Wafer Alignment System and Wafer Alignment Method

Abstract

The present invention relates to a wafer position alignment device and a wafer position alignment method for easily aligning the center point of a wafer with the center point of a mask in response to various types of wafers mounted on a wafer support, comprising: a judgment module for determining the mounting state of a wafer mounted on a plurality of wafer supports; a plurality of push modules for pushing and clamping the wafer to align the center point of the wafer with the center point of the mask according to the judgment state of the judgment module; a driving module for driving each of the plurality of push modules; and a control module for controlling the operation of the driving module. The plurality of push modules are configured to be adjacent to each of the plurality of wafer supports and arranged equiangularly with respect to the center of the mask plate, thereby easily realizing the alignment of the center point of the wafer with the center point of the mask.

Description

Technology Field

[0001] The present invention relates to a wafer position alignment device and a wafer position alignment method applied to a wafer defect inspection system, and more specifically, to a wafer position alignment device and a wafer position alignment method that facilitates the alignment of the center point of a wafer with the center point of a mask in correspondence with various types of wafers mounted on a wafer support. Background Technology

[0003] Generally, semiconductor devices are manufactured by performing various unit processes on a silicon wafer used as a semiconductor wafer to form an electrical circuit containing electrical components on the silicon wafer.

[0004] Meanwhile, as the integration density of semiconductor devices increases, the yield and reliability of these devices are significantly affected by the quality of the wafers on which they are fabricated. Wafer quality is determined by the number of defects generated throughout the entire process of wafering, which involves fabricating the wafer during crystal growth.

[0005] These wafer defects can be classified into defects caused by external contaminants and crystal defects occurring during ingot growth. Among these, external contaminants such as dust are easily removed by etching or cleaning processes; however, crystal defects such as COP (Crystal Originated Particles), FPD (Flow Pattern Defect), OiSF (Oxygen-induced Stacking Fault), BMD (Bulk Micro Defect), and LDP (Large Dislocation Pit) are not removed by cleaning processes and remain, affecting the yield and quality of semiconductor devices; therefore, their occurrence must be suppressed during the wafer fabrication process. Accordingly, verifying and inspecting the accurate distribution and density of these defects prior to implementing semiconductor devices on the wafer is crucial for yield management.

[0006] In other words, wafers used in the manufacture of semiconductor devices are prepared by thinly slicing silicon ingots, and impurities can be introduced due to the high growth temperatures during ingot growth. During this ingot growth, voids or crystal defects caused by the rotation speed or amount of oxygen can lead to the formation of air pockets, and these defects are transferred directly to the sliced ​​wafers. Wafers with defects such as air pockets are mostly discarded. Furthermore, wafers are subjected to thermal or physical stress while undergoing multiple processes. At this time, if even minor defects such as cracks are present on the wafer, new cracks may develop or semiconductor device products may fail due to thermal or physical stress during the process, leading to a decrease in yield.

[0007] A wafer defect inspection system for inspecting defects on the surface or inside a wafer as described above is known. In order to obtain accurate defect inspection results in such a wafer defect inspection system, the wafer mounted on a plurality of supports must be centered.

[0009] An example of such technology is disclosed in the following patent documents 1 to 3, etc.

[0010] For example, the following patent document 1 discloses a wafer holding device comprising a base, a holder plate, a plurality of pushing pins, a linear actuator, and a positioning member, wherein the holder plate is disposed on the base, and an adsorption structure for adsorbing and fixing a wafer is provided on the upper surface of the holder plate, the plurality of pushing pins are disposed on the upper surface in a protruding manner, and each pushing pin is disposed on the holder plate with respect to a predetermined reference center on the holder plate, the linear actuator is disposed on the base, and the operating direction of the linear actuator is parallel to the upper surface, and the positioning member is driven by the linear actuator to move in the operating direction to contact and push against the positioning structure of the wafer.

[0011] In addition, Patent Document 2 below discloses a wafer support device for wafer inspection equipment comprising: a guide block made of metal material installed to extend toward the center of a stage; a support block coupled to the inner end of the guide block and on which the edge of a wafer is seated and supported; and a clamping unit installed to be horizontally reciprocating on the stage by a driving means and which horizontally presses and fixes the edge portion of the wafer seated on the support block in one direction.

[0012] Meanwhile, the following patent document 3 discloses a wafer centering device for a measuring instrument comprising a push module formed to press a wafer to a center position and a driving module that operates the push module in forward and backward directions relative to the wafer, wherein the driving module comprises a cylinder having an internal space having a first area and a second area, a piston disposed in the internal space to distinguish the first area and the second area, a moving unit having a rod connecting the piston to the push module, and an air supply unit having a forward air input unit that inputs a first air to the first area to move the piston and the push module in the forward direction and a backward air input unit that inputs a second air to the second area to move the piston and the push module in the backward direction. Prior art literature

[0014] U.S. Patent Publication No. 2025-0149366 (Published May 8, 2025) Korean Registered Patent Publication No. 10-1595885 (Published Feb. 19, 2016) Korean Registered Patent Publication No. 10-2012339 (Published Aug. 20, 2019) The problem to be solved

[0015] Patent Document 1, as described above, discloses a technology in which a positioning member is driven by a linear actuator to contact and push against a positioning structure of a wafer, Patent Document 2 discloses a technology in which an edge portion is horizontally pressed in one direction, and Patent Document 3 discloses a technology in which a wafer is moved toward a wafer by a driving module that presses the wafer and moves the wafer to a center position, but there is no technology in which a fixed wafer support and a variable wafer support are separated to support the wafer, and the center of the wafer and the center of a mask plate mounted to block light applied from the outside of the wafer are aligned and fixed.

