Apparatus for predicting wafer deformation

Abstract

An apparatus for predicting wafer deformation includes a conveying unit that conveys a wafer, a sensor unit that identifies a plurality of edge points of the wafer conveyed by the conveying unit, and a control unit that projects positions of the plurality of edge points of the wafer identified by the sensor unit onto a coordinate plane and predicts a planar shape of the wafer based on the positions of the plurality of edge points of the wafer projected onto the coordinate plane.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2025-0014031, filed with the Korean Intellectual Property Office on February 4, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to an apparatus for predicting wafer deformation. Background Technology

[0004] During the semiconductor chip manufacturing process, wafers may undergo deformations such as bending and warping (warping) due to factors such as temperature differences. When moving wafers to a warping measurement device to measure their warping, the time required for wafer movement, input, alignment, and measurement is significant, potentially leading to decreased production efficiency. To minimize this efficiency loss, a method of measuring the warping of only a few wafers could be considered. However, in this case, it may not be possible to perfectly detect wafer deformation caused by warping, and the wafers may break as a result. If broken wafers contaminate the internal components of the equipment, it can significantly impact production efficiency due to production interruptions. Summary of the Invention

[0005] On the one hand, this disclosure attempts to provide an apparatus for predicting wafer deformation, which is capable of predicting wafer deformation without increasing time and cost due to additional processes.

[0006] On the other hand, this disclosure attempts to provide an apparatus for predicting wafer deformation, which can predict the deformation of all wafers and selectively feed only undeformed wafers into the process.

[0007] On the other hand, this disclosure attempts to provide a device for predicting wafer deformation that can prevent wafer breakage and the resulting device contamination.

[0008] As one embodiment, this disclosure provides an apparatus for predicting wafer deformation, comprising: a transfer unit for transferring the wafer; a sensor unit for identifying multiple edge points of the wafer transferred by the transfer unit; and a control unit for projecting the positions of the multiple edge points of the wafer identified by the sensor unit onto a coordinate plane, and predicting the planar shape of the wafer based on the positions of the multiple edge points of the wafer projected onto the coordinate plane.

[0009] As another embodiment, this disclosure provides an apparatus for predicting wafer deformation, comprising: a transfer unit for transferring a wafer to a process chamber and returning a wafer exiting the process chamber; a sensor unit for identifying a plurality of process front edge points of the wafer during wafer transfer via the transfer unit and for identifying a plurality of process back edge points of the wafer during wafer return via the transfer unit; and a control unit for projecting the positions of the plurality of process front edge points of the wafer identified by the sensor unit onto a coordinate plane and predicting a process front plane shape of the wafer based on the positions of the plurality of process front edge points of the wafer projected onto the coordinate plane, and projecting the positions of the plurality of process back edge points of the wafer identified by the sensor unit onto the coordinate plane and predicting a process back plane shape of the wafer based on the positions of the plurality of process back edge points of the wafer projected onto the coordinate plane.

[0010] As another embodiment, this disclosure provides an apparatus for predicting wafer deformation, comprising: a transfer unit for moving a wafer in a first direction, moving the wafer in a second direction opposite to the first direction, and then transferring the wafer in the first direction; a sensor unit for identifying a plurality of first edge points of the wafer during movement of the wafer in the first direction via the transfer unit, and identifying a plurality of second edge points of the wafer during movement of the wafer in the second direction via the transfer unit; and a control unit for projecting the positions of the plurality of first edge points and the plurality of second edge points of the wafer identified by the sensor unit onto a coordinate plane, and predicting a planar morphology of the wafer based on the positions of the plurality of first edge points and the plurality of second edge points of the wafer projected onto the coordinate plane; wherein the wafer passes the sensor unit during movement of the wafer in the first direction via the transfer unit and during movement of the wafer in the second direction via the transfer unit.

[0011] As another embodiment, this disclosure provides a method for predicting wafer deformation, including: a step of passing the wafer through a sensor unit; a step of projecting the positions of a plurality of edge points of the wafer identified by the sensor unit onto a coordinate plane; and a step of predicting the planar morphology of the wafer based on the positions of the plurality of edge points of the wafer projected onto the coordinate plane.

[0012] According to one aspect of this disclosure, an apparatus for predicting wafer deformation can be provided, which is capable of predicting wafer deformation without increasing time and cost due to additional processes.

[0013] According to another aspect of this disclosure, an apparatus for predicting wafer deformation can be provided, which can predict the deformation of all wafers and selectively feed only undeformed wafers into the process.

[0014] According to another aspect of this disclosure, an apparatus for predicting wafer deformation can be provided, which can prevent wafer breakage and the resulting equipment contamination. Attached Figure Description

[0015] Figure 1 , Figure 2 and Figure 3 An operational example of a device for predicting wafer deformation according to an embodiment is shown.

