 0.3 second in total.

As described above, since the substrate size is 320 mm x 400 mm, (320/20) x (400/20) = 320 irradiation areas are sequentially crystallized.

Therefore, (time required to crystallize the substrate front)

= {(Time to crystallize one irradiation area) + (time required for movement to an adjacent irradiation area)} x (number of irradiation areas) = (0.333 + 0.3) x 320 = 203 seconds.

Next, the time required for crystallizing the entire substrate surface is calculated for the crystallization method according to Example 1 of the present invention. As in the prior art described in the above publication, crystallization time calculation conditions and manufacturing conditions are as follows.

Length of needle crystal due to super side growth p: 50μm

(Pitch of slit beam on the substrate surface)

Magnification Ratio of Mask: 1/5

Area of irradiation area: 20mm × 20mm

(Effective area on mask surface: lOOmm × 1OOmm)

The moving speed s of the substrate for crystallizing the band-shaped region of width a (= 20 mm) in Fig. 7 is

s = c x f = b / n x f = b x f x q / p = 20 x 300 x 0.0005 / 0.05 = 60 (mm / sec).

In order to crystallize the entire substrate, one band region is crystallized and then moved to an adjacent band region, and the same process is repeated. The movement to the adjacent band-like region is performed by, for example, moving the substrate, but the time required for moving the substrate and stopping the substrate is about 0.3 seconds as in the prior art.

As described above, since the substrate size is 320 mm x 400 mm, 320/20 = 16 band-shaped regions are sequentially crystallized.

Thus, (time required to crystallize the substrate front)

= {(Time required for crystallization of 20 mm wide band-shaped region) + (time to move to adjacent band-shaped region)} × (number of band-shaped regions). In order to crystallize the band-shaped region 400 mm long, the beam must be irradiated while traveling 400 + bc = 400 + 20 × (l-0.0005 / 0.05) = 419.8, so the time required to crystallize the entire surface of the substrate is (4l9). .8 / 60 + 0.3) × l6 = 117 seconds. Therefore, the crystallization time can be shortened by about 42% compared to the method described in Japanese Patent Laid-Open No. 2000-306859.

If the length of the needle-shaped crystal due to super side growth is 20 µm, this time reduction effect is further remarkable. If the same calculation is performed on the basis of various manufacturing conditions as mentioned above, in the method of Unexamined-Japanese-Patent No. 2000-306859, it is (0.133 + 0.3) * 320 = 139 second.

In the case of the crystallization method according to the present invention, (419.5 / 150 + 0.3) x 16 = 50 seconds, the crystallization time can be shortened by about 64%.

Moreover, according to the Example of this invention, although the shape of the light transmitting part of a mask was made into the rectangular slit, the shape is not limited to this, It can be made into various shapes, such as mesh shape, a saw tooth shape, and a wave shape.

According to the crystal growth method of the present invention, after forming the k-th crystallization region of m-th and m + 1, after the distance r longer than the length t of one crystal growth, it is separated from the k-th crystallization region of m-th. Since the m-th k + 1th crystallization region is formed in the thin film, it is possible to form the next crystallization region at a further spaced distance than before. As a result, the movement time of the band-shaped beam can be shortened as compared with the conventional one, and the manufacturing time of the crystalline thin film can be shortened. In addition, by increasing the moving amount, it is possible to crystallize sequentially while varying the time for performing each step between the regions. This is a conveyor systemization of the crystallization process. That is, crystallization of a wide area can be performed uniformly and for a short time by periodic repetition of a simple process.

Further, according to the present invention, since the moving distance T of the band beam and the shape of the band beam are constant, the crystallization region can be formed in a regular pattern.

Further, in the present invention, each of the first to n-th band-like beam groups includes y beams formed side by side in the direction 1 with an interval p therebetween, and m-th k + l from the k-th crystallization region of m + 1 Since the distance q to the crystallization region is 0.2 to 0.8 times the length t of the single crystal growth, the first to n-th band-like beam groups are irradiated on the thin film, and then the next beam is positioned at a position shifted by a predetermined distance q. By irradiating with, a plurality of crystallization regions can be formed accurately and in a short time by using the band-like beam group.

In addition, in the present invention, when n satisfies p / q, the crystallization region can be produced most efficiently.

Further, the thin film is moved at a constant speed s to irradiate the band-like beams of m-th and m + 1 at a constant period f to the thin film so that the crystallization regions are parallel to the moving direction of the band-like beams of m-th and m + 1. Can be efficiently produced in a short time.

In the beam branching apparatus according to the present invention, the distance from the boundary between the S area and the S + 1 area adjacent to the S area to the slit located at the portion closest to the S area of the S + 1 area is Since S x Q and Q is a distance on the beam branching device corresponding to 0.2 times or more and 0.8 times or less the length of the crystal growth of one time, after irradiating the thin film with the beam through the S area and the S + l area, When the beam irradiating apparatus is moved by a predetermined distance to irradiate a beam onto the thin film, a next crystallization region overlapping with the first crystallization region formed is formed. As a result, the moving distance of the beam irradiation apparatus can be increased, and a thin film can be manufactured in a short time.

In the display device according to the present invention, since the width of one pixel along the direction in which the polycrystal extends is almost a natural multiple of the length of the polycrystal of the outer circumferential region, the pixel column group for a pixel column group consisting of a specific number and successively formed pixel columns. Since the transistor corresponding to can be formed, the design becomes easy. It also has a simple structure.

In the display device according to the present invention, since the length of the polycrystal in the outer circumferential region is almost a natural multiple of the width of one pixel along the direction in which the polycrystal extends, a transistor corresponding to the pixel column can be formed for one pixel column. Easy to design It also has a simple structure.

