Laser annealing device and laser annealing method

The present invention relates to a laser annealing apparatus that irradiates an amorphous silicon film formed on a substrate with a plurality of laser beams through a plurality of microlenses to perform an annealing treatment, and in particular, it is easy to maintain and manage the irradiation energy of the laser beams. The present invention relates to a laser annealing apparatus and a laser annealing method capable of suppressing irregular shape of an irradiation pattern.

Conventionally, in this type of laser annealing device, a plurality of laser beams are formed by a microlens array, a focal point is formed for each beam, and each focal point of the beam is transferred to an amorphous silicon film surface side by a reduced transfer optical system. The amorphous silicon film in the thin film transistor (hereinafter referred to as "TFT") formation region is polysilicon by performing laser treatment by irradiating the amorphous silicon film surface with a beam. Has been able to prevent contaminants scattered during annealing from adhering to the optical system by installing a quartz plate as a protective member (see, for example, Patent Document 1).

Further, as an optical system protection means for preventing contaminants from adhering to the optical system, in a device for condensing and processing a laser beam on a work piece by a condensing lens, between a take-up reel and a delivery reel. to multiply passed off to transmit a laser beam are followed by a Irumu was arranged to be movable between the condenser lens and the workpiece (e.g., see Patent Document 2).

<p><patcit num="1"><text>Japanese Unexamined Patent Publication No. 2004-311906</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 7-100670</text></patcit></p>

<p> However, in the laser annealing apparatus described in Patent Document 1, since a quartz plate is used as a protective member for preventing contaminants from adhering to the optical system, the surface can be formed flat. Although the shape of the irradiation pattern is not disturbed, there is a problem that the contaminated quartz plate must be replaced after each use for a certain period of time, which complicates the work. Therefore, there is a problem that the irradiation energy of the laser beam cannot be stably maintained in a high state for a long time.</p><p> Further, since the optical system protection means described in Patent Document 2 has a film arranged so as to be movable between the condenser lens and the work piece, it is not necessary to replace the film every time it is used for a certain period of time. Although it has the advantage of being simple, the back tension on the film is due to the fact that the pair of rolls that guide the film are not placed facing each other at the edges of the condenser lens and the distance between the pair of rolls is long. There is a problem that vertical wrinkles parallel to the moving direction are likely to occur in the film between the pair of rolls. Therefore, when such an optical system protection means is applied to the laser annealing apparatus of Patent Document 1, the irradiation pattern shape of the laser beam irradiating the substrate is disturbed by the vertical wrinkles of the film, and the TFT formation region is formed. There is a problem that it cannot be annealed to a predetermined shape.</p><p> Therefore, the present invention provides a laser annealing device and a laser annealing method that can deal with such problems, facilitate maintenance and management of the irradiation energy of the laser beam, and suppress the shape disorder of the irradiation pattern. The purpose.</p>

