KR102384289B1 - Laser crystalling apparatus - Google Patents

Abstract

In the laser crystallization apparatus according to an embodiment of the present invention, a light source unit generating a plurality of input lights in the form of a laser beam, an optical system converting the input lights provided from the light source unit into at least one output light, and a target substrate are seated, a stage to which the output light is irradiated, wherein the optical system includes a mixing unit for dividing and mixing incident light, a first polarization modulator disposed between the light source unit and the mixing unit on an optical path, and the optical system on the optical path and a second polarization modulator including a processing unit disposed behind the mixing unit to form the output light, and at least one quarter wave plate disposed between the processing unit and the mixing unit on the optical path.

Description

LASER CRYSTALLING APPARATUS

The present invention relates to a laser crystallization apparatus, and to a laser crystallization apparatus with improved laser beam stability.

In general, an electric and electronic device such as a display device is driven by a thin film transistor. In order to use crystalline silicon having advantages such as high mobility as an active layer of a thin film transistor, a process of crystallizing an amorphous polycrystalline thin film, for example, an amorphous silicon thin film is required.

In order to crystallize an amorphous silicon thin film into a crystalline silicon thin film, it is necessary to irradiate a laser with a certain amount of energy.

An object of the present invention is to provide a laser crystallization apparatus with improved laser beam stability.

A laser crystallization apparatus according to an embodiment of the present invention includes a light source unit that generates at least one input light in the form of a laser beam, an optical system that converts the input light provided from the light source unit into at least one output light, and a target substrate is seated therein; , a stage to which the output light is irradiated, wherein the optical system includes at least one beam splitter and at least one mirror, a mixing unit for splitting incident light into a plurality of lights, the light source unit and the light source unit on an optical path A first polarization modulator disposed between the mixing units and including at least one quarter wave plate for delaying one component of incident light by λ/4, disposed behind the mixing unit on the optical path, and at least one lens including, a processing unit forming the output light, and at least one quarter wavelength disposed between the processing unit and the mixing unit on the optical path and delaying one component of the light provided from the mixing unit by λ/4 and a second polarization modulator including a plate.

The first polarization modulator converts the incident linearly polarized light into a circularly polarized state, and the second polarization modulator converts the incident circularly polarized light into a linearly polarized state.

The input light is a solid-state laser.

The optical system may further include a third polarization modulator disposed between the second polarization modulator and the processing unit on the optical path and configured to change a polarization direction of the light provided from the second polarization modulator.

The third polarization modulator includes at least one half-wave plate.

The third polarization modulator further includes a half-wavelength driver for receiving an electrical signal and controlling an optical axis of the half-wavelength plate.

The optical system may further include a fourth polarization modulator disposed between the first polarization modulator and the light source on the optical path and configured to convert the input light provided from the light source into a linearly polarized state.

The input light is an excimer laser.

The fourth polarization modulator includes at least one linear polarizer.

Line modulated light defined as light converted into a circularly polarized state by the first polarization modulator is incident on the mixing unit, and the mixing unit includes a first mirror for changing the direction of the line modulated light, and a part of the line modulated light A first beam splitter that reflects and transmits the remaining portion to split the linearly modulated light into a plurality of mixing lights, and a second mirror that changes the direction of at least some of the mixing lights split by the first beam splitter include

The processing unit forms the at least one output light by synthesizing the plurality of incident lights.

The processing unit, each having a plate shape in which a plurality of lenses are arranged, at least one homogenizer to equalize incident light, and a linear shape by adjusting the size and focus of light passing through the homogenizer At least one cylindrical lens (Cylindrical lens) for forming the light of.

The light source unit generates first to n-th input lights, and the first to n-th input lights are first to n-th linear modulated lights defined as lights converted into a circularly polarized state by the first polarization modulator, respectively. are incident to the mixing unit, and the mixing unit includes a plurality of beam splitters for splitting each of the first to n-th line modulated lights into n pieces, and a plurality of beam splitters for changing directions of the first to n-th line modulated lights. Including mirrors, lights divided into n pieces from the modulated light are mixed in a one-to-one correspondence with the divided lights divided into n pieces from each of the n-1 modulated lights except for the one modulated light, n is a natural number greater than 1 .

First to n-th mixing lights defined as lights emitted from the mixing unit have the same mixing ratio with respect to the first to n-th linear modulation lights. At least any two of the plurality of quarter wavelength plates of the first polarization modulator The optical axes of the quarter wave plates are not parallel to each other.

Optical axes of at least any two quarter-wave plates among the plurality of quarter-wave plates of the second polarization modulator are not parallel to each other.

The plurality of input lights oscillate at different times.

Further comprising a time delay unit disposed between the processing unit and the stage on the optical path, the time delay unit, a delay beam splitter that transmits a portion of the light synthesized in the processing unit and reflects the remaining portion, and the processing a plurality of delay mirrors for increasing the optical path of the light reflected by the time delay beam splitter among the lights synthesized in the unit, and the half maximum width of the output light increases by the time delay unit.