[0016] In other words, the prior art described above did not disclose a technology for adjusting the center position of a wafer using a variable wafer support for individual position adjustment and aligning it with the center of a mask plate when the initial setting value of the wafer support device is misaligned or when a deviation in the center value occurs depending on the wafer size.

[0018] The objective of the present invention is to solve the problems described above by providing a wafer position alignment device and a wafer position alignment method that can easily align the center point of a wafer with the center point of a mask in correspondence with various types of wafers mounted on a wafer support.

[0019] Another objective of the present invention is to provide a wafer position alignment device and a wafer position alignment method that can improve wafer defect inspection accuracy by aligning the center point of a wafer with the center point of a mask.

[0020] Another objective of the present invention is to provide a wafer position alignment device and a wafer position alignment method that can reduce the time required for wafer defect inspection by reducing the time required for wafer centering. means of solving the problem

[0022] To achieve the above-mentioned objective, the wafer position alignment device according to the present invention is a device for aligning the position of a wafer mounted on a plurality of wafer supports on a wafer stage equipped with a mask plate, comprising: a judgment module for determining the mounting state of the wafer mounted on the plurality of wafer supports; a plurality of push modules for pushing and clamping the wafer to align the center point of the wafer with the center point of the mask according to the judgment state of the judgment module; a driving module for driving each of the plurality of push modules; and a control module for controlling the operation of the driving module, wherein the plurality of push modules are adjacent to each of the plurality of wafer supports and are equiangularly arranged with respect to the center of the mask plate.

[0023] In addition, in the wafer position alignment device according to the present invention, the plurality of push modules are provided as a first push module, a second push module, and a third push module, and are characterized by simultaneously pushing a wafer placed on the wafer support in the direction of the center of the mask plate.

[0024] In addition, in the wafer position alignment device according to the present invention, each of the first push module, the second push module, and the third push module is characterized by comprising a pusher that pushes and clamps the wafer, a pusher bracket coupled to the pusher, a moving member that moves the pusher bracket linearly in a horizontal direction, a cylinder rod connected to the moving member, and a connecting bracket coupled to the pusher bracket and the cylinder rod.

[0025] In addition, in the wafer position alignment device according to the present invention, each pusher position provided in the first push module, the second push module, and the third push module is characterized by being mounted to maintain an equal spacing from the mask plate.

[0026] In addition, in the wafer position alignment device according to the present invention, the cylinder rod is provided to move back and forth at the leading end of the moving member, and the connecting bracket is provided in an "L" shape so that the cylinder rod is mounted inside the front and is integrally coupled with the pusher bracket on the side.

[0027] In addition, in the wafer position alignment device according to the present invention, the pusher is provided as a V-shape or C-shape guide (V-shape / C-shape guide) in a shape corresponding to the edge of the wafer, and is made of PEEK (Polyether Ether Ketone) to clamp the wafer.

[0028] In addition, in the wafer position alignment device according to the present invention, the moving member is characterized by including a pneumatic cylinder or a hydraulic cylinder.

[0029] In addition, in the wafer position alignment device according to the present invention, the moving member is characterized by including a ball screw member.

[0030] In addition, the wafer position alignment device according to the present invention further includes a sensing module that detects the seating state of the wafer, and the control module controls the operation of the driving module according to the detection result of the sensing module.

[0031] In addition, the wafer position alignment device according to the present invention is characterized in that a first groove and a second groove are provided in the periphery portion of the mask plate to avoid contact with the plurality of wafer supports and the plurality of push modules.

[0032] In addition, the wafer position alignment device according to the present invention is characterized by further including a lifting member for lifting the mask plate and an LM guide member for adjusting the centering position of the mask on the mask plate.

[0033] In addition, to achieve the above objective, the wafer position alignment method according to the present invention is a method for aligning the position of a wafer placed on a plurality of wafer supports on a wafer stage equipped with a mask plate, and is characterized by comprising: (a) a step of placing a wafer transported by a robot arm onto the plurality of wafer supports and raising the mask plate; (b) a step in which a first push module, a second push module, and a third push module push and clamp the wafer placed in step (a); (c) a step in which a wafer defect measurement module performs a defect inspection on the wafer clamped in step (b); (d) a step in which, when the inspection in step (c) is completed, the first push module, the second push module, and the third push module release the clamping and lower the mask plate; and (e) a step in which the wafer inspected in step (c) is withdrawn by the robot arm.