[0016] Figure 4 and Figure 5 The location of the edge point of the wafer projected onto the coordinate plane is shown.

[0017] Figure 6 The predicted planar morphology of the wafer and the derived exemplary characteristic values ​​are shown.

[0018] Figure 7 and Figure 8 A method for identifying edge points of a wafer using a sensor unit, according to an embodiment, is shown.

[0019] Figure 9 An exemplary shape of the wafer and its projection surface is shown.

[0020] Figure 10 This is a graph illustrating an exemplary method for predicting wafer deformation using a device for predicting wafer deformation, according to an embodiment.

[0021] Figure 11 , Figure 12 , Figure 13 and Figure 14 An example of using a device for predicting wafer deformation is shown according to an embodiment.

[0022] Figure 15 and Figure 16 An example of using a device for predicting wafer deformation is shown according to an embodiment.

[0023] Figure 17 This is a flowchart of a method for predicting wafer deformation using a device for predicting wafer deformation, according to an embodiment. Detailed Implementation

[0024] This disclosure will be described more fully below with reference to the accompanying drawings, in which exemplary embodiments of the disclosure are illustrated. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this disclosure.

[0025] The accompanying drawings and descriptions are to be considered illustrative in nature, not restrictive. Similar reference numerals denote similar elements throughout the specification.

[0026] Furthermore, since the dimensions and thicknesses of the constituent components shown in the accompanying drawings are arbitrarily given for better understanding and ease of description, this disclosure is not limited to the dimensions and thicknesses shown.

[0027] In addition, unless explicitly stated to the contrary, the words “comprising” and “including” will be understood to mean that the said element is included, but not that any other element is excluded.

[0028] Furthermore, throughout the instruction manual, the phrase "in a plan view" refers to the view of a portion of the object when viewed from above, and the phrase "in a cross-sectional view" refers to the view of a section taken by vertically cutting the portion of the object when viewed from the side.

[0029] Furthermore, throughout the specification, sequential numbering such as first and second is used to distinguish a component from another component that is the same as or similar to that component, and is not necessarily intended to refer to a specific component. Accordingly, a component referred to as the first component in one part of the specification may be referred to as the second component in another part of the specification.

[0030] Furthermore, throughout the specification, unless otherwise expressly stated, a singular reference to a component also includes references to multiple such components.

[0031] Hereinafter, an apparatus for predicting wafer deformation according to embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0032] Figure 1 , Figure 2 and Figure 3 An operational example of a device for predicting wafer deformation according to an embodiment is shown.

[0033] Figure 4 and Figure 5 The location of the edge point of the wafer projected onto the coordinate plane is shown.

[0034] Figure 6 The predicted planar morphology of the wafer and the derived exemplary characteristic values ​​are shown.

[0035] Figure 7 and Figure 8 A method for identifying edge points of a wafer using a sensor unit, according to an embodiment, is shown.

[0036] The device 100 for predicting wafer deformation according to the embodiment can predict the deformation of wafer 10. For example, the device 100 for predicting wafer deformation can predict whether wafer 10 is deformed, its deformed shape, characteristic values, etc.

[0037] According to an embodiment, a device 100 for predicting wafer deformation includes a transfer unit 110, a sensor unit 120, and a control unit 130.

[0038] The transfer unit 110 transfers the wafer 10, and the wafer 10 may pass through the sensor unit 120 during the transfer. Additionally, the transfer unit 110 may transfer the wafer 10, which has already passed through the sensor unit 120, to a process chamber and return the wafer 10 that has already been transferred from the process chamber. The transfer unit 110 may directly transfer the wafer 10 to and from the process chamber, or it may transfer the wafer 10 to and from the process chamber via another component (e.g., another chamber).

[0039] The transfer unit 110 can be located in at least one of the following positions: between the Equipment Front End Module (EFEM) and the load lock, between the load lock and the transfer module, and between the transfer module and the process chamber. The EFEM can be used to load and align the wafer 10. The load lock can be used to change or regulate the pressure between the EFEM and the transfer module to a vacuum. The transfer module can be used to transfer the wafer 10 to the process chamber, transfer the wafer 10 between process chambers, and return the processed wafer 10 to the load lock. In the process chamber, the processes required for the wafer 10 are performed, and the process chamber can be a chamber in which the wafer 10 is significantly deformed (warped) due to temperature changes within the process chamber, temperature changes between process chambers, etc.

[0040] The transfer unit 110 may include a robotic arm. However, the transfer unit 110 may include other transfer devices (e.g., a track).

[0041] Sensor unit 120 can identify multiple edge points a1, a2, a3, a4 of wafer 10. Sensor unit 120 can identify at least three edge points of wafer 10 to predict the planar morphology of wafer 10. In this disclosure, the term "form" is used to refer to both shape and size.