The beam splitter transmits 50% of the incident light and reflects the remaining 50%.

A laser crystallization apparatus according to an embodiment of the present invention includes a light source unit for generating a plurality of laser beams in a linearly polarized state, a first polarization modulation disposed behind the light source unit on an optical path, and circularly polarizing the laser beams provided from the light source unit unit, a mixing unit disposed behind the first polarization modulator on the optical path and dividing and mixing the circularly polarized laser beams, disposed behind the mixing unit on the optical path, and provided from the mixing unit a second polarization modulator for linearly polarizing laser beams, a processing unit disposed behind the second polarization modulator on the optical path to focus and mix the linearly polarized laser beams to form output light; and a stage disposed behind the processing unit on the optical path and irradiated with the output light.

According to an embodiment of the present invention, the stability of the laser beam may be improved. That is, the laser crystallization apparatus according to an embodiment of the present invention may output a laser beam having an improved energy density (Energy Density, ED) uniformity.

1 is a schematic diagram of a laser crystallization apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic schematic diagram of the optical system shown in FIG. 1
FIG. 3 is an enlarged view of the mixing unit shown in FIG. 2 .
4 is an enlarged view of the processing unit shown in FIG. 2 .
5 is a schematic diagram of a laser crystallization apparatus according to another embodiment of the present invention.
6 is a schematic diagram of a laser crystallization apparatus according to another embodiment of the present invention.
FIG. 7 is an enlarged view of the mixing unit shown in FIG. 6 .
8 is a schematic diagram of a laser crystallization apparatus according to another embodiment of the present invention.
9 is a schematic diagram of a laser crystallization apparatus according to another embodiment of the present invention.
10 is an enlarged view of the time delay unit shown in FIG.

Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and those of ordinary skill in the art to which the present invention pertains. It is provided to fully inform the person of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

Reference to an element or layer “on” or “on” another element or layer includes not only directly on the other element or layer, but also with other layers or other elements intervening. include all On the other hand,

Reference to an element "directly on" or "directly on" indicates that no intervening element or layer is intervening. “and/or” includes each and every combination of one or more of the recited items.

Spatially relative terms "below", "beneath", "lower", "above", "upper", etc. It can be used to easily describe the correlation between an element or components and other elements or components. The spatially relative terms should be understood as terms including different orientations of the device during use or operation in addition to the orientation shown in the drawings. Like reference numerals refer to like elements throughout.

It should be understood that although first, second, etc. are used to describe various elements, components, and/or sections, these elements, components, and/or sections are not limited by these terms. These terms are only used to distinguish one element, component, or sections from another. Accordingly, it goes without saying that the first element, the first element, or the first section mentioned below may be the second element, the second element, or the second section within the spirit of the present invention.

Embodiments described herein will be described with reference to a plan view and a cross-sectional view, which are ideal schematic views of the present invention. Accordingly, the shape of the illustrative drawing may be modified due to manufacturing technology and/or tolerance. Accordingly, embodiments of the present invention are not limited to the specific form shown, but also include changes in the form generated according to the manufacturing process. Accordingly, the regions illustrated in the drawings have schematic properties, and the shapes of the regions illustrated in the drawings are intended to illustrate specific shapes of regions of the device, and not to limit the scope of the invention.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

1 is a schematic diagram of a laser crystallization apparatus according to an embodiment of the present invention.

Referring to FIG. 1 , a laser crystallization apparatus according to an embodiment of the present invention includes a light source unit 100 , an optical system 200 , and a stage 300 .

In this embodiment, the light source unit 100 may be a laser beam. That is, the light source unit 100 may be a laser generator.

The input light IL may be a solid-state laser. That is, the input light IL generated from the light source unit 100 may be linearly polarized light. Exemplarily, the input light IL includes light of a P-polarization state and light of an S-polarization state.

The optical system 200 converts the input light IL provided from the light source unit 100 into at least one output light OL. The optical system 200 is disposed between the stage 300 and the light source unit 100 on the optical path, and irradiates at least one output light OL to the stage 300 . Hereinafter, the optical system 200 will be described in more detail with reference to FIGS. 2 to 4 .

The stage 300 supports the target substrate 10 . The output light OL emitted from the optical system 200 may be irradiated to the target substrate 10 . The output light OL may crystallize a thin film formed on the upper surface of the target substrate 10 .

