Laser Annealing Apparatus and Method for Thin Film Crystallization Using the Same

Abstract

A laser annealing apparatus and a method for thin film crystallization using the laser annealing apparatus are provided. The laser annealing apparatus includes a worktable, a laser generator, and a reflection member. The worktable supports a substrate on which a thin film to be processed is formed and moves in a first direction at a set or predetermined speed. The laser generator irradiates a first region of the thin film with a laser beam while the worktable is moving. The reflection member reflects a part of the laser beam reflected from the first region of the thin film to a second region of the thin film. The first region and the second region are spaced apart from each other.

Description

Technical Field

[0001] One or more aspects of embodiments of the present disclosure relate to a laser annealing apparatus and a method for thin film crystallization using the laser annealing apparatus. One or more aspects of embodiments of the present disclosure relate to a laser annealing apparatus using an incident light beam and a re-incident light beam and a method for thin film crystallization using the laser annealing apparatus. Background Art

[0002] In the manufacturing process of an organic light emitting display device in the related art, a dehydrogenation process and an excimer laser annealing (ELA) process can be performed. The dehydrogenation process can be performed to reduce the hydrogen content of a thin film, and the ELA process (for example, when the thin film is an amorphous silicon layer) can be performed to crystallize the thin film, where the ELA process can be performed after the dehydrogenation process.

[0003] For example, an organic light emitting diode display in the related art may include a semiconductor element, and an active layer included in the semiconductor element may include an amorphous silicon layer. The active layer may include or contain hydrogen (for example, hydrogen atoms). As described above, the hydrogen content included in the active layer can be reduced by the dehydrogenation process. For example, hydrogen included in the amorphous silicon layer can partially escape to the outside (for example, can be removed) through the dehydrogenation process. The ELA process can be performed after the dehydrogenation process. Then, the amorphous silicon layer can be crystallized into a polycrystalline silicon layer through the ELA process. However, hydrogen included in an insulating layer (for example, a buffer layer) formed under the active layer may not escape to the outside during the dehydrogenation process and may move into the active layer during the ELA process (for example, because they may be positioned adjacent to the bottom surface of the active layer). In this case, film breakage may occur on the surface of the active layer, and defects of the semiconductor element may be caused. Summary of the Invention

[0004] One or more aspects of embodiments of the present disclosure relate to a laser annealing apparatus.

[0005] One or more aspects of embodiments of the present disclosure relate to a method for thin film crystallization using a laser annealing apparatus.

[0006] One or more exemplary embodiments of the present disclosure provide a laser annealing apparatus including a workbench, a laser generator, and a reflection member. The workbench supports a substrate on which a thin film to be processed is formed and moves in a first direction at a set or predetermined speed. The laser generator irradiates a first region of the thin film with a laser beam while the workbench is moving. The reflection member reflects a part of the laser beam reflected from the first region of the thin film to a second region of the thin film. The first region and the second region are spaced apart from each other.

[0007] In some embodiments, the reflection angle of the reflecting member can be determined or selected such that the first region and the second region are spaced apart from each other (e.g., by a suitable distance D).

[0008] In some embodiments, the first region and the second region are spaced apart from each other by a set or predetermined distance D in a second direction opposite to the first direction (e.g., spaced apart from each other by a set or predetermined distance D along the first direction).

[0009] In some embodiments, a part of the laser beam emitted from the laser generator can be absorbed in the first region, and the remaining part of the laser beam can be reflected from the first region and then incident on the reflecting member.

[0010] In some embodiments, the laser beam irradiated on the first region can be higher in energy than the laser beam irradiated on the second region.

[0011] In some embodiments, the laser beam irradiated on the first region can be the incident beam, and the laser beam reflected from the first region among the incident beams can be the reflected beam. Among the reflected beams, the laser beam reflected from the reflecting member and irradiated on the second region can be the re-incident beam.

[0012] In some embodiments, the distance (spacing distance) between the incident beam and the re-incident beam on the thin film can be determined by the following expression:

[0013]

Expression

[0014] D>vt.

[0015] Wherein, D is the distance between the incident beam and the re-incident beam, v is the set or predetermined speed of the workbench, and t is the time for the temperature of the thin film to return to room temperature after being irradiated by the re-incident beam.

[0016] In some embodiments, the reflection angle of the reflecting member can be determined according to the distance D between the incident beam and the re-incident beam on the thin film.

[0017] In some embodiments, a crystallization process can be performed on the thin film by the incident beam, and a dehydrogenation process can be performed on the thin film by the re-incident beam.

[0018] In some embodiments, the incident beam can be irradiated at an angle less than 90 degrees with respect to the top surface of the workbench, and the re-incident beam can be irradiated at an angle greater than 90 degrees with respect to the top surface of the workbench.

[0019] In some embodiments, the incident beam and the re-incident beam can intersect or cross each other.

[0020] [[ID=A]]In some embodiments, during the movement of the workbench and after performing the dehydrogenation process on the thin film, the crystallization process can be performed.

