WO2019107108A1 - Laser irradiation device, laser irradiation method, and projection mask - Google Patents

Laser irradiation device, laser irradiation method, and projection mask Download PDF

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Publication number
WO2019107108A1
WO2019107108A1 PCT/JP2018/041562 JP2018041562W WO2019107108A1 WO 2019107108 A1 WO2019107108 A1 WO 2019107108A1 JP 2018041562 W JP2018041562 W JP 2018041562W WO 2019107108 A1 WO2019107108 A1 WO 2019107108A1
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thin film
predetermined
openings
laser
laser light
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PCT/JP2018/041562
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French (fr)
Japanese (ja)
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水村　通伸
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株式会社ブイ・テクノロジー
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Publication of WO2019107108A1 publication Critical patent/WO2019107108A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/20—Deposition of semiconductor materials on a substrate, e.g. epitaxial growth solid phase epitaxy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/26—Bombardment with radiation
    • H01L21/263—Bombardment with radiation with high-energy radiation
    • H01L21/268—Bombardment with radiation with high-energy radiation using electromagnetic radiation, e.g. laser radiation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
    • H01L29/76—Unipolar devices, e.g. field effect transistors
    • H01L29/772—Field effect transistors
    • H01L29/78—Field effect transistors with field effect produced by an insulated gate
    • H01L29/786—Thin film transistors, i.e. transistors with a channel being at least partly a thin film

Definitions

  • the present invention relates to the formation of thin film transistors, and more particularly to a laser irradiation apparatus, a laser irradiation method and a projection mask for forming a polysilicon thin film by irradiating an amorphous silicon thin film with a laser beam.
  • a thin film transistor having a reverse stagger structure there is one using an amorphous silicon thin film in a channel region.
  • the amorphous silicon thin film has a small electron mobility
  • using the amorphous silicon thin film for the channel region has a drawback that the mobility of the charge in the thin film transistor becomes small.
  • a polycrystalline silicon film is formed by instantaneously heating a predetermined region of an amorphous silicon thin film by laser light to form a polycrystalline silicon thin film having high electron mobility and the polysilicon thin film is used for a channel region.
  • Patent Document 1 an amorphous silicon thin film is formed on a substrate, and then the amorphous silicon thin film is irradiated with a laser beam such as an excimer laser and laser annealing is performed to melt polysilicon in a short time. It is disclosed to perform a process of crystallizing a thin film. According to Patent Document 1, by performing the process, the channel region between the source and the drain of the thin film transistor can be made to be a polysilicon thin film having high electron mobility, and it is possible to speed up the transistor operation. Have been described.
  • Patent Document 1 describes that laser light is transmitted through a plurality of microlenses included in a microlens array, and laser annealing is performed on a plurality of locations on a substrate by single laser light irradiation.
  • the shapes of the plurality of microlenses included in the microlens array may be different from one another. Therefore, the energy densities of the laser beams transmitted through the plurality of microlenses may vary from one another, and the electron mobility of the polysilicon thin film formed using the laser beams may also vary.
  • the characteristics of the thin film transistor depend on the electron transfer density, there is a problem that the variations in the energy density of the laser light passing through each of the plurality of microlenses cause the variations in the characteristics of the plurality of thin film transistors on the substrate. It occurs.
  • the object of the present invention is to provide a laser irradiation apparatus, a laser irradiation method and a projection mask capable of suppressing the dispersion of the characteristics of a plurality of thin film transistors included in a substrate. .
  • a laser irradiation apparatus is provided on a light source for generating laser light, a projection lens for irradiating laser light on a predetermined area of a substrate moving in a predetermined direction, and a projection lens
  • a projection mask in which a plurality of openings are arranged in a row in the direction, the projection lens emits a plurality of times of laser light to a predetermined area through each of the plurality of openings,
  • the openings arranged at a predetermined number or more after the first openings through which the laser light initially irradiated to the predetermined region is transmitted have a predetermined value of transmittance, which is a ratio of the laser light transmitting It is characterized by being set as follows.
  • the predetermined number is at least one or more
  • the projection lens is an opening with a transmittance equal to or less than a predetermined value arranged at least one after the first opening.
  • the laser beam may be irradiated to a predetermined region through the
  • the projection lens irradiates laser light to a predetermined region of the substrate on which the amorphous silicon thin film is deposited to form a polysilicon thin film, and the predetermined value is equal to or less than a predetermined value.
  • the irradiation energy of the laser light transmitted through the projection mask may be set to be smaller than the irradiation energy of the laser light which completely melts the polysilicon thin film crystal.
  • the transmittances of the openings arranged in a predetermined number or more after the first opening are set to be sequentially lower in the predetermined direction.
  • the projection lens is a plurality of microlenses included in a microlens array capable of separating laser light, and each of the plurality of openings is in a predetermined direction of the microlens array. It may be characterized in that it corresponds to each of a plurality of microlenses included in one row.
  • each of the plurality of openings may have a size determined based on a projection magnification of each of the plurality of microlenses.
  • the laser irradiation apparatus is characterized in that each of the plurality of openings is rectangular, and the length and width of the rectangular are determined based on the projection magnification of each of the plurality of microlenses. It may be
  • a laser irradiation method includes a first step of generating a laser beam, and a projection in which a plurality of openings are arranged in at least one row in a predetermined direction in a predetermined region of a substrate moving in the predetermined direction.
  • the predetermined number is at least one or more
  • the projection lens is an opening with a transmittance equal to or less than a predetermined value arranged at least one after the first opening.
  • the laser beam may be irradiated to a predetermined region through the
  • a predetermined region of the substrate on which the amorphous silicon thin film is deposited is irradiated with laser light multiple times to form a polysilicon thin film, and a predetermined value is obtained.
  • the irradiation energy of the laser light transmitted through the opening having a predetermined value or less may be set to be smaller than the irradiation energy of the laser light which completely melts the crystal of the polysilicon thin film.
  • the projection mask in one embodiment of the present invention is a projection mask disposed on a projection lens that emits a laser beam generated from a light source to a predetermined area of a substrate moving in a predetermined direction, and the projection mask is A plurality of openings are arranged in at least one row in a predetermined direction, and openings are arranged at a predetermined number or more from a first opening through which a laser beam first irradiated to a predetermined region is transmitted among the plurality of openings.
  • the unit is characterized in that the transmittance, which is the ratio of laser light transmission, is set to a predetermined value or less.
  • the predetermined number is at least one or more, and among the plurality of openings, the openings arranged at least one or more from the first opening have transmittance It may be characterized in that it is set to a predetermined value or less.
  • the laser beam irradiated through the plurality of openings forms a polysilicon thin film on a predetermined region of the substrate on which the amorphous silicon thin film is deposited, and the predetermined value is It may be characterized in that the irradiation energy of the laser beam transmitted through the opening having a predetermined value or less is set smaller than the irradiation energy of the laser beam which completely melts the crystal of the polysilicon thin film.
  • FIG. 1 is a view showing an example of the arrangement of a laser irradiation apparatus 10 according to the first embodiment of the present invention.
  • the laser irradiation apparatus 10 irradiates, for example, laser light to a channel region formation scheduled region and anneals the channel. This is an apparatus for polycrystallizing the region formation scheduled 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.
  • a thin film transistor When such a thin film transistor is formed, first, a gate electrode made of a metal film such as Al (aluminum) is patterned on the substrate 30 by sputtering. Then, a gate insulating film made of a SiN (silicon nitride) film is formed on the entire surface of the substrate 30 by low temperature plasma chemical vapor deposition (CVD). Thereafter, an amorphous silicon thin film is formed on the gate insulating film, for example, by plasma CVD. That is, the amorphous silicon thin film 21 is formed (deposited) on the entire surface of the substrate 30.
  • a silicon dioxide (SiO 2 ) film is formed on the amorphous silicon thin film.
  • the laser irradiation device 10 illustrated in FIG. 1 applies a laser beam 14 to a predetermined region (a region to be a channel region in a thin film transistor) on the gate electrode of the amorphous silicon thin film to perform annealing. Polycrystallize and polycrystallize.
  • the substrate 30 is, for example, a glass substrate, but the substrate 30 is not necessarily a glass material, and may be a substrate of any material such as a resin substrate formed of a material such as a resin.
  • the beam system of the laser light emitted from the laser light source 11 is expanded by the coupling optical system 12, and the luminance distribution is made uniform.
  • the laser light source 11 is an excimer laser which emits, for example, laser light having a wavelength of 308 nm or 248 nm at a predetermined repetition cycle.
  • the laser beam is separated into a plurality of laser beams 14 by a plurality of openings (transmission regions) of the projection mask 15 provided on the microlens array 13, and the predetermined regions of the amorphous silicon thin film 21 are irradiated.
  • the microlens array 13 is provided with a projection mask 15, and the projection mask 15 irradiates a predetermined region with the laser light 14. Then, a predetermined region of the amorphous silicon thin film is instantaneously heated and melted, and a part of the amorphous silicon thin film becomes a polysilicon thin film.
  • the projection mask 15 may be called a projection mask pattern.
  • a polysilicon thin film has higher electron mobility than an amorphous silicon thin film, and is used in a thin film transistor in a channel region electrically connecting a source and a drain.
  • FIG. 1 shows the example using the micro lens array 13
  • the micro lens array 13 is not necessarily used, and laser light may be irradiated using one projection lens.
  • the case where a polysilicon thin film is formed using the microlens array 13 will be described as an example.
  • FIG. 2 is a view showing a configuration example of the microlens array 13 used for the annealing process.
  • the microlens array 13 As shown in FIG. 2, in the microlens array 13, twenty microlenses 17 are disposed in one column (or one row) in the scanning direction.
  • the laser irradiation apparatus 1 uses at least a part of the twenty microlenses 17 included in one column (or one row) of the microlens array 13 to a predetermined region of the amorphous silicon thin film, Irradiate.
  • the number of microlenses 17 in one column (or one row) included in the microlens array 13 is not limited to 20, but may be any number.
  • the microlens array 13 includes twenty microlenses 17 in one column (or row), but includes, for example, 165 microlenses 17 in one row (or one column). Needless to say, one hundred sixty-five is an example, and any number may be used.
  • FIG. 3 is a schematic view showing an example of the thin film transistor 20 in which a predetermined region is annealed.
  • the thin film transistor 20 is formed by first forming the polysilicon thin film 22 and then forming the source 23 and the drain 24 at both ends of the formed polysilicon thin film 22.
  • a polysilicon thin film 22 is formed between the source 23 and the drain 24.
  • the laser irradiation apparatus 10 uses, for example, twenty microlenses 17 included in one column (or one row) of the microlens array 13 shown in FIG. 2 with respect to a predetermined region of the amorphous silicon thin film, Irradiate. That is, the laser irradiation apparatus 10 illustrated in FIG. 1 irradiates 20 shots of laser light 14 to a predetermined region of the amorphous silicon thin film 21. As a result, in a region to be the thin film transistor 20 illustrated in FIG. 3, a predetermined region of the amorphous silicon thin film is instantaneously heated and melted to form a polysilicon thin film 22.
  • FIG. 4 is a schematic view showing an example of the substrate 30 on which the laser irradiation apparatus 10 irradiates the laser light 14.
  • the substrate 30 is not necessarily a glass material, and may be a substrate of any material such as a resin substrate formed of a material such as a resin.
  • the substrate 30 includes a plurality of pixels, and each of the pixels includes a thin film transistor 20.
  • the thin film transistor 20 executes transmission control of light in each of the plurality of pixels 31 by electrically turning ON / OFF.
  • An amorphous silicon thin film 21 is provided on the entire surface of the substrate 30.
  • the predetermined region of the amorphous silicon thin film 21 is a portion to be a channel region of the thin film transistor 20.
  • the laser irradiation apparatus 10 irradiates a predetermined region (a region to be a channel region in the thin film transistor 20) of the amorphous silicon thin film 21 with the laser light.
  • the laser irradiation apparatus 10 illustrated in FIG. 1 irradiates the laser light 14 with a predetermined cycle, moves the substrate 30 during the time when the laser light 14 is not irradiated, and the next predetermined area of the amorphous silicon thin film 21
  • the laser beam 14 is irradiated to the As shown in FIG. 4, the amorphous silicon thin film 21 is disposed on the entire surface of the substrate 30.
  • the laser irradiation apparatus 10 irradiates the laser light 14 to a predetermined region of the amorphous silicon thin film 21 disposed on the substrate 30 at a predetermined cycle.
  • the laser irradiation device 10 illustrated in FIG. 1 irradiates the laser light 14 to a predetermined region of the amorphous silicon thin film 21 on the substrate 30 illustrated in FIG. 4 using the microlens array 13.
  • the laser irradiation apparatus 10 irradiates, for example, the region A of the amorphous silicon thin film 21 provided (deposited) on the entire surface of the substrate 30 as shown in FIG.
  • the laser irradiation apparatus 10 also irradiates the laser beam 14 to the region B shown in FIG. 4 of the amorphous silicon thin film 21 provided (deposited) on the entire surface of the substrate 30.
  • the laser irradiation apparatus 10 irradiates the laser beam 14 using each of the twenty microlenses 17 included in one row (or one row) of the microlens array 13 shown in FIG. 2 in order to perform the annealing process. Do.
  • region A of FIG. 4 of the amorphous silicon thin film 21 provided (deposited) on the entire surface of the substrate 30 is firstly the first row (row 1) of the microlens array 13 shown in FIG.
  • the laser beam 14 is emitted using the first microlens 17 of Thereafter, the substrate 30 is moved by a predetermined interval "H". While the substrate 30 is moving, the laser irradiation apparatus 10 may stop the irradiation of the laser light 14. Then, after the substrate 30 has moved by “H”, the region A of FIG. 4 in the amorphous silicon thin film 21 corresponds to the second microlenses 17 of the second row (row 2) of the microlens array 13 shown in FIG. The laser beam 14 is irradiated using this.
  • the laser irradiation apparatus 10 may stop the irradiation of the laser beam 14 while the substrate 30 is moving, or may irradiate the laser beam 14 to the substrate 30 which is moving continuously.
  • the irradiation head of the laser irradiation apparatus 10 illustrated in FIG. 1 may move with respect to the substrate 30.
  • the laser irradiation apparatus 10 repeatedly executes this, and finally, with respect to the region A of FIG. 4 in the amorphous silicon thin film 21, the microlenses of the 20th row (row 20) of the microlens array 13 shown in FIG.
  • the laser beam 14 is irradiated using 17 (that is, the last micro lens 17).
  • the region A of the amorphous silicon thin film 21 is irradiated with the laser light 14 using each of the twenty microlenses 17 included in one row (or one row) of the microlens array 13 illustrated in FIG. 2. It will be.
  • the laser irradiation apparatus 10 also applies to the region B in FIG. 4 of the amorphous silicon thin film 21 of the twenty microlenses 17 included in one column (or one row) of the microlens array 13 shown in FIG. Each is used to emit a laser beam 14.
  • the region B is different in position by “H” in the moving direction of the substrate 30 compared to the region A, the timing at which the laser light 14 is irradiated is delayed by one irradiation. That is, when the region A is irradiated with the laser light 14 using the second microlens 17 of the second row (row 2) of FIG. 2, the region B is the first row (row 1) of FIG.
  • the laser beam 14 is irradiated using one microlens 17.
  • the region B is The laser beam 14 is irradiated using the microlenses 17 of the S row. Then, the region B is irradiated with the laser light 14 using the microlenses 17 of the T-row (that is, the last microlens 17) at the timing of the next irradiation of the laser light 14.