Specifically, the target substrate 10 may include an amorphous silicon layer. The target substrate 10 may be formed by a method such as a low pressure chemical vapor deposition method, an atmospheric pressure chemical vapor deposition method, a plasma enhanced chemical vapor deposition (PECVD) method, a sputtering method, or a vacuum evaporation method. The laser crystallization apparatus 1000 according to this embodiment irradiates the output light OL to the target substrate 10 to crystallize the amorphous silicon layer of the target substrate 10 into a poly-crystal silicon layer. can

Although not shown in the drawings, the laser crystallization apparatus 1000 according to another embodiment of the present invention may further include a stage moving unit (not shown) disposed on the lower or side surface of the stage 300 to move the stage 300 . can

The laser crystallization apparatus 1000 according to an embodiment of the present invention may further include at least one direction changing member M disposed between the optical system 200 and the stage 300 on the optical path. For example, the direction changing member M may be a mirror. The direction conversion member M changes the direction of the output light OL provided from the optical system 200 to the stage 300 .

FIG. 2 is a schematic schematic diagram of the optical system shown in FIG. 1

Referring to FIG. 2 , the optical system 200 includes a first polarization modulator 210 , a mixing unit 220 , a second polarization modulator 230 , and a processing unit 240 .

The first polarization modulator 210 is disposed at the front of the optical system 200 on the optical path. The first polarization modulator 210 converts the input light IL incident to the first polarization modulator 210 into linear modulated light MLA. The linearly modulated light (MLA) may be circularly polarized light.

Specifically, the first polarization modulator 210 may include at least one quarter wavelength plate QA that delays one component of the incident light by λ/4. That is, as the input light IL provided from the light source unit 100 passes through the first polarization modulator 210 , one component may be delayed by λ/4 to be circularly polarized.

The mixing unit 220 is disposed behind the first polarization modulator 210 on the optical path. The mixing unit 220 may include at least one beam splitter and at least one mirror. The mixing unit 220 may divide the linearly modulated light MLA incident to the mixing unit 220 to form two mixing lights DL1 and DL2 . The mixing lights DL1 and DL2 may have the same energy density. The mixing unit 220 will be described in more detail below with reference to FIG. 3 .

The second polarization modulator 230 is disposed behind the mixing unit 220 on the optical path. The second polarization modulator 230 converts the mixing lights DL1 and DL2 incident to the second polarization modulator 230 into post-modulation lights MLB1 and MLB2. The post-modulated lights MLB1 and MLB2 may be linearly polarized lights.

Specifically, the second polarization modulator 230 may include at least one quarter wavelength plate QB that delays one component of the incident light by λ/4. That is, as the mixing lights DL1 and DL2 provided from the mixing unit 220 pass through the second polarization modulator 230 , one component may be delayed by λ/4 to be linearly polarized.

In FIG. 2 , the second polarization modulator 230 is illustrated to include two quadrant wavelength plates QB. However, the present invention is not limited thereto. In another embodiment of the present invention, the second polarization modulator 230 includes only one quarter-wavelength plate QB, so that the two mixing lights DL1 and DL2 are incident on one quarter-wavelength plate QB. can

In this embodiment, the two quadrant wavelength plates QB of the second polarization modulator 230 have optical axes parallel to each other. However, the present invention is not limited thereto. For example, in the second polarization modulator 230 according to another embodiment of the present invention, the two quadrant wavelength plates QB may have different optical axes.

The processing unit 240 is disposed behind the second polarization modulator 230 on the optical path. Although not shown, the processing unit 240 includes at least one lens. The processing unit 240 forms the output light OL by synthesizing the incident light. The output light OL is emitted from the processing unit 240 and is irradiated to the stage 300 . Hereinafter, the processing unit 240 in FIG. 4 will be described in more detail below.

FIG. 3 is an enlarged view of the mixing unit shown in FIG. 2 .

Referring to FIG. 3 , the mixing unit 220 according to an embodiment of the present invention divides and mixes the incident linear modulated light MLA to form two mixing lights DL1 and DL2 .

The mixing unit 220 includes a first mirror M1 , a second mirror M2 , and a first beam splitter BS1 .

The linearly modulated light MLA, which is circularly polarized from the first polarization modulator 210 , is incident on the first mirror M1 of the mixing unit 220 . The first mirror M1 reflects the incident line modulated light MLA to change the direction of the line modulated light MLA to face the first beam splitter BS1.

The first beam splitter BS1 transmits a portion of the incident linearly modulated light MLA and reflects the remaining portion. For example, the first beam splitter BS1 transmits 50% of the linearly modulated light MLA and reflects 50% of the light. The first mixing light DL1 transmitted by the first beam splitter BS1 is emitted from the mixing unit 220 , and the second mixing light DL2 reflected by the first beam splitter BS1 is reflected by the second mirror It is incident on (M2). The second mirror M2 reflects the incident second mixing light DL2 to change the direction of the second mixing light DL2 . The second mixing light DL2 whose direction is changed is emitted from the mixing unit 220 .