[0021] In some embodiments, the laser annealing apparatus may further include at least one insulating layer disposed between the substrate and the thin film.

[0022] One or more embodiments of the present disclosure provide a method for crystallizing a thin film using a laser annealing apparatus as follows. A substrate on which a thin film to be processed is formed is positioned on a worktable. The worktable is moved in a first direction at a set or predetermined speed. A laser beam is irradiated onto a first region of the thin film. A part of the laser beam reflected from the first region of the thin film is reflected onto a second region of the thin film. During the movement of the worktable, after a dehydrogenation process is performed by a part of the laser beam irradiated onto the second region, a crystallization process is performed by the laser beam irradiated onto the first region.

[0023] In some embodiments, the first region and the second region may be spaced apart from each other, and the second region may be spaced apart from the first region in a second direction opposite to the first direction.

[0024] In some embodiments, the laser beam irradiated onto the first region may be defined as an incident beam, and the laser beam reflected from the first region among the incident beams may be defined as a reflected beam. The laser beam reflected from a reflecting member and irradiated onto the second region may be defined as a re-incident beam. The incident beam may be irradiated at an angle less than 90 degrees with respect to the top surface of the worktable, and the re-incident beam may be irradiated at an angle greater than 90 degrees with respect to the top surface of the worktable. The incident beam and the re-incident beam may intersect or cross each other.

[0025] In some embodiments, a crystallization process may be performed on the thin film by the incident beam, and a dehydrogenation process may be performed on the thin film by the re-incident beam.

[0026] In some embodiments, a part of the laser beam may be absorbed in the first region, and the remaining part of the laser beam may be reflected from the first region.

[0027] In some embodiments, the laser beam irradiated onto the first region may be higher in energy than the laser beam irradiated onto the second region.

[0028] In some embodiments, the method may further include: forming at least one insulating layer between the substrate and the thin film. The insulating layer may include silicon oxide, silicon nitride, silicon oxynitride, carbon oxysilicon, carbon silicon nitride, aluminum oxide, aluminum nitride, tantalum oxide, hafnium oxide, zirconium oxide, and / or titanium oxide, and the thin film may include an amorphous silicon layer.

[0029] One or more exemplary embodiments of the present disclosure provide a laser annealing apparatus that can irradiate a first region with an incident light beam and a second region with a re-incident light beam. The second region may be spaced apart from the first region by a set or predetermined distance in a second direction. During the stage moving in a first direction at a set or predetermined speed, a dehydrogenation process may be performed on a first portion of the amorphous silicon layer by the re-incident light beam, and then a crystallization process may be performed on the first portion by the incident light beam. In other words, after the re-incident light beam irradiates the first portion of the amorphous silicon layer, the stage may move a set or predetermined distance in the first direction, and thus, after the first portion has returned to room temperature, the incident light beam may irradiate the first portion. In this case, film breakage may not occur in the first portion, and the first portion may be crystallized.

[0030] In a method for thin film crystallization of a laser annealing apparatus according to an exemplary embodiment of the present disclosure, hydrogen contained in the amorphous silicon layer may be discharged to the outside through a first dehydrogenation process, and hydrogen contained in the buffer layer may diffuse into the amorphous silicon layer during the first dehydrogenation process. After performing the first dehydrogenation process and during the stage moving in a first direction at a set or predetermined speed, a second dehydrogenation process may be performed on a first portion of the amorphous silicon layer by the re-incident light beam, and then a crystallization process may be performed on the first portion by the incident light beam. For example, the re-incident light beam may partially discharge the diffused hydrogen to the outside of the amorphous silicon layer through the second dehydrogenation process, and the hydrogen content contained in the amorphous silicon layer may be reduced to below a set or predetermined level. After the re-incident light beam irradiates the first portion of the amorphous silicon layer, the stage may move a set or predetermined distance in the first direction, and thus, after the first portion has returned to room temperature, the incident light beam may irradiate the first portion. In this case, film breakage may not occur in the first portion, and the first portion may be crystallized. Accordingly, after performing the second dehydrogenation process on the amorphous silicon layer, the crystallization process is performed so that the amorphous silicon layer can be changed to a polycrystalline silicon layer without film breakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Exemplary embodiments of the present disclosure will be understood in more detail from the following description taken in conjunction with the accompanying drawings, in which:

[0032] Figure 1 is a block diagram showing a laser annealing apparatus according to an exemplary embodiment of the present disclosure;

[0033] Figure 2 is a perspective view showing a state in which an Figure 1 incident light beam is irradiated onto a thin film to be processed;

[0034] Figure 3 is a perspective view showing a state in which a Figure 1 re-incident light beam is irradiated onto a thin film to be processed;

[0035] Figure 4 is a plan view highlighting a region in a thin film to be processed irradiated by an incident light beam and a re-incident light beam; Figure 1 in the thin film to be processed;

[0036] Figure 5 is a graphical side view showing the profiles of the incident light beam and the re-incident light beam in the thin film to be processed; and Figure 1 in the thin film to be processed;

[0037] Figures 6 to 8 is a view showing a thin film crystallization method using a laser annealing apparatus according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0038] Hereinafter, a laser annealing apparatus according to an exemplary embodiment of the present disclosure and a thin film crystallization method using the laser annealing apparatus will be described in more detail with reference to the accompanying drawings. In the drawings, the same or similar symbols denote the same or similar elements, and repeated descriptions thereof may not be provided.