[0042] Sensor unit 120 may be placed on the path of moving wafer 10 via transfer unit 110. Similar to transfer unit 110, sensor unit 120 may be placed in at least one of the following locations: between device front-end module (EFEM) and loading transition chamber, between loading transition chamber and transfer module, and between transfer module and process chamber.

[0043] In one embodiment, the position of the sensor unit 120 may be fixed, and the sensor unit 120 may identify the edge points of the wafer 10 that has been moved by the transfer unit 110 and passed through the sensor unit 120. However, the sensor unit 120 may also identify the edge points of the wafer 10 by moving the wafer 10, whose position is fixed, through the sensor unit 120.

[0044] In an embodiment, sensor unit 120 may include a first sensor unit 120A and a second sensor unit 120B spaced apart in a direction intersecting the transport direction Y of wafer 10 (e.g., in the X direction perpendicular to the Y direction). The first sensor unit 120A can identify a first edge point a1 and a fourth edge point a4 of wafer 10 that pass through the first sensor unit 120A and are spaced apart in the Y direction. The second sensor unit 120B can identify a second edge point a2 and a third edge point a3 of wafer 10 that pass through the second sensor unit 120B and are spaced apart in the Y direction. A first virtual line VL1 connecting the first edge point a1 and the fourth edge point a4 and a second virtual line VL2 connecting the second edge point a2 and the third edge point a3 can each extend in the Y direction. The first virtual line VL1 and the second virtual line VL2 can be spaced apart in the X direction and can be parallel. Since the positions of the first sensor unit 120A and the second sensor unit 120B are fixed, the spacing between the first virtual line VL1 and the second virtual line VL2 can also be fixed.

[0045] refer to Figure 7 and Figure 8 The sensor unit 120 may include a light emitter 121 for emitting light and a light receiver 122 for receiving light emitted from the light emitter 121. The sensor unit 120 can identify multiple edge points a1, a2, a3, a4 of the chip 10 based on whether the light receiver 122 receives light. Whether the light receiver 122 receives light depends on the presence of the chip 10 between the light emitter 121 and the light receiver 122. When the chip 10 is not present between the light emitter 121 and the light receiver 122, the light receiver 122 can receive light emitted from the light emitter 121 (see [link to relevant documentation]). Figure 7 When chip 10 is present between light emitter 121 and light receiver 122, light receiver 122 may not be able to receive light emitted from light emitter 121 (see [link]). Figure 8 The sensor unit 120 can output a digital signal value indicating whether the light receiver 122 has received light. For example, when the light receiver 122 receives light emitted from the light transmitter 121, the sensor unit 120 can output a digital signal value of 1, and when the light receiver 122 does not receive light, the sensor unit 120 can output a digital signal value of 0.

[0046] However, the sensor unit 120 may consist of another type of sensor capable of identifying edge points a1, a2, a3, a4 of the wafer 10. Alternatively, the sensor unit 120 may be configured to identify the positions of edge points a1, a2, a3, a4 of the wafer 10.

[0047] The control unit 130 can receive signals output by the sensor unit 120. The control unit 130 projects the positions of multiple edge points a1, a2, a3, a4 of the wafer 10 identified by the sensor unit 120 onto the coordinate plane, and can predict the planar shape of the wafer 10 based on the projected positions of the multiple edge points a1, a2, a3, a4 of the wafer 10.

[0048] In an embodiment, the control unit 130 can project the positions of multiple edge points a1, a2, a3, a4 of the wafer 10 onto a coordinate plane within the control unit 130 using data including at least one of the moving speed and trajectory of the wafer 10, and the time point at which the sensor unit 120 identifies each of the edge points a1, a2, a3, a4 of the wafer 10. The time point at which the sensor unit 120 identifies the edge points a1, a2, a3, a4 of the wafer 10 can correspond to the time point at which the sensor unit 120 outputs a signal (e.g., a digital signal value of 0 or 1). For example, when the wafer 10 moves linearly along the Y direction, the control unit 130 can project the positions of multiple edge points a1, a2, a3, a4 of the wafer 10 onto the coordinate plane using the output time of each signal output by the sensor unit 120 and the moving speed of the wafer 10. For another example, when the wafer 10 is not moving linearly, the control unit 130 can use the output time of each signal output by the sensor unit 120, as well as the moving speed and trajectory of the wafer 10, to project the positions of multiple edge points a1, a2, a3, a4 of the wafer 10 onto the coordinate plane.

[0049] In an embodiment, the control unit 130 can predict the planar shape of the wafer 10 based on the positions of multiple edge points a1, a2, a3, a4 of the wafer 10 using circular interpolation. For example, the control unit 130 can predict the planar shape of the wafer 10 based on the positions of three or four (e.g., in the case of an isotropic circular wafer) edge points a1, a2, a3, a4 of the wafer 10 using circular interpolation.