  • the irradiation energy of the laser beam 14 is set to such an extent that a predetermined region of the amorphous silicon thin film 21 on the substrate 30 is instantaneously heated and melted. Then, a predetermined region of the amorphous silicon thin film 21 on the substrate 30 is irradiated with the laser light 14 a plurality of times by the plurality of microlenses 17. In this case, each time the laser beam 14 is irradiated, the irradiation energy of each of the plurality of laser beams 14 irradiated to the predetermined region is such that the amorphous silicon thin film 21 is instantaneously heated and melted. The crystal of the formed polysilicon thin film 22 may be melted.
  • laser light of the irradiation energy to such an extent that an amorphous silicon thin film melts may also melt a polysilicon thin film. That is, whenever the laser beam 14 is irradiated, the crystal of the polysilicon thin film 22 may be melted, which causes a problem that the recrystallization of the polysilicon thin film 22 can not be optimized in a predetermined region.
  • the transmittance of the predetermined opening 150 included in the projection mask 15 to a predetermined value or less, the polysilicon thin film 22 once formed is prevented from completely melting, Crystals of polysilicon thin film can be grown to optimize recrystallization of polysilicon thin film 22.
  • the predetermined value is set such that the irradiation energy of the laser beam transmitted through the projection mask is smaller than the irradiation energy of the laser beam 14 which completely melts the crystal of the polysilicon thin film. For example, if the irradiation energy of the laser beam 14 is 98% or less, the predetermined value is set to “98%” if the crystal of the polysilicon thin film is not completely melted. In this case, the predetermined opening 150 blocks the laser beam 14 by "2%" and transmits "98%”.
  • the irradiation energy of the laser beam transmitted through the projection mask may be set to be smaller than the irradiation energy of the laser beam 14 which completely melts the crystal of the amorphous silicon thin film.
  • the transmittance may be set according to the variation of the laser beam 14, and when the irradiation energy of the laser beam 14 varies in the range of “2%”, “2%” of the variation of the laser beam 14. And the predetermined value is "98%".
  • the predetermined value may be any value as long as the crystal of the polysilicon thin film is completely melted.
  • the predetermined openings 150 in which the transmittance is equal to or less than a predetermined value are, for example, openings arranged in a predetermined number or more from the first openings through which the laser light initially irradiated to the predetermined region passes.
  • the predetermined number is at least one or more.
  • the predetermined openings 150 for which the transmittance is equal to or less than a predetermined value are, for example, the openings 150 arranged at least one or more from the first opening through which the laser light initially irradiated to the predetermined region passes. It is. That is, the laser beam 14 transmitted through the openings 150 arranged at least one after the first opening is smaller than the irradiation energy of the laser beam 14 which completely melts the crystal of the polysilicon thin film.
  • the polysilicon thin film 22 formed once is not completely melted, and the recrystallization of the polysilicon thin film 22 is optimal.
  • FIG. 5 is a view showing a configuration example of the projection mask 15 in the first embodiment of the present invention.
  • each of the plurality of openings 150 corresponds to, for example, each of the plurality of microlenses 17 included in one row of the microlens array 17 shown in FIG. 2.
  • the first opening is the opening in the first row (row 1)
  • the predetermined opening 150 having a transmittance not higher than the predetermined value has, for example, a predetermined value of “1”.
  • the openings 150 on the first and subsequent lines are provided.
  • the predetermined number does not have to be one.
  • the predetermined opening 150 for which the transmittance is equal to or less than the predetermined value is, for example, the opening 150 in the third row (row 3) and the fifth row
  • the opening 150 may be the (row 5) and subsequent ones.
  • the predetermined number By setting the predetermined number to three or five, it is possible to irradiate the laser light of the irradiation energy to the extent that the polysilicon thin film is instantaneously heated and melted, to the predetermined region a plurality of times, and the amorphous silicon thin film of the predetermined region Can be dissolved reliably.
  • the transmittance of the predetermined number of openings 150 after the first opening may be set to be sequentially lower in the moving direction of the substrate.
  • the transmittance of a predetermined number of openings 150 after the first opening may be set to be lower stepwise (stepwise) with respect to the moving direction of the substrate, or linearly lower. It may be set to be
  • FIG. 6 is a view showing the relationship between the irradiation energy of laser light and the position of the opening of the projection mask.
  • FIG. 6 shows 20 openings 150 whose horizontal axis is included in one row of the projection mask 15, and the vertical axis is the irradiation energy of the laser beam 14 passing through the openings 150.
  • the transmittance of the predetermined number of openings 150 from the first opening is set to the irradiation energy at which the amorphous silicon thin film dissolves. Therefore, the laser beam transmitted through each of the predetermined number of openings 150 from the first opening may completely melt and microcrystallize the polysilicon thin film.
  • the transmittance of the predetermined number of openings 150 from the first opening may be set to be sequentially lowered as shown in FIG. 6 or may be set to a predetermined value (irradiation energy for dissolving the amorphous silicon thin film). It may be set.
  • the amorphous silicon thin film of the substrate is melted by the laser beam transmitted through each of the predetermined number of openings 150 from the first opening, and microcrystals of the polysilicon thin film are generated.
  • the transmittance of the predetermined number of openings 150 after the first opening is set to a predetermined value or less. Therefore, the laser beam transmitted through the predetermined number of openings 150 from the first opening does not dissolve the polysilicon thin film again. Therefore, the laser beam transmitted from the first opening to the predetermined number of openings 150 can grow microcrystals of the polysilicon thin film and enlarge the crystal of the polysilicon thin film. As a result, the polysilicon thin film 22 formed once does not melt completely, and crystals of the polysilicon thin film can be grown, and recrystallization of the polysilicon thin film 22 can be optimized.
  • the transmittance of the predetermined number of openings 150 after the first opening may be set to be sequentially lower in the moving direction of the substrate. Therefore, the irradiation energy of the laser light passing through the predetermined number of openings 150 from the first opening may be sequentially lowered as illustrated in FIG.
  • the example of FIG. 6 is an example in the case where the transmittance of the predetermined number of openings 150 after the first opening is set to be linearly lower in the moving direction of the substrate.
  • each of the plurality of microlenses 17 included in the microlens array 13 is set before setting the transmittance of the predetermined number of openings from the first opening to a predetermined value or less.
  • the projection magnification of the projection mask 15 may be measured, and the transmittance of each of the openings 150 of the projection mask 15 may be adjusted based on the lowest projection magnification of the measured projection magnifications.
  • the projection magnification of each of the plurality of microlenses 17 included in the microlens array 13 is measured, and each of the plurality of microlenses 17 is measured based on the lowest projection magnification of the measured projection magnifications.
  • the transmittance of the opening (transmission region) of the corresponding projection mask 15 is set.
  • the projection magnification of the microlens 17 is high, the irradiation energy of the laser beam transmitted through the opening 150 is low.
  • the transmittance of the opening 150 can not be 100% or more, so the microlens 17 having the largest projection magnification is used.
  • the transmittance of the other openings 150 is adjusted in accordance with (that is, the lowest transmittance). Thereafter, in the projection mask 15, by setting the transmittance of a predetermined number of openings after the first opening to a predetermined value or less, it is possible to optimize the recrystallization of the polysilicon thin film 22.
  • the projection magnification of each of the plurality of microlenses 17 included in the microlens array 13 was measured and measured before setting the transmittance of the predetermined number of openings from the first opening to a predetermined value or less.
  • the size of the opening 16 of the projection mask 15 may be adjusted based on the projection magnification.
  • the range to be laser-annealed by the laser beam 14 transmitted through each of the plurality of microlenses 17 becomes substantially the same, which makes it possible to reduce the variation in the characteristics of the thin film transistor.
  • the projection mask 15 by setting the transmittance of a predetermined number of openings after the first opening to a predetermined value or less, it is possible to optimize the recrystallization of the polysilicon thin film 22.
  • the transmittance to be set to the openings 150 of the projection mask 15 is set based on the projection magnification of the microlens 17.
  • the size of the opening 150 of the projection mask 15 may also be set.
  • the laser beam 14 transmitted through the projection mask 15 is laser-annealed by the laser beam 14 transmitted through each of the plurality of microlenses 17 in addition to the energy density becoming substantially the same on the substrate 30.
  • the ranges are almost the same.
  • the projection mask 15 by setting the transmittance of a predetermined number of openings after the first opening to a predetermined value or less, it is possible to optimize the recrystallization of the polysilicon thin film 22.
  • FIG. 7 is a flowchart showing an operation example of the laser irradiation apparatus 10 according to the first embodiment of the present invention.
  • the laser light source 11 of the laser irradiation apparatus 10 generates laser light (S101), and a plurality of openings are arranged in at least one row in a predetermined direction in a predetermined area of the substrate moving in the predetermined direction.
  • a laser beam is irradiated using the projection lens provided with the projection mask (S102).
  • the openings arranged at a predetermined number or more after the first opening through which the laser light initially irradiated to the predetermined region is transmitted have a ratio of transmitting the laser light
  • the transmittance is set to a predetermined value or less.
  • the substrate 30 illustrated in FIG. 4 moves by a predetermined distance each time the laser light 14 is irradiated to the microlens array 13 (S103).
  • the predetermined distance is the distance “H” between the plurality of thin film transistors 20 on the substrate 30.
  • the laser irradiation apparatus 10 stops the irradiation of the laser beam 14 while moving the substrate 30 by the predetermined distance.
  • the laser irradiation apparatus 10 irradiates the laser light 14 again using the microlenses 17 included in the microlens array 13.
  • the laser beam 14 is irradiated to one amorphous silicon thin film 21 by twenty microlenses 17 because the microlens array 13 shown in FIG. 2 is used.
  • a polysilicon thin film 22 is formed on a predetermined region of the amorphous silicon thin film 21 of the substrate 30 illustrated in FIG. 4 by using laser annealing, the source thin film transistor illustrated in FIG. And the drain 24 are formed.
  • the transmittance of the predetermined number of openings 150 after the first opening is set to a predetermined value or less. Therefore, the laser beam transmitted through the predetermined number of openings 150 from the first opening does not dissolve the polysilicon thin film again.
  • the laser light transmitted from the first opening through the predetermined number of openings 150 can grow microcrystals of the polysilicon thin film and enlarge the crystal of the polysilicon thin film. Therefore, the polysilicon thin film 22 formed once does not melt completely, and the crystal of the polysilicon thin film can be grown, and the recrystallization of the polysilicon thin film 22 can be optimized.
  • the second embodiment of the present invention is an embodiment in which laser annealing is performed using one projection lens 18 instead of the microlens array 13.
  • the projection magnification of the peripheral portion may be different from that of the central portion due to the influence of aberration and the like.
  • the energy density of the laser beam irradiated to the substrate 30 varies, which causes the result of the annealing process to vary.
  • the electron mobility of the polysilicon thin film formed on the substrate 30 varies, which causes a problem that the characteristics of the thin film transistor 20 vary.
  • the irradiation energy of the laser light 14 from a single projection lens is set to such an extent that a predetermined region of the amorphous silicon thin film 21 on the substrate 30 is instantaneously heated and melted. Then, a predetermined region of the amorphous silicon thin film 21 on the substrate 30 is irradiated with the laser beam 14 a plurality of times. In this case, each time the laser beam 14 is irradiated, the irradiation energy of each of the plurality of laser beams 14 irradiated to the predetermined region is such that the amorphous silicon thin film 21 is instantaneously heated and melted. The crystal of the formed polysilicon thin film 22 may be melted. Since the crystal of the polysilicon thin film 22 melts every time the laser beam 14 is irradiated, there arises a problem that the recrystallization of the polysilicon thin film 22 can not be optimized in a predetermined region.
  • the transmittance of the predetermined opening 150 included in the projection mask 15 to a predetermined value or less, the polysilicon thin film 22 formed once is prevented from completely melting, The recrystallization of the polysilicon thin film 22 is optimized.
  • FIG. 8 is a view showing an example of the configuration of a laser irradiation apparatus 10 according to the second embodiment of the present invention.
  • the laser irradiation apparatus 10 according to the second embodiment of the present invention includes a laser light source 11, a coupling optical system 12, a projection mask 15, and a projection lens 18.
  • the laser light source 11 and the coupling optical system 12 have the same configuration as the laser light source 11 and the coupling optical system 12 in the first embodiment of the present invention shown in FIG. It is omitted.
  • the projection mask since the projection mask has the same configuration as that of the projection mask in the first embodiment of the present invention, detailed description will be omitted.
  • the laser light passes through the opening (transmission region) of the projection mask 15 (not shown), and is irradiated onto a predetermined region of the amorphous silicon thin film 21 by the projection lens 18.
  • a predetermined region of the amorphous silicon thin film 21 is instantaneously heated and melted, and a part of the amorphous silicon thin film 21 becomes the polysilicon thin film 22.
  • the laser irradiation device 10 irradiates the laser light 14 with a predetermined cycle, moves the substrate 30 during the time when the laser light 14 is not irradiated, and the next amorphous silicon thin film 21 is formed.
  • the laser beam 14 is irradiated to the portion.
  • the amorphous silicon thin film 21 is disposed at a predetermined interval “H” in the moving direction. Then, the laser irradiation apparatus 10 irradiates the portion of the amorphous silicon thin film 21 disposed on the substrate 30 with the laser light 14 at a predetermined cycle.
  • the laser beam 14 is converted by the magnification of the optical system of the projection lens 18. That is, the pattern of the projection mask 15 (pattern of the opening 16) is converted by the magnification of the optical system of the projection lens 18, and a predetermined region on the substrate 30 is subjected to laser annealing.
  • the mask pattern (pattern of the opening 16) of the projection mask 15 is converted by the magnification of the optical system of the projection lens 18, and a predetermined region on the substrate 30 is laser annealed.
  • the magnification of the optical system of the projection lens 18 is about twice
  • the mask pattern of the projection mask 15 is multiplied by about 1/2 (0.5) and the predetermined region of the substrate 30 is laser annealed.
  • the magnification of the optical system of the projection lens 18 is not limited to about twice, and may be any magnification.
  • the mask pattern of the projection mask 15 is laser-annealed in a predetermined region on the substrate 30 in accordance with the magnification of the optical system of the projection lens 18.
  • the mask pattern of the projection mask 15 (the pattern of the opening 16) is multiplied by about 1/4 (0.25) and the predetermined area of the substrate 30 is obtained. Is laser annealed.
  • the reduced image of the projection mask 15 irradiated on the substrate 30 has a pattern rotated 180 degrees around the optical axis of the lens of the projection lens 18.
  • the projection lens 18 forms an erect image
  • the reduced image of the projection mask 15 irradiated onto the substrate 30 is the projection mask 15 as it is.
  • the polysilicon thin film 22 formed once is prevented from completely melting, and polysilicon is formed.
  • the recrystallization of the thin film 22 is optimized.
  • the predetermined value is set such that the irradiation energy of the laser beam transmitted through the projection mask is smaller than the irradiation energy of the laser beam 14 which completely melts the polysilicon thin film crystal. For example, if the irradiation energy of the laser beam 14 is 98% or less, the predetermined value is set to “98%” if the crystal of the polysilicon thin film is not completely melted. In this case, the predetermined opening 150 blocks the laser beam 14 by "2%" and transmits "98%”.
  • the transmittance may be set according to the variation of the laser beam 14, and when the irradiation energy of the laser beam 14 varies in the range of “2%”, “2%” of the variation of the laser beam 14.
  • the predetermined value is "98%".
  • the predetermined value may be any value, and the crystal of the polysilicon thin film completely melts.
  • the predetermined openings 150 in which the transmittance is equal to or less than a predetermined value are, for example, openings arranged in a predetermined number or more from the first openings through which the laser light initially irradiated to the predetermined region passes.
  • the predetermined number is at least one or more.