Although two mirrors M1 and M2 and one beam splitter BS1 are illustrated in FIG. 3 , the present invention is not particularly limited to the detailed configuration of the mixing unit 220 . According to another embodiment of the present invention, the mixing unit 220 may include only one mirror M1 and one beam splitter BS1, and the mixing unit 220 according to another embodiment of the present invention It may include three or more mirrors and two or more beam splitters BS1.

Also, in the present embodiment, the mixing unit 220 forms two mixing lights DL1 and DL2, but in another embodiment of the present invention, the mixing unit 220 may form three or more mixing lights.

4 is an enlarged view of the processing unit shown in FIG. 2 .

Referring to FIG. 4 , the processing unit 240 synthesizes the post-modulated lights MLB1 and MLB2 converted from the second polarization modulator 230 to form the output light OLE.

The processing unit 240 includes at least one homogenizer 241 and at least one cylindrical lens 242 , 243 .

The homogenizer 241 has a plate shape in which a plurality of lenses are arranged. The homogenizer 241 equalizes the incident light so that the beam energy density is evenly distributed.

A plurality of cylindrical lenses 242 and 243 are provided. The cylindrical lenses 242 and 243 adjust the size and focus of the light passing through the homogenizer 241 to form the output light OL.

Although not shown in the drawings, the processing unit 240 according to another embodiment of the present invention may further include a telescope lens (not shown). The telescope lens may be disposed in front of the processing unit 240 to enlarge the size of each of the post-modulated lights MLB1 and MBL2.

Unlike the embodiment of the present invention, when the light incident on the mixing unit 220 is linearly polarized light, that is, the light incident on the mixing unit 220 includes S-polarized light and P-polarized light. In this case, the divided ratio in the mixing unit 220 may not be the same. That is, energy density (ED) between the mixing lights DL1 and DL2 divided by the mixing unit 220 may be non-uniform. However, according to an embodiment of the present invention, the input light IL generated from the light source unit 100 is incident on the first polarization modulator 210 before being incident on the mixing unit 220 and is linearly polarized light in a circularly polarized state. (MLA) is converted to That is, since the light of the circular polarization state is incident on the mixing unit 220 , the split ratio of the beam splitter according to the S/P polarization state may be the same.

Also, according to the present embodiment, the mixing lights DL1 and DL2 equally divided from the mixing unit 220 are linearly polarized again by the second polarization modulator 230 and synthesized by the processing unit 240 . Accordingly, the stage 300 may be irradiated with the output light OL having a uniform energy density than the input light IL irradiated from the conventional light source unit 100 . That is, the crystallization uniformity of the target substrate 10 may be improved.

5 is a schematic diagram of a laser crystallization apparatus according to another embodiment of the present invention.

For convenience of description, the description will be focused on the points different from the exemplary embodiment of the present invention, and the omitted parts will be in accordance with the exemplary embodiment of the present invention. In addition, reference numerals are used for the components described above, and duplicate descriptions of the components are omitted.

Referring to FIG. 5 , the optical system 200 of the laser crystallization apparatus 1000 - 1 according to another embodiment of the present invention further includes a third polarization modulator 250 . The third polarization modulator 250 is disposed between the second polarization modulator 230 and the processing unit 240 on the optical path.

The third polarization modulator 250 changes the polarization directions of the post-modulated lights MLB1 and MLB2 provided from the second polarization modulator 230 .

Specifically, the third polarization modulator 250 delays one component of each of the post-modulated lights MLB1 and MLB2 provided from the second polarization modulator 230 by λ/2. That is, the third polarization modulator 250 may include at least one half-wave plate H. The post-modulated lights MLB1 and MLB2 may be converted into the last modulated lights MLC1 and MLC2 by the third polarization modulator 250 .

Although not shown in the drawings, the third polarization modulator 250 according to an embodiment of the present invention further includes a half-wavelength driver (not shown) for receiving an electric signal from the outside and controlling the optical axis of the half-wavelength plate H can do. The last modulated lights MLC1 and MLC2 may be converted into a polarization state desired by a user by a half-wavelength driver (not shown). The last modulated lights MLC1 and MLC2 are incident on the processing unit 240 .

6 is a schematic schematic view of a laser crystallization apparatus according to another embodiment of the present invention, and FIG. 7 is an enlarged view of the mixing unit shown in FIG. 6 .

For convenience of description, the description will be focused on the points different from the exemplary embodiment of the present invention, and the omitted parts will be in accordance with the exemplary embodiment of the present invention. In addition, reference numerals are used for the components described above, and duplicate descriptions of the components are omitted.

6 and 7 , the light source unit 100 - 2 of the laser crystallization apparatus 1000 - 2 according to another embodiment of the present invention generates a plurality of input lights IL1 to IL4.

For convenience of explanation, although the configuration of the four input lights IL1 to IL4 is exemplarily described in FIGS. 6 and 7 , the present invention can be equally applied to n beams.

