TW201820731A - Laser irradiation device and manufacturing method of thin film transistor - Google Patents

Abstract

If there is a bonding portion between annealing treatments on substrate, it is recognized that the bonding is uneven. The laser irradiation device of present invention includes: a light source, which produces laser; a projection lens, which proceeds the annealing by irradiating designated region of amorphous silicon thin film covered by each of thin film transistors on glass substrate with laser; and a projection mask pattern, which is provided on the projection lens and provided with a plurality of openings, so that laser is irradiated onto each of thin film transistors, in the case when annealing of the projection lens in a specified direction on the glass substrate ends, the projection lens moves to the orthogonal direction of the specified direction, and proceeds the annealing in the specified direction again, the projection mask pattern gradually increase the number of openings from outer column to inner column in the orthogonal direction.

Description

Laser irradiation device and method for manufacturing thin film transistor

The invention relates to the formation of a thin film transistor, in particular to a laser irradiation device that irradiates laser light on an amorphous silicon film on the thin film transistor to form a polycrystalline silicon film, a thin film transistor, and the manufacture of a thin film transistor method.

The conventionally known thin film transistors with an inverted staggered structure use an amorphous silicon film in the channel area. However, since the electron mobility of the amorphous silicon thin film is small, the use of the amorphous silicon thin film in the channel region has the disadvantage that the charge mobility of the thin film transistor is small.

Therefore, the specified area of the amorphous silicon film is instantaneously heated by laser light to polycrystallize it to form a polycrystalline silicon film with a high electron mobility, and the use of the polycrystalline silicon film in the channel area is an existing technology.

As described in Patent Document 1 for a laser irradiation device, a semiconductor laser that can be driven continuously and has high output stability is used to form a polycrystalline silicon thin film with good reproducibility, high speed, and good crystal characteristics and high carrier mobility.

In addition, it is disclosed in Patent Document 1 that, as shown in FIG. 10, by operating a scanner with a laser irradiation head for annealing, the transparent substrate is operated in the X direction (vertical), and then moved one step in the Y direction (horizontal) (Step), scan in the X direction (longitudinal direction) again, scan and move repeatedly in this way, and anneal the entire transparent substrate in multiple scans. Patent Document 1: Japanese Patent Laid-Open No. 2004-64066.

Problems to be solved:

As described above, the laser irradiation apparatus disclosed in Patent Document 1 scans the entire transparent substrate and performs annealing treatment while bonding annealing treatment. Therefore, on the annealed transparent substrate, there is a bonding portion (bonding area) between the area annealed in one scan and the area annealed in the next scan.

In addition, as shown in FIG. 10, the laser irradiation apparatus of Patent Document 1 moves in the Y direction (horizontal) by one step after scanning in the X direction (vertical), and then scans in the X direction (vertical). The joining part (joining area) is formed into a "line". In this way, if there is a "linear" bonding portion (bonding area) on the substrate, the bonding portion (bonding area) will be recognized as "uneven bonding".

The purpose of the present invention is to solve the above-mentioned problems and provide that even if the entire substrate is annealed in a plurality of scans, it is possible to reduce the bonding portion (bonding area) between the annealing treatments to be "linear" and to suppress uneven bonding Laser irradiation device, laser irradiation method and program.

Means to solve the problem:

A laser irradiation device according to an embodiment of the present invention includes: a light source that generates laser light; and a projection lens that irradiates the laser on a designated area of an amorphous silicon thin film covered by each of a plurality of thin film transistors on a glass substrate The projected light is annealed; and a projection mask pattern is provided on the projection lens and is provided with a plurality of openings so that the laser light is irradiated onto each of the plurality of thin film transistors, wherein the projection lens is When the annealing process for the designated direction on the glass substrate is completed, after moving to the orthogonal direction of the designated direction, annealing is performed again for the designated direction, and the projection mask pattern is in the orthogonal direction. The outer row of the projection mask pattern is directed toward the inner row, and the number of openings is gradually increased.

In a laser irradiation apparatus according to an embodiment of the present invention, the projection mask pattern is in the orthogonal direction, from the outer row to the inner row of the projection mask pattern, while gradually increasing the number of the openings, the openings are The adjacent columns may be arranged in a step shape.

