Laser processing apparatus and method

Abstract

The present invention comprises: a chamber having a space for processing a substrate inside and a through hole provided on one surface through which a laser beam can pass; an irradiation unit disposed on the outside of the chamber to irradiate the laser beam onto the substrate through the through hole; a transparent window having a portion of its area located in an irradiation path through which the laser beam is irradiated so that the laser beam is transmitted; and a support unit installed in the chamber to movably support the transparent window so that the area located in the irradiation path can be changed, thereby enabling stable transmission of the laser beam even if a portion of the transparent window is contaminated.

Description

Technology Field

[0001] The present invention relates to a laser processing device and a laser processing method, and more specifically, to a laser processing device and a laser processing method capable of stably transmitting a laser beam even if a part of the transmission window is contaminated. Background Technology

[0002] Generally, a laser processing device is a device that processes a substrate using a laser beam. For example, a laser processing device can crystallize a silicon thin film on a substrate by irradiating it with a laser beam.

[0003] At this time, the laser processing device includes a chamber forming a space for processing a substrate inside, a transparent window mounted on the upper part of the chamber, and a laser irradiator positioned outside the chamber. Accordingly, a laser beam generated by the laser irradiator can be irradiated into the chamber through the transparent window to process a silicon thin film on the substrate.

[0004] However, contaminants may adhere to the transmission window during the laser processing. Consequently, these contaminants may obstruct the transmission of the laser beam, preventing it from properly irradiating the silicon thin film on the substrate. This leads to a problem of increased defect rates in the laser processing process. Prior art literature

[0005] (Patent Document 0001) KR 2018-0042970 A The problem to be solved

[0006] The present invention provides a laser processing device and a laser processing method capable of stably transmitting a laser beam even if a part of the transmission window is contaminated.

[0007] The present invention provides a laser processing apparatus and a laser processing method capable of improving the efficiency of a laser processing process. means of solving the problem

[0008] The present invention comprises: a chamber having a space for processing a substrate inside and a through hole provided on one surface through which a laser beam can pass; an irradiation unit disposed on the outside of the chamber to irradiate the laser beam onto the substrate through the through hole; a transparent window having a portion of its area located in an irradiation path through which the laser beam is irradiated so that the laser beam is transmitted; and a support unit installed in the chamber to movably support the transparent window so as to change the area located in the irradiation path.

[0009] It further includes: a contamination verification unit for verifying the location of the contaminated portion in the above-mentioned transparent window; and a control unit for controlling the operation of the support member so that the contaminated portion in the above-mentioned transparent window is not located in the above-mentioned investigation path.

[0010] The contamination verification unit comprises: an energy measuring unit installed inside the chamber to measure the energy density of a laser beam transmitted through different parts of the transmission window while adjusting the position of the transmission window with the support member; and a judgment unit for determining the location where contamination has occurred in the transmission window according to the energy density measured for each part of the transmission window.

[0011] The apparatus further includes a stage installed inside the chamber to support the substrate, and the energy measuring unit is installed on the stage and measures the energy density of the laser beam before the substrate is supported on the stage.

[0012] The contamination verification unit comprises: a light generating unit positioned outside the chamber to irradiate test light toward the transparent window; a reflection measuring unit positioned outside the chamber to measure the amount of reflection of the light irradiated by the light generating unit at different parts of the transparent window; and a judgment unit for determining the location where contamination has occurred in the transparent window based on the amount of reflection measured for each part of the transparent window.

[0013] The light generating unit adjusts the area where the light is irradiated onto the transparent window to match the area of ​​the transparent window.

[0014] The support member comprises: a body member installed on the upper part of the chamber; a support member that supports the transparent window and is movably installed on the body member in a direction intersecting the irradiation path; and a driving member for moving the support member by being controlled by the control unit.

[0015] The above support member further includes a sealing member installed to block the gap between the body member and the support member.

[0016] The above-described control unit further includes a count unit for counting the number of times the driving member controls the position of the transparent window to adjust the position; and an alert unit for generating an alert when the number of times the count unit has counted reaches a preset number.

[0017] It further includes an airflow forming part installed to form an airflow of inert gas moving along the surface of the transparent window facing the interior of the chamber.

[0018] The above airflow forming unit comprises: a spraying unit positioned to spray inert gas obliquely toward one side of the perforating window, intersecting the irradiation path; and a suction unit positioned to suck in inert gas toward the other side opposite to the one side of the perforating window.