The first to fourth input lights IL1 to IL4 emitted from the light source unit 100 are incident on the first polarization modulator 210 . The first polarization modulator 210 includes four quadrant wavelength plates QA1 to QA4 . The first to fourth input lights IL1 to IL4 may be transmitted in a one-to-one correspondence to the four quarter wavelength plates QA1 to QA4 . The transmitted quarter wave plates QA1 to QA4 are converted into first to fourth linear modulated lights MLA1 to MLA4.

According to the present exemplary embodiment, optical axes of at least two of the four quarter wave plates QA1 to QA4 may not be parallel to each other. However, according to another embodiment of the present invention, the four quarter wave plates QA1 to QA4 may have optical axes parallel to each other. QA4) can be substituted.

The first to fourth linear modulated lights MLA1 to MLA4 are incident on the mixing unit 220 - 2 . The incident first to fourth linear modulated lights MLA1 to MLA4 are divided and mixed by the mixing unit 220 - 2 to form first to fourth mixing lights DL1 to DL4 .

Specifically, the mixing unit 220 - 2 includes first to sixth mirrors M1 to M6 and first to fourth beam splitters BS1 to BS4 . The configuration of the mixing unit 220-2 according to this embodiment is only for illustrative purposes, and the present invention is not particularly limited to the number and position of the mirrors and beam splitters of the mixing unit 220-2. not.

The first linear modulated light MLA1 is reflected by the first mirror M1 and is incident on the first beam splitter BS1. The first linear modulated light MLA1 is first split by the first beam splitter BS1. One of the first split beams DLA1 transmitted through the first beam splitter BS1 among the two first split lights DLA1 is incident on the second beam splitter BS2 and is secondarily split. One of the first split lights DLA2 transmitted through the second beam splitter BS2 among the first split lights DLA2 secondarily split by the second beam splitter BS2 is received from the mixing unit 220 - 3 . is released This may be a part of the first mixing light DL1.

The other first split light DLA1 reflected by the first beam splitter BS1 among the two first split lights DLA1 is reflected by the second mirror M2 . The reflected first split light DLA2 is incident on the third beam splitter BS3 and is secondarily split. One first split light DLA2 transmitted through the third beam splitter BS3 among the first split lights DLA2 secondarily split by the third beam splitter BS3 is output from the mixing unit 220 - 3 . is released This may be a part of the second mixing light DL2.

Among the first split lights DLA2 secondarily split by the second beam splitter BS2 , the other first split light DLA2 reflected by the second beam splitter BS2 is transmitted to the third mirror M3 . is reflected and emitted from the mixing unit 220-2. This may be a part of the third mixing light DL3.

Among the first split lights DLA2 secondarily split by the third beam splitter BS3 , the other first split light DLA2 reflected by the third beam splitter BS3 is transmitted to the fourth mirror M4 . is reflected and emitted from the mixing unit 220-2. This may be a part of the fourth mixing light DL4.

The second linear modulated light MLA2 is first split by the first beam splitter BS1 . One second split beam DLB1 reflected from the first beam splitter BS1 among the two first split second split beams DLB1 is incident on the second beam splitter BS2 and is secondarily split. One of the second split lights DLB2 transmitted through the second beam splitter BS2 among the second split lights DLB2 secondarily split by the second beam splitter BS2 is the first mixing light DL1. may be some

The other second split beam DLB1 transmitted through the first beam splitter BS1 among the two first split second split beams DLB1 is reflected by the second mirror M2 . The reflected second split light DLB1 is incident on the third beam splitter BS3 and is secondarily split. One second split light DLB2 passing through the third beam splitter BS3 among the second split lights DLB2 secondarily split by the third beam splitter BS3 is output from the mixing unit 220 - 2 is released This may be a part of the second mixing light DL2.

Among the second split beams DLB2 secondarily split by the second beam splitter BS2 , the other second split beam DLB2 reflected by the second beam splitter BS2 is transmitted to the third mirror M3 . is reflected and emitted from the mixing unit 220-2. This may be a part of the third mixing light DL3.

Among the second split beams DLB2 secondarily split by the third beam splitter BS3 , the other second split beam DLB2 reflected by the third beam splitter BS3 is transmitted to the fourth mirror M4 . is reflected and emitted from the mixing unit 220-2. This may be a part of the fourth mixing light DL4.

The third linearly modulated light MLA3 is reflected by the fifth mirror M5 and is incident on the fourth beam splitter BS4 . The third linear modulated light MLA3 is primarily divided by the fourth beam splitter BS4. One third split light DLC1 passing through the fourth beam splitter BS4 among the two firstly split third split lights DLC1 is secondarily split by the second beam splitter BS2 . The third split light DLC2 reflected by one of the two third split lights DLC2 split by the second beam splitter BS2 is transmitted from the mixing unit 220 - 2 is released This may be a part of the first mixing light DL1.