[0050] In an embodiment, the control unit 130 can predict the planar shape of the wafer 10 based on the positions of multiple edge points a1, a2, a3, a4 of the wafer 10 through closed-loop interpolation. For example, the control unit 130 can predict the planar shape of the wafer 10 based on the positions of four or more edge points a1, a2, a3, a4 of the wafer 10 through closed-loop interpolation.

[0051] Furthermore, the control unit 130 can extract feature values ​​of the wafer 10 from the predicted planar morphology of the wafer 10. For example, the control unit 130 can derive the radius of the wafer 10 from the predicted planar morphology of the wafer 10 through circular interpolation. Alternatively, the control unit 130 can derive at least one of the major axis length and minor axis length of the wafer 10 from the predicted planar morphology of the wafer 10 through closed-loop interpolation.

[0052] In cases where height data at each point of the wafer 10 can be additionally input into the control unit 130, the control unit 130 can also predict the three-dimensional shape of the wafer 10 by combining the height data at each point of the wafer 10 with the predicted planar shape.

[0053] Optionally, the control unit 130 may also perform an additional function of aligning the wafer 10 based on the positions of multiple edge points a1, a2, a3, a4 of the wafer 10. That is, the control unit 130 may predict the deformation of the wafer 10 based on the positions of multiple edge points a1, a2, a3, a4 of the wafer 10, and simultaneously perform the alignment of the wafer 10.

[0054] The following is a step-by-step description of an operational example of the apparatus 100 used to predict wafer deformation during the transport of wafer 10. First, refer to... Figure 1 and Figure 2 The wafer 10 is transported by the transmission unit 110, and the first edge point a1 passes through the first sensor unit 120A, while the second edge point a2 passes through the second sensor unit 120B. The control unit 130 projects the positions of the first edge point a1 and the second edge point a2 onto the coordinate plane (see...). Figure 4 For example, the control unit 130 can set the first edge point a1 as a reference point (in the figures, the position of the reference point is depicted as different from the origin), set the X coordinate (coordinate in the X direction) of the second edge point a2 by a fixed interval between the first virtual line VL1 and the second virtual line VL2 (which may correspond to the interval between the light emitted from the first sensor unit 120A and the second sensor unit 120B), and set the Y coordinate (coordinate in the Y direction) of the second edge point a2 by the output time of the digital signal value 0 of each of the first sensor unit 120A and the second sensor unit 120B and the moving speed of the wafer 10. Next, the reference... Figure 3 The third edge point a3 of the wafer 10 passes through the second sensor unit 120B, and the fourth edge point a4 passes through the first sensor unit 120A. The control unit 130 projects the positions of the third edge point a3 and the fourth edge point a4 onto the coordinate plane (see...). Figure 5For example, the control unit 130 can set the X-coordinate of the third edge point a3 to be the same as that of the second edge point a2, and set the Y-coordinate of the third edge point a3 by using the duration of the digital signal value 0 of the second sensor unit 120B (the time taken for the second sensor unit 120B to output the digital signal value 0 and then output the digital signal value 1 again) and the moving speed of the wafer 10. Additionally, the control unit 130 can set the X-coordinate of the fourth edge point a4 to be the same as that of the first edge point a1, and set the Y-coordinate of the fourth edge point a4 by using the duration of the digital signal value 0 of the first sensor unit 120A and the moving speed of the wafer 10. Next, refer to... Figure 6 The control unit 130 can predict the planar shape of the wafer 10 based on the positions of multiple edge points a1, a2, a3, a4 by using circular interpolation, and derive the radius R of the wafer 10 as a feature value.

[0055] Meanwhile, wafers may undergo deformations such as bowing and warping (warping). When moving wafers to a warping measurement device to measure their warping, the significant TAT (turnaround time) required due to wafer movement, input, alignment, and measurement can lead to decreased production efficiency. To minimize this decrease, a method of measuring the warping of only a few wafers could be considered, but in this case, wafer deformation due to warping may not be perfectly detected, and wafers may break as a result. If broken wafers cause contamination inside the equipment, it can significantly impact production efficiency due to production interruptions.

[0056] According to this disclosure, the deformation of the wafer 10 can be predicted in real time by simply passing the wafer 10 through the sensor unit 120 while performing existing processes, without the additional processes of placing the wafer 10 into a separate device, aligning the wafer 10, and then measuring the warpage. Therefore, the deformation of the wafer 10 can be predicted without the increase in time and cost due to additional processes.

[0057] Furthermore, according to this disclosure, deformation of all wafers 10 can be predicted before they are placed into the process chamber, and it can be determined whether to feed each wafer 10 into subsequent processes based on whether it is deformed and the degree of deformation. By selectively feeding wafers 10 into subsequent processes according to the degree of deformation, wafer breakage can be prevented, and equipment contamination and production downtime caused by wafer breakage can be prevented.