In a laser irradiation apparatus according to an embodiment of the present invention, the projection lens is a microlens array including a plurality of microlenses, and the projection mask pattern includes rows corresponding to each other in the orthogonal direction, which correspond to each other in a group The total number of the openings provided in each of the rows may be the number of the plurality of microlenses included in one row of the microlens array.

In the laser irradiation apparatus according to an embodiment of the present invention, in the projection mask pattern, each of the rows corresponding to each other may be arranged opposite to each other with respect to the center line of the predetermined direction in the projection mask pattern.

In the laser irradiation apparatus according to an embodiment of the present invention, in the projection mask pattern, each of the rows corresponding to each other may be arranged at an equal distance from the center line.

In a laser irradiation apparatus according to an embodiment of the present invention, the projection lens irradiates laser light on a designated area of the amorphous silicon film coated between the source electrode and the drain electrode included in the thin film transistor to form a polycrystalline silicon film. can.

A method for manufacturing a thin film transistor according to an embodiment of the present invention includes: a first step of generating laser light; a second step of designating an amorphous silicon thin film covered by each of a plurality of thin film transistors on a glass substrate Using a projection lens provided with a projection mask pattern including a plurality of openings, irradiating the laser light to perform annealing treatment; and a third step, when the annealing treatment for the specified direction on the glass substrate is completed, move to the After specifying the orthogonal direction of the direction, annealing is performed again for the specified direction. In the second step, due to the orthogonal direction, from the outer row to the inner row of the projection mask pattern, the projection mask pattern gradually increasing the number of the openings illuminates the laser light.

In the manufacturing method of the thin film transistor of an embodiment of the present invention, in the second step, due to the orthogonal direction, from the outer row to the inner row of the projected mask pattern, the number of openings is gradually increased while The opening portion may be irradiated with the laser light by the projection mask pattern arranged in a step shape in an adjacent row.

In a method for manufacturing a thin film transistor according to an embodiment of the present invention, the projection lens is a microlens array including a plurality of microlenses. In the second step, due to the orthogonal direction, a row corresponding to a group is included due to the orthogonal direction. The total number of the openings provided on each of the rows corresponding to one group may be the number of the plurality of microlenses included in one row of the microlens array, and the transmitted light pattern may irradiate the laser light.

In the manufacturing method of the thin film transistor according to an embodiment of the present invention, in the second step, each of the rows corresponding to each other is arranged on the opposite side to the center line of the specified direction in the projection mask pattern The laser light may be irradiated by the projection mask pattern.

In the manufacturing method of the thin film transistor according to an embodiment of the present invention, in the second step, the laser light may be irradiated by the projection mask patterns at equal distances from the center line by arranging the rows corresponding to each other in a group .

In the method for manufacturing a thin film transistor according to an embodiment of the present invention, in the second step, a predetermined area of the amorphous silicon thin film coated between the source electrode and the drain electrode included in the thin film transistor is irradiated with thunder It can also emit light to form a polysilicon film.

The present invention provides a laser irradiation device and a thin-film electrode that can reduce the bonding portion (bonding area) between annealing treatments to be linear even when the entire substrate is annealed in multiple scans, and can suppress uneven bonding Crystal and thin film transistor manufacturing method.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. (First embodiment)

FIG. 1 is a diagram showing a configuration example of a laser irradiation apparatus 10 according to the first embodiment of the present invention.

In the first embodiment of the present invention, the laser irradiation device 10 is used in the manufacturing process of a semiconductor device such as a thin film transistor (TFT) 20. For example, only the region where the channel region is to be formed is irradiated with laser light to anneal to A device for crystallizing the region intended to form the channel region.

The laser irradiation device 10 is used, for example, when forming a thin film transistor of a pixel such as a peripheral circuit of a liquid crystal display device. When forming such a thin film transistor, first, a gate electrode patterned of a metal film such as aluminum is formed on the glass substrate 30 by sputtering. Next, a gate insulating film made of silicon nitride is formed on the glass substrate 30 by a low temperature plasma CVD method. Thereafter, on the gate insulating film, for example, an amorphous silicon thin film 21 is formed by a plasma CVD method. In addition, the laser irradiation device 10 shown in FIG. 1 irradiates a laser beam 14 on a designated area on the gate electrode of the amorphous silicon thin film 21 and anneals to polycrystalline and polysiliconize the designated area.