  • the predetermined openings 150 for which the transmittance is equal to or less than a predetermined value are, for example, the openings 150 arranged at least one or more from the first opening through which the laser light initially irradiated to the predetermined region passes. It is. That is, the laser beam 14 transmitted through the openings 150 arranged at least one after the first opening is smaller than the irradiation energy of the laser beam 14 which completely melts the crystal of the polysilicon thin film.
  • the polysilicon thin film 22 formed once is not completely melted, and the recrystallization of the polysilicon thin film 22 is optimum.
  • the predetermined energy of the projection lens 18 is adjusted in order to adjust the irradiation energy of the laser beam 14 of the projection lens 18 before setting the transmittance of the openings after the predetermined number from the first opening to a predetermined value or less.
  • the transmittance of the opening 16 (transmission region) of the projection mask 15 corresponding to the portion may be adjusted. Specifically, the projection magnification of each of the predetermined portions of the projection lens 18 is measured, and based on the lowest projection magnification of the measured projection magnifications (projection magnification of one of the predetermined portions), The transmittance of the opening 16 (transmission region) of the projection mask 15 corresponding to each of the other predetermined portions is set.
  • the transmittance of the other portion is adjusted in accordance with the portion where the projection magnification is the largest (that is, the lowest transmittance). Thereafter, in the projection mask 15, by setting the transmittance of a predetermined number of openings after the first opening to a predetermined value or less, it is possible to optimize the recrystallization of the polysilicon thin film 22.
  • either (1) changing the transmittance of the opening 16 of the projection mask 15 or (2) adjusting the size of the opening 16 of the projection mask 15 is either Or only one may be performed.
  • the projection magnification of each of the predetermined portions of the single projection lens 18 is measured, and the measured projection magnification
  • the size of the opening 16 of the projection mask 15 is adjusted based on As a result, the range to be laser-annealed by the laser beam 14 transmitted through each of the predetermined portions of the single projection lens 18 becomes substantially the same, thereby making it possible to reduce the variation in the characteristics of the thin film transistor 20. Become. Thereafter, in the projection mask 15, by setting the transmittance of a predetermined number of openings after the first opening to a predetermined value or less, it is possible to optimize the recrystallization of the polysilicon thin film 22.
  • the transmittance of the predetermined opening 150 included in the projection mask 15 is set to a predetermined value or less.
  • the laser beam transmitted from the first opening through the predetermined number of openings 150 does not dissolve the polysilicon thin film again.
  • the laser light transmitted from the first opening through the predetermined number of openings 150 can grow microcrystals of the polysilicon thin film and enlarge the crystal of the polysilicon thin film. Therefore, the polysilicon thin film 22 formed once does not melt completely, and the crystal of the polysilicon thin film can be grown, and the recrystallization of the polysilicon thin film 22 can be optimized.

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Abstract

Provided are a laser irradiation device, a laser irradiation method, and a projection mask that are capable of suppressing variation in characteristics of multiple thin-film transistors included in a substrate. A laser irradiation device according to an embodiment of the present invention is characterized by being provided with: a light source that generates a laser beam; a projection lens that irradiates a prescribed region of a substrate which moves in a prescribed direction with the laser beam; and a projection mask which is provided on the projection lens and in which multiple openings are arrayed in a row at least in a prescribed direction, wherein the projection lens irradiates, multiple times, the prescribed region with the laser beam through the openings, and the transmittance, which is the proportion of transmission of the laser beam, is set to a prescribed value or lower for the openings that are among the multiple openings and that are arrayed after a prescribed number of openings from a first opening through which the laser beam is first applied to the prescribed region.

Description

レーザ照射装置、レーザ照射方法及び投影マスクLaser irradiation apparatus, laser irradiation method and projection mask
　本発明は、薄膜トランジスタの形成に関するものであり、特に、アモルファスシリコン薄膜にレーザ光を照射して、ポリシリコン薄膜を形成するためのレーザ照射装置、レーザ照射方法及び投影マスクに関する。 The present invention relates to the formation of thin film transistors, and more particularly to a laser irradiation apparatus, a laser irradiation method and a projection mask for forming a polysilicon thin film by irradiating an amorphous silicon thin film with a laser beam.
　逆スタガ構造の薄膜トランジスタとして、アモルファスシリコン薄膜をチャネル領域に使用したものが存在する。ただ、アモルファスシリコン薄膜は電子移動度が小さいため、当該アモルファスシリコン薄膜をチャネル領域に使用すると、薄膜トランジスタにおける電荷の移動度が小さくなるという難点があった。 As a thin film transistor having a reverse stagger structure, there is one using an amorphous silicon thin film in a channel region. However, since the amorphous silicon thin film has a small electron mobility, using the amorphous silicon thin film for the channel region has a drawback that the mobility of the charge in the thin film transistor becomes small.
　そこで、アモルファスシリコン薄膜の所定の領域をレーザ光により瞬間的に加熱することで多結晶化し、電子移動度の高いポリシリコン薄膜を形成して、当該ポリシリコン薄膜をチャネル領域に使用する技術が存在する。 Therefore, there is a technology in which a polycrystalline silicon film is formed by instantaneously heating a predetermined region of an amorphous silicon thin film by laser light to form a polycrystalline silicon thin film having high electron mobility and the polysilicon thin film is used for a channel region. Do.
　例えば、特許文献１には、基板にアモルファスシリコン薄膜を形成し、その後、このアモルファスシリコン薄膜にエキシマレーザ等のレーザ光を照射してレーザアニールすることにより、短時間での溶融凝固によって、ポリシリコン薄膜に結晶化させる処理を行うことが開示されている。特許文献１には、当該処理を行うことにより、薄膜トランジスタのソースとドレイン間のチャネル領域を、電子移動度の高いポリシリコン薄膜とすることが可能となり、トランジスタ動作の高速化が可能になる旨が記載されている。 For example, in Patent Document 1, an amorphous silicon thin film is formed on a substrate, and then the amorphous silicon thin film is irradiated with a laser beam such as an excimer laser and laser annealing is performed to melt polysilicon in a short time. It is disclosed to perform a process of crystallizing a thin film. According to Patent Document 1, by performing the process, the channel region between the source and the drain of the thin film transistor can be made to be a polysilicon thin film having high electron mobility, and it is possible to speed up the transistor operation. Have been described.
特開２０１６－１００５３７号公報Unexamined-Japanese-Patent No. 2016-100537
　ここで、特許文献１には、レーザ光をマイクロレンズアレイに含まれる複数のマイクロレンズを透過させて、１回のレーザ光の照射により、基板上の複数個所をレーザアニールすることが記載されている。しかしながら、マイクロレンズアレイに含まれる複数のマイクロレンズの各々は、その形状が互いに異なっている場合がある。そのため、複数のマイクロレンズを透過するレーザ光のエネルギ密度は、互いにばらつきが生じ、当該レーザ光を用いて形成されるポリシリコン薄膜の電子移動度にもばらつきが生じるおそれがある。薄膜トランジスタの特性は電子移動密度に依存するため、複数のマイクロレンズの各々を透過するレーザ光のエネルギ密度にばらつきがあることにより、基板上の複数の薄膜トランジスタの特性にばらつきが生じてしまうという問題が生じる。 Here, Patent Document 1 describes that laser light is transmitted through a plurality of microlenses included in a microlens array, and laser annealing is performed on a plurality of locations on a substrate by single laser light irradiation. There is. However, the shapes of the plurality of microlenses included in the microlens array may be different from one another. Therefore, the energy densities of the laser beams transmitted through the plurality of microlenses may vary from one another, and the electron mobility of the polysilicon thin film formed using the laser beams may also vary. Since the characteristics of the thin film transistor depend on the electron transfer density, there is a problem that the variations in the energy density of the laser light passing through each of the plurality of microlenses cause the variations in the characteristics of the plurality of thin film transistors on the substrate. It occurs.
　本発明の目的は、かかる問題点に鑑みてなされたものであって、基板に含まれる複数の薄膜トランジスタの特性のばらつきを抑制可能なレーザ照射装置、レーザ照射方法及び投影マスクを提供することである。 SUMMARY OF THE INVENTION The object of the present invention is to provide a laser irradiation apparatus, a laser irradiation method and a projection mask capable of suppressing the dispersion of the characteristics of a plurality of thin film transistors included in a substrate. .
　本発明の一実施形態におけるレーザ照射装置は、レーザ光を発生する光源と、所定方向に移動する基板の所定の領域に、レーザ光を照射する投影レンズと、投影レンズ上に設けられ、少なくとも所定方向の一列に複数の開口部が配列された投影マスクと、を備え、投影レンズは、複数の開口部の各々を介して、所定の領域に対して複数回のレーザ光を照射し、複数の開口部のうち、所定の領域に対して最初に照射されるレーザ光が透過する第１開口部から所定数以降に配列された開口部は、レーザ光が透過する割合である透過率が所定値以下に設定されることを特徴とする。 A laser irradiation apparatus according to an embodiment of the present invention is provided on a light source for generating laser light, a projection lens for irradiating laser light on a predetermined area of a substrate moving in a predetermined direction, and a projection lens A projection mask in which a plurality of openings are arranged in a row in the direction, the projection lens emits a plurality of times of laser light to a predetermined area through each of the plurality of openings, Among the openings, the openings arranged at a predetermined number or more after the first openings through which the laser light initially irradiated to the predetermined region is transmitted have a predetermined value of transmittance, which is a ratio of the laser light transmitting It is characterized by being set as follows.
　本発明の一実施形態におけるレーザ照射装置において、所定数は、少なくとも１つ以上であり、投影レンズは、第１開口部から少なくとも１つ目以降に配列された透過率が所定値以下の開口部を介して、所定の領域に対してレーザ光を照射することを特徴としてもよい。 In the laser irradiation apparatus according to an embodiment of the present invention, the predetermined number is at least one or more, and the projection lens is an opening with a transmittance equal to or less than a predetermined value arranged at least one after the first opening. The laser beam may be irradiated to a predetermined region through the
　本発明の一実施形態におけるレーザ照射装置において、投影レンズは、アモルファスシリコン薄膜が被着した基板の所定の領域にレーザ光を照射して、ポリシリコン薄膜を形成し、所定値は、所定値以下の投影マスクを透過するレーザ光の照射エネルギが、ポリシリコン薄膜の結晶が完全融解するレーザ光の照射エネルギよりも小さくなるように設定されることを特徴としてもよい。 In the laser irradiation apparatus according to an embodiment of the present invention, the projection lens irradiates laser light to a predetermined region of the substrate on which the amorphous silicon thin film is deposited to form a polysilicon thin film, and the predetermined value is equal to or less than a predetermined value. The irradiation energy of the laser light transmitted through the projection mask may be set to be smaller than the irradiation energy of the laser light which completely melts the polysilicon thin film crystal.
　本発明の一実施形態におけるレーザ照射装置において、複数の開口部のうち、第１開口部から所定数以降に配列された開口部の透過率は、所定方向に対して順に低くなるように設定されることをしてもよい。 In the laser irradiation apparatus according to an embodiment of the present invention, among the plurality of openings, the transmittances of the openings arranged in a predetermined number or more after the first opening are set to be sequentially lower in the predetermined direction. You may
　本発明の一実施形態におけるレーザ照射装置において、投影レンズは、レーザ光を分離可能なマイクロレンズアレイに含まれる複数のマイクロレンズであり、複数の開口部の各々は、マイクロレンズアレイの所定方向の一列に含まれる複数のマイクロレンズの各々に対応する、ことを特徴としてもよい。 In the laser irradiation apparatus according to one embodiment of the present invention, the projection lens is a plurality of microlenses included in a microlens array capable of separating laser light, and each of the plurality of openings is in a predetermined direction of the microlens array. It may be characterized in that it corresponds to each of a plurality of microlenses included in one row.
　本発明の一実施形態におけるレーザ照射装置において、複数の開口部の各々は、複数のマイクロレンズの各々の投影倍率に基づいて決定された大きさであることを特徴としてもよい。 In the laser irradiation apparatus according to an embodiment of the present invention, each of the plurality of openings may have a size determined based on a projection magnification of each of the plurality of microlenses.
　本発明の一実施形態におけるレーザ照射装置において、複数の開口部の各々は長方形状であり、複数のマイクロレンズの各々の投影倍率に基づいて長方形状の長さ及び幅が決定されることを特徴としてもよい。 The laser irradiation apparatus according to an embodiment of the present invention is characterized in that each of the plurality of openings is rectangular, and the length and width of the rectangular are determined based on the projection magnification of each of the plurality of microlenses. It may be
　本発明の一実施形態におけるレーザ照射方法は、レーザ光を発生する第１のステップと、所定方向に移動する基板の所定の領域に、少なくとも所定方向の一列に複数の開口部が配列された投影マスクが設けられた投影レンズを用いて、複数回のレーザ光を照射する第２のステップと、レーザ光が照射されるごとに、基板を所定の方向に移動する第３のステップと、を含み、複数の開口部のうち、所定の領域に対して最初に照射されるレーザ光が透過する第１開口部から所定数以降に配列された開口部は、レーザ光が透過する割合である透過率が所定値以下に設定されることを特徴とする。 A laser irradiation method according to an embodiment of the present invention includes a first step of generating a laser beam, and a projection in which a plurality of openings are arranged in at least one row in a predetermined direction in a predetermined region of a substrate moving in the predetermined direction. A second step of irradiating the laser light a plurality of times using a projection lens provided with a mask, and a third step of moving the substrate in a predetermined direction each time the laser light is irradiated Among the plurality of openings, the openings, which are arranged at a predetermined number or more after the first opening through which the laser light to be irradiated first to the predetermined area is transmitted, have a transmittance that is a ratio of transmitting the laser light Is set to a predetermined value or less.
　本発明の一実施形態におけるレーザ照射方法において、所定数は、少なくとも１つ以上であり、投影レンズは、第１開口部から少なくとも１つ目以降に配列された透過率が所定値以下の開口部を介して、所定の領域に対してレーザ光を照射することを特徴としてもよい。 In the laser irradiation method according to one embodiment of the present invention, the predetermined number is at least one or more, and the projection lens is an opening with a transmittance equal to or less than a predetermined value arranged at least one after the first opening. The laser beam may be irradiated to a predetermined region through the
　本発明の一実施形態におけるレーザ照射方法において、第２のステップにおいて、アモルファスシリコン薄膜が被着した基板の所定の領域に複数回のレーザ光を照射して、ポリシリコン薄膜を形成し、所定値は、所定値以下の開口部を透過するレーザ光の照射エネルギが、ポリシリコン薄膜の結晶が完全融解するレーザ光の照射エネルギよりも小さくなるように設定されることを特徴としてもよい。 In the laser irradiation method according to an embodiment of the present invention, in the second step, a predetermined region of the substrate on which the amorphous silicon thin film is deposited is irradiated with laser light multiple times to form a polysilicon thin film, and a predetermined value is obtained. Alternatively, the irradiation energy of the laser light transmitted through the opening having a predetermined value or less may be set to be smaller than the irradiation energy of the laser light which completely melts the crystal of the polysilicon thin film.
　本発明の一実施形態における投影マスクは、所定方向に移動する基板の所定の領域に、光源から発生されたレーザ光を照射する投影レンズ上に配置される投影マスクであって、投影マスクは、少なくとも所定方向の一列に複数の開口部が配列され、複数の開口部のうち、所定の領域に対して最初に照射されるレーザ光が透過する第１開口部から所定数以降に配列された開口部は、レーザ光が透過する割合である透過率が所定値以下に設定されることを特徴とする。 The projection mask in one embodiment of the present invention is a projection mask disposed on a projection lens that emits a laser beam generated from a light source to a predetermined area of a substrate moving in a predetermined direction, and the projection mask is A plurality of openings are arranged in at least one row in a predetermined direction, and openings are arranged at a predetermined number or more from a first opening through which a laser beam first irradiated to a predetermined region is transmitted among the plurality of openings. The unit is characterized in that the transmittance, which is the ratio of laser light transmission, is set to a predetermined value or less.