[0039] Figure 1 is a block diagram showing a laser annealing apparatus according to an exemplary embodiment of the present disclosure. Figure 2 is a perspective view showing a state in which an incident light beam is irradiated onto a thin film to be processed; Figure 1 in the thin film to be processed; Figure 3 is a perspective view showing a state in which a re-incident light beam is irradiated onto a thin film to be processed; Figure 1 in the thin film to be processed; Figure 4 is a plan view highlighting a region in a thin film to be processed irradiated by an incident light beam and a re-incident light beam; Figure 1 in the thin film to be processed; Figure 5 is a graphical side view showing the profiles of the incident light beam and the re-incident light beam in a thin film to be processed; For example, Figure 1 in the thin film to be processed. In Figure 1 the horizontal axis represents the width of the laser beam, and the vertical axis represents the energy of the laser beam. Figure 5 in the thin film to be processed;

[0040] Referring to Figure 1 and Figure 2 and Figure 3 and Figure 4 the laser annealing apparatus 100 may include a laser generator 500, a workbench 300, a reflection member 570, and / or the like.

[0041] A substrate 110 including a glass substrate and / or a plastic substrate may be disposed on a workbench 300, and a buffer layer 105 (e.g., an insulating layer) may be formed on the substrate 110. An amorphous silicon layer 130 (e.g., a thin film to be processed) may be formed on the buffer layer 105. The workbench 300 may support the substrate 110 on which the amorphous silicon layer 130 and the buffer layer 105 are formed, and may move in a first direction D1 (along the first direction D1) at a set or predetermined speed. For example, the set or predetermined speed of the workbench 300 may be approximately (or about) 8.75×10 -3 m / s. The first direction D1 may be a direction parallel to the top surface of the workbench 300.

[0042] The buffer layer 105 may have a structure formed of a single layer, or a structure formed of at least two insulating layers stacked together. For example, the buffer layer 105 may include silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), silicon oxycarbide (SiOC), silicon carbonitride (SiCN), aluminum oxide (AlO), aluminum nitride (AlN), tantalum oxide (TaO), hafnium oxide (HfO), zirconium oxide (ZrO), titanium oxide (TiO), and / or the like.

[0043] A laser generator 500 may be disposed on the amorphous silicon layer 130. The laser generator 500 may generate a laser beam and may emit the laser beam to the amorphous silicon layer 130 (e.g., at or onto it) during the movement of the workbench 300. The laser generator 500 may have a fixed angle with respect to the top surface of the amorphous silicon layer 130. In some embodiments, the laser beam may irradiate a first region 111 of the amorphous silicon layer 130. The laser generator 500 may generate a gas laser. For example, the laser generator 500 may include or be an XeCl excimer laser.

[0044] As Figure 1 and Figure 4 shown, in some embodiments, a part (portion) of the laser beam emitted from the laser generator 500 may be absorbed in the first region 111, and the remaining part of the laser beam (e.g., the unabsorbed part) may be reflected from the first region 111 and then incident on a reflection member 570. The laser beam emitted from the laser generator 500 and irradiated onto the first region 111 of the amorphous silicon layer 130 is defined as an incident beam LB1. The laser beam reflected from the first region 111 of the amorphous silicon layer 130 and incident on the reflection member 570 is defined as a reflected beam LB2. The laser beam reflected from the reflection member 570 and irradiated onto a second region 112 of the amorphous silicon layer 130 is defined as a re-incident beam LB3. As Figure 4As shown, the second region 112 may be spaced apart from the first region 111 by a set or predetermined distance (e.g., the set or predetermined distance D) in a second direction D2 opposite to the first direction D1. For example, the first region 111 and the second region 112 may be spaced apart by a set or predetermined distance D in the first direction D1. In addition, the laser annealing apparatus 100 may perform a dehydrogenation process on the amorphous silicon layer 130 using the re-incident beam LB3, and may perform a crystallization process using the incident beam LB1. For example, the dehydrogenation process may be performed on the amorphous silicon layer 130 during the movement of the stage 300 (e.g., in the first direction D1), and then the crystallization process may be performed. As used herein, the terms "first region 111" and "second region 112" may respectively correspond to the beam regions of the incident beam LB1 and the re-incident beam LB3, or for example, the exposure regions of those beams. In some embodiments, for example, the "first region 111" and the "second region 112" may not indicate fixed regions of the amorphous silicon layer 130, but rather indicate portions of the amorphous silicon layer 130 that are exposed to the beam in a shifted order as the underlying stage 300 moves in the first direction D1.