As shown in FIG. 1, in the laser irradiation device 10, the laser light 14 emitted from the laser light source 11 is expanded into a beam system by the coupling optical system 12, and the brightness distribution is uniform. The laser light source 11 is, for example, an excimer laser, which irradiates laser light with a wavelength of 308 nm or 248 nm or the like at a specified repetition period.

Thereafter, the laser light 14 is separated into a plurality of laser light 14 by a plurality of openings (transmissive areas) of the projection mask pattern 15 (not shown) provided on the microlens array 13 and irradiated to the amorphous silicon In the designated area of the film 21. The microlens array 13 is provided with a projection mask pattern 15, and the projection mask pattern 15 is used to irradiate laser light 14 in a designated area. In addition, the designated area of the amorphous silicon thin film 21 is instantly heated and melted, so that a part of the amorphous silicon thin film 21 becomes the polycrystalline silicon thin film 22.

The polysilicon film 22 has a higher electron mobility than the amorphous silicon film 21, and is used in the thin film transistor 20 in the channel region electrically connecting the source electrode 23 and the drain electrode 24. In addition, in the example of FIG. 1, although the microlens array 13 is shown as an example, the microlens array 13 is not necessarily used, and the laser light 14 may be irradiated by using one projection lens. In addition, in the first embodiment, the case where the polycrystalline silicon thin film 22 is formed using the microlens array 13 will be described as an example.

FIG. 2 is a schematic diagram showing an example of a thin film transistor in which a specified area is annealed. In addition, the thin film transistor 20 is formed by first forming a polycrystalline silicon thin film 22 and then forming a source electrode 23 and a drain electrode 24 at both ends of the formed polycrystalline silicon thin film 22.

As shown in FIG. 2, the thin film transistor 20 forms a polysilicon film 22 between the source electrode 23 and the drain electrode 24. The laser irradiation device 10 irradiates laser light 14 to one thin film transistor 20 using, for example, 20 microlenses 17 included in one column (or row) of the microlens array 13 shown in FIG. 2. That is, the laser irradiation device 10 irradiates the polycrystalline silicon film 22 with 20 shots of laser light 14. As a result, in the thin film transistor 20, the designated area of the amorphous silicon thin film 21 is instantly heated and melted to become the polycrystalline silicon thin film 22.

FIG. 3 is a schematic diagram showing an example of the glass substrate 30 where the laser irradiation device 10 irradiates the laser light 14. As shown in FIG. 3, the glass substrate 30 includes a plurality of pixels 31 each of which has a thin film transistor 20. The thin-film transistor 20 performs the light transmission control of each pixel 31 by electrical ON / OFF. As shown in FIG. 3, an amorphous silicon film 21 is provided on the glass substrate 30 at a predetermined pitch "H". The part of the amorphous silicon thin film 21 is a part that becomes the thin film transistor 20.

The laser irradiation device 10 irradiates the amorphous silicon thin film 21 with laser light 14. Here, the laser irradiation device 10 irradiates the laser light 14 at a predetermined cycle, and moves the glass substrate 30 at a time when the laser light 14 is not irradiated, so that the next portion of the amorphous silicon thin film 21 will be irradiated by the laser light 14. As shown in FIG. 3, the amorphous silicon thin film 21 is arranged at a predetermined pitch “H” with respect to the moving direction of the glass substrate 30. In addition, the laser irradiation device 10 irradiates the laser light 14 to a portion of the amorphous silicon thin film 21 disposed on the glass substrate 30 at a predetermined cycle.

In addition, the laser irradiation device 10 uses the microlens array 13 to irradiate the plurality of amorphous silicon thin films 21 on the glass substrate 30 with the same laser light 14. The laser irradiation device 10 irradiates the same laser light 14 to a plurality of amorphous silicon thin films 21 included in the area A shown in FIG. 3, for example. In addition, the laser irradiation device 10 also irradiates the same laser light 14 to the plurality of amorphous silicon thin films 21 included in the region B shown in FIG. 3.