<p> In order to achieve the above object, the laser annealing device according to the present invention is a laser annealing device that irradiates an amorphous silicon film formed on a substrate with a plurality of laser beams to perform an annealing treatment, and is to be annealed on the substrate. A mask having a plurality of openings having a shape similar to the shape of the region and the plurality of laser beams passing through the plurality of openings of the mask are collected on the substrate via a plurality of microlenses formed on one surface. A semi-cylindrical shape is formed with a microlens substrate that imparts a certain amount of light energy to the amorphous silicon film, and the microlens substrate is sandwiched between the microlens substrate and arranged so as to face each other with the axes substantially parallel to the positions of both edges thereof. It is provided with a pair of guides whose tops project toward the substrate side from the position of the tops of the microlenses, and a film which is movably stretched between the pair of guides and transmits the laser beam. is there.</p><p> With such a configuration, a plurality of laser beams each passing through the plurality of openings of the mask having a plurality of openings having a shape similar to the shape of the region to be annealed on the substrate are formed on one surface of the microlens substrate. It is collected on a substrate by a microlens, and a constant light energy is applied to an amorphous silicon film formed on the substrate for annealing treatment. At this time, a pair of semi-cylindrical guides are arranged so as to face the positions of both edges of the microlens substrate with their axes substantially parallel to each other, and the top portion protrudes toward the substrate side from the position of the top portion of the microlens. A film that transmits a laser beam is movably stretched around the lens to prevent contaminants from adhering to the surface of the microlens substrate.</p><p> Further, a delivery reel for feeding the film is provided on one side with the mask in between, and a take-up reel for winding the film is provided on the other side, and the pair of guides are provided with a constant back tension. The film is allowed to pass continuously at a constant speed or in a fixed amount at regular time intervals. As a result, the film is sent out from the delivery reel provided on one side with the mask in between, and the film is wound by the take-up reel provided on the other side while a constant back tension is applied between the pair of guides. The film is passed continuously at a constant speed or at regular intervals in a fixed amount.</p><p> Further, a transport means for moving the substrate at a constant speed in a direction intersecting the axes of the pair of guides is provided. As a result, the transfer means moves the substrate at a constant speed in the direction intersecting the axes of the pair of guides.</p><p> Furthermore, the substrate is a thin film transistor (hereinafter referred to as TFT) substrate for a display device, and the region to be annealed is a TFT formation region. As a result, the TFT formation region of the TFT substrate for the display device is laser-annealed.</p><p> The microlens is formed so as to have a focal point between the top of the microlens and the film, or between the film and the substrate. As a result, the microlens once focuses the laser beam on the focal point between the top of the microlens and the film, or between the film and the substrate.</p><p> Further, in the laser annealing method according to the present invention, a mask having a plurality of openings having a constant shape and a microlens substrate provided with a plurality of microlenses corresponding to the plurality of openings of the mask are interposed on the substrate. This is a laser annealing method in which a plurality of laser beams are irradiated to the amorphous silicon film formed in the lens to anneal it. The shape is a semi-cylindrical shape, and the axis is located at both edges of the microlens substrate. The pair of guides transmit the laser beam in a state where the centers are arranged so as to face each other with the centers substantially parallel to each other and the tops of the microlenses are stretched between a pair of guides protruding toward the substrate side from the position of the top of the microlens. A step of moving the substrate in a direction intersecting the axis of the lens, a step of moving the substrate facing the microlens substrate at a constant speed in the moving direction of the film, and a step of passing the film through the plurality of microlenses. It includes a step of collecting a plurality of transmitted laser beams on the substrate and applying a constant light energy to the amorphous silicon film.</p>

<p> According to the inventions according to claims 1 and 2, a movable film is provided between the microlens substrate to prevent contaminants from adhering to the surface of the microlens substrate, so that the film is frequently used. There is no need to replace the lens, and the maintenance of the irradiation energy of the laser beam can be easily performed. Moreover, since the film is supported by a pair of guides arranged so as to face each other across the microlens substrate, the distance between the pair of guides can be made much narrower than that in the prior art, and the film can move in the direction of movement of the film. It is possible to suppress the occurrence of parallel vertical wrinkles and suppress the shape disorder of the irradiation pattern. Therefore, the region to be annealed can be annealed with high shape accuracy.</p><p> Further, according to the invention of claim 3, since the laser annealing treatment is performed while moving the substrate at a constant speed, the laser annealing treatment of a large substrate can be performed using a small mask, and the cost of the laser annealing treatment step is high. Can be cheaper. In addition, the tact of the annealing process for a large substrate can be shortened.</p><p> Further, according to the invention of claim 4, the annealing treatment of the TFT forming region of the display TFT substrate can be uniformly performed. Therefore, the operating performance of the thin film transistor can be made substantially constant over the entire display area, and the quality of the displayed image can be improved.</p><p> According to the invention of claim 5, it is possible to suppress a part of the laser energy from being absorbed by the silicon vapor floating between the substrate surface and the film to cause energy loss. Further, since the film has no focus, the laser energy is not concentrated on the film, and it is possible to prevent the film from burning.</p><p> Further, according to the invention of claim 6, since a movable film is provided between the microlens substrate and the substrate to prevent contaminants from adhering to the surface of the microlens substrate, the film is frequently used. There is no need to replace the lens, and the maintenance of the irradiation energy of the laser beam can be easily performed. Moreover, since the film is supported by a pair of guides arranged so as to face each other across the microlens substrate, the distance between the pair of guides can be made much narrower than that in the prior art, and the film can move in the direction of movement of the film. It is possible to suppress the occurrence of parallel vertical wrinkles and suppress the shape disorder of the irradiation pattern. Therefore, the region to be annealed can be annealed with high shape accuracy. Further, since the laser annealing process is performed while moving the substrate at a constant speed, the laser annealing process of a large substrate can be performed using a small mask, and the cost of the laser annealing process can be reduced. In addition, the tact of the annealing process for a large substrate can be shortened.</p>