[0034] In addition, in the wafer position alignment method according to the present invention, in step (b), the first push module, the second push module, and the third push module simultaneously push the wafer seated on the wafer support in the direction of the center of the mask plate.

[0035] In addition, in the wafer position alignment method according to the present invention, the first push module, the second push module, and the third push module are adjacent to each of the plurality of wafer supports and are arranged equiangularly with respect to the center of the mask plate.

[0036] In addition, in the wafer position alignment method according to the present invention, each pusher position provided in the first push module, the second push module, and the third push module is characterized by performing a push while maintaining the same spacing from the mask plate.

[0037] In addition, in the wafer position alignment method according to the present invention, the pusher is provided as a V-shape or C-shape guide (V-shape / C-shape guide) in a shape corresponding to the edge of the wafer, and is made of PEEK (Polyether Ether Ketone) to clamp the wafer.

[0038] In addition, in the wafer position alignment method according to the present invention, step (b) is characterized in that a sensing module detects the seating state of the wafer and a control module controls the operation of a driving module according to the detection result of the sensing module. Effects of the invention

[0040] As described above, according to the wafer position alignment device and wafer position alignment method applied to the wafer defect inspection system of the present invention, by arranging and driving a plurality of push modules in an isogonal state, the effect of easily aligning the center point of a wafer with the center point of a mask corresponding to various types of wafers is obtained.

[0041] In addition, according to the wafer position alignment device and wafer position alignment method of the present invention, the position of the wafer can be accurately aligned in correspondence with the mask, thereby obtaining the effect of improving inspection accuracy and reliability during wafer defect inspection.

[0042] In addition, according to the wafer position alignment device and wafer position alignment method of the present invention, the effect of easily realizing wafer position alignment and enabling high-speed wafer defect inspection is also obtained.

[0043] Meanwhile, according to the wafer position alignment device and wafer position alignment method of the present invention, since a plurality of push modules can be easily mounted on existing equipment, the effect of reducing installation costs is also obtained. Brief explanation of the drawing

[0045] FIG. 1 is a configuration diagram of a wafer defect inspection system to which a wafer position alignment device according to the present invention is applied. FIG. 2 is a block diagram of a wafer position alignment device according to the present invention, FIG. 3 is a perspective view of a wafer stage including the push module shown in FIG. 2, FIG. 4 is a perspective view showing the configuration of the mask plate illustrated in FIG. 3. FIG. 5 is a drawing showing the state in which a wafer is positioned and aligned on the mask plate shown in FIG. 3. FIG. 6 is a perspective view showing the structure of the wafer support illustrated in FIG. 3. FIG. 7 is a perspective view showing the configuration of the push module illustrated in FIG. 3, FIGS. 8 to 10 are drawings for explaining the operating state of a wafer position alignment device according to the present invention. FIG. 11 is a drawing illustrating a comparison example of the mounting state and operation of a push module. Specific details for implementing the invention

[0046] The above and other objects and novel features of the present invention will become more apparent from the description in this specification and the accompanying drawings.

[0047] In the description of the present invention, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Furthermore, since the size and thickness of each component shown in the description and drawings of the present invention are depicted arbitrarily for convenience of explanation, the present invention is not necessarily limited to what is depicted.

[0048] Additionally, the terms “part,” “module,” or “part” used herein may perform at least one function or operation and may be implemented as hardware or software consisting of mechanical or electrical / electronic configurations, or as a combination of hardware and software; and, excluding the “part,” “module,” or “part” that need to be implemented in specific hardware, the plurality of “parts,” “modules,” or “parts” may be integrated into at least one module and implemented by at least one processor.

[0049] Additionally, in the description of the present invention, terms including ordinal numbers such as first, second, third, etc., may be used to describe various components, but said components are not limited by said terms. Such terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be named the first component, and similarly, the first component may also be named the second component.

[0050] Meanwhile, the term "wafer" as used herein generally refers to a substrate formed of semiconductor or non-semiconductor materials, non-limiting examples of semiconductor materials include single-crystal silicon, gallium arsenide, and indium phosphide, and such substrates can be typically processed in semiconductor manufacturing facilities, and the substrate may be made of glass, sapphire, or other insulating materials, and "notch" refers to a cutout in a semiconductor wafer that specifies the direction to indicate the crystal orientation.

[0051] Additionally, as used herein, "left-right direction and front-back direction" refers to the X-axis and Y-axis directions as directions parallel to the surface on which the wafer is mounted, and "up-down direction" refers to the Z-axis direction as a direction perpendicular to the horizontal direction formed by the X-axis and Y-axis, and "wafer defect" may include defects such as cracks, defects, or damage in the edge region of the wafer, defects on the surface or inside the wafer, and "wafer defect measurement" may include inspection of the wafer edge region, detection of wafer defects and detection of defect depth, measurement of the type of defect, size of the defect, depth of the defect, and defect image.

[0053] Hereinafter, an embodiment according to the present invention will be described with reference to the drawings.