[0058] Alternatively, the disclosure can be utilized in the following manner: the shape of the wafer 10 can be predicted based on data with a specific shape (e.g., the position of edge points in the coordinate plane, the predicted planar shape, eigenvalues, etc.) output by learning data of the wafer 10 with a specific shape through machine learning.

[0059] Figure 9 An exemplary shape of the wafer and its projection surface is shown.

[0060] Before deformation, the wafer may have a disk-shaped form. During the process, the wafer may be deformed (warped) due to bending and twisting. For example, the wafer may be deformed into various shapes (e.g., a saddle-shaped shape as shown in deformation example 1, a dome-shaped shape as shown in deformation example 2, a bowl-shaped shape as shown in deformation example 3, a smiley face shape with convex sides, and a sad face shape with sloping sides). When the wafer is deformed into a saddle-shaped shape, its projected surface is elliptical, and when it is deformed into a dome-shaped or spherical shape, its projected surface is a reduced circle. According to this disclosure, wafer deformation can be predicted by utilizing the fact that each projected surface exhibits a different morphology (shape and / or size) depending on the deformed form.

[0061] Figure 10 This is a graph illustrating an exemplary method for predicting wafer deformation using a device for predicting wafer deformation, according to an embodiment.

[0062] The horizontal axis of the graph represents the time each wafer 10 is released from the facility (trajectory output time TKOUT_TIME), and the vertical axis represents the characteristic values ​​of each wafer 10. The control unit 130 can load numerical characteristic values ​​for the predicted planar morphology of the wafer 10. For example, the radius value of the wafer 10 can be loaded into the control unit 130. Since undeformed wafers exhibit similar characteristic values, and deformed wafers exhibit different characteristic values, deformed wafers can be detected by comparing the characteristic values ​​loaded into the control unit 130.

[0063] Figure 11 , Figure 12 , Figure 13 and Figure 14 An example of using a device for predicting wafer deformation is shown according to an embodiment.

[0064] The morphology of the wafer 10 before and after the process can be compared using the device for predicting wafer deformation according to the embodiment.

[0065] Figure 11 (a), (b), (c), (d), (e), and (f) progressively show the wafer 10 passing through the sensor 120 during the transfer of the wafer 10.

[0066] Figure 12 The predicted pre-process planar morphology of wafer 10 and the derived exemplary characteristic values ​​are shown.

[0067] Figure 13(a), (b), (c), (d), (e), and (f) progressively show the wafer 10 passing through the sensor unit 120 during the return of the wafer 10.

[0068] Figure 14 The predicted post-process planar morphology of wafer 10 and derived exemplary characteristic values ​​are shown. The predicted pre-process planar morphology is also shown in dashed lines for comparison with wafer 10 before processing.

[0069] exist Figure 11 and Figure 13 In the diagram, only the position 120p of the sensor unit 120 in the Y direction is depicted with a dashed line. Additionally, the control unit 130 is omitted.

[0070] As described above, the transfer unit 110 can transfer the wafer 10 to the process chamber and return the wafer 10 from the process chamber. During the transfer of the wafer 10, the wafer 10 can be transferred in the Y direction and pass through the sensor unit 120, and during the return of the wafer 10, the wafer 10 can return in the opposite direction of the Y direction (hereinafter, it may be referred to as the -Y direction) and pass through the sensor unit 120.

[0071] The sensor unit 120 can identify multiple process front edge points a1, a2, a3, a4 of the wafer 10 during the transfer of the wafer 10 through the transfer unit 110, and can identify multiple process back edge points a1', a2', a3', a4' of the wafer 10 during the return of the wafer 10 through the transfer unit 110.

[0072] In an embodiment, the sensor unit 120 sequentially identifies the first process front edge point a1, the second process front edge point a2, the third process front edge point a3, and the fourth process front edge point a4 of the wafer 10 during the transfer of the wafer 10 through the transfer unit 110, and sequentially identifies the fourth process back edge point a4', the third process back edge point a3', the second process back edge point a2', and the first process back edge point a1' of the wafer 10 during the return of the wafer 10 through the transfer unit 110.

[0073] The control unit 130 can project the positions of multiple front-process edge points a1, a2, a3, a4 identified by the sensor unit 120 onto the coordinate plane, and predict the front-process planar shape of the wafer 10 based on the projected positions of the multiple front-process edge points a1, a2, a3, a4. Additionally, the control unit 130 can project the positions of multiple back-process edge points a1', a2', a3', a4' identified by the sensor unit 120 onto the coordinate plane, and predict the back-process planar shape of the wafer 10 based on the projected positions of the multiple back-process edge points a1', a2', a3', a4'.