<figref num="1">It is a front view which shows the embodiment of the laser annealing apparatus by this invention.</figref><figref num="2">It is a top view which shows the TFT substrate used for a laser annealing process.</figref><figref num="3">It is a figure which shows the assembly structure example of the mask and the microlens substrate used for the laser annealing apparatus by this invention, (a) is a plan view, (b) is the OO line cross-sectional arrow view of (a).</figref><figref num="4">It is a partial cross-sectional front view which shows the main part of the laser annealing apparatus by this invention in an enlarged manner.</figref><figref num="5">It is explanatory drawing which shows the laser annealing process by the laser annealing apparatus of this invention.</figref>

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a front view showing an embodiment of the laser annealing apparatus according to the present invention. This laser annealing device irradiates an amorphous silicon film formed on a substrate with a plurality of laser beams through a plurality of microlenses to perform an annealing treatment. It includes a microlens substrate 4, an optical system protection means 5, and an alignment means 6.

Here, as shown in FIG. 2, the substrate has a TFT forming region 9 (annealed region) on the gate electrode at a portion corresponding to an intersection between a plurality of gate lines 7 and data lines 8 formed vertically and horizontally. ) Is a preset TFT substrate 10 for a display device, and a plurality of TFT forming regions 9 are set in a matrix with the same arrangement pitch (X in the vertical direction and Y in the horizontal direction) as the arrangement pitch of the pixel 11. Here, the transport direction of the TFT substrate 10 indicated by the arrow A (hereinafter, referred to as board transport direction) is referred to as vertical, and the direction intersecting the transport direction is referred to as horizontal. Then, on the TFT substrate 10, an alignment reference position, which is a reference for alignment between the TFT forming region 9 and the opening 16 of the mask 3 described later, is set at the edge of, for example, the gate wire 7 parallel to the substrate transport direction. .. In the present embodiment, the alignment reference position is set at the right edge of the gate line 7 located at the left end in the substrate transport direction. At this time, the horizontal distance between the right edge of the gate line 7 and the center of the TFT forming region 9 is determined by the design value. Although both the gate line 7 and the data line 8 are shown in FIG. 2, only the gate line 7 is formed in the laser annealing step.

In the transport means 1, the TFT substrate 10 is placed on the upper surface and the TFT substrate 10 is transported at a constant speed in one of the vertical and horizontal arrangement directions of the TFT forming region 9, for example, the arrow A direction shown in FIG. A plurality of unit stages 12 having a large number of ejection holes for ejecting gas and a large number of suction holes for sucking gas are arranged side by side in the substrate transport direction, and a plurality of TFT substrates 10 are arranged by balancing gas ejection and suction. In a state where a predetermined amount is floated on the unit stage 12, for example, a transfer roller 13 supports both end edges of the TFT substrate 10 for transfer.

A laser light source 2 is provided above the transport means 1. The laser light source 2 is an excimer laser that emits a laser beam L having a wavelength of, for example, 308 nm or 353 nm at a repetition period of, for example, 50 Hz.

A mask 3 is provided on the optical path of the laser beam L emitted from the laser light source 2. As shown in FIG. 3, the mask 3 has a shape similar to the shape of the TFT forming region 9 on the TFT substrate 10 on the light-shielding film 15 formed on one surface 14a of the transparent eg quartz substrate 14, for example, a plurality of circular openings 16 As shown in FIG. 3A, a pitch that is an integral multiple of 2 or more of the array pitch Y of the TFT formation regions 9 that are set in a plurality of directions intersecting the substrate transport direction (arrow A direction) ( (Indicated by 2Y in FIG. 3), for example, 6 rows of opening rows 17 are arranged side by side and arranged in parallel with each other separated by a distance X, and 3 rows are located on the leading side in the substrate transport direction. The subsequent three rows of opening rows 17 (hereinafter referred to as "second opening group 19") are opened so as to complement each of the openings 16 of the opening row 17 (hereinafter referred to as "first opening group 18"). It is formed by shifting it by a predetermined dimension (indicated by Y in FIG. 3) in the arrangement direction of 16. The surface 14b opposite to the surface 14a on which the light-shielding film 15 is formed is installed so as to be on the transport means 1 side.