FIG. 4 is a diagram showing a configuration example of the microlens array 13 used for annealing. As shown in FIG. 4, in the microlens array 13, 20 microlenses 17 are arranged in a row (or row) in the scanning direction. The laser irradiation device 10 irradiates the laser light 14 to at least one thin film transistor 20 using a part of the 20 microlenses 17 included in one column (or row) of the microlens array 13. In addition, the number of microlenses 17 included in one column (or one row) in the microlens array 13 is not limited to 20, and any number may be sufficient.

As shown in FIG. 4, the microlens array 13 includes 20 microlenses 17 in a row (or row) in the scanning direction, and for example, a row (or row) in a direction (orthogonal direction) orthogonal to the scanning direction. There are 83. In addition, 83 are just examples, and a few can be used without further explanation.

Here, the number of microlenses 17 that can be included in a row (or a column) orthogonal to the scanning direction of the microlens array 13 depends on the output of the laser light 14 by the laser irradiation device 10. Therefore, when the laser irradiation apparatus 10 performs laser annealing on the entire glass substrate 30, it is necessary to repeatedly scan in the scanning direction and move one step in the orthogonal direction of the scanning direction (the long side of the microlens array 13) To scan in the scanning direction again. Therefore, there is a "line-shaped" joint portion (joint area) between the area annealed in one scan and the area annealed in the next scan. In this way, if the laser light 14 is irradiated in a state where a “line-shaped” joint portion (joint area) appears, the joint portion (joint area) is recognized as “uneven joint” on the liquid crystal screen.

Therefore, in the first embodiment of the present invention, an area annealed in one scan and an area annealed in the next scan are annealed without causing a "linear" joint portion (bonding area). Treatment to reduce the occurrence of "uneven joining".

Therefore, in the first embodiment of the present invention, the openings of the projection mask pattern 15 provided on the microlens array 13 are arranged in a stepped (stepped) arrangement from the outside to the inside.

FIG. 5 is a diagram showing a configuration example of the projection mask pattern 15 in the first embodiment of the present invention. As shown in FIG. 5, the projection mask pattern 15 includes a mask 150 with an opening (a region with an opening), and a mask 151 without an opening (a region without an opening). For example, the first column in FIG. 5 includes a mask 150 with an opening.

As shown in FIG. 5, the projection mask pattern 15 arranges the mask 150 having an opening in a stepped shape (step shape) from the side parallel to the scanning direction toward the inside. For example, projecting the light pattern 15 in the first row closest to the A side, a mask 150 with an opening is arranged. Specifically, the projection mask pattern 15 is provided with a mask 150 having an opening at the position of “first column, first row”. In addition, in the projection mask pattern 15, three masks 150 having openings are arranged in the second row beside the first row. Specifically, the mask pattern 15 is projected in the second column, and each of the first row to the third row is provided with a mask 150 having an opening. In addition, in the projection mask pattern 15, five masks 150 with openings are arranged in the third row beside the second row. Specifically, the mask pattern 15 is projected in the third column, and each of the first row to the fifth row is provided with a mask 150 having an opening. In this way, the openings are arranged in steps (steps) in the rows adjacent to each other. In addition, the number of openings arranged in each row may be any number, and is not limited to one in the first row, three in the second row, and five in the third row.

In addition, on the projection mask pattern 15, a mask 150 having an opening is arranged in the Z-th row which is the highest among the B sides facing the A side. The mask 150 with an opening in the Zth row is arranged on the projection mask pattern 15 at a position diagonal to the mask 150 with an opening in the first row. Specifically, the projection mask pattern 15 is provided with a mask 150 having an opening at the position of the "Z-th row and the twentieth row", that is, the diagonal position of the "first-row and first row". In addition, in the projection mask pattern 15, three masks 150 having openings are arranged in the Y-th row beside the Z-th row. The mask 150 with an opening in the Y-th row is arranged on the projection mask pattern 15 at a position diagonal to the mask 150 with an opening in the second row. In addition, in the projection mask pattern 15, the Xth row beside the Yth row includes five masks 150 with openings. On the side of the B side, the mask 150 having an opening is arranged in a stepped shape (step shape) in a row adjacent to each other. In addition, the number of masks with openings arranged in each row may be any number, and is not limited to one in the Zth row, three in the Yth row, five in the Xth row ...