[0045] The reflection member 570 may be disposed in the traveling direction of the reflected beam LB2. For example, the reflection member 570 may be positioned to further reflect the laser beam (e.g., the reflected beam LB2) reflected from the first region 111 of the amorphous silicon layer 130 to the second region 112 of the amorphous silicon layer 130. The reflection member 570 may have a fixed angle with respect to the top surface of the amorphous silicon layer 130. For example, as Figure 1 shown, the reflection member 570 may be positioned above and further above the initial position of the stage 300 (e.g., before the movement of the stage 300) in the first direction D1, and the reflection member 570 may be angled to generally face the top surface of the amorphous silicon layer 130 (e.g., before the movement of the stage 300).

[0046] In an exemplary embodiment, the reflection member 570 may reflect substantially all of the reflected beam LB2 that is reflected from the first region 111 of the amorphous silicon layer 130 and incident on the reflection member 570 at a set or predetermined angle (e.g., the reflection angle θ of the reflection member 570), and the re-incident beam LB3 reflected from the reflection member 570 may irradiate the second region 112 of the amorphous silicon layer 130. In some embodiments, the reflection angle θ of the reflection member 570 may be determined or selected such that the second region 112 may be spaced apart (e.g., separated) from the first region 111. In other words, the position and / or separation of the second region 112 (e.g., relative to the first region 111) may be determined or selected according to the reflection angle θ of the reflection member 570.

[0047] The reflecting member 570 may include a material capable of reflecting a laser beam, such as a metal, an alloy, or a mirror. For example, the reflecting member 570 may include gold (Au), silver (Ag), aluminum (Al), tungsten (W), copper (Cu), platinum (Pt), nickel (Ni), titanium (Ti), palladium (Pd), magnesium (Mg), calcium (Ca), lithium (Li), chromium (Cr), tantalum (Ta), molybdenum (Mo), scandium (Sc), neodymium (Nd), iridium (Ir), an aluminum alloy, aluminum nitride (AlN), a silver alloy, tungsten nitride (WN), a copper alloy, a molybdenum alloy, titanium nitride (TiN), chromium nitride (CrN), tantalum nitride (TaN), strontium ruthenate (SrRuO), zinc oxide (ZnO), indium tin oxide (ITO), tin oxide (SnO), indium oxide (InO), gallium oxide (GaO), indium zinc oxide (IZO), and / or the like.

[0048] As Figure 2 As shown, during the stage 300 moving at a set or predetermined speed, the incident light beam LB1 may irradiate the first region 111 of the amorphous silicon layer 130. The incident light beam LB1 may irradiate at an angle less than 90 degrees with respect to the top surface of the stage 300 (for example, the angle between a first vector that bisects the incident light beam LB1 with respect to the first direction D1 and a second vector that starts from the point where the first vector impinges on the top surface of the amorphous silicon layer 130 and extends along the second direction D2 is less than 90 degrees), and may irradiate in the form of a line having a set or constant width (for example, the width in the first direction D1) and length (for example, the length in a third direction D3 orthogonal to the first direction D1 and the second direction D2).

[0049] Although Figure 2 the incident light beam LB1 is shown to have a converging shape (for example, the shape of a converging light beam), the configuration of the present disclosure is not limited thereto. In some embodiments, for example, the incident light beam LB1 may have a diverging shape or a parallel shape.

[0050] As Figure 3As shown, during the movement of the workbench 300 at a set or predetermined speed, the re-incident beam LB3 can irradiate the second region 112 of the amorphous silicon layer 130. The re-incident beam LB3 can be incident at an angle greater than 90 degrees with respect to the top surface of the workbench 300 (for example, the angle between the third vector that bisects the re-incident beam LB3 with respect to the first direction D1 and the second vector is greater than 90 degrees), and the incident beam LB1 and the re-incident beam LB3 can intersect or cross each other. In some embodiments, the re-incident beam LB3 can be irradiated in the form of a line having a constant width (for example, the width in the first direction D1) and length (for example, the length in the third direction D3). In addition, the incident angle of the re-incident beam LB3 can be adjusted or selected by the reflection angle θ of the reflection member 570. By adjusting the reflection angle θ of the reflection member 570, the second region 112 irradiated with the re-incident beam LB3 on the amorphous silicon layer 130 can be spaced apart from the first region 111 irradiated with the incident beam LB1 in the second direction D2.

[0051] Although Figure 3 it is shown that the re-incident beam LB3 has a converging shape (for example, the shape of a converging beam), the configuration of the present disclosure is not limited thereto. For example, the re-incident beam LB3 can have a diverging shape or a parallel shape.

[0052] As Figure 5 shown, the cross-sectional profile of each of the incident beam LB1 and the re-incident beam LB3 can have a symmetric shape on both sides (for example, simultaneously) of each beam with respect to the central axis of the direction in which the laser beam is irradiated (for example, with respect to the central axis perpendicular to the surface of the amorphous silicon layer 130). In some embodiments, the incident beam LB1 can have a first energy E1, and the re-incident beam LB3 can have a second energy E2, where the first energy E1 can be greater than the second energy E2. The first energy E1 can correspond to an energy level capable of (suitable for) changing the amorphous silicon layer 130 into a polycrystalline silicon layer, and the second energy E2 can correspond to an energy level capable of reducing the hydrogen content contained in the amorphous silicon layer 130. For example, the first energy E1 can have a relatively high energy level for use in the crystallization process, and the second energy E2 can have a relatively low energy level for use in the dehydrogenation process. In some embodiments, the incident beam LB1 can be spaced apart from the re-incident beam LB3 by a set or predetermined distance D.