BACKGROUND OF THE INVENTION Field of the Invention The present invention is applied to the field of a display device having a crystal growth method using a beam such as a laser light, a crystal growth device and a beam branching device, and a thin film transistor using the polycrystalline thin film as an active layer.

Claims (17)

M-th (m is an integer of 1 or more) and m + 1 band-like beams 30lA, 30lB are irradiated toward the thin film 20l, so that the m-th and m + 1th kth crystallization regions 202a, 202b), and The distance r (r is greater than the length t of one crystal growth) from the k-th kth crystallization region, and is formed in a region overlapping a part of the k-th crystallization region 202b of m + 1. irradiating an m band-shaped beam (30lA) and forming an m-th k + l-crystallization region (203a) continuous to the m-th k-th crystallization region in a thin film. The crystal growth method according to claim 1, wherein the step of forming the k-th crystallization region comprises a step of branching the beam radiated from the beam source (1l) to form the m-th and m + 1 band-like beams. The method of claim 1, wherein the distance r is constant regardless of the value of m, and the shape of the m-th and m + l band-like beams is constant regardless of the value of m, and the plurality of k-th crystallization regions Side-by-side direction is a constant crystal growth method regardless of the value of k. The process of claim 1, wherein the forming of the k-th crystallization regions 202a through 202n and the forming of the k + 1th crystallization regions 203a through 203n include the first through n-th band-shaped beams 301A through 30LN. Including the step of irradiating the group toward the thin film, Each of the first to nth band-shaped beam groups includes y (y is greater than 1) beams formed parallel to the direction 1 with an interval p therebetween, And the distance q from the m-th k + th crystallization region to the m-th k + 1th crystallization region is 0.2 to 0.8 times the length t of one crystal growth. The crystal growth method of claim 4, wherein n satisfies a relation of n = p / q. 5. The process of claim 4, wherein the forming of the k + 1th crystallization regions 203a to 203n comprises moving the thin film at a constant speed to irradiate the mth and m + 1 band-like beams at a predetermined period. Crystal growth method. The crystal growth method according to claim 6, wherein the frequency f of irradiating the m-th and m + 1 band-like beams (30lA, 30lB) and the moving speed s of the thin film satisfy a relational expression of s = r × f. Support means 21 for supporting a thin film, Irradiation means 10 for crystallizing the thin film by irradiating m (m is an integer of 1 or more) and m + 1 band-shaped beams 30lA and 30lB; Drive means 9 for moving said support means relative to said irradiating means, and And a control means 20 for controlling the irradiation means and the driving means, The irradiating means irradiates the m-th and m + 1 band-shaped beams 30lA and 30lB toward the thin film and forms m-th and m + 1th k-th crystallization regions 202a and 202b in the thin film. The driving means moves the supporting means with respect to the irradiating means by a distance r (r is longer than the length t of one crystal growth), and the control means is an area separated by the distance r from the kth crystallization region of the mth. The m-th k + l crystallization continuous to the k-th crystallization region of the mth + 1 by the irradiation means by irradiating an m-th band-shaped beam to a region partially overlapping the k-th crystallization region of the mth + 1th A crystal growth apparatus for controlling the driving means and the irradiation means to form a region in the thin film. 9. The control means according to claim 8, wherein the driving means moves the support means with respect to the irradiating means at a constant speed, and the irradiating means irradiates the thin film at regular intervals with the driving means. Crystal growth apparatus to control. The crystal growth apparatus according to claim 8, further comprising a beam source (l1) for generating a beam. 11. The apparatus of claim 10, wherein said irradiating means comprises a mask (16) having a plurality of slits (102), said mask diverging light emitted from said beam source and shaping into said m &lt; th &gt; Crystal growth apparatus. 12. The mask of claim 11, wherein the mask includes first to Nth (N is an integer of 2 or more) slit groups 102A to 102N formed in parallel with each other in direction 1, wherein each of the first to Nth slit groups is predetermined. And a plurality of said slits (102) formed side by side in the direction 1 at an interval P, wherein each of said plurality of slits has the same shape. The crystal according to claim 12, wherein the number N of the slit groups satisfies a relation of N = P / Q, and Q is a distance on the mask corresponding to 0.2 times or more and 0.8 times or less the length t of one crystal growth. Growth device. The crystal growth apparatus according to claim 8, wherein the driving means moves the supporting means at a constant speed with respect to the irradiating means. The first to Nth regions 10lA to 10lN arranged side by side in the direction 1 and the first to Nth slits formed in each of the first to Nth regions (N is an integer of 2 or more). It is equipped with a beam branch device, Each of the first to Nth slit groups includes a plurality of slits 102 formed side by side in the same direction 1 at the same interval P, so that the S region (S is an integer of 1 or more and N-1 or less) and its S region At the boundary with the S + 1 region adjacent to, the distance from the S + 1 region to the slit closest to the S region is S × Q, and Q is the length t of one crystal growth. A beam branching apparatus, the distance on the beam branching apparatus corresponding to 0.2 to 0.8 times. A pixel region 3l in which a plurality of pixels 31a are disposed, and an outer circumferential region 32 formed by polycrystals arranged to surround the pixel region and extending in a substantially constant direction, the direction in which the polycrystals extend And the width of one of the pixels is a natural number multiple of the length of the polycrystal of the outer circumferential region. A pixel region 31 in which a plurality of pixels 3la are disposed, and an outer peripheral region 32 formed by a polycrystal 210 which is provided to surround the pixel region and extends in a substantially constant direction. And a length of the polycrystal of the region is a natural number multiple of the width of one pixel along the direction in which the polycrystal extends.