The other third split light DLC1 reflected by the fourth beam splitter BS4 among the two third split lights DLC1 firstly split by the fourth beam splitter BS4 is the sixth mirror ( After being reflected by M6), it is incident on the third beam splitter BS3 and is secondarily split. One third split light DLC2 reflected by the third beam splitter BS3 among the third split lights DLC2 secondarily split by the third beam splitter BS3 is output from the mixing unit 220 - 2 is released This may be a part of the second mixing light DL2.

Among the two third split beams DLC2 secondarily split by the second beam splitter BS2, the other third split beam DLC2 that has passed through the second beam splitter BS2 is the third mirror M3. ) and is reflected from the mixing unit 220-2. This may be a part of the third mixing light DL3.

Among the third split beams DLC2 secondarily split by the third beam splitter BS3 , the other third split beam DLC2 passing through the third beam splitter BS3 is generated by the fourth mirror M4 . It is reflected and emitted from the mixing unit 220-2. This may be a part of the fourth mixing light DL4.

The fourth linear modulated light MLA4 is primarily divided by the fourth beam splitter BS4. One fourth split light DLD1 passing through the fourth beam splitter BS4 among the two firstly split fourth split lights DLD1 is incident on the second beam splitter BS2 and is secondarily split. One fourth split light DLD2 reflected by the second beam splitter BS2 among the fourth split lights DLD2 secondarily split by the second beam splitter BS2 is generated by the mixing unit 220 - 2 . is emitted from This may be a part of the first mixing light DL1.

Among the fourth split lights DLD1 firstly split by the fourth beam splitter BS4 , the other fourth split light DLD2 reflected by the fourth beam splitter BS4 is transmitted to the sixth mirror M6 . After being reflected by the third beam splitter (BS3), it is secondarily split. One fourth split light DLD2 reflected by the third beam splitter BS3 among the two fourth split lights DLD2 secondarily split by the third beam splitter BS3 is generated by the mixing unit 220 - 2 ) is emitted from This may be a part of the second mixing light DL2.

Among the fourth split lights DLD2 secondarily split by the second beam splitter BS2 , the other fourth split light DLD2 that has passed through the second beam splitter BS2 is generated by the third mirror M3 . It is reflected and emitted from the mixing unit 220-2. This may be a part of the third mixing light DL3.

Among the two fourth split beams DLD2 secondarily split by the third beam splitter BS3 , the other fourth split beam DLD2 passing through the third beam splitter BS3 is the fourth mirror M4 . ) and then emitted from the mixing unit 220-2. This may be a part of the fourth mixing light DL4.

As described above, each of the first to fourth linear modulated lights MLA1 to MLA4 is divided into four divided lights and is emitted from the mixing unit 220 - 2 . The first split lights DLA2 divided into four in the first line modulated lights MLA1 are one-to-one with the second to fourth split lights divided into four from each of the second to fourth linear modulated lights MLA2 to MLA4. mixed to match. Specifically, one of the first split lights DLA2 divided into four in the first linear modulated light MLA1 is one of the second split lights DLB2 split into four in the second linear modulated light MLA2, the second One of the third divided lights DLC2 divided into four in the three linear modulated lights MLA3 and one of the fourth divided lights DLD2 divided into four in the fourth linear modulated light MLA4 are mixed to form one Light DL1 is formed.

According to this embodiment, the first to fourth beam splitters BS1 transmit 50% of the incident light and reflect 50% of the incident light. That is, since the first to fourth linear modulated lights MLA1 to MLA4 incident on the mixing unit 220 - 2 are light in a circularly polarized state, each of the beam splitters BS1 to BS4 according to the S/P polarization state Transmission and reflection ratios may be the same. Accordingly, the first to fourth mixing lights DL1 to DL4 emitted from the mixing unit 220 - 2 may have the same mixing ratio with respect to the first to fourth linear modulation lights MLA1 to MLA4 .

The first to fourth mixing lights DL1 to DL4 emitted from the mixing unit 220 - 2 are incident on the second polarization modulator 230 - 2 . The second polarization modulator 230 - 2 includes four quadrant wavelength plates QB1 to QB4 . The first to fourth mixing lights DL1 to DL4 may be transmitted in one-to-one correspondence to the four quarter wavelength plates QB1 to QB4. The transmitted quarter wavelength plates QB1 to QB4 are converted into first to fourth post-modulation lights MLB1 to MLB4.

According to the present embodiment, the optical axes of at least any two quarter wavelength plates among the four quarter wavelength plates QB1 to QB4 may not be parallel to each other. However, according to another embodiment of the present invention, all four quadrant wavelength plates QB1 to QB4 may have the same optical axis. ) can be substituted.

8 is a schematic diagram of a laser crystallization apparatus according to another embodiment of the present invention.