A microlens substrate 4 is provided on the surface 14b of the mask 3 on the transport means 1 side. In this microlens substrate 4, a plurality of laser beams Lb that have passed through a plurality of openings 16 of the mask 3 are collected on the TFT substrate 10 via a plurality of microlenses, and are formed on an amorphous silicon film, for example, 2 J / cm.²As shown in FIG. 3, the width in the substrate transport direction (arrow A direction) is about 10 mm to about 15 mm, and the width in the direction intersecting the substrate transport direction is about 50 mm. A plurality of microlenses 20 are formed on one surface 21a of a transparent substrate 21 with the same arrangement pitch (X in the vertical direction and 2Y in the horizontal direction) as the plurality of openings 16 provided in the mask 3 (see the figure (a)). The other surface 21b is joined to the surface 14b of the mask 3 in a state where these optical axes are aligned with the center of the opening 16 of the mask 3 (see FIG. 3B). Here, the position of the back focus of each microlens 20 is between the apex of the microlens 20 and the film 22 described later passing under the microlens substrate 4, or between the film 22 and the substrate 21. It is good to design as follows. As a result, the light energy of the laser beam Lb focused by the microlens 20 is not absorbed by the silicon vapor floating between the 10 surfaces of the TFT substrate and the film 22 by the annealing treatment, and there is no possibility of causing energy loss. Further, since the film 22 has no focus, there is no possibility that the laser energy is concentrated on the film 22 and the film 22 is burnt.

An optical system protective means 5 is provided between the microlens substrate 4 and the upper surface of the conveying means 1 so that the film 22 that transmits the laser beam Lb can be moved. The optical system protective means 5 makes it possible to prevent contaminants scattered during the annealing process from adhering to the optical system. It is configured to include a take-up reel 24 and a pair of guides 25. In this case, the film 22 has an ultraviolet transmittance of 90% or more and a laser resistance of 10 J / cm.²As described above, for example, a polyethylene film having a thickness of about 10 μm is suitable.

Specifically, the delivery reel 23 feeds out the film 22 wound by a certain amount, and the back tension motor 27 provided in connection with the rotating shaft 26 sets the film 22 in the delivery direction (arrow B direction). The film 22 can be delivered in a state where the film 22 is constantly subjected to the tension in the opposite direction and the back tension is applied, and one side with the mask 3 in between (in FIG. 4, the substrate transport direction (arrow A direction)). It is provided on the front side of the mask 3 toward. Further, the take-up reel 24 is rotated in the direction of arrow C by a take-up motor 29 provided connected to the rotating shaft 28 to take up the film 22, and the take-up reel 23 is sandwiched between the masks 3. It is provided on the opposite side. Further, the pair of guides 25 is for suppressing the occurrence of vertical wrinkles parallel to the moving direction of the film 22 passing through the lower surface of the microlens substrate 4, and is a semicircle having a smooth surface. It has a columnar shape and is placed facing the lower surface 3b of the mask 3 at positions of both edges 4a and 4b of the microlens substrate 4 with the axis substantially parallel to each other, and the top is the top of the microlens 20. It is provided so as to protrude by a certain amount on the transport means 1 side (the TFT substrate 10 side passing below) from the position. As a result, the film 22 can move between the pair of guides 25 continuously at a constant speed or by a constant amount at a constant time interval in a state where a constant back tension is applied. In FIG. 4, reference numeral 30 is a guide roller that changes the moving direction of the film 22 and stabilizes the movement of the film 22.

An alignment means 6 is provided so that the mask 3 and the microlens substrate 4 can be finely moved in a direction intersecting the substrate transport direction. The alignment means 6 is for aligning the center of the aperture 16 (or the center of the microlens 20) of the mask 3 with the TFT forming region 9, and the drive is controlled by a control means (not shown). It has become.

The alignment by the alignment means 6 can be performed as follows. That is, 10 planes of the TFT substrate are imaged by a line camera (not shown) having a plurality of light receiving elements arranged in a straight line in a plane parallel to the upper surface of the unit stage 12 in a direction intersecting the substrate transport direction, and the captured image is captured. The image processing unit of the control means performs image processing to detect the position of the alignment reference of the TFT substrate 10, and compares the distance between the position of the alignment reference and the image pickup center of the line camera with the target value stored in the memory. It is preferable that the alignment means 6 is driven by the control means to move the mask 3 and the microlens 20 so as to calculate the deviation amount and correct the deviation amount. In this case, the image pickup center of the line camera and the reference position provided on the mask 3 (for example, the center of any opening 16 of the mask 3) are aligned in advance.