[0019] The present invention comprises: a process of identifying the location of a contaminated portion in a transparent window that transmits a laser beam; a process of selecting an area of ​​the transparent window located in the irradiation path by adjusting the position of the transparent window so that the contaminated portion in the transparent window is not located in the irradiation path where the laser beam is irradiated; and a process of transmitting the laser beam through the transparent window and irradiating it onto a substrate.

[0020] The process of determining the location of the contaminated portion in the above-mentioned transparent window comprises: a process of transmitting a laser beam to different portions of the above-mentioned transparent window while adjusting the position of the above-mentioned transparent window; a process of measuring the energy density of the laser beam transmitted to different portions of the above-mentioned transparent window; and a process of comparing the energy density measured for each portion of the above-mentioned transparent window with a preset energy density and determining that contamination has occurred in the portion of the above-mentioned transparent window having an energy density less than the preset energy density.

[0021] The process of determining the location of the contaminated portion in the above-mentioned transparent window comprises: a process of irradiating test light toward the above-mentioned transparent window; a process of measuring the amount of reflection of the light reflected from different portions of the above-mentioned transparent window; and a process of comparing the amount of reflection measured for each portion of the above-mentioned transparent window with a preset amount of reflection, and determining that contamination has occurred in the portion of the above-mentioned transparent window having a reflection amount exceeding the preset amount of reflection.

[0022] The process of irradiating test light toward the above-mentioned transparent window includes the process of adjusting the area where the light is irradiated onto the above-mentioned transparent window to match the area of ​​the above-mentioned transparent window.

[0023] The process of selecting an area of ​​the transparent window located in the investigation path by adjusting the position of the transparent window comprises: a process of identifying an area among the areas of the transparent window that does not include a contaminated portion; and a process of moving the transparent window so that the area not including the contaminated portion is located in the investigation path.

[0024] The method further includes: a process of selecting an area of ​​the transparent window located in the investigation path by adjusting the position of the transparent window, and counting the number of times the position of the transparent window is adjusted; and a process of generating a notification when the counted number reaches a preset number.

[0025] The method further includes a process of forming an airflow in which an inert gas moves along the surface of the transparent window facing the substrate before transmitting the laser beam to irradiate the substrate. Effects of the invention

[0026] According to embodiments of the present invention, a laser beam can be stably transmitted even if a portion of the transmission window is contaminated. Accordingly, it is possible to suppress or prevent defects occurring in the laser processing process due to a decrease in the transmittance of the laser beam. Thus, the efficiency of the laser processing process can be improved. Brief explanation of the drawing

[0027] FIG. 1 is a diagram showing the configuration of a laser processing device according to an embodiment of the present invention. FIG. 2 is a drawing showing the configuration of an airflow forming unit according to an embodiment of the present invention. FIG. 3 is a flowchart illustrating a laser processing method according to an embodiment of the present invention. Specific details for implementing the invention

[0028] Hereinafter, embodiments of the present invention will be described in more detail with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms, and these embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. To describe the invention in detail, the drawings may be exaggerated, and like reference numerals in the drawings refer to like elements.

[0030] FIG. 1 is a diagram showing the configuration of a laser processing device according to an embodiment of the present invention, and FIG. 2 is a diagram showing the configuration of an airflow forming unit according to an embodiment of the present invention. Below, a laser processing device according to an embodiment of the present invention will be described.

[0031] The laser processing device may be a laser crystallization device that crystallizes a silicon thin film by irradiating a laser beam onto a silicon thin film on a substrate. Referring to FIG. 1, the laser processing device (100) includes a chamber (110), an irradiation unit (120), a transparent window (130), and a support unit (140).

[0032] At this time, the substrate (S) may be formed in a shape such as a circular plate or a square plate. The substrate (S) may include a glass substrate having an amorphous silicon thin film formed on its upper surface. However, it is not limited thereto, and the substrate (S) may include a silicon substrate for manufacturing semiconductor devices or a glass substrate for manufacturing display devices in which a process of forming various thin films or devices on its upper surface is in progress or has been completed.

[0033] The chamber (110) has a space inside where a substrate is processed. For example, the chamber (110) may be formed in the shape of a cuboid having an internal space. A gate (not shown) for the entry and exit of the substrate (S) may be provided on the side of the chamber (110). The chamber (110) may be provided with an exhaust port (not shown) for exhausting by-products, a vacuum port (not shown) for forming a vacuum, a nozzle (not shown) for controlling the internal atmosphere, etc. A rectangular through-hole (H) through which a laser beam can pass may be provided on one side (or, the upper side) of the chamber (110). That is, the through-hole (H) may be positioned in the irradiation path where the laser beam is irradiated onto the substrate (S). However, the structure of the chamber (110) and the shape of the through-hole (H) are not limited to this and may vary.