[0074] In this embodiment, the control unit 130 can predict the pre-process planar shape of the wafer 10 using four pre-process edge points a1, a2, a3, a4, and can predict the post-process planar shape of the wafer 10 using four post-process edge points a1', a2', a3', a4'. For example, the control unit 130 can predict the pre-process planar shape or post-process planar shape of the wafer 10 using circular interpolation based on the positions of the pre-process edge points a1, a2, a3, a4 or the post-process edge points a1', a2', a3', a4'.

[0075] Furthermore, the control unit 130 can extract pre-process and post-process feature values ​​of the wafer 10 from its planar morphology, and / or compare the pre-process and post-process feature values. For example, the control unit 130 can extract and compare the pre-process radius R and the post-process radius R' of the wafer 10 from its planar morphology.

[0076] By comparing the morphology of wafer 10 before and after the process, the stress applied to wafer 10 due to the process can be monitored, and the morphology of wafer 10 after the process can be predicted.

[0077] Figure 15 and Figure 16 An example of using a device for predicting wafer deformation is shown according to an embodiment.

[0078] The device for predicting wafer deformation according to the embodiments can be used for more complex wafer deformation prediction. For example, the device for predicting wafer deformation can be used for anisotropic circular (e.g., elliptical) wafer measurement.

[0079] Figure 15 (a), (b), (c), (d) and (e) progressively show the wafer 10 passing through the sensor 120 during the transfer of the wafer 10.

[0080] Figure 16 The predicted planar morphology of wafer 10 and the derived exemplary characteristic values ​​are shown.

[0081] exist Figure 15 In the diagram, only the position 120p of the sensor unit 120 in the Y direction is depicted with a dashed line. Additionally, the control unit 130 is omitted.

[0082] The transfer unit 110 can cause the wafer 10 to pass through the sensor unit 120 multiple times. For example, the transfer unit 110 can move the wafer 10 in the Y direction, move the wafer 10 in the -Y direction, and then transfer the wafer 10 in the Y direction. The wafer 10 can pass through the sensor unit 120 during movement through the transfer unit 110 in the Y direction and during movement through the transfer unit 110 in the -Y direction. The transferred wafer 10 can then be placed into the process chamber. In this disclosure, the wafer 10 transferred by the transfer unit 110 is described as an example for reference, but it is of course possible for a wafer returned by the transfer unit 110 to pass through the sensor unit 120 multiple times after being returned.

[0083] After the sensor unit 120 identifies the first edge points a1, a2, a3, a4, and before the sensor unit 120 identifies the second edge points b1, b2, b3, b4, the transfer unit 110 can further move the wafer 10 such that the sensor unit 120 identifies multiple second edge points b1, b2, b3, b4 that are different from the multiple first edge points a1, a2, a3, a4 while the wafer 10 is moving in the -Y direction. For example, the transfer unit 110 can move the wafer 10 in a direction intersecting the Y direction (e.g., in the X direction perpendicular to the Y direction). However, the transfer unit 110 can also move the wafer 10 in other ways (e.g., rotational movement, rotational and linear movement). If necessary, the transfer unit 110 can be fixed, and the sensor unit 120 can be implemented to move to identify multiple second edge points b1, b2, b3, b4 that are different from the multiple first edge points a1, a2, a3, a4 while the wafer 10 is moving in the -Y direction.

[0084] Moving wafer 10 in the X direction can be used to align wafer 10 for process movement. To align wafer 10, control unit 130 can deduce the center position of wafer 10 in the X direction (e.g., centerline CL or center point) based on the positions of multiple first edge points a1, a2, a3, a4 identified by sensor unit 120. Subsequently, transfer unit 110 can move wafer 10 in the X direction to move the deduced center position of wafer 10 to a predetermined alignment position (e.g., alignment line AL or alignment point) (see [link to relevant documentation]). Figure 15 (b) and (c)). While aligning for transfer of wafer 10, additional planar coordinates of edge points can be ensured.

[0085] The sensor unit 120 can identify multiple first edge points a1, a2, a3, a4 of the wafer 10 while the wafer 10 moves in the Y direction, and can identify multiple second edge points b1, b2, b3, b4 of the wafer 10 while the wafer 10 moves in the opposite direction of the Y direction. The first edge points a1, a2, a3, a4 can be the primary edge points identified by the sensor unit 120, and the second edge points b1, b2, b3, b4 can be the secondary edge points identified by the sensor unit 120.

[0086] In this embodiment, the sensor unit 120 can sequentially identify the first-first edge point a1, the first-second edge point a2, the first-third edge point a3, and the first-fourth edge point a4 of the wafer 10 while the wafer 10 moves in the Y direction. Additionally, during the movement of the wafer 10 in the -Y direction (when the wafer 10 is aligned and then moved in the -Y direction), the sensor unit 120 can simultaneously identify the second-fourth edge point b4 and the second-third edge point b3 of the wafer 10, and then simultaneously identify the second-second edge point b2 and the second-first edge point b1 of the wafer 10.