[0054] FIG. 1 is a configuration diagram of a wafer defect inspection system to which a wafer position alignment device according to the present invention is applied.

[0055] A wafer defect inspection system to which a wafer position alignment device according to the present invention is applied may include a wafer defect measurement module (100), a wafer load module (200), a wafer transfer module (300), and a wafer edge area inspection module (400) as shown in FIG. 1.

[0056] The wafer defect measurement module (100) can mount the wafer (1) on a wafer stage to inspect for defects in the wafer (1). That is, the wafer defect measurement module (100) can detect the defect state of the wafer (1) by light transmitted through the wafer (1). The wafer defect measurement module (100) can be positioned within the stroke area of ​​the robot arm (310) so as to inspect for defects in the wafer (1) as a substrate transported by the robot arm (310).

[0057] The wafer load module (200) may include an inspection load section (210) and a storage load section (220). The inspection load section (210) may be equipped with an inspection wafer cassette on which a plurality of wafers (1), for example, 25 wafers, to be inspected by the wafer defect measurement module (100) are placed. The storage load section (220) may be equipped with a storage wafer cassette on which a plurality of wafers, for example, 25 wafers, that have been inspected according to the present invention are placed.

[0058] The wafer transfer module (300) may be equipped with a robot arm (310) that is mounted on the inspection load portion (210) of the wafer load module (200) to load and unload the wafer (1) to be inspected to the wafer edge region inspection module (400) and the wafer defect measurement module (100). In addition, although the robot arm (310) has been described as having a single robot arm structure in the above description, it is not limited thereto and two or more robot arms may be applied.

[0059] The robot arm (310) may be provided with an edge grip portion for holding the wafer (1) or a vacuum suction portion such as a vacuum chuck. The robot arm (310) may be provided on the main body of the wafer transfer module (300) fixed within the wafer defect inspection system, and may be provided to move up and down and / or move left and right and forward and backward within the stroke area on the main body of the wafer transfer module.

[0060] The wafer edge region inspection module (400) above may be provided as a device for inspecting defects such as cracks, defects, or damage in the edge region of a wafer (1) and for inspecting the edge region of a wafer for aligning notches.

[0061] The wafer defect measurement module (100) may include a defect detection module (110) that detects the type of defect, the size of the defect, and the defect image of the wafer (1), and a defect depth detection module (120) that detects the depth of the defect detected through the defect detection module (110).

[0062] Additionally, the wafer defect measurement module (100) may include a main body and a gantry as a structure for installing measurement modules, such as a line scan camera and a review camera, on the main body. The main body may be provided, for example, as an aluminum plate. A bracket for a line camera, on which a line scan camera for detecting defects in the wafer (1) can be mounted, may be attached to the upper plate of the gantry. Additionally, a bracket for a depth camera, on which a depth detection camera can be mounted, may be attached to the outside of the bracket for the line camera. Furthermore, a bracket for fixing the bracket for the line camera and the bracket for the depth camera from the outside may be included.

[0063] Meanwhile, the wafer defect measurement module (100) may be provided with a light source module for irradiating light to measure defects on a wafer (1) mounted on a wafer stage. The light source module may be provided at the bottom of the wafer stage and may apply NIR (near-infrared) wavelength transmission illumination between 750 nm and 2500 nm to inspect internal defects of the wafer (1), and may include a light guide capable of controlling the light source, light source brightness, and angle.

[0064] Next, a wafer position alignment device according to the present invention will be described with reference to FIGS. 2 and FIGS. 3.

[0065] FIG. 2 is a block diagram of a wafer position alignment device according to the present invention, and FIG. 3 is a perspective view of a wafer stage including a push module shown in FIG. 2.

[0066] A wafer position alignment device according to the present invention may include a judgment module (500), a push module (600), a driving module (700), a sensing module (800), and a control module (900) as shown in FIG. 2.

[0067] Meanwhile, the wafer defect measurement module (100) may include a wafer stage for wafer defect inspection, and the wafer stage may be provided in the main body. As shown in FIG. 3, the wafer stage may include a main table (30) and / or a sub table (40), a mask plate (50), and a plurality of wafer supports (60), and the push module (600) may be provided on the sub table (40).

[0068] The main table (30) is configured to be movable along the Y-axis by a driving member on the upper part of the main body, and the sub table (40) can be configured to be movable along the X-axis by the driving member on the upper part of the main table (30). The driving member may be provided, for example, as a linear servo, an LM guide, a servo actuator, etc.

[0069] The mask plate (50) is provided on the sub-table (40) as shown in FIG. 3, and can be formed in a roughly circular shape as shown in FIG. 4 to block light that may be applied from the outside of the wafer (1) during inspection of the wafer. In addition, an opening (51) corresponding to the wafer (1) is provided in the central part of the mask plate (50) and can be provided corresponding to the outer circumference of the wafer (1). FIG. 4 is a perspective view showing the configuration of the mask plate shown in FIG. 3.