　本発明の一実施形態における投影マスクにおいて、所定数は、少なくとも１つ以上であり、複数の開口部のうち、第１開口部から少なくとも１つ目以降に配列された開口部は、透過率が所定値以下に設定されることを特徴としてもよい。 In the projection mask in one embodiment of the present invention, the predetermined number is at least one or more, and among the plurality of openings, the openings arranged at least one or more from the first opening have transmittance It may be characterized in that it is set to a predetermined value or less.
　本発明の一実施形態における投影マスクにおいて、複数の開口部を介して照射されるレーザ光は、アモルファスシリコン薄膜が被着した基板の所定の領域に、ポリシリコン薄膜を形成し、所定値は、所定値以下の開口部を透過するレーザ光の照射エネルギが、ポリシリコン薄膜の結晶が完全融解するレーザ光の照射エネルギよりも小さくなるように設定されることを特徴としてもよい。 In the projection mask according to an embodiment of the present invention, the laser beam irradiated through the plurality of openings forms a polysilicon thin film on a predetermined region of the substrate on which the amorphous silicon thin film is deposited, and the predetermined value is It may be characterized in that the irradiation energy of the laser beam transmitted through the opening having a predetermined value or less is set smaller than the irradiation energy of the laser beam which completely melts the crystal of the polysilicon thin film.
　本発明によれば、基板に含まれる複数の薄膜トランジスタの特性のばらつきを抑制可能な、レーザ照射装置、レーザ照射方法及び投影マスクを提供することである。 According to the present invention, it is an object of the present invention to provide a laser irradiation apparatus, a laser irradiation method, and a projection mask which can suppress variations in the characteristics of a plurality of thin film transistors included in a substrate.
レーザ照射装置の構成例を示す図である。It is a figure which shows the structural example of a laser irradiation apparatus. マイクロレンズアレイの構成例を示す図である。It is a figure which shows the structural example of a microlens array. 所定の領域がアニール処理された薄膜トランジスタの例を示す模式図である。It is a schematic diagram which shows the example of the thin-film transistor in which the predetermined area | region was annealed. レーザ照射装置がレーザ光を照射する基板の例を示す模式図である。It is a schematic diagram which shows the example of the board | substrate which a laser irradiation apparatus irradiates a laser beam. 投影マスクの構成例を示す図である。It is a figure which shows the structural example of a projection mask. レーザ光の照射エネルギと投影マスクの開口部の位置の関係を示す図である。It is a figure which shows the relationship between the irradiation energy of a laser beam, and the position of the opening part of a projection mask. レーザ照射装置の動作例を示すフローチャートである。It is a flowchart which shows the operation example of a laser irradiation apparatus. レーザ照射装置の他の構成例を示す図である。It is a figure which shows the other structural example of a laser irradiation apparatus.
　以下、本発明の実施形態について、添付の図面を参照して具体的に説明する。 Hereinafter, embodiments of the present invention will be specifically described with reference to the attached drawings.
　（第１の実施形態）
　図１は、本発明の第１の実施形態におけるレーザ照射装置１０の構成例を示す図である。 First Embodiment
FIG. 1 is a view showing an example of the arrangement of a laser irradiation apparatus 10 according to the first embodiment of the present invention.
　本発明の第１の実施形態において、レーザ照射装置１０は、薄膜トランジスタ（ＴＦＴ）のような半導体装置の製造工程において、例えば、チャネル領域形成予定領域にレーザ光を照射してアニール処理し、当該チャネル領域形成予定領域を多結晶化するための装置である。 In the first embodiment of the present invention, in the process of manufacturing a semiconductor device such as a thin film transistor (TFT), the laser irradiation apparatus 10 irradiates, for example, laser light to a channel region formation scheduled region and anneals the channel. This is an apparatus for polycrystallizing the region formation scheduled region.
　レーザ照射装置１０は、例えば、液晶表示装置の周辺回路などの画素の薄膜トランジスタを形成する際に用いられる。このような薄膜トランジスタを形成する場合、まず、基板３０上にＡｌ（アルミニウム）等の金属膜からなるゲート電極を、スパッタによりパターン形成する。そして、低温プラズマＣＶＤ（Ｃｈｅｍｉｃａｌ　Ｖａｐｏｒ　Ｄｅｐｏｓｉｔｉｏｎ）法により、基板３０上の全面にＳｉＮ（窒化ケイ素）膜からなるゲート絶縁膜を形成する。その後、ゲート絶縁膜上に、例えば、プラズマＣＶＤ法によりアモルファスシリコン薄膜を形成する。すなわち、基板３０の全面にアモルファスシリコン薄膜２１が形成（被着）される。最後に、アモルファスシリコン薄膜上に二酸化ケイ素（ＳｉＯ２）膜を形成する。そして、図１に例示するレーザ照射装置１０により、アモルファスシリコン薄膜のゲート電極上の所定の領域（薄膜トランジスタにおいてチャネル領域となる領域）にレーザ光１４を照射してアニール処理し、当該所定の領域を多結晶化してポリシリコン化する。なお、基板３０は、例えばガラス基板であるが、基板３０は必ずしもガラス素材である必要はなく、樹脂などの素材で形成された樹脂基板など、どのような素材の基板であってもよい。 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 such a thin film transistor is formed, first, a gate electrode made of a metal film such as Al (aluminum) is patterned on the substrate 30 by sputtering. Then, a gate insulating film made of a SiN (silicon nitride) film is formed on the entire surface of the substrate 30 by low temperature plasma chemical vapor deposition (CVD). Thereafter, an amorphous silicon thin film is formed on the gate insulating film, for example, by plasma CVD. That is, the amorphous silicon thin film 21 is formed (deposited) on the entire surface of the substrate 30. Finally, a silicon dioxide (SiO 2 ) film is formed on the amorphous silicon thin film. Then, the laser irradiation device 10 illustrated in FIG. 1 applies a laser beam 14 to a predetermined region (a region to be a channel region in a thin film transistor) on the gate electrode of the amorphous silicon thin film to perform annealing. Polycrystallize and polycrystallize. The substrate 30 is, for example, a glass substrate, but the substrate 30 is not necessarily a glass material, and may be a substrate of any material such as a resin substrate formed of a material such as a resin.
　図１に示すように、レーザ照射装置１０において、レーザ光源１１から出射されたレーザ光は、カップリング光学系１２によりビーム系が拡張され、輝度分布が均一化される。レーザ光源１１は、例えば、波長が３０８ｎｍや２４８ｎｍなどのレーザ光を、所定の繰り返し周期で放射するエキシマレーザである。 As shown in FIG. 1, in the laser irradiation apparatus 10, the beam system of the laser light emitted from the laser light source 11 is expanded by the coupling optical system 12, and the luminance distribution is made uniform. The laser light source 11 is an excimer laser which emits, for example, laser light having a wavelength of 308 nm or 248 nm at a predetermined repetition cycle.
　その後、レーザ光は、マイクロレンズアレイ１３上に設けられた投影マスク１５の複数の開口部（透過領域）により、複数のレーザ光１４に分離され、アモルファスシリコン薄膜２１の所定の領域に照射される。マイクロレンズアレイ１３には、投影マスク１５が設けられ、当該投影マスク１５によって所定の領域にレーザ光１４が照射される。そして、アモルファスシリコン薄膜の所定の領域が瞬間加熱されて溶融し、アモルファスシリコン薄膜の一部がポリシリコン薄膜となる。なお、投影マスク１５は、投影マスクパターンと呼称されてもよい。 Thereafter, the laser beam is separated into a plurality of laser beams 14 by a plurality of openings (transmission regions) of the projection mask 15 provided on the microlens array 13, and the predetermined regions of the amorphous silicon thin film 21 are irradiated. . The microlens array 13 is provided with a projection mask 15, and the projection mask 15 irradiates a predetermined region with the laser light 14. Then, a predetermined region of the amorphous silicon thin film is instantaneously heated and melted, and a part of the amorphous silicon thin film becomes a polysilicon thin film. The projection mask 15 may be called a projection mask pattern.
　ポリシリコン薄膜は、アモルファスシリコン薄膜に比べて電子移動度が高く、薄膜トランジスタにおいて、ソースとドレインとを電気的に接続させるチャネル領域に用いられる。なお、図１の例では、マイクロレンズアレイ１３を用いた例を示しているが、必ずしもマイクロレンズアレイ１３を用いる必要はなく、１個の投影レンズを用いてレーザ光を照射してもよい。なお、第１の実施形態では、マイクロレンズアレイ１３を用いて、ポリシリコン薄膜を形成する場合を例にして説明する。 A polysilicon thin film has higher electron mobility than an amorphous silicon thin film, and is used in a thin film transistor in a channel region electrically connecting a source and a drain. Although the example of FIG. 1 shows the example using the micro lens array 13, the micro lens array 13 is not necessarily used, and laser light may be irradiated using one projection lens. In the first embodiment, the case where a polysilicon thin film is formed using the microlens array 13 will be described as an example.
　図２は、アニール処理に用いるマイクロレンズアレイ１３の構成例を示す図である。図２に示すように、マイクロレンズアレイ１３において、スキャン方向の１列（又は１行）には、２０個のマイクロレンズ１７が配置される。レーザ照射装置１は、アモルファスシリコン薄膜の所定の領域に対して、マイクロレンズアレイ１３の１列（又は１行）に含まれる２０個のマイクロレンズ１７の少なくとも一部を用いて、レーザ光１４を照射する。なお、なお、マイクロレンズアレイ１３に含まれる一列（又は一行）のマイクロレンズ１７の数は、２０個に限られず、いくつであってもよい。 FIG. 2 is a view showing a configuration example of the microlens array 13 used for the annealing process. As shown in FIG. 2, in the microlens array 13, twenty microlenses 17 are disposed in one column (or one row) in the scanning direction. The laser irradiation apparatus 1 uses at least a part of the twenty microlenses 17 included in one column (or one row) of the microlens array 13 to a predetermined region of the amorphous silicon thin film, Irradiate. Note that the number of microlenses 17 in one column (or one row) included in the microlens array 13 is not limited to 20, but may be any number.
　図２に示すように、マイクロレンズアレイ１３は、その一列（または一行）にマイクロレンズ１７を２０個含むが、一行（または一列）には例えば１６５個含む。なお、１６５個は例示であって、いくつであってもよいことは言うまでもない。 As shown in FIG. 2, the microlens array 13 includes twenty microlenses 17 in one column (or row), but includes, for example, 165 microlenses 17 in one row (or one column). Needless to say, one hundred sixty-five is an example, and any number may be used.
　図３は、所定の領域がアニール処理された薄膜トランジスタ２０の例を示す模式図である。なお、薄膜トランジスタ２０は、最初にポリシリコン薄膜２２を形成し、その後、形成されたポリシリコン薄膜２２の両端にソース２３とドレイン２４を形成することで、作成される。 FIG. 3 is a schematic view showing an example of the thin film transistor 20 in which a predetermined region is annealed. The thin film transistor 20 is formed by first forming the polysilicon thin film 22 and then forming the source 23 and the drain 24 at both ends of the formed polysilicon thin film 22.
　図３に示すように、薄膜トランジスタ２０は、ソース２３とドレイン２４との間に、ポリシリコン薄膜２２が形成されている。レーザ照射装置１０は、アモルファスシリコン薄膜の所定の領域に対して、図２に示したマイクロレンズアレイ１３の一列（または一行）に含まれる例えば２０個のマイクロレンズ１７を用いて、レーザ光１４を照射する。すなわち、図１に例示するレーザ照射装置１０は、アモルファスシリコン薄膜２１の所定の領域に対して、２０ショットのレーザ光１４を照射する。その結果、図３に例示する薄膜トランジスタ２０となる領域において、アモルファスシリコン薄膜の所定の領域が瞬間加熱されて溶融し、ポリシリコン薄膜２２となる。 As shown in FIG. 3, in the thin film transistor 20, a polysilicon thin film 22 is formed between the source 23 and the drain 24. The laser irradiation apparatus 10 uses, for example, twenty microlenses 17 included in one column (or one row) of the microlens array 13 shown in FIG. 2 with respect to a predetermined region of the amorphous silicon thin film, Irradiate. That is, the laser irradiation apparatus 10 illustrated in FIG. 1 irradiates 20 shots of laser light 14 to a predetermined region of the amorphous silicon thin film 21. As a result, in a region to be the thin film transistor 20 illustrated in FIG. 3, a predetermined region of the amorphous silicon thin film is instantaneously heated and melted to form a polysilicon thin film 22.
　図４は、レーザ照射装置１０がレーザ光１４を照射する基板３０の例を示す模式図である。なお、基板３０は、必ずしもガラス素材である必要はなく、樹脂などの素材で形成された樹脂基板など、どのような素材の基板であってもよい。図４に示すように、基板３０は、複数の画素を含み、当該画素の各々に薄膜トランジスタ２０を備える。薄膜トランジスタ２０は、複数の画素３１の各々における光の透過制御を、電気的にＯＮ／ＯＦＦすることにより実行するものである。基板３０には、その全面にアモルファスシリコン薄膜２１が設けられている。当該アモルファスシリコン薄膜２１の所定の領域は、薄膜トランジスタ２０のチャネル領域となる部分である。 FIG. 4 is a schematic view showing an example of the substrate 30 on which the laser irradiation apparatus 10 irradiates the laser light 14. The substrate 30 is not necessarily a glass material, and may be a substrate of any material such as a resin substrate formed of a material such as a resin. As shown in FIG. 4, the substrate 30 includes a plurality of pixels, and each of the pixels includes a thin film transistor 20. The thin film transistor 20 executes transmission control of light in each of the plurality of pixels 31 by electrically turning ON / OFF. An amorphous silicon thin film 21 is provided on the entire surface of the substrate 30. The predetermined region of the amorphous silicon thin film 21 is a portion to be a channel region of the thin film transistor 20.
　レーザ照射装置１０は、アモルファスシリコン薄膜２１の所定の領域（薄膜トランジスタ２０においてチャネル領域となる領域）にレーザ光１４を照射する。ここで、図１に例示するレーザ照射装置１０は所定の周期でレーザ光１４を照射し、レーザ光１４が照射されていない時間に基板３０を移動させ、次のアモルファスシリコン薄膜２１の所定の領域に当該レーザ光１４が照射されるようにする。図４に示すように、基板３０は、その全面にアモルファスシリコン薄膜２１が配置される。そして、レーザ照射装置１０は、所定の周期で、基板３０上に配置されたアモルファスシリコン薄膜２１の所定の領域に、レーザ光１４を照射する。 The laser irradiation apparatus 10 irradiates a predetermined region (a region to be a channel region in the thin film transistor 20) of the amorphous silicon thin film 21 with the laser light. Here, the laser irradiation apparatus 10 illustrated in FIG. 1 irradiates the laser light 14 with a predetermined cycle, moves the substrate 30 during the time when the laser light 14 is not irradiated, and the next predetermined area of the amorphous silicon thin film 21 The laser beam 14 is irradiated to the As shown in FIG. 4, the amorphous silicon thin film 21 is disposed on the entire surface of the substrate 30. Then, the laser irradiation apparatus 10 irradiates the laser light 14 to a predetermined region of the amorphous silicon thin film 21 disposed on the substrate 30 at a predetermined cycle.