[0087] The control unit 130 can project the positions of multiple first edge points a1, a2, a3, a4 and multiple second edge points b1, b2, b3, b4 identified by the sensor unit 120 onto the coordinate plane, and predict the planar shape of the wafer 10 based on the projected positions of the multiple first edge points a1, a2, a3, a4 and multiple second edge points b1, b2, b3, b4.

[0088] In this embodiment, the control unit 130 can predict the planar shape of the wafer 10 using four first edge points a1, a2, a3, a4 and four second edge points b1, b2, b3, b4. For example, the control unit 130 can predict the planar shape of the wafer 10 using closed-loop interpolation based on the positions of multiple edge points a1, a2, a3, a4, b1, b2, b3, b4 of the wafer 10.

[0089] Furthermore, the control unit 130 can extract feature values ​​of the wafer 10 from the predicted planar morphology of the wafer 10. For example, the control unit 130 can deduce at least one of the major axis length L1 and minor axis length L2 of the wafer 10 from the planar morphology of the wafer 10.

[0090] Based on the positions of multiple edge points a1, a2, a3, a4, b1, b2, b3, b4, the deformation of the wafer 10 can be predicted more accurately.

[0091] Figure 17 This is a flowchart of a method for predicting wafer deformation using a device for predicting wafer deformation, according to an embodiment.

[0092] The wafer deformation prediction method according to this disclosure includes: step S11 of passing the wafer 10 through the sensor unit 120, step S12 of projecting the positions of multiple edge points a1, a2, a3, a4 of the wafer 10 identified by the sensor unit 120 onto a coordinate plane, and step S13 of predicting the planar shape of the wafer 10 based on the positions of the multiple edge points a1, a2, a3, a4 of the wafer 10 projected onto the coordinate plane.

[0093] In an embodiment, wafer deformation prediction can be performed after the wafer is placed into a facility that may include equipment for predicting wafer deformation according to the present disclosure, but before the start of the process. That is, wafer deformation prediction can be performed between step S10, where the wafer is placed into the facility, and step S20, where the process is performed. Therefore, the process can be selectively performed on each wafer based on whether the wafer 10 is deformed and the degree of deformation. After step S30, where the process is completed, step S40, where the wafer 10 is moved outside the facility, can be performed.

[0094] In one embodiment, wafer deformation prediction can be performed at a step between the first and second processes, and the second process can be performed only on wafers determined to be undeformed after the first process. In another embodiment, wafer deformation prediction can be performed before and after the first process to monitor the stress applied to the wafer due to the first process and predict the wafer deformation caused by the first process.

[0095] In this embodiment, step S13, which predicts the planar shape of the wafer based on the positions of multiple edge points a1, a2, a3, a4 of the wafer 10, can be performed by circular interpolation or closed-loop interpolation.

[0096] In an embodiment, step S14, which extracts feature values ​​of wafer 10 from the predicted planar morphology of wafer 10, may be additionally performed. For example, in step S14, the radius of wafer 10 may be derived from the planar morphology of wafer 10 as a feature value, or at least one of the major axis length and minor axis length may be derived as a feature value.

[0097] In addition, step S15 of loading feature values ​​of wafer 10 can be performed additionally. Since undeformed wafers exhibit similar feature values ​​and deformed wafers exhibit different feature values, deformed wafers can be detected by comparing the loaded feature values.

[0098] Although embodiments of the present disclosure have been described in detail above, the scope of the present disclosure is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concepts of the present disclosure as defined in the appended claims also fall within the scope of the present disclosure.

[0099] Additionally, the embodiments of this disclosure are not independent of each other and can be combined with each other unless there is a specific contradiction. Therefore, combined embodiments of this disclosure should also be considered as included in this disclosure.

Claims

1. An apparatus for predicting wafer deformation, the apparatus comprising: Transmission unit, transmission chip; A sensor unit identifies multiple edge points of the wafer transmitted by the transmission unit; as well as The control unit projects the positions of the plurality of edge points of the wafer identified by the sensor unit onto a coordinate plane, and predicts the planar shape of the wafer based on the positions of the plurality of edge points of the wafer projected onto the coordinate plane.

2. The apparatus for predicting wafer deformation according to claim 1, wherein, The sensor unit includes a first sensor unit and a second sensor unit spaced apart in a second direction intersecting the first direction, which is the direction in which the transmission unit transmits the wafer.

3. The apparatus for predicting wafer deformation of claim 2, wherein, The first sensor unit identifies a first edge point and a second edge point that pass through the first sensor unit and are spaced apart in the first direction among the plurality of edge points, and the second sensor unit identifies a third edge point and a fourth edge point that pass through the second sensor unit and are spaced apart in the first direction among the plurality of edge points.