In FIG. 1, reference numeral 31 is a beam expander that expands the diameter of the laser beam L emitted from the laser light source 2, and reference numeral 32 is a homogenizer that equalizes the brightness distribution in the cross section of the laser beam L. Reference numeral 33 denotes a condenser lens that makes the laser beam L parallel and irradiates the mask 3.

Next, the operation of the laser annealing apparatus configured as described above and the laser annealing method will be described. First, the TFT substrate 10 on which the amorphous silicon film is formed so as to cover the entire surface is positioned with the amorphous silicon film facing up so that the gate wire 7 is parallel to the transport direction and placed on the upper surface of the transport means 1. To do.

Next, when the start switch is turned on, the TFT substrate 10 is floated on the upper surface of the unit stage 12 of the transfer means 1 by a predetermined amount, and the transfer means 1 is pulse-controlled by a control means (not shown) to perform the TFT. The substrate 10 is conveyed at a constant speed in the direction of arrow A shown in FIG.

Subsequently, the surface of the moving TFT substrate 10 is sequentially imaged by a line camera (not shown), the one-dimensional image is processed in real time by the image processing unit of the control means, and the brightness in the arrangement direction of the plurality of light receiving elements of the line camera is processed. Based on the change, a preset alignment reference position on the TFT substrate 10 (for example, the right edge of the gate line 7 located at the left end in the substrate transport direction in FIG. 2) is detected, and the detected alignment reference position is detected. And the distance between the image center of the line camera and the image center of the line camera are calculated. Next, the calculation result is set in advance and compared with the stored target value to calculate the amount of deviation from the target value. Then, the alignment means 6 is driven and controlled by the control means so as to correct the deviation amount, the mask 3 is moved in the direction intersecting the substrate transport direction, and the mask 3 and the TFT substrate 10 are aligned. As a result, the mask 3 can be made to follow the TFT substrate 10 that is moving while swinging sideways.

As the TFT substrate 10 moves, as shown in FIG. 5A, a row of TFT forming regions 9 located on the leading side in the transport direction is an opening row 17b on the leading side in the transport direction of the second opening group 19 of the mask 3. When it reaches directly below, the laser light source 2 lights up for a certain period of time, and the laser beam L irradiates the mask 3. Then, the plurality of laser beams Lb that have passed through the plurality of openings 16 of the mask 3 are collected on the TFT substrate 10 by the plurality of microlenses 20 of the microlens substrate 4, and the TFT forming region 9 corresponding to the second aperture group 19 is collected. Amorphous silicon film is annealed to be polysilicon.

Laser light source every time the TFT substrate 10 is moved by a distance equal to 3X, which is the distance between the aperture rows 17a and 17b located on the leading side of the first opening group 18 and the second opening group 19 of the mask 3 in the substrate transport direction, respectively. 2 is driven to light for a certain period of time. As a result, all the TFT forming regions 9 set on the TFT substrate 10 are sequentially annealed to be polysilicon, and the polysilicon film 34 is formed. Note that FIG. 5 (b) shows a state in which the TFT substrate 10 has moved by a distance of 3X from the state of FIG. 5 (a), and the TFT forming region 9 between the TFT forming regions 9 corresponding to the second opening group 19 is It shows the state of being annealed in the first opening group 18.

In such an annealing treatment, a part of the amorphous silicon film is vaporized by irradiation with the laser beam Lb and floats between the 10 surfaces of the TFT substrate and the microlens substrate 4, and this silicon vapor is used as a pollutant in the microlens 20. It may adhere to the surface of the lens and reduce the transmittance of the laser beam Lb. Therefore, in the present invention, the optical system protective means 5 is provided, and the film 22 that moves between the microlens substrate 4 and the upper surface (or TFT substrate 10) of the transport means 1 causes contaminants to be deposited on the 20 surfaces of the microlens. It prevents it from adhering. Hereinafter, the operation of the optical system protection means 5 will be described.