[0034] At this time, the laser processing device (100) may further include a stage (150) installed inside the chamber (110) to support the substrate (S) as shown in FIG. 1. The stage (150) may be positioned on the lower side inside the chamber (110). The substrate (S) may be placed and supported on the upper surface of the stage (150). The stage (150) may move inside the chamber (110) while supporting the substrate (S). Thus, the stage (150) may be moved along one direction so that a laser beam can be irradiated and processed over the entire upper surface of the substrate (S).

[0035] Additionally, the laser processing device (100) may further include a deoxygenation unit (160) as shown in FIG. 1. The deoxygenation unit (160) may be installed between the through hole (H) formed in the chamber (110) and the stage (150). The deoxygenation unit (160) may be formed to surround the irradiation path. For example, the deoxygenation unit (160) may be formed in a hollow shape so that a laser beam can pass through the center and irradiate the substrate (S), and an opening may be formed at the top and bottom of the deoxygenation unit (160) that is aligned in the vertical direction with the through hole (H) of the chamber (110). The deoxygenation unit (160) may be equipped with a supply device (not shown) that supplies inert gas to the inside. Accordingly, an inert gas supplied to the inside of the deoxygenation unit (160) is ejected through the opening at the bottom of the deoxygenation unit (160) onto the substrate (S) on the stage (150), thereby pushing oxygen outward from the portion of the substrate (S) where the laser beam is irradiated. Therefore, when the substrate (S) is treated with a laser beam, the portion of the substrate (S) being treated with the laser beam is not exposed to oxygen, so the formation of silicon oxide by combining with oxygen on the silicon thin film formed on the upper surface of the substrate (S) can be suppressed or prevented.

[0036] The irradiation unit (120) is positioned outside the chamber (110) and can irradiate a laser beam onto a substrate (S) through a through hole (H). Specifically, the irradiation unit (120) is spaced apart from the upper side of the chamber (110) and can face the substrate (S) on the stage (150) through a through hole (H) formed in the chamber (110). Accordingly, a straight irradiation path of the laser beam can be formed between the irradiation unit (120) and the substrate (S). Therefore, when the irradiation unit (120) irradiates a laser beam, the laser beam can pass through the through hole (H) (or the through hole (H) and the deoxygenation unit (160)) and reach the substrate (S) inside the chamber (110). The irradiation unit (120) can irradiate a line-shaped laser beam. However, it is not limited to this, and the irradiation unit (120) can irradiate various shapes of laser beams.

[0037] A portion of the transparent window (130) may be located in the irradiation path. The transparent window (130) may be made of a transparent material and formed in the shape of a rectangular plate having an area greater than that of the through hole (H), following the shape of the through hole (H). For example, the transparent window (130) may be positioned between the through hole (H) and the irradiation unit (120), so that its upper surface faces the irradiation unit (120) and its lower surface faces the through hole (H). Accordingly, when the irradiation unit (120) irradiates a laser beam, the laser beam can pass through the transparent window (130) and reach the substrate (S) inside the chamber (110). Contamination may occur in the transparent window (130) as contaminants adhere to it while performing the laser processing process. However, it is not limited to this, and the transparent window (130) may be positioned inside the chamber (110), and the shape of the transparent window (130) may be formed in various ways.

[0038] A support member (140) is installed in the chamber (110) and can movably support the transparent window (130). Accordingly, the support member (140) can move the transparent window (130) to change the area of ​​the transparent window (130) located in the irradiation path. For example, the support member (140) is installed on the upper part of the chamber (110) and can move the transparent window (130) in a direction that intersects the irradiation path (or a horizontal direction). Therefore, if contamination occurs in a part of the transparent window (130) placed in the irradiation path, the position of the transparent window (130) can be adjusted by the support member (140) so that the area of ​​the transparent window (130) that is not contaminated is located in the irradiation path. The support member (140) includes a body member (141), a support member (142), and a driving member (143).