Here, since there is only one mask 150 having an opening in the first row of the projected mask pattern 15, the laser light is irradiated only once on the area where the first row of the glass substrate 30 is scanned. Therefore, the glass substrate 30 is moved in the Y direction so that the area scanned in the first row can be scanned to the area corresponding to the P row (there are 19 openings) in the next scan. .

That is, in the projection mask pattern 15, the first row (one opening) corresponds to the Q row (19 openings), and on the glass substrate 30, the scanned area of the first row is after the glass substrate 30 is moved Scanned in column Q. With this, the laser light 14 is irradiated on the glass substrate 30 in total 20 times. Similarly, in the projection mask pattern 15, the second row (3 openings) corresponds to the Rth row (17 openings), and the third row (5 openings) corresponds to the Sth row (15 openings) ), Both of the glass substrate 30 are annealed for the corresponding row. In this manner, by scanning corresponding rows, the entire glass substrate 30 is annealed by laser irradiation in total 20 times.

FIG. 6 is a diagram for explaining a state where the glass substrate 30 is annealed by the projection mask pattern 15 arranged in the microlens array 13 illustrated in FIG. 5. As shown in FIG. 6, after the laser irradiation device 10 scans in the X direction, the glass substrate 30 moves one step in the Y direction, and the laser irradiation device 10 scans in the X direction again.

Here, the movement of the glass substrate 30 in the Y direction is performed on the projection mask pattern 15 only within a distance that can be scanned by both rows corresponding to each other. As described above, in the example of FIG. 5, the area where the “first row” of the projection mask pattern 15 is scanned can be scanned in the “row Q” during the next X-direction scan, and the glass is moved Substrate 30.

In addition, the irradiation head of the laser irradiation device 10 (that is, the laser light source 11, the coupling optical system 12, the microlens array 13, and the projection mask 150) can also move relative to the glass substrate 30.

In this way, in the projection mask pattern 15, the number of "projection mask patterns including openings" included in the corresponding row is 20 in total. In other words, the projection mask pattern 15 is such that the total number of "projection mask patterns including openings" included in the corresponding row becomes 20, and the projection mask 150 with openings is arranged.

In addition, although the moving distance of the glass substrate 30 depends on the size of the microlens array 13 and the number of microlenses 17 included in the microlens array 13, it can be set in advance.

FIG. 7 is a diagram for explaining the corresponding “rows” in the projection mask pattern 15 of FIG. 6. As shown in FIG. 7, in the projection mask pattern 15, for example, the first row (one opening) corresponds to the Q row (19 openings). In the same manner, in the projection mask pattern 15, for example, the fifth row (3 openings) corresponds to the Uth row (15 openings), and the tenth row (19 openings) corresponds to the Zth row ( One opening) corresponds. In this way, the total number of openings included in the corresponding row is 20. In addition, in order to irradiate the laser light 14 through the corresponding row, the glass substrate 30 moves in a direction (Y direction) orthogonal to the scanning direction (X direction). Therefore, the laser lens 14 is irradiated with the microlens array 13 projecting the mask pattern, and the entire thin film transistor 20 is irradiated with the laser light 14 20 times.

FIG. 8 is a diagram for comparing annealing treatment of a conventional laser irradiation apparatus and annealing treatment of a laser irradiation apparatus according to the first embodiment of the present invention.

As shown in FIG. 8 (a), the conventional laser irradiation device (for example, the laser irradiation device described in Patent Document 1) has a difference between the n-th scan area in the X direction and the n + 1 th X-direction. The scanning area is completely separated, so its boundary is clear. That is, in the conventional laser irradiation apparatus, there is a joint portion between the annealing processes by different scanning processes on the glass substrate 30. In addition, the joined portion is recognized as "uneven joining".

On the other hand, as shown in FIG. 8 (b), in the first embodiment of the present invention, the annealing process of the laser irradiation device 10 does not suddenly change the nth scan area in the X direction to the n + 1th time. The X-direction scanning area, but the mutual scanning area has an overlapping area. In addition, in the overlapping area, the ratio of the area annealed by different scans gradually changes in a stepped shape (stepped shape). Therefore, unlike the case of the conventional laser irradiation apparatus as shown in FIG. 8 (a), the joint portion between the annealing processes by different scanning processes will not exist. Since there is no joint part, "joint unevenness" does not occur, and the annealing process of the laser irradiation apparatus 10 according to the first embodiment of the present invention can provide a high-quality liquid crystal screen and the like. (About annealing process)

In the first embodiment of the present invention, the laser irradiation device 10 irradiates the laser light 14 to the glass substrate 30 using the microlens array 13 provided with the projection mask pattern 15 shown in FIG. 5.