[0070] In addition, since the inner diameter of the mask plate (50) is provided to be approximately the same size as the outer diameter of the wafer, the mask plate (50) does not come into contact with the wafer (1) during inspection, but can be provided as close as possible to the wafer.

[0071] Additionally, as shown in FIG. 4, a first groove (53) and a second groove (54) may be provided on the periphery portion of the mask plate (50) to avoid contact with a plurality of wafer supports (60) and a push module (600). As shown in FIG. 3 and FIG. 4, the first groove (53) and the second groove (54) are provided adjacent to each other in correspondence with the wafer supports (60) and the push module (600), and may be provided at three locations at an angle of approximately 120 degrees. That is, a plurality of wafer supports (60) and a push module (600) that support the wafer (1) along the periphery portion of the mask plate (50) may be mounted on the sub-table (40). FIG. 3 shows a structure in which three wafer supports (60) and push modules (600) are provided at 120-degree intervals, but this is not limited thereto and may be provided in four or more.

[0072] Meanwhile, as shown in FIG. 4, the mask plate (50) may be provided to be movable in the vertical direction (Z-axis direction) on the sub-table (40) by means of a lifting member (52) equipped with an up-down cylinder that can be operated by pneumatic or hydraulic pressure. Accordingly, the mask plate (50) may be provided to be movable in the vertical direction inside a plurality of wafer supports (60) to block light irradiated to the edge area of ​​the wafer, etc., during the defect inspection process of the wafer (1). To this end, a cutout portion for the movable of the mask plate (50) may be provided inside the wafer supports (60).

[0073] Additionally, as shown in FIG. 4, an LM guide member (56) for adjusting the centering position of the mask may be provided on the sub-table (40) on the side facing the lifting member (52) of the mask plate (50). The LM guide member (56) may be provided with a rail so that the mask plate (50) moves in a straight reciprocating motion along the rail. The LM guide member (56) may also function as a compensation member to maintain the horizontal state of the mask plate (50) by compensating for positional deviations occurring in the mask plate (50) according to the up-and-down movement of the lifting member (52).

[0074] Additionally, a display cover may be provided on the upper part of the mask plate (50) to cover a display portion (e.g., a notch portion, a flat zone portion) provided on the wafer (1) and to block light emitted from a light source module provided on the lower part of the main body from leaking. The display cover may be provided with a shape corresponding to the notch portion or flat zone portion provided on the wafer, for example, with a front surface in the shape of a triangle, so as to protrude toward the opening (51) of the mask plate (50) in order to cover the notch portion or flat zone portion provided on the wafer.

[0075] As described above, the mask plate (50) is positioned close to the wafer (1), and since the inner diameter of the mask plate (50) is provided to be approximately the same size as the outer diameter of the wafer (1), light irradiated from the light source module provided at the bottom of the main body is prevented from being irradiated to a part outside the wafer (1) area, thereby enabling precise wafer defect measurement in the wafer defect measurement module (100). That is, as shown in FIG. 5, the center point of the wafer (1) and the center point of the mask are aligned by the push module (600) and the LM guide member (56), and since the inner diameter of the mask plate (50) is provided to be approximately the same size as the outer diameter of the wafer (1), the light irradiated from the light source module is blocked from being irradiated to the edge area of ​​the wafer (1) and directly exposed to the camera of the defect measurement module (100), thereby increasing the precision of wafer defect measurement. FIG. 5 is a drawing showing the state in which the wafer is positioned on the mask plate shown in FIG. 3.

[0076] As shown in FIG. 3, the plurality of wafer supports (60) are provided on the sub-table (40) as a first wafer support, a second wafer support, and a third wafer support, and are arranged isogonally along the periphery of the mask plate (50) to support the wafer of the wafer stage. Meanwhile, although FIG. 3 shows a structure in which three wafer supports (60) are provided, it is not limited thereto and may be provided in four or more.

[0077] As shown in FIG. 6, the wafer support (60) may include a mounting portion (61) on which the wafer (1) is placed, and a support (62) for maintaining the mounting portion (61) on the sub-table (40). FIG. 6 is a perspective view showing the structure of the wafer support shown in FIG. 3.

[0078] As shown in FIG. 6, the above-mentioned mounting portion (61) may be formed in a shape approximately like an 'L' when the end is shown planarly from the side to support the wafer (1), and may be formed inclined from the upper side to the lower side to facilitate mounting of the wafer (1). The tip of the above-mentioned mounting portion (61) does not come into contact with the surface of the wafer (1), but can support the wafer from the bottom. Additionally, the tip of the above-mentioned mounting portion (611) may be formed as a curved surface to allow the wafer (1) to move.

[0079] Meanwhile, the judgment module (500) can determine the state in which the wafer (1) transported by the robot arm (310) is placed on the first wafer support, the second wafer support, and the third wafer support provided on the sub-table (40) of the wafer defect measurement module (100), as shown in FIGS. 1 and 5. Such judgment in the judgment module (500) can be determined according to the transport path of the robot arm (310).