[0039] The body member (141) may be installed on the upper part of the chamber (110). The body member (141) may be formed in the shape of a rectangular plate having an area larger than the through hole (H) of the chamber (110), and a first through path may be formed in the center. The first through path may be formed along the shape of the through hole (H) and may be in communication with the through hole (H). However, the shape of the body member (141) is not limited thereto and may vary.

[0040] The support member (142) may be movably installed on the body member (141) in a direction intersecting the investigation path (or, horizontal direction). The support member (142) may be formed in the shape of a rectangular plate having an area larger than the through hole (H) of the chamber (110), and a second through path may be formed in the center. The second through path may be formed along the shape of the through hole (H) and may be in communication with the first through path and the through hole (H). A transparent window (130) may be fitted into the support member (142) to close the upper part of the second through path, and the transparent window (130) may be supported by the support member (142). Therefore, when the support member (142) moves on the body member (141), the transparent window (130) may also move together. However, the shape of the support member (142) is not limited to this and may vary.

[0041] The driving member (143) is connected to the supporting member (142) and can move the supporting member (142). For example, the driving member (143) may be a Linear Motion (LM) guide and can move the supporting member (142) in a horizontal direction (e.g., either the forward / backward direction or the left / right direction) on the body member (141). Accordingly, the transparent window (130) supported by the supporting member (142) can move together and its position can be adjusted in the horizontal direction. In addition, the driving member (143) can be controlled by a control unit (180) to be described later. Thus, the control unit (180) can control the operation of the driving member (143) to adjust the position of the transparent window (130) and select the portion of the transparent window (130) located in the irradiation path. However, the method by which the driving member (143) moves the supporting member (142) is not limited to this and can be varied.

[0042] At this time, the support member (140) may further include a sealing member (144) as shown in FIG. 1. The sealing member (144) may be installed between the body member (141) and the support member (142). For example, the sealing member (144) may be positioned on the upper part of the body member (141) in a manner that surrounds the perimeter of the first through path formed in the body member (141). Accordingly, since the sealing member (144) is compressed between the support member (142) and the body member (141) by the load of the support member (142), even if the support member (142) is moved by the driving member (143), it can block the gap between the body member (141) and the support member (142) while maintaining the state of being compressed by the load. Accordingly, it is possible to suppress or prevent gas inside the chamber (110) from leaking out to the outside.

[0043] Meanwhile, the laser processing device (100) may further include a contamination verification unit (170) and a control unit (180) as shown in FIG. 1. Accordingly, the location of the part where contamination has occurred and the part where contamination has not occurred in the transparent window (130) can be identified, and the position of the transparent window (130) can be automatically adjusted so that the area where contamination has not occurred in the transparent window (130) is located in the irradiation path.

[0044] The contamination verification unit (170) can check the condition of the transparent window (130). Accordingly, the contamination verification unit (170) can check the location of the part where contamination has occurred due to the attachment of contaminants in the transparent window (130), and the location of the part where contamination has not occurred due to the attachment of contaminants.

[0045] A contamination confirmation unit (170) according to one embodiment may include an energy measurement unit and a judgment unit. The energy measurement unit may be installed inside the chamber (110) (e.g., stage (150)) to measure the energy density of a laser beam that has passed through the transmission window (130). Accordingly, before the substrate (S) is supported on the stage (150), the energy density of a laser beam that has passed through different parts of the transmission window (130) can be measured by the energy measurement unit while adjusting the position of the transmission window (130) with the support unit (140). The judgment unit may be connected to receive the measurement results from the energy measurement unit. Thus, the judgment unit can determine the location where contamination has occurred in the transmission window (130) based on the energy density measured for each part of the transmission window (130). That is, the judgment unit compares the energy density measured for each part of the transparent window (130) with a preset energy density, and determines that the laser beam cannot normally pass through the part of the transparent window (130) having an energy density less than the preset energy density due to contaminants, thereby determining that contamination has occurred at the location of the part, and determines that the laser beam passes through the part of the transparent window (130) normally because there are no contaminants in the part of the transparent window (130) having an energy density greater than the preset energy density, thereby determining that contamination has occurred at the location of the part.