4. The apparatus for predicting wafer deformation according to claim 1, wherein, The sensor unit includes a light emitter that emits light and a light receiver that receives light emitted from the light emitter, and identifies the plurality of edge points of the wafer based on whether the light receiver receives light, wherein whether the light receiver receives light depends on the presence of the wafer between the light emitter and the light receiver.

5. The apparatus for predicting wafer deformation of claim 1, wherein, The control unit uses data to project the positions of the plurality of edge points of the wafer onto the coordinate plane, the data including the time point at which the sensor unit identifies each of the plurality of edge points of the wafer and the moving speed of the wafer.

6. The apparatus for predicting wafer deformation of claim 5, wherein, The control unit uses the data to project the positions of the plurality of edge points of the wafer onto the coordinate plane, and the data also includes the movement trajectory of the wafer.

7. The apparatus for predicting wafer deformation of claim 1, wherein, The sensor unit identifies at least three edge points of the wafer.

8. The apparatus for predicting wafer deformation of claim 1, wherein, The control unit predicts the planar shape of the wafer based on the positions of the plurality of edge points of the wafer through circular interpolation.

9. The apparatus for predicting wafer deformation of claim 8, wherein, The control unit derives the radius of the wafer from the predicted planar shape of the wafer.

10. The apparatus for predicting wafer deformation of claim 1, wherein, The control unit predicts the planar shape of the wafer by using closed-loop interpolation based on the positions of the plurality of edge points of the wafer.

11. The apparatus for predicting wafer deformation of claim 10, wherein, The control unit derives at least one of the major axis length and minor axis length of the wafer from the predicted planar shape of the wafer.

12. The apparatus for predicting wafer deformation of claim 1, wherein, The transfer unit includes a robotic arm.

13. The apparatus for predicting wafer deformation of claim 1, wherein, The position of the sensor unit is fixed.

14. An apparatus for predicting wafer deformation, the apparatus comprising: The transfer unit transfers the wafer to the process chamber and returns the wafer that has exited the process chamber. The sensor unit identifies multiple process front edge points of the wafer during the transfer of the wafer through the transfer unit, and identifies multiple process back edge points of the wafer during the return of the wafer through the transfer unit; as well as The control unit projects the positions of the plurality of pre-process edge points of the wafer identified by the sensor unit onto a coordinate plane, and predicts the pre-process planar shape of the wafer based on the positions of the plurality of pre-process edge points of the wafer projected onto the coordinate plane. It also projects the positions of the plurality of post-process edge points of the wafer identified by the sensor unit onto the coordinate plane, and predicts the post-process planar shape of the wafer based on the positions of the plurality of post-process edge points of the wafer projected onto the coordinate plane.

15. The apparatus for predicting wafer deformation of claim 14, wherein, The wafer is transported in a first direction and passes through the sensor unit during the transport of the wafer, and the wafer returns in a second direction and passes through the sensor unit during the return of the wafer, the second direction being the opposite direction to the first direction.

16. The apparatus for predicting wafer deformation of claim 15, wherein, The sensor unit includes a first sensor unit and a second sensor unit spaced upwards on a third direction intersecting the first direction.

17. An apparatus for predicting wafer deformation, the apparatus comprising: The transfer unit moves the wafer in a first direction, moves the wafer in a second direction opposite to the first direction, and then transfers the wafer in the first direction. The sensor unit identifies a plurality of first edge points of the wafer during the movement of the wafer in the first direction via the transfer unit, and identifies a plurality of second edge points of the wafer during the movement of the wafer in the second direction via the transfer unit; as well as The control unit projects the positions of the plurality of first edge points and the plurality of second edge points of the wafer, identified by the sensor unit, onto a coordinate plane, and predicts the planar shape of the wafer based on the projected positions of the plurality of first edge points and the plurality of second edge points of the wafer onto the coordinate plane. The wafer passes through the sensor unit while moving through the transfer unit in the first direction and while moving through the transfer unit in the second direction.

18. The apparatus for predicting wafer deformation according to claim 17, wherein, After the sensor unit identifies the plurality of first edge points and before the sensor unit identifies the plurality of second edge points, the transfer unit further moves the wafer upward on a third side intersecting the first direction, such that the sensor unit identifies the plurality of second edge points that are different from the plurality of first edge points during the movement of the wafer in the second direction.

19. The apparatus for predicting wafer deformation according to claim 18, wherein, The control unit derives the center position of the wafer in the third direction based on the positions of the plurality of first edge points of the wafer identified by the sensor unit, and the transfer unit moves the wafer in the third direction to move the derived center position of the wafer to a predetermined alignment position.

20. The apparatus for predicting wafer deformation according to claim 17, wherein, The sensor unit includes a first sensor unit and a second sensor unit spaced upwards on a third direction intersecting the first direction.

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