First, the take-up motor 29 is driven to rotate the take-up reel 24 in the direction of arrow C shown in FIG. 4, and the film 22 is taken up. As a result, the film 22 spanned between the pair of guides 25 provided on both edges 4a and 4b of the microlens substrate 4 moves continuously at a constant speed or by a fixed amount at regular time intervals. Therefore, the silicon vapor (pollutant) vaporized by the irradiation of the laser beam Lb and suspended between the 10th surface of the TFT substrate and the 4th surface of the microlens substrate adheres to the 22nd surface of the film and does not adhere to the 20th surface of the microlens. At this time, since the film 22 moves continuously at a constant speed or by a fixed amount at regular time intervals, the 22nd surface of the film, which is unacceptably soiled due to the adhesion of contaminants, moves to the downstream side and becomes microscopic. On the lower side of the lens substrate 4, 22 surfaces of a film having a transmittance of a certain level or higher always exist. Therefore, the transmittance of the laser beam Lb is always maintained above the permissible value, and the laser annealing treatment can be appropriately performed. In the experiment, it is known that when the laser beam Lb is shot at 1000 shots, the transmittance of the film 22 is reduced by about 7% of the permissible limit. Therefore, for example, it is preferable to move the film 22 by an amount corresponding to the distance between the pair of guides 25 for every 1000 shots of the laser beam Lb.

At this time, the back tension motor 27 connected to the rotating shaft 26 of the sending reel 23 generates a rotational force in the direction opposite to the sending direction of the film 22 indicated by the arrow B in FIG. Is giving tension in the opposite direction. Therefore, back tension is applied to the film 22, and the film 22 is stretched between the pair of guides 25. However, the distance between the pair of guides 25 can be made much narrower than the distance between the pair of rolls in the prior art, and even if the film 22 is back-tensioned, the pair of guides 25 of the film 22 The generation of vertical wrinkles parallel to the moving direction of the film 22 is suppressed in the intermediate portion. Therefore, the irradiation pattern shape of the laser beam Lb transmitted through the film 22 and irradiated onto the TFT substrate 10 is maintained to be substantially the same as the opening 16 of the mask 3, and the TFT formation region 9 of the TFT substrate 10 is accurately annealed. Can be processed.

When the series of annealing processes in the substrate transport direction is completed, the TFT substrate 10 is returned to the start position at high speed. After that, the step is moved by a certain distance in the direction intersecting the substrate transport direction, and the annealing treatment for the adjacent region is executed in the same manner as described above. Then, by repeating this, the entire surface of the TFT substrate 10 is annealed. Alternatively, when the first annealing process in the arrow A direction is completed, the TFT substrate 10 is stepped by a certain distance relative to the mask 3 in the direction intersecting the substrate transport direction, and then the transport direction is reversed. While transporting the TFT substrate 10 in the direction opposite to the arrow A, the annealing treatment for the adjacent region may be performed in the same manner as described above.

In any of the above cases, for example, a photo sensor is provided at the end point position in the substrate transport direction, and when the first annealing treatment on the TFT substrate 10 is completed, the transmittance of the film 22 is measured to estimate the allowable number of shots of the laser beam Lb. You may do so. Specifically, after performing the first annealing process while transporting the substrate to the end point position with the film 22 stopped moving, the transmittance of the film 22 is measured to calculate the amount of decrease in the transmittance. Estimate the allowable number of shots for the allowable decrease in transmittance from the number of shots of the laser beam Lb during the first annealing treatment. After that, the film 22 is stepped by a certain amount each time the number of shots of the laser beam Lb reaches the estimated allowable number of shots. As a result, the permissible number of shots of the laser beam Lb for determining the step movement timing of the film 22 is set from the measured value of the transmittance of the film 22, so that the transmittance of the film 22 is stabilized above a certain value. It can be maintained and the annealing process can always be performed properly.

In the above description, the case where the TFT substrate 10 is a substrate for a display device has been described, but the present invention is not limited to this, and the substrate is any kind such as a semiconductor substrate on which an amorphous silicon film is formed. You may.

1 ... Transport means 3 ... mask 4 ... Micro lens substrate 9 ... TFT formation region (annealed region) 10 ... TFT board 16 ... opening 20 ... micro lens 22 ... film 23 ... Sending reel 24 ... Take-up reel 25 ... Guide Lb ... laser beam