For convenience of description, the description will be focused on the points different from the exemplary embodiment of the present invention, and the omitted parts will be in accordance with the exemplary embodiment of the present invention. In addition, reference numerals are used for the components described above, and duplicate descriptions of the components are omitted.

Referring to FIG. 8 , the input light ILA generated by the light source unit 100 of the laser crystallization apparatus 1000 - 3 according to another embodiment of the present invention may be light in an unpolarized state. For example, the input light ILA according to the present embodiment may be an eximer laser.

In addition, the optical system 200 according to the present embodiment further includes a fourth polarization modulator 260 . The fourth polarization modulator 260 is disposed between the light source unit 100 and the first polarization modulator 210 on the optical path.

The fourth polarization modulator 260 changes the polarization direction of the input light ILA provided from the light source unit 100 . Specifically, the fourth polarization modulator 260 converts the input light ILA provided from the light source unit 100 into linearly polarized light ILB. For example, the fourth polarization modulator 260 may include at least one linear polarizer (POL).

9 is a schematic diagram of a laser crystallization apparatus according to another embodiment of the present invention.

10 is an enlarged view of the time delay unit shown in FIG.

For convenience of description, the description will be focused on the points different from the exemplary embodiment of the present invention, and the omitted parts will be in accordance with the exemplary embodiment of the present invention. In addition, reference numerals are used for the components described above, and duplicate descriptions of the components are omitted.

9 and 10 , the optical system 200 - 4 of the laser crystallization apparatus 1000 - 4 according to another embodiment of the present invention further includes a time delay unit 270 . The time delay unit 270 is disposed between the processing unit 240 and the stage 300 on the optical path.

The time delay unit 270 divides the preliminary output light OL1 synthesized by the processing unit 240 and emits them differently in time, thereby increasing the oscillation duration of the output light OL2 irradiated to the stage 300 . plays a role That is, the time delay unit 270 according to the present embodiment serves to increase the full width at half maximum (FWHM) of the output light OL2.

The time delay unit 270 includes at least one delay splitter TBS and a plurality of delay mirrors TM1 to TM4.

The configuration of the time delay unit 270 according to the present embodiment is only for illustrative purposes, and the present invention is not particularly limited to the number and positions of delay mirrors and delay splitters of the time delay unit 270 . .

The preliminary output light OL1 emitted from the processing unit 240 is incident on the delay splitter TBS of the time delay unit 270 . A portion of the preliminary output light OL1 incident on the delay splitter TBS passes through the delay splitter TBS and is emitted from the time delay unit 270 . This is defined as the first output light OL2A.

The remaining portion of the preliminary output light OL1 incident on the delay splitter TBS is reflected by the delay splitter TBS and is incident on a time delay loop including the first to fourth delay mirrors TM1 to TM4 . The time delay loop serves to slow the oscillation time by increasing the optical path of the incident light. In detail, a portion of the preliminary output light OL1 reflected by the delay splitter TBS is sequentially reflected by the first to fourth delay mirrors TM1 to TM4 and is incident on the delay splitter TBS again. Among the light incident on the delay splitter TBS through the time delay loop, some light reflected by the delay splitter TBS is emitted from the time delay unit 270, and the remaining partial light passing through the delay splitter TBS is also It is incident on the time delay loop composed of the first to fourth delay mirrors TM1 to TM4 again. Lights output through the time delay loop are defined as the second output light OL2B.

In the present embodiment, the number of times n of the preliminary output light OL1 oscillated once is incident on the time delay loop through the delay splitter TBS is not particularly limited. Exemplarily, n may be 3 or more and 5 or less.

According to the present exemplary embodiment, since the first output light OL2A and the second output light OL2B oscillate with a time difference, the oscillation duration of the output light OL2 may increase. In other words. According to the present exemplary embodiment, since the time delay unit 270 extends the oscillation duration of the output light OL2 , the target substrate 10 may be more easily crystallized.

Although not shown in the drawings, according to another embodiment of the present invention, the light source unit 100 includes a plurality of input lights and the input lights are all oscillated at different times to increase the half width of the output light OL. there is. According to the present embodiment, the function of the time delay unit 270 may be replaced by oscillating the plurality of input lights IL generated from the light source unit 100 with a time difference.

Although described with reference to the above embodiments, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. will be able In addition, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, and all technical ideas within the scope of the following claims and their equivalents should be construed as being included in the scope of the present invention. .