[0046] According to another embodiment, the contamination verification unit (170) may include a light generating unit, a reflection amount measuring unit, and a judgment unit. The light generating unit may be positioned on the outside of the chamber (110) (e.g., above the transparent window (130)) to irradiate test light onto the transparent window (130). The light generating unit may adjust the area over which light is irradiated onto the transparent window (130) to match the area of ​​the transparent window (130). Accordingly, light may be irradiated onto the entire upper surface of the transparent window (130). The reflection amount measuring unit may be installed on the outside of the chamber (110) together with the light generating unit to measure the amount of reflection reflected from different parts of the transparent window (130) by the light irradiated onto the transparent window (130) by the light generating unit. The judgment unit may be connected to receive the measurement results from the reflection amount measuring unit. Accordingly, the judgment unit can determine the location where contamination has occurred in the transparent window (130) based on the amount of reflection measured for each part of the transparent window (130). That is, the judgment unit compares the amount of reflection measured for each part of the transparent window (130) with a preset amount of reflection, and determines that in the part of the transparent window (130) having a reflection amount exceeding the preset amount, light is not transmitted to that part due to contaminants and is reflected, thereby determining that contamination has occurred at that location of the part, and in the part of the transparent window (130) having a reflection amount less than or equal to the preset amount, light is not reflected and is transmitted to that part without contaminants, thereby determining that contamination has not occurred at that location of the part.

[0047] The control unit (180) can be connected to receive the confirmation result of the contamination confirmation unit (170) and control the operation of the support unit (140). Accordingly, the control unit (180) can control the operation of the support unit (140) so that the part of the transparent window (130) where contamination has occurred is not located in the investigation path. More specifically, the control unit (180) can analyze the confirmation result of the contamination confirmation unit (170) to distinguish between the area where contamination has occurred and the area where contamination has not occurred in the transparent window (130). If the part of the transparent window (130) where contamination has not occurred is located in the investigation path, the control unit (180) may not adjust the position of the transparent window (130). If a portion of the transparent window (130) that has become contaminated is located in the irradiation path, the control unit (180) can operate the driving member (143) to adjust the position of the transparent window (130) so that a portion of the transparent window (130) that has not become contaminated is located in the irradiation path. Therefore, when processing the substrate (S) with a laser beam, the decrease in the transmittance of the laser beam passing through the transparent window (130) is suppressed or prevented, thereby allowing the laser beam to be stably irradiated onto the substrate (S).

[0048] In this way, if a part of the transparent window (130) becomes contaminated, the position of the transparent window (130) can be adjusted to stably transmit the laser beam to an area where no contamination has occurred. Therefore, it is possible to suppress or prevent defects from occurring in the laser processing process due to a decrease in the transmittance of the laser beam. Accordingly, the efficiency of the laser processing process can be improved.

[0049] Meanwhile, the laser processing device (100) may further include a count unit (not shown) and a notification unit (not shown). Accordingly, depending on the number of times the position of the transparent window (130) is adjusted, it is possible to check whether the transparent window (130) is contaminated overall and generate a notification to the manager of the laser processing device (100).

[0050] The count unit can be connected to receive control results from the control unit (180). Accordingly, the count unit can count the number of times the control unit (180) controls the driving member (143) to adjust the position of the transparent window (130).

[0051] The notification unit can be connected to receive information regarding the number of times the count unit has counted. Accordingly, the notification unit can compare the number of times the count unit has counted with a preset number of times. When the count unit reaches the preset number, the notification unit can generate a visual or auditory notification to the manager. That is, when the count unit reaches the preset number, it can determine that the transparent window (130) is in a contaminated state by determining that more than the number of times the count unit has counted has attached to the transparent window (130). Therefore, the notification unit can determine that cleaning of the transparent window (130) is necessary and generate a notification to the manager. After generating the notification, the notification unit can reset the number of times the count unit has counted to 0. Additionally, if the control unit (180) cannot find a part of the transparent window (130) that is not contaminated, the notification unit may generate a notification to the manager. The manager can check the notification from the notification unit and take action.

[0052] Meanwhile, the laser processing device may further include an airflow forming unit (190) as shown in FIG. 2. The airflow forming unit (190) may be installed to form an airflow of inert gas moving along the surface of a transparent window (130) facing the interior of the chamber (110). In detail, the airflow forming unit (190) may be installed on a support member (140) to supply inert gas along the surface of the transparent window (130). Accordingly, the inert gas may form an air curtain to suppress or prevent contaminants from adhering to the transparent window (130). The airflow forming unit (190) includes a spraying unit (191) and a suction unit (192).