The glass substrate 30 is moved (scanned) only a specified distance every time the microlens array 13 is illuminated by the laser light 14. As illustrated in FIG. 3, the specified distance is the distance “H” between the plurality of thin film transistors 20 in the glass substrate 30. The laser irradiation device 10 stops the irradiation of the laser light 14 between the glass substrate 30 moving by the specified distance.

After the glass substrate 30 moves by a predetermined distance “H”, the laser irradiation device 10 irradiates the laser light 14 using the microlens array 13. The laser irradiation device 10 repeatedly irradiates the laser light 14 using the microlens array 13 and the movement of the glass substrate 30, and performs an annealing process on the longitudinal direction of the glass substrate 30 (scanning direction. That is, a direction moving only a specified distance) .

Thereafter, the glass substrate 30 is moved by one step (the long side of the microlens array) in a direction orthogonal to the scanning direction. The laser irradiation device 10 stops the irradiation of the laser light 14 between the glass substrate 30 moving by one step.

After the glass substrate 30 is moved by one step, the laser irradiation device 10 irradiates the laser light 14 using the microlens array 13 and performs longitudinal annealing treatment of the glass substrate 30.

In addition, after forming the polycrystalline silicon thin film 22 using laser annealing on all the thin film transistors 20 included in the glass substrate 30, in another process, the source electrode 23 and the drain electrode 24 are formed on the thin film transistor 20.

In this way, in the first embodiment of the present invention, in the annealing process of the laser irradiation device 10 of the first embodiment of the present invention, the junction part of the annealing process by the different scanning process will not exist. Since there is no joint portion, "joint unevenness" does not occur, and the laser irradiation apparatus 10 of the first embodiment of the present invention performs annealing treatment to provide a high-quality liquid crystal screen and the like. (Second embodiment)

The second embodiment of the present invention is an embodiment in which one projection lens 18 is used in place of the microlens array 13 for laser annealing.

9 is a diagram showing a configuration example of a laser irradiation device 10 in the second embodiment of the present invention. As shown in FIG. 9, the laser irradiation device 10 of the second embodiment of the present invention includes a laser light source 11, a coupling optical system 12, a projection mask pattern 15 and a projection lens 18. The laser light source 11 and the coupling optical system 12 have the same structure as the laser light source 11 and the coupling optical system 12 according to the first embodiment of the present invention shown in FIG. 1, and detailed descriptions are omitted here. The projection mask pattern 15 has the same structure as the projection mask pattern 15 according to the first embodiment of the present invention, so detailed description is omitted here.

The laser light 14 penetrates the opening (transmissive area) of the projection mask pattern 15 as shown in FIG. 5, and is irradiated to the designated area of the amorphous silicon 21 by the projection lens 18. As a result, the designated area of the amorphous silicon thin film 21 is instantly heated and melted, so that a part of the amorphous silicon thin film 21 becomes the polycrystalline silicon thin film 22.

In the second embodiment of the present invention, the laser irradiation device 10 irradiates the laser light 14 at a predetermined period, and the glass substrate 30 is moved when the laser light 14 is not irradiated, so that the next part of the amorphous silicon thin film 21 The beam 14 is irradiated. Also in the second embodiment, as shown in FIG. 3, the amorphous silicon thin film 21 is arranged at a predetermined distance “H” with respect to the moving direction of the glass substrate 30. In addition, the laser irradiation device 10 irradiates the laser light 14 to a portion of the amorphous silicon thin film 21 disposed on the glass substrate 30 at a predetermined cycle.

Here, when the projection lens 18 is used, the laser light 14 is converted by the magnification of the optical system of the projection lens 18. That is, the pattern of the projection mask pattern 15 is converted by the magnification of the optical system of the projection lens 18, and laser-annealing a specified area on the glass substrate 30.