　そして、図１に例示するレーザ照射装置１０は、マイクロレンズアレイ１３を用いて、図４に例示する基板３０上のアモルファスシリコン薄膜２１の所定の領域に対して、レーザ光１４を照射する。レーザ照射装置１０は、例えば、基板３０の全面に設けられている（被着している）アモルファスシリコン薄膜２１のうち図４に示す領域Ａに対して、レーザ光１４を照射する。また、レーザ照射装置１０は、基板３０の全面に設けられている（被着している）アモルファスシリコン薄膜２１のうち図４に示す領域Ｂに対しても、レーザ光１４を照射する。 Then, the laser irradiation device 10 illustrated in FIG. 1 irradiates the laser light 14 to a predetermined region of the amorphous silicon thin film 21 on the substrate 30 illustrated in FIG. 4 using the microlens array 13. The laser irradiation apparatus 10 irradiates, for example, the region A of the amorphous silicon thin film 21 provided (deposited) on the entire surface of the substrate 30 as shown in FIG. The laser irradiation apparatus 10 also irradiates the laser beam 14 to the region B shown in FIG. 4 of the amorphous silicon thin film 21 provided (deposited) on the entire surface of the substrate 30.
　ここで、レーザ照射装置１０は、アニール処理を行うために、図２に示すマイクロレンズアレイ１３の一列（又は一行）に含まれる２０個のマイクロレンズ１７の各々を用いて、レーザ光１４を照射する。 Here, the laser irradiation apparatus 10 irradiates the laser beam 14 using each of the twenty microlenses 17 included in one row (or one row) of the microlens array 13 shown in FIG. 2 in order to perform the annealing process. Do.
　この場合、基板３０の全面に設けられている（被着している）アモルファスシリコン薄膜２１のうち図４の領域Ａは、まず、図２に示すマイクロレンズアレイ１３の１行目（行１）の第１のマイクロレンズ１７を用いて、レーザ光１４が照射される。その後、基板３０を所定の間隔「Ｈ」だけ移動させる。基板３０が移動している間、レーザ照射装置１０は、レーザ光１４の照射を停止してもよい。そして、基板３０が「Ｈ」だけ移動した後、アモルファスシリコン薄膜２１のうち図４の領域Ａは、図２に示すマイクロレンズアレイ１３の２行目（行２）の第２のマイクロレンズ１７を用いて、レーザ光１４が照射される。なお、レーザ照射装置１０は、基板３０が移動している間レーザ光１４の照射を停止してもよいし、移動し続けている当該基板３０に対してレーザ光１４を照射してもよい。 In this case, region A of FIG. 4 of the amorphous silicon thin film 21 provided (deposited) on the entire surface of the substrate 30 is firstly the first row (row 1) of the microlens array 13 shown in FIG. The laser beam 14 is emitted using the first microlens 17 of Thereafter, the substrate 30 is moved by a predetermined interval "H". While the substrate 30 is moving, the laser irradiation apparatus 10 may stop the irradiation of the laser light 14. Then, after the substrate 30 has moved by “H”, the region A of FIG. 4 in the amorphous silicon thin film 21 corresponds to the second microlenses 17 of the second row (row 2) of the microlens array 13 shown in FIG. The laser beam 14 is irradiated using this. The laser irradiation apparatus 10 may stop the irradiation of the laser beam 14 while the substrate 30 is moving, or may irradiate the laser beam 14 to the substrate 30 which is moving continuously.
　なお、図１に例示するレーザ照射装置１０の照射ヘッド（すなわち、レーザ光源１１、カップリング光学系１２、マイクロレンズアレイ１３及び投影マスク１５）が、基板３０に対して移動してもよい。 The irradiation head of the laser irradiation apparatus 10 illustrated in FIG. 1 (that is, the laser light source 11, the coupling optical system 12, the microlens array 13, and the projection mask 15) may move with respect to the substrate 30.
　レーザ照射装置１０は、これを繰り返し実行して、最後に、アモルファスシリコン薄膜２１のうち図４の領域Ａに対して、図２に示すマイクロレンズアレイ１３の２０行目（行２０）のマイクロレンズ１７（すなわち、最後のマイクロレンズ１７）を用いて、レーザ光１４を照射する。その結果、アモルファスシリコン薄膜２１のうち領域Ａは、図２に例示するマイクロレンズアレイ１３の一列（又は一行）に含まれる２０個のマイクロレンズ１７の各々を用いて、レーザ光１４が照射されることになる。 The laser irradiation apparatus 10 repeatedly executes this, and finally, with respect to the region A of FIG. 4 in the amorphous silicon thin film 21, the microlenses of the 20th row (row 20) of the microlens array 13 shown in FIG. The laser beam 14 is irradiated using 17 (that is, the last micro lens 17). As a result, the region A of the amorphous silicon thin film 21 is irradiated with the laser light 14 using each of the twenty microlenses 17 included in one row (or one row) of the microlens array 13 illustrated in FIG. 2. It will be.
　同様にして、レーザ照射装置１０は、アモルファスシリコン薄膜２１のうち図４の領域Ｂに対しても、図２に示すマイクロレンズアレイ１３の一列（又は一行）に含まれる２０個のマイクロレンズ１７の各々を用いて、レーザ光１４を照射する。ただ、領域Ｂは、領域Ａに比べて基板３０の移動方向に対して「Ｈ」だけ位置が異なるため、レーザ光１４が照射されるタイミングが、１照射分だけ遅れる。すなわち、領域Ａが図２の２行目（行２）の第２のマイクロレンズ１７を用いてレーザ光１４を照射される時に、領域Ｂは、図２の１行目（行１）の第１のマイクロレンズ１７を用いてレーザ光１４が照射される。そして、領域Ａが図２のＴ列の２０行目（第２０）のマイクロレンズ１７（すなわち、最後のマイクロレンズ１７）を用いてレーザ光１４を照射される時には、領域Ｂは、一つ前のＳ列のマイクロレンズ１７を用いて、レーザ光１４が照射されることになる。そして、領域Ｂは、次のレーザ光１４の照射のタイミングで、Ｔ列のマイクロレンズ１７（すなわち、最後のマイクロレンズ１７）を用いて、レーザ光１４が照射されることになる。 Similarly, the laser irradiation apparatus 10 also applies to the region B in FIG. 4 of the amorphous silicon thin film 21 of the twenty microlenses 17 included in one column (or one row) of the microlens array 13 shown in FIG. Each is used to emit a laser beam 14. However, since the region B is different in position by “H” in the moving direction of the substrate 30 compared to the region A, the timing at which the laser light 14 is irradiated is delayed by one irradiation. That is, when the region A is irradiated with the laser light 14 using the second microlens 17 of the second row (row 2) of FIG. 2, the region B is the first row (row 1) of FIG. The laser beam 14 is irradiated using one microlens 17. Then, when the region A is irradiated with the laser light 14 using the 20th (twentieth) micro lens 17 in the T row of FIG. 2 (ie, the last micro lens 17), the region B is The laser beam 14 is irradiated using the microlenses 17 of the S row. Then, the region B is irradiated with the laser light 14 using the microlenses 17 of the T-row (that is, the last microlens 17) at the timing of the next irradiation of the laser light 14.
　ここで、上述したように、レーザ光１４は、基板３０上のアモルファスシリコン薄膜２１の所定の領域が瞬間加熱されて溶融する程度に照射エネルギが設定される。そして、基板３０上のアモルファスシリコン薄膜２１の所定の領域は、複数のマイクロレンズ１７により、複数回のレーザ光１４が照射される。この場合において、所定の領域に照射される複数回のレーザ光１４の各々の照射エネルギが、いずれもアモルファスシリコン薄膜２１が瞬間加熱されて溶融する程度であると、レーザ光１４が照射されるごとに、形成されたポリシリコン薄膜２２の結晶が融解してしまうおそれがある。アモルファスシリコン薄膜が融解してしまう程度の照射エネルギのレーザ光は、ポリシリコン薄膜も融解するおそれがあるからである。すなわち、レーザ光１４が照射されるごとに、ポリシリコン薄膜２２の結晶が融解するおそれがあり、所定の領域において、ポリシリコン薄膜２２の再結晶化が最適化できないという問題が生じる。 Here, as described above, the irradiation energy of the laser beam 14 is set to such an extent that a predetermined region of the amorphous silicon thin film 21 on the substrate 30 is instantaneously heated and melted. Then, a predetermined region of the amorphous silicon thin film 21 on the substrate 30 is irradiated with the laser light 14 a plurality of times by the plurality of microlenses 17. In this case, each time the laser beam 14 is irradiated, the irradiation energy of each of the plurality of laser beams 14 irradiated to the predetermined region is such that the amorphous silicon thin film 21 is instantaneously heated and melted. The crystal of the formed polysilicon thin film 22 may be melted. It is because laser light of the irradiation energy to such an extent that an amorphous silicon thin film melts may also melt a polysilicon thin film. That is, whenever the laser beam 14 is irradiated, the crystal of the polysilicon thin film 22 may be melted, which causes a problem that the recrystallization of the polysilicon thin film 22 can not be optimized in a predetermined region.
　そこで、本発明の第１の実施形態では、投影マスク１５に含まれる所定の開口部１５０の透過率を所定値以下とすることにより、一度形成したポリシリコン薄膜２２が完全融解しないようにして、ポリシリコン薄膜の結晶を成長させることができ、ポリシリコン薄膜２２の再結晶化を最適化する。 Therefore, in the first embodiment of the present invention, by setting the transmittance of the predetermined opening 150 included in the projection mask 15 to a predetermined value or less, the polysilicon thin film 22 once formed is prevented from completely melting, Crystals of polysilicon thin film can be grown to optimize recrystallization of polysilicon thin film 22.
　所定値は、投影マスクを透過するレーザ光の照射エネルギは、ポリシリコン薄膜の結晶が完全融解するレーザ光１４の照射エネルギよりも小さくなるように設定される。例えば、レーザ光１４の照射エネルギが９８％以下であれば、ポリシリコン薄膜の結晶が完全融解しない場合、所定値は「９８％」に設定される。この場合、所定の開口部１５０は、該レーザ光１４を「２％」遮断し、「９８％」だけ透過する。なお、投影マスクを透過するレーザ光の照射エネルギは、アモルファスシリコン薄膜の結晶が完全融解するレーザ光１４の照射エネルギよりも小さくなるように設定されてもよい。 The predetermined value is set such that the irradiation energy of the laser beam transmitted through the projection mask is smaller than the irradiation energy of the laser beam 14 which completely melts the crystal of the polysilicon thin film. For example, if the irradiation energy of the laser beam 14 is 98% or less, the predetermined value is set to “98%” if the crystal of the polysilicon thin film is not completely melted. In this case, the predetermined opening 150 blocks the laser beam 14 by "2%" and transmits "98%". The irradiation energy of the laser beam transmitted through the projection mask may be set to be smaller than the irradiation energy of the laser beam 14 which completely melts the crystal of the amorphous silicon thin film.
　なお、透過率は、レーザ光１４のばらつきに応じて設定されてもよく、該レーザ光１４の照射エネルギが「２％」の範囲でばらつく場合、該レーザ光１４をばらつき分の「２％」だけ遮断する（すなわち、所定値は「９８％」）ようにしてもよい。なお、所定値は、ポリシリコン薄膜の結晶が完全融解する程度であれば、どのような値であってもよい。 The transmittance may be set according to the variation of the laser beam 14, and when the irradiation energy of the laser beam 14 varies in the range of “2%”, “2%” of the variation of the laser beam 14. And the predetermined value is "98%". The predetermined value may be any value as long as the crystal of the polysilicon thin film is completely melted.
　透過率が所定値以下となる所定の開口部１５０は、例えば、所定の領域に対して最初に照射されるレーザ光が透過する第１開口部から所定数以降に配列された開口部である。所定数は、少なくとも１つ以上である。透過率が所定値以下となる所定の開口部１５０は、例えば、所定の領域に対して最初に照射されるレーザ光が透過する第１開口部から少なくとも１つ目以降に配列された開口部１５０である。すなわち、第１開口部から少なくとも１つ目以降に配列された開口部１５０を透過するレーザ光１４は、ポリシリコン薄膜の結晶が完全融解するレーザ光１４の照射エネルギよりも小さくなる。そのため、少なくとも１つ目以降に配列された開口部１５０を通過するレーザ光１４を照射しても、一度形成されたポリシリコン薄膜２２は完全融解せず、ポリシリコン薄膜２２の再結晶化が最適化される。 The predetermined openings 150 in which the transmittance is equal to or less than a predetermined value are, for example, openings arranged in a predetermined number or more from the first openings through which the laser light initially irradiated to the predetermined region passes. The predetermined number is at least one or more. The predetermined openings 150 for which the transmittance is equal to or less than a predetermined value are, for example, the openings 150 arranged at least one or more from the first opening through which the laser light initially irradiated to the predetermined region passes. It is. That is, the laser beam 14 transmitted through the openings 150 arranged at least one after the first opening is smaller than the irradiation energy of the laser beam 14 which completely melts the crystal of the polysilicon thin film. Therefore, even if the laser beam 14 passing through the openings 150 arranged at least the first one or more is irradiated, the polysilicon thin film 22 formed once is not completely melted, and the recrystallization of the polysilicon thin film 22 is optimal. Be
　図５は、本発明の第１の実施形態における投影マスク１５の構成例を示す図である。図５において、複数の開口部１５０の各々は、例えば、図２に示すマイクロレンズアレイ１７の一列に含まれる複数のマイクロレンズ１７の各々に対応する。 FIG. 5 is a view showing a configuration example of the projection mask 15 in the first embodiment of the present invention. In FIG. 5, each of the plurality of openings 150 corresponds to, for example, each of the plurality of microlenses 17 included in one row of the microlens array 17 shown in FIG. 2.
　図５に例示する投影マスク１５において、第１開口部は１行目（行１）の開口部であり、透過率が所定値以下となる所定の開口部１５０は、例えば、所定値が「１」の場合、１行目以降の開口部１５０である。なお、所定数は、１つでなくてもよく、例えば、透過率が所定値以下となる所定の開口部１５０は、例えば、３行目（行３）以降の開口部１５０や、５行目（行５）以降の開口部１５０であってもよい。所定数を３つや５つとすることにより、ポリシリコン薄膜が瞬間加熱されて溶融する程度の照射エネルギのレーザ光を、複数回所定の領域に照射することができ、該所定の領域のアモルファスシリコン薄膜を確実に溶解することが可能となる。 In the projection mask 15 illustrated in FIG. 5, the first opening is the opening in the first row (row 1), and the predetermined opening 150 having a transmittance not higher than the predetermined value has, for example, a predetermined value of “1”. In the case of “1”, the openings 150 on the first and subsequent lines are provided. The predetermined number does not have to be one. For example, the predetermined opening 150 for which the transmittance is equal to or less than the predetermined value is, for example, the opening 150 in the third row (row 3) and the fifth row The opening 150 may be the (row 5) and subsequent ones. By setting the predetermined number to three or five, it is possible to irradiate the laser light of the irradiation energy to the extent that the polysilicon thin film is instantaneously heated and melted, to the predetermined region a plurality of times, and the amorphous silicon thin film of the predetermined region Can be dissolved reliably.
　なお、第１開口部から所定数以降の開口部１５０の透過率は、基板の移動方向に対して、順次低くなるように設定されてもよい。なお、第１開口部から所定数以降の開口部１５０の透過率は、基板の移動方向に対して、段階的に（ステップ状に）低くなるように設定されてもよいし、直線的に低くなるように設定されてもよい。 The transmittance of the predetermined number of openings 150 after the first opening may be set to be sequentially lower in the moving direction of the substrate. The transmittance of a predetermined number of openings 150 after the first opening may be set to be lower stepwise (stepwise) with respect to the moving direction of the substrate, or linearly lower. It may be set to be
　図６は、レーザ光の照射エネルギと投影マスクの開口部の位置の関係を示す図である。図６は、横軸を投影マスク１５の１列に含まる２０個の開口部１５０であり、縦軸が該開口部１５０を通過するレーザ光１４の照射エネルギである。 FIG. 6 is a view showing the relationship between the irradiation energy of laser light and the position of the opening of the projection mask. FIG. 6 shows 20 openings 150 whose horizontal axis is included in one row of the projection mask 15, and the vertical axis is the irradiation energy of the laser beam 14 passing through the openings 150.