[0053] The injection unit (191) can inject inert gas at an angle toward one side of the transparent window (130) and intersect with the irradiation path. For example, the injection unit (191) may extend through the support member (142), and one end of the injection unit (191) may be connected to a gas storage unit (not shown) in which inert gas is stored, and the other end of the injection unit (191) in which inert gas is injected may be formed to be inclined upward toward one side of the transparent window (130) at least partially lower than the transparent window (130). The other end of the injection unit (191) may be formed in the shape of a slit or may be formed as a structure having a plurality of injection nozzles. Since the injection unit (191) injects inert gas obliquely toward one side of the transparent window (130), the inert gas is injected only toward the transparent window (130), thereby reducing the impact on the substrate (S) during processing, and the inert gas can move along the surface of the transparent window (130) and move to the other side of the transparent window (130).

[0054] The suction part (192) may be positioned to suck in inert gas to the other side opposite to one side of the transparent window (130). For example, the suction part (192) may be installed by penetrating the support member (142), and one end of the suction part (192) may be connected to a suction device (not shown) that generates a suction force for sucking in inert gas, and the other end of the suction part (192) into which inert gas is sucked may be formed to be inclined downward, intersecting the irradiation path, while facing the other side of the transparent window (130) at least partially lower than the transparent window (130). The other end of the suction part (192) may be formed in a slit shape or may be formed as a structure having a plurality of nozzles. Since the suction part (192) draws in inert gas obliquely while facing the other side of the transparent window (130), the suction force of the suction part (192) can reduce the effect on the airflow in the space where the substrate (S) is processed (or the space between the space where the substrate (S) is processed and the space inside the deoxygenation part (160), and the inert gas that has moved along the surface of the transparent window (130) can be drawn into the suction part (192). However, the structure of the suction part (192) is not limited to this and can be varied.

[0056] FIG. 3 is a flowchart illustrating a laser processing method according to an embodiment of the present invention. Below, a laser processing method according to an embodiment of the present invention will be described.

[0057] The laser processing method may be a laser crystallization method that crystallizes a silicon thin film by irradiating a silicon thin film on a substrate with a laser beam. Referring to FIG. 3, the laser processing method includes a process of identifying the location of a contaminated part in a transparent window that transmits a laser beam (S110), a process of selecting an area of ​​the transparent window located in the irradiation path by adjusting the position of the transparent window so that the contaminated part in the transparent window does not exist in the irradiation path where the laser beam is irradiated (S120), and a process of transmitting a laser beam through the transparent window to irradiate the substrate (S130).

[0058] At this time, the laser processing method may be performed by a laser processing device according to an embodiment of the present invention having the configuration shown in FIGS. 1 and 2. Accordingly, the process of performing the laser processing method will be described below with reference to FIGS. 1 and 2. However, the laser processing method may be performed by a laser processing device of various configurations, not limited thereto.

[0059] First, the location of the contaminated part in the transparent window through which the laser beam is transmitted is checked (S110). That is, by checking the condition of the transparent window (130), the location of the part where contaminants are attached and contaminated in the transparent window (130), and the location of the part where contaminants are not attached and contaminants are not attached can be checked.

[0060] In one embodiment, to determine the location of the contaminated part in the transparent window (130), the position of the transparent window (130) is adjusted by the support member (140) and a laser beam is transmitted to different parts of the transparent window (130), and the energy density of the laser beam transmitted to different parts of the transparent window (130) can be measured by an energy measuring unit installed inside the chamber (110). When the energy density is measured for each part of the transparent window (130), each energy density measured for each part can be compared with a preset energy density. For parts of the transparent window (130) having an energy density less than the preset energy density, it is determined that the laser beam cannot normally transmit to that part due to contaminants, and thus it can be determined that contaminants have occurred at that location. For parts of the transparent window (130) having an energy density greater than the preset energy density, it is determined that there are no contaminants and the laser beam transmits to that part normally, and thus it can be determined that contaminants have occurred at that location.

[0061] In another embodiment, to identify the location of the contaminated part in the transparent window (130), a light generating unit positioned outside the chamber (110) can be used to irradiate test light toward the transparent window (130). The light generating unit can adjust the area of ​​the transparent window (130) to which light is irradiated so that light can be irradiated over the entire transparent window (130), in accordance with the area of ​​the transparent window (130). Subsequently, a reflection measuring unit can be used to measure the amount of light reflected from different parts of the transparent window (130). When the amount of reflection is measured for each part of the transparent window (130), the amount of reflection measured for each part can be compared with a preset amount of reflection. In the part of the transparent window (130) that has a reflection amount exceeding the preset amount, it can be determined that light is not transmitted through that part due to contaminants and is reflected, and thus it can be determined that contamination has occurred at that location. In the part of the transparent window (130) having a reflection amount less than or equal to the set reflection amount, it can be determined that light is transmitted without being reflected and that there is no contamination at that location.