[0080] The push module (600) can push and clamp the wafer (1) mounted on the plurality of wafer supports (60) according to the judgment state of the judgment module (500). The push module (600) is provided in multiple units corresponding to the plurality of wafer supports (60) so that a uniform action can be applied to the outer periphery of the wafer (1), thereby enabling adjustment of the center point of the wafer (1). That is, as shown in FIG. 3, the push module (600) can be provided as a first push module (610), a second push module (620), and a third push module (630) corresponding to the first wafer support, the second wafer support, and the third wafer support, and can be arranged isogonally along the periphery of the mask plate (50). In the wafer position alignment device according to the present invention, as shown in FIG. 3, the first push module (610), the second push module (620), and the third push module (630) are arranged at equal angles, and the wafer (1) seated on the wafer support (60) is pushed simultaneously from three directions, so the center point of the wafer (1) can be maintained at a constant level.

[0081] As shown in FIG. 7, the push module (600) may include a pusher (601) for pushing and clamping the wafer, a pusher bracket (602) coupled to the pusher (601), a distance adjustment shaft (603) of the pusher (601), a moving member (604) for moving the pusher bracket (602) in a horizontal linear direction, a push holding member (605) provided on the sub-table (40) and for holding the moving member (604) on the sub-table (40), a cylinder rod (606) connected to the moving member (604), and a connecting bracket (607) coupled to the pusher bracket (602) and the cylinder rod (606).

[0082] The above pusher (601) is a part that comes into direct contact with the wafer (1), and may be provided in the form of a pair of arms branched vertically to prevent the wafer from coming out of the pusher (601) when the wafer (1) is pushed by the operation of the moving member (604). In addition, the end of the pusher (601) may be provided with a V-shaped or C-shaped guide (V-shape / C-shape guide) in a shape corresponding to the wafer edge, as shown in FIG. 7, to clamp the wafer.

[0083] Additionally, the pusher (601) may be made of an anti-static (ESD-safe) material to prevent wafer damage and contamination. That is, the pusher (601) may be primarily an engineering plastic with anti-static properties, such as PEEK (Polyether Ether Ketone), Delrin, or specially coated ceramic, to clamp the wafer. As described above, since the pushers (601) provided in the first push module (610), the second push module (620), and the third push module (630) respectively clamp the wafer simultaneously, the wafer can be stably maintained during wafer inspection.

[0084] As shown in FIG. 7, the pusher bracket (602) is coupled to the connecting bracket (607) on the side of the moving member (604), and a distance adjustment shaft (603) is provided at the tip of the pusher bracket (602), and the pusher (601) can be coupled to the tip of the distance adjustment shaft (603). That is, the pusher (601), the pusher bracket (602), and the distance adjustment shaft (603) can be provided as an integrated unit.

[0085] The moving member (604) is provided to move the pusher bracket (602) in a straight line in a horizontal direction by a preset distance. As shown in FIG. 7, the moving member (604) may be a pneumatic cylinder or a hydraulic cylinder having a plurality of cylinder tubes. The moving member (604) can freely change the stroke of the pusher (601) down to 0.01 mm by simply inputting a value in the software. However, it is not limited to this and may be configured as an electric cylinder including a ball screw mechanism for precise position control as needed.

[0086] The above push holding member (605) is provided on a sub-table (40) at the outer circumference of the vertically moving mask plate (50) and can hold the moving member (603).

[0087] The cylinder rod (606) is provided to move back and forth at the front end of the moving member (604), and the connecting bracket (607) is provided in a roughly "L" shape as shown in FIG. 7, so that the cylinder rod (606) is mounted inside the front and can be integrally coupled with the pusher bracket (602) on the side. As described above, by coupling the pusher bracket (602) to the side of the connecting bracket (607), the height of the pusher (601) can be aligned with the position of the seating portion (61).

[0088] As described above, by providing a push module (600), the pusher (601) can move in a forward and backward direction relative to the edge of the wafer (1) to maintain the center point of the wafer (1) constant and clamp the wafer.

[0089] The above drive module (700) is equipped with a hydraulic fluid tank, a hydraulic pump, a hydraulic motor, etc., and can supply hydraulic fluid to the moving member (603) and / or lifting member (52), LM guide member (56), etc. at regular intervals.

[0090] The above detection module (800) may include a detection camera mounted on a gantry, and the detection camera may capture the state of a wafer (1) placed on a plurality of wafer supports (60) as shown in FIG. 5 or the state of a wafer (1) clamped by a pusher (601) provided in each of the first push module (610), second push module (620), and third push module (630).

[0091] The control module (900) may include a microprocessor, memory, etc., and when the judgment module (500) determines that the wafer (1) transported by the robot arm (310) is seated on the wafer support (60), the driving module (700) may be operated to control the push module (600) to push and clamp the wafer (1) so that the center point of the wafer and the center point of the mask coincide. In addition, the control module (900) may control the lifting member (52) and the LM guide member (56) to control the lifting of the mask plate (50) and the centering position of the mask. Additionally, the control module (900) may set the initial position of the pusher (601) by controlling the moving member (604) so ​​that the position of the pusher (601) maintains the same spacing from the mask plate (50), even if the first push module (610), the second push module (620), and the third push module (630) are mounted at different positions on the sub-table (40), that is, at different intervals from the mask plate (50). Thus, a margin of error can be secured regarding the mounting positions of the first push module (610), the second push module (620), and the third push module (630) on the sub-table (40).