　図６に例示するように、第１開口部から所定数の開口部１５０の透過率は、アモルファスシリコン薄膜が溶解する照射エネルギに設定される。そのため、第１開口部から所定数の開口部１５０の各々を透過するレーザ光は、ポリシリコン薄膜を完全融解させ微結晶化させる可能性がある。なお、第１開口部から所定数の開口部１５０の透過率は、図６のように、順次低くなるように設定されてもよいし、一定の値（アモルファスシリコン薄膜が溶解する照射エネルギ）に設定されていてもよい。第１開口部から所定数の開口部１５０の各々を透過するレーザ光によって、基板のアモルファスシリコン薄膜は融解し、ポリシリコン薄膜の微結晶が生成される。 As illustrated in FIG. 6, the transmittance of the predetermined number of openings 150 from the first opening is set to the irradiation energy at which the amorphous silicon thin film dissolves. Therefore, the laser beam transmitted through each of the predetermined number of openings 150 from the first opening may completely melt and microcrystallize the polysilicon thin film. The transmittance of the predetermined number of openings 150 from the first opening may be set to be sequentially lowered as shown in FIG. 6 or may be set to a predetermined value (irradiation energy for dissolving the amorphous silicon thin film). It may be set. The amorphous silicon thin film of the substrate is melted by the laser beam transmitted through each of the predetermined number of openings 150 from the first opening, and microcrystals of the polysilicon thin film are generated.
　また、第１開口部から所定数以降の開口部１５０の透過率は、所定値以下に設定される。そのため、第１開口部から所定数以降の開口部１５０を透過するレーザ光は、ポリシリコン薄膜を再溶解しない。そのため、第１開口部から所定数以降の開口部１５０を透過するレーザ光は、ポリシリコン薄膜の微結晶を成長させ、該ポリシリコン薄膜の結晶を大きくすることができる。その結果、一度形成したポリシリコン薄膜２２が完全融解せず、ポリシリコン薄膜の結晶を成長させることができ、ポリシリコン薄膜２２の再結晶化を最適化することが可能となる。 Further, the transmittance of the predetermined number of openings 150 after the first opening is set to a predetermined value or less. Therefore, the laser beam transmitted through the predetermined number of openings 150 from the first opening does not dissolve the polysilicon thin film again. Therefore, the laser beam transmitted from the first opening to the predetermined number of openings 150 can grow microcrystals of the polysilicon thin film and enlarge the crystal of the polysilicon thin film. As a result, the polysilicon thin film 22 formed once does not melt completely, and crystals of the polysilicon thin film can be grown, and recrystallization of the polysilicon thin film 22 can be optimized.
　なお、第１開口部から所定数以降の開口部１５０の透過率は、基板の移動方向に対して、順次低くなるように設定されてもよい。そのため、第１開口部から所定数以降の開口部１５０を通過するレーザ光の照射エネルギは、図６に例示するように、順次低くなってもよい。なお、図６の例は、第１開口部から所定数以降の開口部１５０の透過率は、基板の移動方向に対して、直線的に低くなるように設定されている場合の例である。 The transmittance of the predetermined number of openings 150 after the first opening may be set to be sequentially lower in the moving direction of the substrate. Therefore, the irradiation energy of the laser light passing through the predetermined number of openings 150 from the first opening may be sequentially lowered as illustrated in FIG. The example of FIG. 6 is an example in the case where the transmittance of the predetermined number of openings 150 after the first opening is set to be linearly lower in the moving direction of the substrate.
　ここで本発明の第１の実施形態では、第１開口部から所定数以降の開口部の透過率を所定値以下に設定する前に、マイクロレンズアレイ１３に含まれる複数のマイクロレンズ１７の各々の投影倍率を測定し、測定された投影倍率のうちの最低の投影倍率に基づいて、投影マスク１５の開口部１５０の各々の透過率を調整してもよい。具体的には、マイクロレンズアレイ１３に含まれる複数のマイクロレンズ１７の各々の投影倍率を測定し、測定された投影倍率のうちの最低の投影倍率に基づいて、複数のマイクロレンズ１７の各々に対応する投影マスク１５の開口部（透過領域）の透過率を設定する。マイクロレンズ１７の投影倍率が高いと開口部１５０を透過するレーザ光の照射エネルギは低くなるところ、開口部１５０の透過率は１００％以上にすることはできないため、投影倍率が最も大きいマイクロレンズ１７（すなわち、最低の透過率）にあわせて、他の開口部１５０の透過率を調整する。その後、投影マスク１５において、第１開口部から所定数以降の開口部の透過率を所定値以下に設定することにより、ポリシリコン薄膜２２の再結晶化を最適化することが可能となる。 Here, in the first embodiment of the present invention, each of the plurality of microlenses 17 included in the microlens array 13 is set before setting the transmittance of the predetermined number of openings from the first opening to a predetermined value or less. The projection magnification of the projection mask 15 may be measured, and the transmittance of each of the openings 150 of the projection mask 15 may be adjusted based on the lowest projection magnification of the measured projection magnifications. Specifically, the projection magnification of each of the plurality of microlenses 17 included in the microlens array 13 is measured, and each of the plurality of microlenses 17 is measured based on the lowest projection magnification of the measured projection magnifications. The transmittance of the opening (transmission region) of the corresponding projection mask 15 is set. When the projection magnification of the microlens 17 is high, the irradiation energy of the laser beam transmitted through the opening 150 is low. However, the transmittance of the opening 150 can not be 100% or more, so the microlens 17 having the largest projection magnification is used. The transmittance of the other openings 150 is adjusted in accordance with (that is, the lowest transmittance). Thereafter, in the projection mask 15, by setting the transmittance of a predetermined number of openings after the first opening to a predetermined value or less, it is possible to optimize the recrystallization of the polysilicon thin film 22.
　また、第１開口部から所定数以降の開口部の透過率を所定値以下に設定する前に、マイクロレンズアレイ１３に含まれる複数のマイクロレンズ１７の各々の投影倍率を測定し、測定された投影倍率に基づいて、投影マスク１５の開口部１６の大きさを調整してもよい。その結果、複数のマイクロレンズ１７の各々を透過するレーザ光１４によってレーザアニール処理される範囲が略同一となるため、それにより薄膜トランジスタの特性のばらつきを低減することが可能となる。その後、投影マスク１５において、第１開口部から所定数以降の開口部の透過率を所定値以下に設定することにより、ポリシリコン薄膜２２の再結晶化を最適化することが可能となる。 In addition, the projection magnification of each of the plurality of microlenses 17 included in the microlens array 13 was measured and measured before setting the transmittance of the predetermined number of openings from the first opening to a predetermined value or less. The size of the opening 16 of the projection mask 15 may be adjusted based on the projection magnification. As a result, the range to be laser-annealed by the laser beam 14 transmitted through each of the plurality of microlenses 17 becomes substantially the same, which makes it possible to reduce the variation in the characteristics of the thin film transistor. Thereafter, in the projection mask 15, by setting the transmittance of a predetermined number of openings after the first opening to a predetermined value or less, it is possible to optimize the recrystallization of the polysilicon thin film 22.
　なお、第１開口部から所定数以降の開口部の透過率を所定値以下に設定する前に、マイクロレンズ１７の投影倍率に基づいて、投影マスク１５の開口部１５０に設定する透過率が設定されるとともに、投影マスク１５の開口部１５０の大きさも設定されてもよい。その結果、（１）投影マスク１５の開口部１５０の各々の透過率（すなわち、投影マスク１５の開口部（透過領域）の透過率）は、レーザ光１４の基板上におけるエネルギ密度が略同一となるように設定されるとともに、（２）投影倍率に基づいて、投影マスク１５の開口部１６の大きさも調整される。その結果、投影マスク１５を透過したレーザ光１４は、基板３０上において、エネルギ密度が略同一となることに加えて、複数のマイクロレンズ１７の各々を透過するレーザ光１４によってレーザアニール処理される範囲が略同一となる。その後、投影マスク１５において、第１開口部から所定数以降の開口部の透過率を所定値以下に設定することにより、ポリシリコン薄膜２２の再結晶化を最適化することが可能となる。 In addition, before setting the transmittance of a predetermined number or more of openings from the first opening to a predetermined value or less, the transmittance to be set to the openings 150 of the projection mask 15 is set based on the projection magnification of the microlens 17. And the size of the opening 150 of the projection mask 15 may also be set. As a result, (1) the transmittance of each of the openings 150 of the projection mask 15 (that is, the transmittance of the opening (transmission region) of the projection mask 15) is substantially the same as the energy density of the laser light 14 on the substrate. The size of the opening 16 of the projection mask 15 is also adjusted based on (2) the projection magnification. As a result, the laser beam 14 transmitted through the projection mask 15 is laser-annealed by the laser beam 14 transmitted through each of the plurality of microlenses 17 in addition to the energy density becoming substantially the same on the substrate 30. The ranges are almost the same. Thereafter, in the projection mask 15, by setting the transmittance of a predetermined number of openings after the first opening to a predetermined value or less, it is possible to optimize the recrystallization of the polysilicon thin film 22.
　ここで、本発明の第１の実施形態におけるレーザ照射装置１０の動作例について説明する。図７は、本発明の第１の実施形態におけるレーザ照射装置１０の動作例を示すフローチャートである。図７に示すように、レーザ照射装置１０のレーザ光源１１がレーザ光を発生し（Ｓ１０１）、所定方向に移動する基板の所定の領域に、少なくとも所定方向の一列に複数の開口部が配列された投影マスクが設けられた投影レンズを用いて、レーザ光が照射される（Ｓ１０２）。ここで、複数の開口部のうち、所定の領域に対して最初に照射されるレーザ光が透過する第１開口部から所定数以降に配列された開口部は、レーザ光が透過する割合である透過率が所定値以下に設定される。図４に例示する基板３０は、マイクロレンズアレイ１３に対してレーザ光１４が照射されるごとに、所定の距離だけ移動する（Ｓ１０３）。所定の距離は、基板３０における複数の薄膜トランジスタ２０間の距離「Ｈ」である。レーザ照射装置１０は、基板３０を当該所定の距離移動させる間、レーザ光１４の照射を停止する。 Here, an operation example of the laser irradiation apparatus 10 according to the first embodiment of the present invention will be described. FIG. 7 is a flowchart showing an operation example of the laser irradiation apparatus 10 according to the first embodiment of the present invention. As shown in FIG. 7, the laser light source 11 of the laser irradiation apparatus 10 generates laser light (S101), and a plurality of openings are arranged in at least one row in a predetermined direction in a predetermined area of the substrate moving in the predetermined direction. A laser beam is irradiated using the projection lens provided with the projection mask (S102). Here, among the plurality of openings, the openings arranged at a predetermined number or more after the first opening through which the laser light initially irradiated to the predetermined region is transmitted have a ratio of transmitting the laser light The transmittance is set to a predetermined value or less. The substrate 30 illustrated in FIG. 4 moves by a predetermined distance each time the laser light 14 is irradiated to the microlens array 13 (S103). The predetermined distance is the distance “H” between the plurality of thin film transistors 20 on the substrate 30. The laser irradiation apparatus 10 stops the irradiation of the laser beam 14 while moving the substrate 30 by the predetermined distance.
　基板３０が所定の距離「Ｈ」を移動した後、レーザ照射装置１０は、マイクロレンズアレイ１３に含まれるマイクロレンズ１７を用いて、レーザ光１４を再度照射する。なお、本発明の第１の実施形態では、図２に示すマイクロレンズアレイ１３を用いるため、１つのアモルファスシリコン薄膜２１に対して、２０個のマイクロレンズ１７によりレーザ光１４が照射される。 After the substrate 30 moves the predetermined distance “H”, the laser irradiation apparatus 10 irradiates the laser light 14 again using the microlenses 17 included in the microlens array 13. In the first embodiment of the present invention, the laser beam 14 is irradiated to one amorphous silicon thin film 21 by twenty microlenses 17 because the microlens array 13 shown in FIG. 2 is used.
　そして、図４に例示する基板３０のアモルファスシリコン薄膜２１の所定の領域に、レーザアニールを用いてポリシリコン薄膜２２を形成した後、別の工程において、当該薄膜トランジスタに、図３に例示するソース２３とドレイン２４とが形成される。 Then, after a polysilicon thin film 22 is formed on a predetermined region of the amorphous silicon thin film 21 of the substrate 30 illustrated in FIG. 4 by using laser annealing, the source thin film transistor illustrated in FIG. And the drain 24 are formed.
　上記の通り、本発明の第１の実施形態の投影マスク１５において、第１開口部から所定数以降の開口部１５０の透過率は、所定値以下に設定される。そのため、第１開口部から所定数以降の開口部１５０を透過するレーザ光は、ポリシリコン薄膜を再溶解しない。その結果、第１開口部から所定数以降の開口部１５０を透過するレーザ光は、ポリシリコン薄膜の微結晶を成長させ、該ポリシリコン薄膜の結晶を大きくすることができる。したがって、一度形成したポリシリコン薄膜２２が完全融解せず、ポリシリコン薄膜の結晶を成長させることができ、ポリシリコン薄膜２２の再結晶化を最適化することが可能となる。 As described above, in the projection mask 15 of the first embodiment of the present invention, the transmittance of the predetermined number of openings 150 after the first opening is set to a predetermined value or less. Therefore, the laser beam transmitted through the predetermined number of openings 150 from the first opening does not dissolve the polysilicon thin film again. As a result, the laser light transmitted from the first opening through the predetermined number of openings 150 can grow microcrystals of the polysilicon thin film and enlarge the crystal of the polysilicon thin film. Therefore, the polysilicon thin film 22 formed once does not melt completely, and the crystal of the polysilicon thin film can be grown, and the recrystallization of the polysilicon thin film 22 can be optimized.
　（第２の実施形態）
　本発明の第２の実施形態は、マイクロレンズアレイ１３の代わりに、１個の投影レンズ１８を用いて、レーザアニールを行う場合の実施形態である。 Second Embodiment
The second embodiment of the present invention is an embodiment in which laser annealing is performed using one projection lens 18 instead of the microlens array 13.
　単一の投影レンズにおいて、例えば、収差等の影響で、中央部に比べて周辺部の投影倍率が異なることがある。そのような場合、投影倍率が異なると、基板３０に照射されるレーザ光のエネルギ密度がばらつき、それによって、アニール処理の結果がばらつく要因となっていた。その結果、基板３０上に形成されるポリシリコン薄膜の電子移動度にもばらつきが生じることにより、薄膜トランジスタ２０の特性にばらつきが生じるという問題が発生していた。 In a single projection lens, for example, the projection magnification of the peripheral portion may be different from that of the central portion due to the influence of aberration and the like. In such a case, when the projection magnification is different, the energy density of the laser beam irradiated to the substrate 30 varies, which causes the result of the annealing process to vary. As a result, the electron mobility of the polysilicon thin film formed on the substrate 30 varies, which causes a problem that the characteristics of the thin film transistor 20 vary.