[0053] Although Figure 5It is shown that the cross-sectional profiles of each of the incident light beam LB1 and the re-incident light beam LB3 have a symmetric shape on both sides (e.g., simultaneously) with respect to the central axis in the direction in which the laser beam is irradiated, but the configuration of the present disclosure is not limited thereto. For example, the cross-sectional profile of each of the incident light beam LB1 and the re-incident light beam LB3 may have an asymmetric shape (e.g., different shapes or slopes between the two sides) with respect to the central axis in the direction in which the laser beam is irradiated.

[0054] Referring again to Figures 1 to 5 , the set or predetermined distance D (e.g., the distance by which the second region 112 is spaced apart from the first region 111) can be determined by the following expression:

[0055]

Expression

[0056] D > vt.

[0057] Wherein, D is the spacing (e.g., the set or predetermined distance D) between adjacent or neighboring sides of the incident light beam LB1 and the re-incident light beam LB3, v is the speed of the workbench 300, and t is the time for the temperature of the amorphous silicon layer 130 to return to room temperature after being irradiated by the re-incident light beam LB3.

[0058] In some embodiments of the present disclosure, v may be approximately (or about) 8.75×10 -3 m / s, and t may be approximately (or about) 10 -2 s. Accordingly, in some embodiments, D may be approximately (or about) 87.5 μm. In other words, the second region 112 may be spaced apart from the first region 111 by 87.5 μm in the second direction D2, and the reflection angle θ of the reflection member 570 can be determined or selected based on the desired value of D. However, the embodiments of the present disclosure are not limited thereto, and the variables v, t, and D can be changed as long as they satisfy the expression.

[0059] For example, in the manufacturing process of an organic light-emitting display device in the related art, a dehydrogenation process and an ELA process can be performed. The dehydrogenation process can be performed to reduce the hydrogen content present in the amorphous silicon layer, and the ELA process can crystallize the amorphous silicon layer, wherein the ELA process can be performed after the dehydrogenation process.

[0060] An organic light-emitting diode display of the related art may include a semiconductor element, and an active layer included in the semiconductor element may include an amorphous silicon layer. The amorphous silicon layer may contain hydrogen. As described above, the hydrogen content included in the amorphous silicon layer may be reduced by a dehydrogenation process. For example, a part of the hydrogen included in the amorphous silicon layer may escape or be released to the outside (e.g., the environment) as a result of the dehydrogenation process. After the dehydrogenation process, an ELA process may be performed. The amorphous silicon layer may be crystallized into a polycrystalline silicon layer by the ELA process. However, the hydrogen included in an insulating layer (e.g., a buffer layer) formed under the amorphous silicon layer may not escape to the outside during the dehydrogenation process and may diffuse into the amorphous silicon layer. In this case, due to the increased hydrogen content, film rupture may occur on the surface of the active layer during the ELA process, and defects of the semiconductor element may be caused. In addition, when an insulating layer is not formed under the amorphous silicon layer, but the hydrogen content in the amorphous silicon layer is about 3% or more, the hydrogen content included in the amorphous silicon layer cannot be reduced below a set or predetermined level by the dehydrogenation process, and thus, film rupture may occur on the surface of the amorphous silicon layer during the ELA process.

[0061] In addition, when the second region 112 is not spaced apart from the first region 111 by a set or predetermined distance D, film rupture may occur on the amorphous silicon layer 130. For example, when the spaced-apart distance from the first region 111 to the second region 112 (between the first region 111 and the second region 112) is less than the set or predetermined distance D, after the re-incident beam LB3 irradiates a first part of the amorphous silicon layer 130 (e.g., when the first part is located within the second region 112), as the workbench 300 moves in the first direction D1, before the temperature of the first part returns to room temperature, the incident beam LB1 may irradiate the first part (e.g., when the first part is located within the first region 111). In this case, film rupture may occur within the first part.

[0062] The laser annealing apparatus 100 according to an exemplary embodiment of the present disclosure can irradiate a first region 111 with an incident light beam LB1 and can irradiate a second region 112 with a re-incident light beam LB3. The second region 112 can be spaced apart from the first region 111 by a set or predetermined distance D in a second direction D2. During the stage 300 moving in a first direction D1 at a set or predetermined speed, a dehydrogenation process can be performed on a first portion of the amorphous silicon layer 130 by the re-incident light beam LB3, and then a crystallization process can be subsequently performed on the first portion by the incident light beam LB1. In other words, after the re-incident light beam LB3 irradiates the first portion of the amorphous silicon layer 130, the stage 300 can move a set or predetermined distance D in the first direction D1, and thus, after the temperature of the first portion returns to room temperature, the incident light beam LB1 can subsequently irradiate the first portion. In this case, film breakage can not occur in the first portion, and the first portion can be appropriately crystallized.