[0062] Next, the position of the transparent window is adjusted so that the area of ​​the transparent window located in the irradiation path is selected so that the contaminated part of the transparent window is not located in the irradiation path where the laser beam is irradiated (S120). That is, the area of ​​the transparent window (130) that does not include the contaminated part is identified, and the transparent window can be moved so that the area that does not include the contaminated part is located in the irradiation path. In detail, by using the results of checking the location of the contaminated part and the area of ​​the non-contaminated part in the transparent window (130), it can be checked whether the contaminated part of the transparent window (130) is located in the irradiation path. If the non-contaminated part of the transparent window (130) is located in the irradiation path, the position of the transparent window (130) is not adjusted so that the corresponding part of the transparent window (130) is selected to be located in the irradiation path. If a contaminated portion of the transparent window (130) is located in the irradiation path, the position of the transparent window (130) can be adjusted so that a non-contaminated portion of the transparent window (130) is located in the irradiation path. Thus, it is possible to prevent the contaminated portion of the transparent window (130) from being located in the irradiation path and obstructing the transmission of the laser beam.

[0063] Meanwhile, after selecting an area of ​​the transparent window located in the inspection path by adjusting the position of the transparent window (130), the number of times the position of the transparent window (130) is adjusted can be counted using a count unit, and the counted number can be compared with a preset number. When the counted number reaches the preset number, it can be determined that the transparent window (130) is contaminated by determining that more than the number of times the count unit has counted the number of contaminants attached to the transparent window (130). Therefore, when the counted number reaches the preset number, the notification unit can determine that cleaning of the transparent window (130) is necessary and generate a notification to the manager. After generating the notification, the notification unit can reset the number counted by the count unit to 0. The manager can check the notification from the notification unit and take action.

[0064] Next, a laser beam is transmitted through the transparent window to irradiate the substrate (S130). Since the position of the transparent window (130) is adjusted so that the laser beam passes through the part of the transparent window (130) where no contamination occurs and is stably irradiated to the substrate (S), the laser processing process can be performed stably. For example, a silicon thin film on the substrate (S) can be crystallized by the laser beam.

[0065] In this way, if a part of the transparent window (130) becomes contaminated, the position of the transparent window (130) can be adjusted to stably transmit the laser beam to an area where no contamination has occurred. Therefore, it is possible to suppress or prevent defects from occurring in the laser processing process due to a decrease in the transmittance of the laser beam. Accordingly, the efficiency of the laser processing process can be improved.

[0066] Meanwhile, before transmitting a laser beam to irradiate the substrate, an airflow of inert gas can be formed along the surface of the transparent window (130) facing the substrate (S). That is, an inert gas can be supplied to one side of the transparent window (130) through the airflow forming unit (190) and inhaled to the other side of the transparent window (130) to form an air curtain of inert gas on the surface of the transparent window (130). Thus, the inert gas protects the surface of the transparent window (130), thereby suppressing or preventing contaminants from adhering to the transparent window (130) and contaminating the transparent window (130) when performing the laser processing process.

[0068] As such, although specific embodiments have been described in the detailed description of the present invention, various modifications are possible within the scope of the invention, and various combinations between embodiments are also possible. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims set forth below as well as equivalents thereof. Explanation of the symbols

[0069] 100: Laser processing unit 110: Chamber 120: Investigation Department 130: Transparent Window 140: Support 150: Stage 170: Contamination Confirmation Section 180: Control unit 190: Airflow forming section