[0092] Meanwhile, although the above description describes a structure in which the push module (600) is driven when the judgment module (500) determines that the wafer (1) is seated on the wafer support (60), it is not limited to this, and a structure in which the push module (600) is driven according to the detection result of the detection module (800) may be applied to prevent repetitive operation of the push module (600).

[0093] That is, when the judgment module (500) determines that the wafer (1) transported by the robot arm (310) is placed on the wafer support (60), the detection module (800) detects whether the wafer (1) is placed in a normal position, and when the control module (900) determines that it is placed in a normal position, the driving module (700) can be stopped and the defect detection module (110) can be controlled to proceed with defect detection of the wafer.

[0094] Additionally, if the control module (900) determines that the wafer (1) is placed in an abnormal position based on the detection result from the detection module (800), the control module (900) can operate the driving module (700) to control the push module (600) to push and clamp the wafer (1).

[0096] Next, a wafer position alignment process according to the present invention will be described with reference to FIGS. 8 to 10. FIGS. 8 to 10 are drawings for explaining the operating state of a wafer position alignment device according to the present invention.

[0097] A wafer (1) transported by a robot arm (310) is placed on the wafer support (60), and the mask plate (50) is raised by a lifting member (52). Although the wafer (1) is placed on the wafer support (60), as shown in FIG. 8, it may be placed abnormally so that the opening (51) in the mask plate (50) is exposed.

[0098] When the detection module (800) detects the seating state of the wafer (1) as shown in FIG. 8, and the control module (900) determines that the wafer (1) is seated in an abnormal position, the control module (900) can operate the driving module (700) to control the first push module (610), the second push module (620), and the third push module (630) to push the wafer (1) as indicated by the arrow in FIG. 9.

[0099] That is, by operating the respective moving members (604) of the first push module (610), the second push module (620), and the third push module (630) simultaneously, the respective cylinder rods (606) advance, and accordingly, the connecting bracket (607) and the pusher bracket (602) advance and the pusher (601) advance, thereby pushing the wafer (1) to clamp the wafer (1), and by the control module (900) controlling the LM guide member (56) to adjust the centering position of the mask, the center point of the wafer and the center point of the mask can be arranged to coincide.

[0100] If the judgment module (500) determines that the center point of the wafer and the center point of the mask coincide as shown in FIG. 9, the wafer defect measurement module (100) can perform a defect inspection on the wafer (1) while the wafer (1) is clamped.

[0101] When the inspection of the wafer (1) as described above is completed, the control module (900) can control the drive module (700) to simultaneously release the clamping by the first push module (610), the second push module (620), and the third push module (630) as shown in FIG. 10, thereby keeping the pusher (601) in a retracted state. Additionally, as the pusher (601) retracts, the mask plate (50) can also be lowered. As described above, by the retraction of the pusher (601), the wafer (1) can be placed on a plurality of wafer supports (60).

[0102] Next, the robot arm (310) can automatically repeat the process described above by withdrawing the inspected wafer (1) and placing the wafer to be inspected.

[0103] Meanwhile, in the case where a single push module (600') is provided as a comparative example shown in FIG. 11, if the push module (600') pushes the wafer (1) as indicated by the arrow, it may be difficult to fine-tune the force because the direction of force application is limited. FIG. 11 is a drawing for explaining a comparative example of the mounting state and operation of a push module.

[0104] That is, as illustrated in FIG. 11, the wafer (1) pushed by the single push module (600') located at the 11 o'clock position is subjected to point contact and surface contact by the second wafer support and the third wafer support located in the opposite direction acting as a support, so the opening (51) is exposed and the wafer position alignment may be performed inaccurately. Therefore, an additional wafer centering process is required. In addition, the cylinder applied to the push module (600') as illustrated in FIG. 11 is of the air slide type, and there was a cumbersome problem in that the length of the cylinder's movement could only be adjusted through physical manipulation.

[0105] In the wafer position alignment device and wafer position alignment method according to the present invention, as shown in FIG. 8, a plurality of wafer supports (60) arranged in an equal position and a first push module (610), a second push module (620), and a third push module (630) are arranged on the side of each wafer support (60). Therefore, when the first push module (610), the second push module (620), and the third push module (630) push the wafer (1) as indicated by the arrow in FIG. 9, the wafer centering can be accurately performed and clamped by the pusher operation in the equal position configuration.

[0106] As described above, in the wafer position alignment device according to the present invention, as shown in FIG. 10, the center of the wafer (1) placed on the wafer stage can be aligned to increase positional precision during wafer defect inspection. When the positional precision of the wafer is improved, the advantages of maximizing inspection accuracy and reliability, increasing inspection speed and throughput, and facilitating process control and yield management can be obtained.