[0063] For example, since the stage 300 moves in the first direction D1, in the second region 112 where the dehydrogenation process has been previously performed by the re-incident light beam LB3 (for example, a portion located in the second region 112 that was previously located within the first region 111), the crystallization process can be performed on it by the incident light beam LB1 after a set or predetermined time. As described above, the buffer layer 105 can be disposed under the amorphous silicon layer 130, and the dehydrogenation process can be performed on the hydrogen in the buffer layer 105 diffused into the amorphous silicon layer 130 by the re-incident light beam LB3 having relatively low energy, thereby preventing or reducing film breakage caused by the hydrogen in the buffer layer 105.

[0064] Figures 6 to 8 is a view showing a thin film crystallization method using a laser annealing apparatus according to an exemplary embodiment of the present disclosure. For example, Figure 6 corresponds to a side view of the laser annealing apparatus, Figure 7 and Figure 8 is a perspective view showing a state where the incident light beam LB1 and the re-incident light beam LB3 irradiate a film to be processed.

[0065] Referring to Figure 6 , in a thin film crystallization method according to an embodiment of the present disclosure, a stage 300 can be provided. A substrate 110 can be formed on the stage 300. The substrate 110 can be formed using a glass substrate and / or a plastic substrate.

[0066] A buffer layer 105 (e.g., an insulating layer) may be formed on the substrate 110. The buffer layer 105 may have a structure formed of a single layer or a structure formed of at least two insulating layers stacked together. For example, the buffer layer 105 may be formed using SiO, SiN, SiON, SiOC, SiCN, AlO, AlN, TaO, HfO, ZrO, TiO, and / or the like.

[0067] An amorphous silicon layer 130 (e.g., a thin film to be processed) may be formed on the buffer layer 105. Accordingly, the substrate 110 on which the amorphous silicon layer 130 and the buffer layer 105 are formed may be located on the workbench 300, and the workbench 300 may support the substrate 110 on which the amorphous silicon layer 130 and the buffer layer 105 are formed.

[0068] After the workbench 300 is positioned, a first dehydrogenation process may be performed (e.g., across the entire surface of the amorphous silicon layer 130). Hydrogen contained in the amorphous silicon layer 130 may partially escape to the outside through the first dehydrogenation process, and thus the hydrogen content contained in the amorphous silicon layer 130 may be reduced. However, the hydrogen contained in the buffer layer 105 cannot escape to the outside during the first dehydrogenation process and may diffuse into the amorphous silicon layer 130. For example, through the first dehydrogenation process, the hydrogen content contained in the amorphous silicon layer 130 may not be reduced below a set or predetermined level.

[0069] Refer to Figure 1 、 Figure 7 and Figure 8 , the workbench 300 may move in the first direction D1 at a set or predetermined speed. For example, the set or predetermined speed of the workbench 300 may be approximately (or about) 8.75×10 -3 m / s. The first direction D1 may be a direction parallel to the top surface of the workbench 300.

[0070] A laser generator 500 may be located above the amorphous silicon layer 130. The laser generator 500 may generate a laser beam and may emit the laser beam onto the amorphous silicon layer 130 during the movement of the workbench 300. The laser generator 500 may have a fixed angle with respect to the top surface of the amorphous silicon layer 130. In some embodiments, the laser beam may irradiate a first region 111 of the amorphous silicon layer 130. The laser generator 500 may generate a gas laser. For example, the laser generator 500 may include a XeCl excimer laser.

[0071] A part or portion of the laser beam emitted from the laser generator 500 may be absorbed in the first region 111, and the remaining portion of the laser beam (e.g., the unabsorbed portion) may be reflected from the first region 111 and then incident on the reflection member 570. The reflection member 570 may be located in the traveling direction of the laser beam reflected from the first region 111. For example, the reflection member 570 may be positioned to reflect a part of the laser beam reflected from the first region 111 of the amorphous silicon layer 130 to the second region 112 of the amorphous silicon layer 130. For example, the reflection member 570 may have a fixed angle with respect to the top surface of the amorphous silicon layer 130.

[0072] In some embodiments, the reflection member 570 may reflect all of the part of the laser beam reflected from the first region 111 of the amorphous silicon layer 130 and incident on the reflection member 570 at a set or predetermined angle (e.g., the reflection angle θ of the reflection member 570), and at least a part of the laser beam reflected from the reflection member 570 may irradiate the second region 112 of the amorphous silicon layer 130. In some embodiments, the reflection angle θ of the reflection member 570 may be determined or selected such that the second region 112 is spaced apart from the first region 111. For example, the position of the second region 112 (e.g., relative to the first region 111) may be determined or selected according to the reflection angle θ of the reflection member 570.