1000: laser crystallization device 10: target substrate
100: light source unit 200: optical system
300: stage 210: first polarization modulator
220: mixing unit 230: second polarization modulator
240: processing unit 250: third polarization modulator
260: fourth polarization modulator 270: time delay unit

Claims (20)

a light source for generating at least one input light in the form of a laser beam;
an optical system for converting the input light received from the light source unit into at least one output light; and
A target substrate is seated, comprising a stage to which the output light is irradiated,
The optical system is
a mixing unit including at least one beam splitter and at least one mirror and splitting the incident light into a plurality of lights;
a first polarization modulator disposed between the light source unit and the mixing unit on an optical path, the first polarization modulator including at least one quarter wavelength plate delaying one component of incident light by λ/4;
a processing unit disposed behind the mixing unit on the optical path, including at least one lens, and configured to form the output light; and
A laser crystallization apparatus including a second polarization modulator disposed between the processing unit and the mixing unit on the optical path and including at least one quarter wave plate that delays one component of the light provided from the mixing unit by λ/4 . The method of claim 1,
The first polarization modulator converts incident linearly polarized light into a circularly polarized state, and the second polarization modulator converts the incident circularly polarized light into a linearly polarized light. 3. The method of claim 2,
The input light is a solid-state laser laser crystallization device. 3. The method of claim 2,
The optical system is
and a third polarization modulator disposed between the second polarization modulator and the processing unit on the optical path and configured to change a polarization direction of the light provided from the second polarization modulator. 5. The method of claim 4,
and the third polarization modulator includes at least one half-wave plate. 6. The method of claim 5,
The third polarization modulator further includes a half-wavelength driver for receiving an electrical signal and controlling an optical axis of the half-wavelength plate. 3. The method of claim 2,
The optical system is
disposed between the first polarization modulator and the light source on the optical path,
The laser crystallization apparatus further comprising a fourth polarization modulator for converting the input light provided from the light source into a linearly polarized state. 8. The method of claim 7,
The input light is an excimer laser laser crystallization apparatus. 8. The method of claim 7,
The fourth polarization modulator includes at least one linear polarizer. The method of claim 1,
Line modulated light defined as light converted into a circularly polarized state by the first polarization modulator is incident on the mixing unit,
The mixing unit,
a first mirror for changing the direction of the linear modulated light;
a first beam splitter that reflects a portion of the line modulated light and transmits the remaining portion to split the line modulated light into a plurality of mixing lights; and
and a second mirror configured to change a direction of at least a portion of the mixing lights divided by the first beam splitter. The method of claim 1,
The processing unit is a laser crystallization apparatus for forming the at least one output light by synthesizing a plurality of incident lights. 11. The method of claim 10,
The processing unit,
at least one homogenizer each having a plate shape in which a plurality of lenses are arranged and uniformizing incident light; and
Laser crystallization apparatus comprising at least one cylindrical lens (Cylindrical lens) for forming a linear light by adjusting the size and focus of the light passing through the homogenizer. The method of claim 1,
The light source unit generates first to n-th input lights,
First to n-th line modulated lights defined as lights converted into circularly polarized states by the first polarization modulator, respectively, from the first to n-th input lights are incident on the mixing unit,
The mixing unit,
a plurality of beam splitters dividing each of the first to n-th linear modulated lights into n pieces; and
a plurality of mirrors for changing directions of the first to n-th linear modulated lights;
Lights divided into n pieces from one modulated light are mixed in a one-to-one correspondence with the divided lights divided into n pieces from each of n-1 pieces of modulated lights except for the one modulated light, and n is a natural number greater than 1. 14. The method of claim 13,
The first to n-th mixing lights defined as lights emitted from the mixing unit have the same mixing ratio with respect to the first to n-th linear modulated lights. 14. The method of claim 13,
Optical axes of at least any two quarter-wavelength plates among the plurality of quarter-wavelength plates of the first polarization modulator are not parallel to each other. 14. The method of claim 13,
Optical axes of at least any two quarter-wavelength plates among the plurality of quarter-wavelength plates of the second polarization modulator are not parallel to each other. 14. The method of claim 13,
A laser crystallization apparatus in which the plurality of input lights oscillate at different times. The method of claim 1,
Further comprising a time delay unit disposed between the processing unit and the stage on the optical path,
The time delay unit,
a delay beam splitter that transmits a portion of the light synthesized by the processing unit and reflects the remaining portion; and
A plurality of delay mirrors for increasing the optical path of the light reflected by the time delay beam splitter among the light synthesized in the processing unit,
A laser crystallization device in which a half width of output light is increased by the time delay unit. The method of claim 1,
The beam splitter is a laser crystallization device that transmits 50% of the incident light and reflects the remaining 50%. a light source for generating a plurality of laser beams in a linearly polarized state;
a first polarization modulator disposed behind the light source unit on an optical path and circularly polarizing the laser beams provided from the light source unit;
a mixing unit disposed behind the first polarization modulator on the optical path and dividing and mixing the circularly polarized laser beams;
a second polarization modulator disposed behind the mixing unit on the optical path and configured to linearly polarize the laser beams provided from the mixing unit;
a processing unit disposed behind the second polarization modulator on the optical path and configured to focus and mix the linearly polarized laser beams to form output light; and
and a stage disposed behind the processing unit on the optical path and irradiated with the output light.

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