　また、上述したように、単一の投影レンズからのレーザ光１４は、基板３０上のアモルファスシリコン薄膜２１の所定の領域が瞬間加熱されて溶融する程度に照射エネルギが設定される。そして、基板３０上のアモルファスシリコン薄膜２１の所定の領域は、複数回のレーザ光１４が照射される。この場合において、所定の領域に照射される複数回のレーザ光１４の各々の照射エネルギが、いずれもアモルファスシリコン薄膜２１が瞬間加熱されて溶融する程度であると、レーザ光１４が照射されるごとに、形成されたポリシリコン薄膜２２の結晶が融解してしまうおそれがある。レーザ光１４が照射されるごとに、ポリシリコン薄膜２２の結晶が融解してしまうため、所定の領域において、ポリシリコン薄膜２２の再結晶化を最適化できないという問題が生じる。 Further, as described above, the irradiation energy of the laser light 14 from a single projection lens is set to such an extent that a predetermined region of the amorphous silicon thin film 21 on the substrate 30 is instantaneously heated and melted. Then, a predetermined region of the amorphous silicon thin film 21 on the substrate 30 is irradiated with the laser beam 14 a plurality of times. In this case, each time the laser beam 14 is irradiated, the irradiation energy of each of the plurality of laser beams 14 irradiated to the predetermined region is such that the amorphous silicon thin film 21 is instantaneously heated and melted. The crystal of the formed polysilicon thin film 22 may be melted. Since the crystal of the polysilicon thin film 22 melts every time the laser beam 14 is irradiated, there arises a problem that the recrystallization of the polysilicon thin film 22 can not be optimized in a predetermined region.
　そこで、本発明の第２の実施形態では、投影マスク１５に含まれる所定の開口部１５０の透過率を所定値以下とすることにより、一度形成したポリシリコン薄膜２２が完全融解しないようにして、ポリシリコン薄膜２２の再結晶化を最適化する。 Therefore, in the second embodiment of the present invention, by setting the transmittance of the predetermined opening 150 included in the projection mask 15 to a predetermined value or less, the polysilicon thin film 22 formed once is prevented from completely melting, The recrystallization of the polysilicon thin film 22 is optimized.
　図８は、本発明の第２の実施形態におけるレーザ照射装置１０の構成例を示す図である。図８に示すように、本発明の第２の実施形態におけるレーザ照射装置１０は、レーザ光源１１と、カップリング光学系１２と、投影マスク１５と、投影レンズ１８とを含む。なお、レーザ光源１１と、カップリング光学系１２とは、図１に示す本発明の第１の実施形態におけるレーザ光源１１と、カップリング光学系１２と同様の構成であるため、詳細な説明は省略される。また、投影マスクは、本発明の第１の実施形態における投影マスクと同様の構成であるため、詳細な説明は省略される。 FIG. 8 is a view showing an example of the configuration of a laser irradiation apparatus 10 according to the second embodiment of the present invention. As shown in FIG. 8, the laser irradiation apparatus 10 according to the second embodiment of the present invention includes a laser light source 11, a coupling optical system 12, a projection mask 15, and a projection lens 18. The laser light source 11 and the coupling optical system 12 have the same configuration as the laser light source 11 and the coupling optical system 12 in the first embodiment of the present invention shown in FIG. It is omitted. In addition, since the projection mask has the same configuration as that of the projection mask in the first embodiment of the present invention, detailed description will be omitted.
　レーザ光は、投影マスク１５（図示しない）の開口（透過領域）を透過し、投影レンズ１８により、アモルファスシリコン薄膜２１の所定の領域に照射される。その結果、アモルファスシリコン薄膜２１の所定の領域が瞬間加熱されて溶融し、アモルファスシリコン薄膜２１の一部がポリシリコン薄膜２２となる。 The laser light passes through the opening (transmission region) of the projection mask 15 (not shown), and is irradiated onto a predetermined region of the amorphous silicon thin film 21 by the projection lens 18. As a result, a predetermined region of the amorphous silicon thin film 21 is instantaneously heated and melted, and a part of the amorphous silicon thin film 21 becomes the polysilicon thin film 22.
　本発明の第２の実施形態においても、レーザ照射装置１０は所定の周期でレーザ光１４を照射し、レーザ光１４が照射されていない時間に基板３０を移動させ、次のアモルファスシリコン薄膜２１の箇所に当該レーザ光１４が照射されるようにする。第２の実施形態においても、図３に示すように、基板３０は、移動方向に対して、所定の間隔「Ｈ」でアモルファスシリコン薄膜２１が配置される。そして、レーザ照射装置１０は、所定の周期で、基板３０上に配置されたアモルファスシリコン薄膜２１の部分に、レーザ光１４を照射する。 Also in the second embodiment of the present invention, the laser irradiation device 10 irradiates the laser light 14 with a predetermined cycle, moves the substrate 30 during the time when the laser light 14 is not irradiated, and the next amorphous silicon thin film 21 is formed. The laser beam 14 is irradiated to the portion. Also in the second embodiment, as shown in FIG. 3, in the substrate 30, the amorphous silicon thin film 21 is disposed at a predetermined interval “H” in the moving direction. Then, the laser irradiation apparatus 10 irradiates the portion of the amorphous silicon thin film 21 disposed on the substrate 30 with the laser light 14 at a predetermined cycle.
　ここで、投影レンズ１８を用いる場合、レーザ光１４が、当該投影レンズ１８の光学系の倍率で換算される。すなわち、投影マスク１５のパターン（開口部１６のパターン）が、投影レンズ１８の光学系の倍率で換算され、基板３０上の所定の領域がレーザアニールされる。 Here, when the projection lens 18 is used, the laser beam 14 is converted by the magnification of the optical system of the projection lens 18. That is, the pattern of the projection mask 15 (pattern of the opening 16) is converted by the magnification of the optical system of the projection lens 18, and a predetermined region on the substrate 30 is subjected to laser annealing.
　すなわち、投影マスク１５のマスクパターン（開口部１６のパターン）は、投影レンズ１８の光学系の倍率で換算され、基板３０上の所定の領域がレーザアニールされる。例えば、投影レンズ１８の光学系の倍率が約２倍であると、投影マスク１５のマスクパターンは、約１／２（０．５）倍され、基板３０の所定の領域がレーザアニールされる。なお、投影レンズ１８の光学系の倍率は、約２倍に限られず、どのような倍率であってもよい。投影マスク１５のマスクパターンは、投影レンズ１８の光学系の倍率に応じて、基板３０上の所定の領域がレーザアニールされる。例えば、投影レンズ１８の光学系の倍率が４倍であれば、投影マスク１５のマスクパターン（開口部１６のパターン）は、約１／４（０．２５）倍され、基板３０の所定の領域がレーザアニールされる。 That is, the mask pattern (pattern of the opening 16) of the projection mask 15 is converted by the magnification of the optical system of the projection lens 18, and a predetermined region on the substrate 30 is laser annealed. For example, when the magnification of the optical system of the projection lens 18 is about twice, the mask pattern of the projection mask 15 is multiplied by about 1/2 (0.5) and the predetermined region of the substrate 30 is laser annealed. The magnification of the optical system of the projection lens 18 is not limited to about twice, and may be any magnification. The mask pattern of the projection mask 15 is laser-annealed in a predetermined region on the substrate 30 in accordance with the magnification of the optical system of the projection lens 18. For example, if the magnification of the optical system of the projection lens 18 is four times, the mask pattern of the projection mask 15 (the pattern of the opening 16) is multiplied by about 1/4 (0.25) and the predetermined area of the substrate 30 is obtained. Is laser annealed.
　また、投影レンズ１８が倒立像を形成する場合、基板３０に照射される投影マスク１５の縮小像は、投影レンズ１８のレンズの光軸を中心に１８０度回転したパターンとなる。一方、投影レンズ１８が正立像を形成する場合、基板３０に照射される投影マスク１５の縮小像は、当該投影マスク１５そのままとなる。 When the projection lens 18 forms an inverted image, the reduced image of the projection mask 15 irradiated on the substrate 30 has a pattern rotated 180 degrees around the optical axis of the lens of the projection lens 18. On the other hand, when the projection lens 18 forms an erect image, the reduced image of the projection mask 15 irradiated onto the substrate 30 is the projection mask 15 as it is.
　本発明の第２の実施形態では、投影マスク１５に含まれる所定の開口部１５０の透過率を所定値以下とすることにより、一度形成したポリシリコン薄膜２２が完全融解しないようにして、ポリシリコン薄膜２２の再結晶化を最適化する。 In the second embodiment of the present invention, by setting the transmittance of the predetermined opening 150 included in the projection mask 15 to a predetermined value or less, the polysilicon thin film 22 formed once is prevented from completely melting, and polysilicon is formed. The recrystallization of the thin film 22 is optimized.
　所定値は、投影マスクを透過するレーザ光の照射エネルギが、ポリシリコン薄膜の結晶が完全融解するレーザ光１４の照射エネルギよりも小さくなるように設定される。例えば、レーザ光１４の照射エネルギが９８％以下であれば、ポリシリコン薄膜の結晶が完全融解しない場合、所定値は「９８％」に設定される。この場合、所定の開口部１５０は、該レーザ光１４を「２％」遮断し、「９８％」だけ透過する。 The predetermined value is set such that the irradiation energy of the laser beam transmitted through the projection mask is smaller than the irradiation energy of the laser beam 14 which completely melts the polysilicon thin film crystal. For example, if the irradiation energy of the laser beam 14 is 98% or less, the predetermined value is set to “98%” if the crystal of the polysilicon thin film is not completely melted. In this case, the predetermined opening 150 blocks the laser beam 14 by "2%" and transmits "98%".
　なお、透過率は、レーザ光１４のばらつきに応じて設定されてもよく、該レーザ光１４の照射エネルギが「２％」の範囲でばらつく場合、該レーザ光１４をばらつき分の「２％」だけ遮断する（すなわち、所定値は「９８％」）ようにしてもよい。なお、所定値は、どのような値であってもよく、ポリシリコン薄膜の結晶が完全融解する。 The transmittance may be set according to the variation of the laser beam 14, and when the irradiation energy of the laser beam 14 varies in the range of “2%”, “2%” of the variation of the laser beam 14. And the predetermined value is "98%". The predetermined value may be any value, and the crystal of the polysilicon thin film completely melts.
　透過率が所定値以下となる所定の開口部１５０は、例えば、所定の領域に対して最初に照射されるレーザ光が透過する第１開口部から所定数以降に配列された開口部である。所定数は、少なくとも１つ以上である。透過率が所定値以下となる所定の開口部１５０は、例えば、所定の領域に対して最初に照射されるレーザ光が透過する第１開口部から少なくとも１つ目以降に配列された開口部１５０である。すなわち、第１開口部から少なくとも１つ目以降に配列された開口部１５０を透過するレーザ光１４は、ポリシリコン薄膜の結晶が完全融解するレーザ光１４の照射エネルギよりも小さくなる。そのため、少なくとも１つ目以降に配列された開口部１５０を通過するレーザ光１４を照射しても、一度形成されたポリシリコン薄膜２２は完全融解せず、ポリシリコン薄膜２２の再結晶化を最適化する。 The predetermined openings 150 in which the transmittance is equal to or less than a predetermined value are, for example, openings arranged in a predetermined number or more from the first openings through which the laser light initially irradiated to the predetermined region passes. The predetermined number is at least one or more. The predetermined openings 150 for which the transmittance is equal to or less than a predetermined value are, for example, the openings 150 arranged at least one or more from the first opening through which the laser light initially irradiated to the predetermined region passes. It is. That is, the laser beam 14 transmitted through the openings 150 arranged at least one after the first opening is smaller than the irradiation energy of the laser beam 14 which completely melts the crystal of the polysilicon thin film. Therefore, even if the laser beam 14 passing through the openings 150 arranged at least the first one or more is irradiated, the polysilicon thin film 22 formed once is not completely melted, and the recrystallization of the polysilicon thin film 22 is optimum. Turn
　また、第１開口部から所定数以降の開口部の透過率を所定値以下に設定する前に、投影レンズ１８のレーザ光１４の照射エネルギを調整するために、本当該投影レンズ１８の所定の部分に対応する投影マスク１５の開口部１６（透過領域）の透過率を調整してもよい。具体的には、投影レンズ１８の所定の部分の各々の投影倍率を測定し、測定された投影倍率のうち最低の投影倍率（所定の部分のうちの一の部分の投影倍率）に基づいて、他の所定の部分の各々に対応する投影マスク１５の開口部１６（透過領域）の透過率を設定する。 In addition, the predetermined energy of the projection lens 18 is adjusted in order to adjust the irradiation energy of the laser beam 14 of the projection lens 18 before setting the transmittance of the openings after the predetermined number from the first opening to a predetermined value or less. The transmittance of the opening 16 (transmission region) of the projection mask 15 corresponding to the portion may be adjusted. Specifically, the projection magnification of each of the predetermined portions of the projection lens 18 is measured, and based on the lowest projection magnification of the measured projection magnifications (projection magnification of one of the predetermined portions), The transmittance of the opening 16 (transmission region) of the projection mask 15 corresponding to each of the other predetermined portions is set.
　投影レンズ１８の所定の部分において、透過率を上げることはできないため、投影倍率が最も大きい位置の部分（すなわち、最低の透過率）にあわせて、他の部分の透過率を調整する。その後、投影マスク１５において、第１開口部から所定数以降の開口部の透過率を所定値以下に設定することにより、ポリシリコン薄膜２２の再結晶化を最適化することが可能となる。なお、第２の実施形態において、（１）投影マスク１５の開口部１６の透過率を変更することと、（２）投影マスク１５の開口部１６の大きさを調整することは、いずれか一方のみが実施されても、いずれもが実施されてもよい。 Since the transmittance can not be increased in a predetermined portion of the projection lens 18, the transmittance of the other portion is adjusted in accordance with the portion where the projection magnification is the largest (that is, the lowest transmittance). Thereafter, in the projection mask 15, by setting the transmittance of a predetermined number of openings after the first opening to a predetermined value or less, it is possible to optimize the recrystallization of the polysilicon thin film 22. In the second embodiment, either (1) changing the transmittance of the opening 16 of the projection mask 15 or (2) adjusting the size of the opening 16 of the projection mask 15 is either Or only one may be performed.
　また、第１開口部から所定数以降の開口部の透過率を所定値以下に設定する前に、単一の投影レンズ１８の所定の部分の各々の投影倍率を測定し、測定された投影倍率に基づいて、投影マスク１５の開口部１６の大きさを調整する。その結果、単一の投影レンズ１８の所定の部分の各々を透過するレーザ光１４によってレーザアニール処理される範囲が略同一となるため、それにより薄膜トランジスタ２０の特性のばらつきを低減することが可能となる。その後、投影マスク１５において、第１開口部から所定数以降の開口部の透過率を所定値以下に設定することにより、ポリシリコン薄膜２２の再結晶化を最適化することが可能となる。 Also, before setting the transmittance of a predetermined number of openings from the first opening to a predetermined value or less, the projection magnification of each of the predetermined portions of the single projection lens 18 is measured, and the measured projection magnification The size of the opening 16 of the projection mask 15 is adjusted based on As a result, the range to be laser-annealed by the laser beam 14 transmitted through each of the predetermined portions of the single projection lens 18 becomes substantially the same, thereby making it possible to reduce the variation in the characteristics of the thin film transistor 20. Become. Thereafter, in the projection mask 15, by setting the transmittance of a predetermined number of openings after the first opening to a predetermined value or less, it is possible to optimize the recrystallization of the polysilicon thin film 22.
　上記の通り、本発明の第２の実施形態では、単一の投影レンズを用いた場合であっても、投影マスク１５に含まれる所定の開口部１５０の透過率を所定値以下とすることにより、第１開口部から所定数以降の開口部１５０を透過するレーザ光は、ポリシリコン薄膜を再溶解しない。その結果、第１開口部から所定数以降の開口部１５０を透過するレーザ光は、ポリシリコン薄膜の微結晶を成長させ、該ポリシリコン薄膜の結晶を大きくすることができる。したがって、一度形成したポリシリコン薄膜２２が完全融解せず、ポリシリコン薄膜の結晶を成長させることができ、ポリシリコン薄膜２２の再結晶化を最適化することが可能となる。 As described above, in the second embodiment of the present invention, even when a single projection lens is used, the transmittance of the predetermined opening 150 included in the projection mask 15 is set to a predetermined value or less. The laser beam transmitted from the first opening through the predetermined number of openings 150 does not dissolve the polysilicon thin film again. As a result, the laser light transmitted from the first opening through the predetermined number of openings 150 can grow microcrystals of the polysilicon thin film and enlarge the crystal of the polysilicon thin film. Therefore, the polysilicon thin film 22 formed once does not melt completely, and the crystal of the polysilicon thin film can be grown, and the recrystallization of the polysilicon thin film 22 can be optimized.