That is, the mask pattern of the projection mask pattern 15 is converted by the magnification of the optical system of the projection lens 18, and laser-annealing the designated area on the glass substrate 30. For example, when the magnification of the optical system of the projection lens 18 is about 2 times, the mask pattern of the projection mask pattern 15 laser-anneals a specified area on the glass substrate 30 at about 1/2 (0.5) times. In addition, the magnification of the optical system of the projection lens 18 is not limited to 2 times, and any magnification is acceptable. The mask pattern of the projection mask pattern 15 corresponds to the magnification of the optical system of the projection lens 18, and laser-annealing a specified area on the glass substrate 30. For example, when the magnification of the optical system of the projection lens 18 is 4 times, the mask pattern of the projection mask pattern 15 laser-anneals a specified area on the glass substrate 30 at about 1/4 (0.25) times.

In addition, when the projection lens 18 forms an inverted image, the reduced image of the projection mask pattern 15 irradiated on the glass substrate 30 is a pattern in which the lens optical axis of the projection lens 18 is rotated by 180 degrees. On the other hand, when the projection lens 18 forms an upright image, the reduced image of the projection mask pattern 15 irradiated on the glass substrate 30 is the same as the projection mask pattern 15. In the example of FIG. 9, since the projection lens 18 forming the erect image is used, the pattern of the projection mask pattern 15 is reduced on the glass substrate 30 as it is.

As described above, in the second embodiment of the present invention, even if one projection lens 18 is used for laser annealing, it is the same as in the first embodiment using the microlens array 13, and the joint portion by the annealing process of different scanning processes Will not exist. Since there is no joint part, "joint unevenness" does not occur, and the annealing process of the laser irradiation apparatus 10 according to the second embodiment of the present invention can provide a high-quality liquid crystal screen and the like.

In addition, in the above description, when there are descriptions such as "vertical", "parallel", "planar", "orthogonal", etc., these descriptions do not have a strict meaning. In other words, the so-called "vertical", "parallel", "planar", "orthogonal" means that the tolerance or error in design or manufacturing is allowed to be "substantially vertical" and "substantially parallel" , "Substantially flat", "substantially orthogonal". In addition, the tolerance or error mentioned herein means a unit within the scope of the structure, function, and effect of the present invention.

In addition, in the above description, when there are descriptions such as "same", "equal", and "different" in the dimensions or sizes in appearance, these descriptions do not have a strict meaning. That is to say, "the same", "equal", "different" means that the tolerance or error in design or manufacturing is allowed to be "substantially the same", "substantially equal", "substantially different" . In addition, the tolerance or error mentioned herein means a unit within the scope of the structure, function, and effect of the present invention.

Although the present invention has been described based on the drawings or embodiments, those skilled in the art should note that it is easy to make various modifications or corrections based on the present disclosure. Therefore, it should be noted that such variations or modifications are included in the scope of the present invention. For example, functions included in each device, each step, etc. may be rearranged in a manner that is not logically contradictory, and plural devices, steps, etc. may be combined into one, or divided. In addition, the structures shown in the above embodiments may be combined as appropriate.

10‧‧‧Laser irradiation device

11‧‧‧Laser light source

12‧‧‧Coupling optical system

13‧‧‧Microlens array

14‧‧‧Laser

15‧‧‧Transmission mask pattern

150‧‧‧ Mask with opening

151‧‧‧ Mask without opening

16‧‧‧Transparent area

17‧‧‧Microlens

18‧‧‧Projection lens

20‧‧‧thin film transistor

21‧‧‧Amorphous silicon film

22‧‧‧Polycrystalline silicon film

23‧‧‧Source

24‧‧‧ Jiji

30‧‧‧Glass substrate

Fig. 1: A diagram showing a configuration example of a laser irradiation device. Fig. 2: A schematic diagram showing an example of a thin film transistor in which a specified area is annealed. FIG. 3 is a schematic diagram showing an example of a glass substrate on which a laser irradiation device irradiates laser light. Fig. 4: A diagram showing an example of the structure of a microlens array. Fig. 5: A diagram showing an example of the structure of a projection mask pattern. FIG. 6 is a diagram for explaining the annealing state of a glass substrate by a microlens array provided with a projection mask pattern. Fig. 7 is a diagram for explaining the corresponding "rows" of the projection mask pattern. FIG. 8 is a diagram for comparing annealing treatment of a conventional laser irradiation apparatus and annealing treatment of a laser irradiation apparatus according to the first embodiment of the present invention. 9 is a diagram showing a configuration example of a laser irradiation apparatus according to a second embodiment of the present invention. FIG. 10 is a diagram for explaining the state of annealing treatment of a conventional laser irradiation device.