[0107] In addition, although the wear rate of the PEEK of the wafer support (60) and the pusher (601) of the push module (600) may differ, the advantage of being able to reduce maintenance costs and time by replacing only the specific parts that are worn out can also be obtained.

[0109] Although the invention made by the inventors has been specifically described according to the above embodiments, the present invention is not limited to the above embodiments and can be modified in various ways without departing from the gist thereof. Industrial applicability

[0111] By using the wafer position alignment device and wafer position alignment method according to the present invention, the alignment of the center point of a wafer and the center point of a mask for various types of wafers can be easily realized.

[0112] No content Explanation of the symbols

[0113] 500 : Judgment Module 600 : Push Module 700: Drive module 800: Detection module 900: Control Module

Claims

Claim 1 A wafer position alignment device comprising: a judgment module for determining the seating state of a wafer seated on a plurality of wafer supports on a wafer stage equipped with a mask plate; a plurality of push modules for pushing and clamping the wafer to align the center point of the wafer with the center point of the mask according to the judgment state of the judgment module; a driving module for driving each of the plurality of push modules; and a control module for controlling the operation of the driving module, wherein the plurality of push modules are adjacent to each of the plurality of wafer supports and are equiangularly arranged with respect to the center of the mask plate. Claim 2 A wafer position alignment device according to claim 1, wherein the plurality of push modules are provided as a first push module, a second push module, and a third push module, and simultaneously pushes a wafer mounted on the wafer support in the direction of the center of the mask plate. Claim 3 A wafer position alignment device according to claim 2, wherein each of the first push module, second push module, and third push module comprises a pusher for pushing and clamping the wafer, a pusher bracket coupled to the pusher, a moving member for moving the pusher bracket in a horizontal linear direction, a cylinder rod connected to the moving member, and a connecting bracket coupled to the pusher bracket and the cylinder rod. Claim 4 A wafer position alignment device according to claim 3, characterized in that each pusher position provided in the first push module, the second push module, and the third push module is mounted to maintain an equal spacing from the mask plate. Claim 5 A wafer position alignment device characterized in that, in paragraph 4, the cylinder rod is provided to move back and forth at the leading end of the moving member, and the connecting bracket is provided in an "L" shape so that the cylinder rod is mounted inside the front and the pusher bracket is integrally coupled to the side. Claim 6 A wafer position alignment device according to claim 5, wherein the pusher is provided as a V-shape or C-shape guide (V-shape / C-shape guide) in a shape corresponding to the edge of the wafer and is made of PEEK (Polyether Ether Ketone) to clamp the wafer. Claim 7 A wafer position alignment device according to claim 5, wherein the moving member comprises a pneumatic cylinder or a hydraulic cylinder. Claim 8 A wafer position alignment device characterized in that, in claim 5, the moving member includes a ball screw member. Claim 9 A wafer position alignment device according to claim 1, further comprising a sensing module for detecting the seating state of the wafer, wherein the control module controls the operation of the driving module according to the detection result of the sensing module. Claim 10 A wafer position alignment device according to claim 1, characterized in that a first groove and a second groove are provided in the periphery portion of the mask plate to avoid contact with the plurality of wafer supports and the plurality of push modules. Claim 11 A wafer position alignment device according to claim 10, further comprising a lifting member for raising and lowering the mask plate and an LM guide member for adjusting the centering position of the mask on the mask plate. Claim 12 A method for aligning the position of a wafer placed on a plurality of wafer supports on a wafer stage equipped with a mask plate, comprising: (a) a step of placing a wafer transported by a robot arm onto the plurality of wafer supports and raising the mask plate; (b) a step in which a first push module, a second push module, and a third push module push and clamp the wafer placed in step (a); (c) a step in which a wafer defect measurement module performs a defect inspection on the wafer clamped in step (b); (d) a step in which, when the inspection in step (c) is completed, the first push module, the second push module, and the third push module release the clamping and lower the mask plate; and (e) a step in which the wafer inspected in step (c) is retrieved by the robot arm. Claim 13 A wafer position alignment method according to claim 12, wherein in step (b), the first push module, the second push module, and the third push module simultaneously push the wafer seated on the wafer support toward the center of the mask plate. Claim 14 A wafer position alignment method according to claim 12, wherein the first push module, the second push module, and the third push module are adjacent to each of the plurality of wafer supports and are equiangularly arranged with respect to the center of the mask plate. Claim 15 In paragraph 12, each pusher position provided in the first push module, the second push module, and the third push module executes a push while maintaining the same spacing from the mask plate. A wafer position alignment method characterized by the following. Claim 16 A wafer position alignment method according to claim 15, wherein the pusher is provided as a V-shape or C-shape guide (V-shape / C-shape guide) in a shape corresponding to the edge of the wafer and is made of PEEK (Polyether Ether Ketone) to clamp the wafer. Claim 17 A wafer position alignment method according to claim 12, wherein step (b) is executed by a sensing module detecting the seating state of the wafer, and a control module controls the operation of a driving module according to the detection result of the sensing module.

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