Claims

Claim 1 A laser processing device comprising: a chamber having a space for processing a substrate inside and a through hole provided on one side through which a laser beam can pass; an irradiation unit disposed on the outside of the chamber to irradiate a laser beam onto the substrate through the through hole; a transparent window having a portion of which is located in an irradiation path through which the laser beam is irradiated so as to transmit the laser beam; and a support unit installed in the chamber to movably support the transparent window so as to change the portion located in the irradiation path. Claim 2 A laser processing device according to claim 1, further comprising: a contamination confirmation unit for confirming the location of a contaminated portion in the transparent window; and a control unit for controlling the operation of the support member so that the contaminated portion in the transparent window is not located in the irradiation path. Claim 3 A laser processing apparatus according to claim 2, wherein the contamination confirmation unit comprises: an energy measuring unit installed inside the chamber to measure the energy density of a laser beam transmitted through different parts of the transmission window while adjusting the position of the transmission window with the support unit; and a judgment unit for determining the location where contamination occurred in the transmission window according to the energy density measured for each part of the transmission window. Claim 4 A laser processing apparatus according to claim 3, further comprising a stage installed inside the chamber to support the substrate, wherein the energy measuring unit is installed on the stage and measures the energy density of the laser beam before the substrate is supported on the stage. Claim 5 A laser processing apparatus according to claim 2, wherein the contamination confirmation unit comprises: a light generating unit disposed outside the chamber to irradiate test light toward the transparent window; a reflection amount measuring unit disposed outside the chamber to measure the amount of reflection reflected from different parts of the transparent window by the light irradiated by the light generating unit; and a determination unit for determining the location where contamination has occurred in the transparent window according to the amount of reflection measured for each part of the transparent window. Claim 6 In claim 5, the light generating unit is a laser processing device that adjusts the area where the light is irradiated onto the transparent window to match the area of ​​the transparent window. Claim 7 A laser processing apparatus according to claim 2, wherein the support member comprises: a body member installed on the upper part of the chamber; a support member movably installed on the body member in a direction intersecting the irradiation path and supporting the transparent window; and a driving member controlled by the control member to move the support member. Claim 8 A laser processing device according to claim 7, wherein the support member further comprises a sealing member installed to block the gap between the body member and the support member. Claim 9 A laser processing device according to claim 7, further comprising: a count unit for counting the number of times the control unit controls the driving member to adjust the position of the transparent window; and an alert unit for generating an alert when the number of times the count unit has counted reaches a preset number of times. Claim 10 A laser processing apparatus according to claim 1, further comprising an airflow forming part installed to form an airflow in which an inert gas moves along the surface of the transparent window facing the interior of the chamber. Claim 11 A laser processing device according to claim 10, wherein the airflow forming part comprises: a spraying part arranged to spray inert gas obliquely toward one side of the transparent window and intersect with the irradiation path; and a suction part arranged to suck in inert gas toward the other side opposite to one side of the transparent window. Claim 12 A laser processing method comprising: a process of identifying the location of a contaminated portion in a transparent window that transmits a laser beam; a process of selecting an area of ​​the transparent window located in the irradiation path by adjusting the position of the transparent window so that the contaminated portion in the transparent window is not located in the irradiation path where the laser beam is irradiated; and a process of transmitting the laser beam through the transparent window and irradiating it onto a substrate. Claim 13 A laser processing method according to claim 12, wherein the process of determining the location of a contaminated portion in the transparent window comprises: a process of transmitting a laser beam to different portions of the transparent window while adjusting the position of the transparent window; a process of measuring the energy density of the laser beam transmitted to different portions of the transparent window; and a process of comparing the energy density measured for each portion of the transparent window with a preset energy density and determining that contamination has occurred in the portion of the transparent window having an energy density less than the preset energy density. Claim 14 A laser processing method according to claim 12, wherein the process of determining the location of a contaminated portion in the transparent window comprises: a process of irradiating test light toward the transparent window; a process of measuring the amount of reflection of the light reflected from different portions of the transparent window; and a process of comparing the amount of reflection measured for each portion of the transparent window with a preset amount of reflection, and determining that contamination has occurred in the portion of the transparent window having a amount of reflection exceeding the preset amount of reflection. Claim 15 A laser processing method according to claim 14, wherein the process of irradiating test light toward the transparent window includes the process of adjusting the area where the light is irradiated onto the transparent window to match the area of ​​the transparent window. Claim 16 A laser processing method according to claim 12, wherein the process of selecting an area of ​​the transparent window located in the irradiation path by adjusting the position of the transparent window comprises: a process of identifying an area that does not include a contaminated portion among the areas of the transparent window; and a process of moving the transparent window so that the area that does not include the contaminated portion is located in the irradiation path. Claim 17 A laser processing method according to claim 12, further comprising: a process of adjusting the position of the transparent window to select an area of ​​the transparent window located in the irradiation path, and then counting the number of times the position of the transparent window is adjusted; and a process of generating a notification when the counted number reaches a preset number. Claim 18 A laser processing method according to claim 12, further comprising the process of forming an airflow in which an inert gas moves along the surface of the transparent window facing the substrate before transmitting the laser beam to irradiate the substrate.

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