Claims (12)

A laser irradiation device, comprising: a light source, which generates laser light; a projection lens, which irradiates the laser light on a designated area of an amorphous silicon thin film covered by each of a plurality of thin film transistors on a glass substrate for annealing Processing; and a projection mask pattern, which is provided on the projection lens and provided with a plurality of openings, so that the laser light is irradiated on each of the plurality of thin film transistors, wherein the projection lens is on the glass When the annealing process in the designated direction on the substrate is completed, after moving to the orthogonal direction of the designated direction, annealing is performed again for the designated direction, and the projection mask pattern is in the orthogonal direction, and the projected light The outer row of the cover pattern is directed toward the inner row, and the number of openings is gradually increased. The laser irradiation device according to claim 1, wherein the projection mask pattern is in the orthogonal direction from the outer row to the inner row of the projection mask pattern, while gradually increasing the number of the openings, the opening The parts are arranged in a step shape in the adjacent row. The laser irradiation device according to claim 1 or 2, wherein the projection lens is a microlens array including a plurality of microlenses, and the projection mask pattern includes columns corresponding to one group in the orthogonal direction, The total number of the openings provided on each of the rows corresponding to one group is the number of the plurality of microlenses included in one row of the microlens array. The laser irradiation device according to claim 3, wherein in the projection mask pattern, each of the columns corresponding to each other in a group is arranged on the opposite side to the center line of the specified direction in the projection mask pattern. The laser irradiation device according to claim 4, wherein in the projection mask pattern, each of the columns corresponding to one group is arranged to be equidistant from the center line. The laser irradiation device according to any one of claims 1 or 2, wherein the projection lens irradiates a designated area of the amorphous silicon thin film coated between the source electrode and the drain electrode included in the thin film transistor Laser light forms a polysilicon film. A method for manufacturing a thin film transistor, which includes: a first step of generating laser light; a second step of using a designated area of an amorphous silicon thin film covered by each of a plurality of thin film transistors on a glass substrate A projection lens including a plurality of openings for projecting a mask pattern, irradiating the laser light to perform annealing treatment; and a third step, when the annealing treatment for the designated direction on the glass substrate is completed, moving to the designated direction After the orthogonal direction, the annealing process is performed again for the specified direction, wherein in the second step, due to the orthogonal direction, the number of openings is gradually increased from the outer row to the inner row of the projected mask pattern The projection mask pattern illuminates the laser light. The method for manufacturing a thin film transistor according to claim 7, wherein in the second step, due to the orthogonal direction, the number of openings is gradually increased from the outer row to the inner row of the projected mask pattern At the same time, the opening portion irradiates the laser light to the projection mask pattern arranged in a step shape in the adjacent row. The method for manufacturing a thin film transistor according to claim 8, wherein the projection lens is a microlens array including a plurality of microlenses, and in the second step, due to the orthogonal direction, the In the column, the total number of the openings provided on each of the columns corresponding to a group of columns is the number of the plurality of microlenses included in a column of the microlens array. The transmitted light pattern illuminates the laser light. The method for manufacturing a thin film transistor according to claim 9, wherein, in the second step, each of the rows corresponding to each other is arranged in a reverse direction to the center line of the specified direction in the projection mask pattern The projection mask pattern on the side irradiates the laser light. The method for manufacturing a thin film transistor according to claim 10, wherein, in the second step, the laser light is irradiated from the projection mask pattern at equal distances from the center line through each of the columns corresponding to the group . The method for manufacturing a thin film transistor according to any one of claims 7 to 11, wherein in the second step, an amorphous layer is coated between the source electrode and the drain electrode included in the thin film transistor The specified area of the silicon film is irradiated with laser light to form a polycrystalline silicon film.