　なお、以上の説明において、「垂直」「平行」「平面」「直交」等の記載がある場合に、これらの各記載は厳密な意味ではない。すなわち、「垂直」「平行」「平面」「直交」とは、設計上や製造上等における公差や誤差が許容され、「実質的に垂直」「実質的に平行」「実質的に平面」「実質的に直交」という意味である。なお、ここでの公差や誤差とは、本発明の構成・作用・効果を逸脱しない範囲における単位のことを意味するものである。 In the above description, when there are descriptions such as “vertical”, “parallel”, “plane”, “orthogonal”, etc., each of these descriptions does not have a strict meaning. That is, “perpendicular”, “parallel”, “plane” and “orthogonal” mean that tolerances and errors in design and manufacture etc. are allowed, “substantially perpendicular”, “substantially parallel”, “substantially planar” “ It means "substantially orthogonal". Here, the tolerance and the error mean a unit in the range which does not deviate from the configuration, operation and effect of the present invention.
　また、以上の説明において、外観上の寸法や大きさが「同一」「等しい」「異なる」等の記載がある場合に、これらの各記載は厳密な意味ではない。すなわち、「同一」「等しい」「異なる」とは、設計上や製造上等における公差や誤差が許容され、「実質的に同一」「実質的に等しい」「実質的に異なる」という意味である。なお、ここでの公差や誤差とは、本発明の構成・作用・効果を逸脱しない範囲における単位のことを意味するものである。 Further, in the above description, when there are descriptions such as “same”, “equal”, “different” and the like in terms of size and size in appearance, these respective descriptions do not have a strict meaning. That is, “identical” “equal” “different” means that “substantially identical” “substantially equal” “substantially different” as tolerances or errors in design, manufacture, etc. are allowed. . Here, the tolerance and the error mean a unit in the range which does not deviate from the configuration, operation and effect of the present invention.
　本発明を諸図面や実施形態に基づき説明してきたが、当業者であれば本開示に基づき種々の変形や修正を行うことが容易であることに注意されたい。従って、これらの変形や修正は本発明の範囲に含まれることに留意されたい。例えば、各手段、各ステップ等に含まれる機能等は論理的に矛盾しないように再配置可能であり、複数の手段やステップ等を１つに組み合わせたり、或いは分割したりすることが可能である。また、上記実施の形態に示す構成を適宜組み合わせることとしてもよい。 Although the present invention has been described based on the drawings and embodiments, it should be noted that those skilled in the art can easily make various changes and modifications based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention. For example, each means, functions included in each step, etc. can be rearranged so as not to be logically contradictory, and it is possible to combine or divide a plurality of means, steps, etc. into one. . Further, the structures described in the above embodiments may be combined as appropriate.
　１０　レーザ照射装置
　１１　レーザ光源
　１２　カップリング光学系
　１３　マイクロレンズアレイ
　１４　レーザ光
　１５　投影マスク
　１６　開口部（透過領域）
　１７　マイクロレンズ
　１８　投影レンズ
　２０　薄膜トランジスタ
　２１　アモルファスシリコン薄膜
　２２　ポリシリコン薄膜
　２３　ソース
　２４　ドレイン
　３０　基板 DESCRIPTION OF SYMBOLS 10 Laser irradiation apparatus 11 Laser light source 12 Coupling optical system 13 Micro lens array 14 Laser beam 15 Projection mask 16 Opening part (transmission area)
17 micro lens 18 projection lens 20 thin film transistor 21 amorphous silicon thin film 22 polysilicon thin film 23 source 24 drain 30 substrate

Claims (15)

  1. 　レーザ光を発生する光源と、
    　所定方向に移動する基板の所定の領域に、前記レーザ光を照射する投影レンズと、
    　前記投影レンズ上に設けられ、少なくとも前記所定方向の一列に複数の開口部が配列された投影マスクと、を備え、
    　前記投影レンズは、前記複数の開口部の各々を介して、前記所定の領域に対して複数回のレーザ光を照射し、
    　前記複数の開口部のうち、前記所定の領域に対して最初に照射されるレーザ光が透過する第１開口部から所定数以降に配列された開口部は、前記レーザ光が透過する割合である透過率が所定値以下に設定される、ことを特徴とするレーザ照射装置。     A light source generating laser light;
    A projection lens for irradiating the laser beam to a predetermined area of the substrate moving in a predetermined direction;
    A projection mask provided on the projection lens and having a plurality of openings arranged in at least one row in the predetermined direction;
    The projection lens emits a plurality of times of laser light to the predetermined area through each of the plurality of openings.
    Among the plurality of openings, the openings arranged at a predetermined number or more after the first opening through which the laser light initially irradiated to the predetermined region is transmitted have a ratio of transmitting the laser light A laser irradiation apparatus characterized in that the transmittance is set to a predetermined value or less.
  2. 　前記所定数は、少なくとも１つ以上であり、
    　前記投影レンズは、前記第１開口部から少なくとも１つ目以降に配列された前記透過率が所定値以下の開口部を介して、前記所定の領域に対して前記レーザ光を照射することを特徴とする請求項１に記載のレーザ照射装置。     The predetermined number is at least one or more,
    The projection lens is characterized in that the laser beam is irradiated to the predetermined area through the opening portion whose transmittance is equal to or less than a predetermined value arranged at least one or more from the first opening portion. The laser irradiation apparatus according to claim 1.
  3. 　前記投影レンズは、アモルファスシリコン薄膜が被着した前記基板の前記所定の領域に前記レーザ光を照射して、ポリシリコン薄膜を形成し、
    　前記所定値は、前記所定値以下の投影マスクを透過するレーザ光の照射エネルギが、前記ポリシリコン薄膜の結晶が完全融解する前記レーザ光の照射エネルギよりも小さくなるように設定されることを特徴とする請求項１に記載のレーザ照射装置。     The projection lens irradiates the laser light to the predetermined region of the substrate on which the amorphous silicon thin film is deposited to form a polysilicon thin film.
    The predetermined value is set such that the irradiation energy of the laser beam transmitted through the projection mask having the predetermined value or less is smaller than the irradiation energy of the laser beam which completely melts the crystal of the polysilicon thin film. The laser irradiation apparatus according to claim 1.
  4. 　前記複数の開口部のうち、前記第１開口部から所定数以降に配列された開口部の透過率は、前記所定方向に対して順に低くなるように設定されることを特徴とする請求項１に記載のレーザ照射装置。 Among the plurality of openings, the transmittances of the openings arranged from the first opening to a predetermined number or more are set to be lower in order with respect to the predetermined direction. The laser irradiation apparatus as described in.
  5. 　前記投影レンズは、前記レーザ光を分離可能なマイクロレンズアレイに含まれる複数のマイクロレンズであり、
    　前記複数の開口部の各々は、前記マイクロレンズアレイの前記所定方向の一列に含まれる複数の前記マイクロレンズの各々に対応する、ことを特徴とする請求項１に記載のレーザ照射装置。     The projection lens is a plurality of microlenses included in a microlens array capable of separating the laser light,
    2. The laser irradiation apparatus according to claim 1, wherein each of the plurality of openings corresponds to each of the plurality of microlenses included in one row of the microlens array in the predetermined direction.
  6. 　前記複数の開口部の各々は、前記複数のマイクロレンズの各々の投影倍率に基づいて決定された大きさである
    ことを特徴とする請求項５に記載のレーザ照射装置。     The laser irradiation apparatus according to claim 5, wherein each of the plurality of openings has a size determined based on a projection magnification of each of the plurality of microlenses.
  7. 　前記複数の開口部の各々は長方形状であり、前記複数のマイクロレンズの各々の投影倍率に基づいて前記長方形状の長さ及び幅が決定される
    ことを特徴とする請求項５に記載のレーザ照射装置。     The laser according to claim 5, wherein each of the plurality of openings has a rectangular shape, and the length and the width of the rectangular shape are determined based on the projection magnification of each of the plurality of microlenses. Irradiation device.
  8. 　前記複数の開口部の各々は長方形状であり、前記複数のマイクロレンズの各々の投影倍率に基づいて前記長方形状の長さ及び幅が決定される
    ことを特徴とする請求項６に記載のレーザ照射装置。     The laser according to claim 6, wherein each of the plurality of openings has a rectangular shape, and the length and the width of the rectangular shape are determined based on the projection magnification of each of the plurality of microlenses. Irradiation device.
  9. 　レーザ光を発生する第１のステップと、
    　所定方向に移動する基板の所定の領域に、少なくとも前記所定方向の一列に複数の開口部が配列された投影マスクが設けられた投影レンズを用いて、前記レーザ光を照射する第２のステップと、
    　前記レーザ光が照射されるごとに、前記基板を所定の方向に移動する第３のステップと、を含み、
    　前記複数の開口部のうち、前記所定の領域に対して最初に照射されるレーザ光が透過する第１開口部から所定数以降に配列された開口部は、前記レーザ光が透過する割合である透過率が所定値以下に設定される、ことを特徴とするレーザ照射方法。     A first step of generating a laser beam,
    A second step of irradiating the laser beam using a projection lens provided with a projection mask in which a plurality of openings are arranged in at least one row in the predetermined direction in a predetermined area of the substrate moving in the predetermined direction; ,
    Moving the substrate in a predetermined direction each time the laser light is emitted; and
    Among the plurality of openings, the openings arranged at a predetermined number or more after the first opening through which the laser light initially irradiated to the predetermined region is transmitted have a ratio of transmitting the laser light A laser irradiation method characterized in that the transmittance is set to a predetermined value or less.
  10. 　前記所定数は、少なくとも１つ以上であり、
    　前記投影レンズは、前記第１開口部から少なくとも１つ目以降に配列された前記透過率が所定値以下の開口部を介して、前記所定の領域に対して前記レーザ光を照射する、ことを特徴とする請求項９に記載のレーザ照射方法。     The predetermined number is at least one or more,
    The projection lens may irradiate the laser light to the predetermined area through the opening having the predetermined value or less, the transmittance being arranged at least one or more from the first opening. The laser irradiation method according to claim 9, characterized in that:
  11. 　前記第２のステップにおいて、アモルファスシリコン薄膜が被着した前記基板の前記所定の領域に複数回の前記レーザ光を照射して、ポリシリコン薄膜を形成し、
    　前記所定値は、前記所定値以下の前記開口部を透過するレーザ光の照射エネルギが、前記ポリシリコン薄膜の結晶が完全融解する前記レーザ光の照射エネルギよりも小さくなるように設定される、ことを特徴とする請求項９に記載のレーザ照射方法。     In the second step, the predetermined region of the substrate on which the amorphous silicon thin film is deposited is irradiated a plurality of times of the laser light to form a polysilicon thin film.
    The predetermined value is set such that the irradiation energy of the laser light transmitted through the opening having the predetermined value or less is smaller than the irradiation energy of the laser light which causes the crystal of the polysilicon thin film to completely melt. The laser irradiation method according to claim 9, characterized in that
  12. 　所定方向に移動する基板の所定の領域に、光源から発生されたレーザ光を照射する投影レンズ上に配置される投影マスクであって、
    　前記投影マスクは、
    　　少なくとも前記所定方向の一列に複数の開口部が配列され、
    　　前記複数の開口部のうち、前記所定の領域に対して最初に照射されるレーザ光が透過する第１開口部から所定数以降に配列された開口部は、前記レーザ光が透過する割合である透過率が所定値以下に設定される、ことを特徴とする投影マスク。     A projection mask disposed on a projection lens for irradiating a predetermined area of a substrate moving in a predetermined direction with laser light generated from a light source, the projection mask comprising:
    The projection mask is
    A plurality of openings are arranged in at least one row in the predetermined direction,
    Among the plurality of openings, the openings arranged at a predetermined number or more after the first opening through which the laser light initially irradiated to the predetermined region is transmitted have a ratio of transmitting the laser light A projection mask characterized in that the transmittance is set to a predetermined value or less.
  13. 　前記所定数は、少なくとも１つ以上であり、
    　前記複数の開口部のうち、前記第１開口部から少なくとも１つ目以降に配列された開口部は、前記透過率が所定値以下に設定される、ことを特徴とする請求項１２に記載の投影マスク。     The predetermined number is at least one or more,
    13. The apparatus according to claim 12, wherein the transmittance of the plurality of openings arranged at least one or more from the first opening is set to a predetermined value or less. Projection mask.
  14. 　複数の前記開口部を介して照射される前記レーザ光は、アモルファスシリコン薄膜が被着した前記基板の前記所定の領域に、ポリシリコン薄膜を形成し、
    　前記所定値は、前記所定値以下の前記開口部を透過するレーザ光の照射エネルギが、前記ポリシリコン薄膜の結晶が完全融解する前記レーザ光の照射エネルギよりも小さくなるように設定される、ことを特徴とする請求項１２に記載の投影マスク。     The laser beam irradiated through the plurality of openings forms a polysilicon thin film on the predetermined region of the substrate on which an amorphous silicon thin film is deposited;
    The predetermined value is set such that the irradiation energy of the laser light transmitted through the opening having the predetermined value or less is smaller than the irradiation energy of the laser light which causes the crystal of the polysilicon thin film to completely melt. A projection mask according to claim 12, characterized in that.
  15. 　複数の前記開口部を介して照射される前記レーザ光は、アモルファスシリコン薄膜が被着した前記基板の前記所定の領域に、ポリシリコン薄膜を形成し、
    　前記所定値は、前記所定値以下の前記開口部を透過するレーザ光の照射エネルギが、前記ポリシリコン薄膜の結晶が完全融解する前記レーザ光の照射エネルギよりも小さくなるように設定される、ことを特徴とする請求項１３に記載の投影マスク。     The laser beam irradiated through the plurality of openings forms a polysilicon thin film on the predetermined region of the substrate on which an amorphous silicon thin film is deposited;
    The predetermined value is set such that the irradiation energy of the laser light transmitted through the opening having the predetermined value or less is smaller than the irradiation energy of the laser light which causes the crystal of the polysilicon thin film to completely melt. The projection mask according to claim 13, characterized in that:
PCT/JP2018/041562 2017-11-30 2018-11-08 Laser irradiation device, laser irradiation method, and projection mask WO2019107108A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006013050A (en) * 2004-06-24 2006-01-12 Sharp Corp Laser beam projection mask, laser processing method using the same and laser processing system
JP2007207896A (en) * 2006-01-31 2007-08-16 Sharp Corp Laser beam projection mask, laser processing method using same, laser processing apparatus
WO2016186043A1 (en) * 2015-05-19 2016-11-24 株式会社ブイ・テクノロジー Laser annealing method, laser annealing device, and method for manufacturing thin-film transistor

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006013050A (en) * 2004-06-24 2006-01-12 Sharp Corp Laser beam projection mask, laser processing method using the same and laser processing system
JP2007207896A (en) * 2006-01-31 2007-08-16 Sharp Corp Laser beam projection mask, laser processing method using same, laser processing apparatus
WO2016186043A1 (en) * 2015-05-19 2016-11-24 株式会社ブイ・テクノロジー Laser annealing method, laser annealing device, and method for manufacturing thin-film transistor

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