[0073] The reflection member 570 may be formed using a material capable of reflecting the laser beam (such as a metal, an alloy, or a mirror). For example, the reflection member 570 may include Au, Ag, Al, W, Cu, Pt, Ni, Ti, Pd, Mg, Ca, Li, Cr, Ta, Mo, Sc, Nd, Ir, aluminum-containing alloy, AlN, silver-containing alloy, WN, copper-containing alloy, molybdenum-containing alloy, TiN, CrN, TaN, SrRuO, ZnO, ITO, SnO, InO, GaO, IZO, and / or the like.

[0074] During the movement of the workbench 300, the second dehydrogenation process may be performed by the laser beam (e.g., the re-incident beam LB3) irradiated to the second region 112, and then the crystallization process may be performed by the laser beam (e.g., the incident beam LB1) irradiated to the first region 111. The hydrogen content in the amorphous silicon layer 130 may be reduced to a level below a set or predetermined level by the second dehydrogenation process.

[0075] A laser beam emitted from a laser generator 500 and irradiated onto a first region 111 of the amorphous silicon layer 130 is defined as an incident beam LB1. A laser beam reflected from the first region 111 of the amorphous silicon layer 130 and incident on a reflection member 570 is defined as a reflected beam LB2. A laser beam reflected from the reflection member 570 and irradiated onto a second region 112 of the amorphous silicon layer 130 is defined as a re-incident beam LB3. The second region 112 may be spaced apart from the first region 111 by a set or predetermined distance (e.g., a set or predetermined distance D) in a second direction D2 opposite to the first direction D1. In addition, a second dehydrogenation process may be performed on the amorphous silicon layer 130 by using the re-incident beam LB3, and a crystallization process may be performed by using the incident beam LB1.

[0076] As Figure 7 and Figure 8 shown, during the stage table 300 moving at a set or predetermined speed, the incident beam LB1 may be irradiated onto the first region 111 of the amorphous silicon layer 130. The incident beam LB1 may be irradiated at an angle less than 90 degrees with respect to the top surface of the stage table 300, and may be irradiated in the form of a line having a set or constant width and length.

[0077] In some embodiments, during the stage table 300 moving at a set or predetermined speed, the re-incident beam LB3 may be irradiated onto the second region 112 of the amorphous silicon layer 130. The re-incident beam LB3 may be irradiated at an angle greater than 90 degrees with respect to the top surface of the stage table 300, and the incident beam LB1 and the re-incident beam LB3 may intersect or cross each other. The re-incident beam LB3 may be irradiated in the form of a line having a set or constant width and length. The incident angle of the re-incident beam LB3 may be adjusted by the reflection angle θ of the reflection member 570. By adjusting the reflection angle θ of the reflection member 570, the second region 112 irradiated with the re-incident beam LB3 on the amorphous silicon layer 130 may be spaced apart from the first region 111 irradiated with the incident beam LB1 in the second direction D2.

[0078] As Figure 5 shown, the incident beam LB1 may have a first energy E1, and the re-incident beam LB3 may have a second energy E2, wherein the first energy E1 may be greater than the second energy E2. The first energy E1 may correspond to an energy level capable of changing the amorphous silicon layer 130 into a polycrystalline silicon layer, and the second energy E2 may correspond to an energy level capable of reducing the hydrogen content contained in the amorphous silicon layer 130. For example, the first energy E1 may have a relatively high energy level for use in the crystallization process, and the second energy E2 may have a relatively low energy level for use in the dehydrogenation process. In some embodiments, the incident beam LB1 may be spaced apart from the re-incident beam LB3 by a set or predetermined distance D.

[0079] In the method for thin film crystallization of a laser annealing apparatus according to an exemplary embodiment of the present disclosure, hydrogen contained in the amorphous silicon layer 130 can be discharged to the outside through a first dehydrogenation process, and hydrogen contained in the buffer layer 105 can diffuse into the amorphous silicon layer 130 during the first dehydrogenation process. After performing the first dehydrogenation process and during the stage where the stage 300 moves in the first direction D1 at a set or predetermined speed, a second dehydrogenation process can be performed on a first portion of the amorphous silicon layer 130 by the re-incident beam LB3, and then a crystallization process can be performed on the first portion by the incident beam LB1. For example, the re-incident beam LB3 can partially discharge the diffused hydrogen to the outside of the amorphous silicon layer 130 through the second dehydrogenation process, and the hydrogen content contained in the amorphous silicon layer 130 can be reduced below a set or predetermined level. After the re-incident beam LB3 irradiates the first portion of the amorphous silicon layer 130, the stage 300 can move a set or predetermined distance D in the first direction D1, and accordingly, after the temperature of the first portion returns to room temperature, the incident beam LB1 can irradiate the first portion. In this case, film breakage does not occur in the first portion, and the first portion can be properly crystallized. Accordingly, after performing the second dehydrogenation process on the amorphous silicon layer 130, a crystallization process is performed so that the amorphous silicon layer 130 can be changed into a polycrystalline silicon layer without film breakage.

[0080] The present disclosure can be applied to various electronic devices including display devices manufactured by a laser annealing apparatus. For example, the present disclosure can be applied to vehicle display devices, ship display devices, aircraft display devices, portable communication devices, display devices for display or information transfer, medical display devices, and the like.

[0081] The foregoing is illustrative of exemplary embodiments and should not be construed as being limited thereto. Although some exemplary embodiments have been described, those skilled in the art will readily understand that many modifications can be made to the exemplary embodiments without substantially departing from the novel teachings and advantages of the present disclosure. Accordingly, all such modifications are intended to be included within the scope of the present disclosure as defined in the claims. Therefore, it should be understood that the foregoing is illustrative of various exemplary embodiments and should not be construed as being limited to the specific exemplary embodiments disclosed, and it should be understood that modifications to the disclosed exemplary embodiments and other exemplary embodiments are intended to be included within the scope of the appended claims and equivalents.

Claims

1. A laser annealing apparatus, comprising: A workbench that supports a substrate on which a film to be processed is formed and moves in a first direction at a set speed; A laser generator that irradiates a first region of the film with a laser beam during the movement of the workbench; And A reflection member that reflects a part of the laser beam reflected from the first region of the film to a second region of the film, Wherein the first region and the second region are spaced apart from each other by a set distance in a second direction opposite to the first direction.

2. The laser annealing device according to claim 1, wherein, The reflection angle of the reflection member is determined such that the first region and the second region are spaced apart from each other.

3. The laser annealing apparatus according to claim 1, wherein, A part of the laser beam emitted from the laser generator is absorbed in the first region, and the remaining part of the laser beam is incident on the reflection member after being reflected from the first region.

4. The laser annealing apparatus according to claim 1, wherein, The laser beam irradiated on the first region is higher in energy than the laser beam irradiated on the second region.

5. The laser annealing apparatus according to claim 1, wherein, The laser beam irradiated on the first region is an incident beam, the laser beam reflected from the first region among the incident beams is a reflected beam, and the laser beam reflected from the reflection member and irradiated on the second region among the reflected beams is a re-incident beam.

6. The laser annealing apparatus according to claim 5, wherein, The distance between the incident beam and the re-incident beam on the film is determined by the following expression: Expression: D>vt Where D is the distance between the incident beam and the re-incident beam, v is the set speed of the workbench, and t is the time for the temperature of the film to return to room temperature after being irradiated by the re-incident beam.

7. The laser annealing apparatus according to claim 6, wherein, The reflection angle of the reflection member is determined according to the distance D between the incident beam and the re-incident beam on the film.

8. The laser annealing apparatus according to claim 5, wherein, A crystallization process is performed on the film by the incident beam, and a dehydrogenation process is performed on the film by the re-incident beam.

9. The laser annealing apparatus according to claim 5, wherein, The incident beam irradiates the top surface of the workbench at an angle less than 90 degrees, and the re-incident beam irradiates the top surface of the workbench at an angle greater than 90 degrees.

10. The laser annealing apparatus according to claim 9, wherein, The incident beam and the re-incident beam cross each other.

11. The laser annealing apparatus according to claim 8, wherein, During the movement of the workbench and after performing the dehydrogenation process on the film, the crystallization process is performed.

12. The laser annealing apparatus according to claim 1, further comprising: At least one insulating layer located between the substrate and the film.

13. A method for crystallizing a film using a laser annealing apparatus, the method comprising: Positioning a substrate on which a film to be processed is formed on a workbench; Moving the workbench in a first direction at a set or predetermined speed; Irradiating a first region of the film with a laser beam; And Reflecting a part of the laser beam reflected from the first region of the film to a second region of the film through a reflection member During the movement of the workbench, after performing a dehydrogenation process by a part of the laser beam irradiated to the second region, a crystallization process is performed by the laser beam irradiated to the first region, and wherein the first region and the second region are spaced apart from each other by a set distance in a second direction opposite to the first direction.

14. The method according to claim 13, wherein, The laser beam irradiated to the first region is an incident beam, the laser beam reflected from the first region among the incident beams is a reflected beam, and the laser beam reflected from the reflection member and irradiated to the second region among the reflected beams is a re-incident beam, and wherein the incident beam is irradiated at an angle less than 90 degrees with respect to the top surface of the workbench, the re-incident beam is irradiated at an angle greater than 90 degrees with respect to the top surface of the workbench, and the incident beam and the re-incident beam cross each other.

15. The method according to claim 14, wherein, A crystallization process is performed on the thin film by the incident beam, and a dehydrogenation process is performed on the thin film by the re-incident beam.

16. The method according to claim 13, wherein, A part of the laser beam is absorbed in the first region, and the remaining part of the laser beam is reflected from the first region.

17. The method according to claim 13, wherein, The laser beam irradiated to the first region is higher in energy than the laser beam irradiated to the second region.

18. The method according to claim 13, further comprising: forming at least one insulating layer between the substrate and the thin film, wherein the at least one insulating layer includes silicon oxide, silicon nitride, silicon oxynitride, carbon silicon oxide, carbon silicon nitride, aluminum oxide, aluminum nitride, tantalum oxide, hafnium oxide, zirconium oxide, and / or titanium oxide, and the thin film includes an amorphous silicon layer.

Images