Wafer guiding device and wafer guiding method using the same

Abstract

The present invention relates to a wafer guiding device and a wafer guiding method using the same. The present invention provides a wafer guiding device for adjusting a position of a wafer disposed on an electrostatic chuck, wherein the wafer guiding device includes a laser distance sensor disposed on an upper side of the electrostatic chuck, and a control unit for controlling a robot for transferring the wafer, wherein the control unit confirms a relative position of the electrostatic chuck and the wafer disposed on the electrostatic chuck by using the laser distance sensor, and guides the position of the wafer by using the confirmed relative position of the electrostatic chuck and the wafer, so that the wafer can be transferred to a prescribed position.

Description

Technical Field

[0001] This invention relates to a wafer position detection device and a wafer position detection and correction method using the same. Background Technology

[0002] To manufacture semiconductor components or liquid crystal displays, various processes such as photolithography, etching, ion implantation, vapor deposition, and cleaning are performed on the wafer.

[0003] In these processes, the etching operation is performed on an electrostatic chuck (ESC) located within the etching chamber. To precisely execute the aforementioned processes, the wafer must be precisely positioned at a predetermined location on the ESC; the operation used to position the wafer at this predetermined location on the ESC is called the guidance operation.

[0004] Various methods for precision guidance operations have been disclosed. For example, Korean Patent Publication No. 10-2018-0109300 discloses a method for guiding the position of a wafer by providing a light-receiving area on an electrostatic chuck and having a light-receiving component receive light reflected from the light-receiving area.

[0005] In addition, a method for guiding wafer fabrication using video has also been disclosed.

[0006] However, most of the methods disclosed so far are for cases where the electrostatic chuck has an area larger than the wafer, which makes them difficult to apply to situations where the wafer covers the electrostatic chuck because the wafer area is wider than the electrostatic chuck area. Summary of the Invention

[0007] The present invention is proposed to address the problems of the prior art. The problem to be solved by the present invention is to provide a wafer guiding device and a wafer guiding method that can accurately guide the position of the wafer even when the wafer has an area wider than the electrostatic chuck.

[0008] As a solution to the aforementioned problem, the present invention provides a wafer guiding device for adjusting the position of a wafer disposed on an electrostatic chuck. The wafer guiding device includes: a laser distance sensor disposed on the upper side of the electrostatic chuck; and a control unit for controlling a robot that transfers the wafer. The control unit uses the laser distance sensor to confirm the relative position of the electrostatic chuck and the wafer disposed on the electrostatic chuck, and uses the confirmed relative position of the electrostatic chuck and the wafer to guide the position of the wafer so that the wafer can be moved to a predetermined position.

[0009] Preferably, three or more laser distance sensors are provided. Each laser distance sensor measures the distance from a first fixed point to the edge of the electrostatic chuck located on a first straight line, and the distance from a first fixed point on the first straight line to the edge of the wafer when the wafer is positioned on the electrostatic chuck. The first fixed point is any point located inside the electrostatic chuck among the points on the first straight line, and the first straight line is a virtual straight line passing through the center of the electrostatic chuck. The difference between the distance between the first fixed point and the edge of the electrostatic chuck and the distance from the first fixed point to the edge of the wafer is calculated, and the difference in distances measured by each laser distance sensor is compared to guide the wafer.

[0010] Preferably, the distance from a first fixed point on the first straight line to the edge of the electrostatic chuck is obtained by repeatedly measuring the distances between each point of a line segment extending from the first fixed point to a second fixed point and the laser distance sensor, wherein the second fixed point is any point on the first straight line and outside the electrostatic chuck.

[0011] Preferably, the distance from a first fixed point on the first straight line to the edge of the wafer is obtained by repeatedly measuring the distance between each point of the line segment extending from the first fixed point to a third fixed point and the laser distance sensor, wherein the third fixed point is any point on the first straight line outside the wafer.

[0012] Preferably, the laser distance sensor is configured as a module comprising multiple laser distance sensors.

[0013] Preferably, the laser distance sensor is configured as a module combining multiple distance sensors. Specifically, three or more laser distance sensors are provided. The coordinates of the electrostatic chuck edge are determined by measuring the distance from a first fixed point to the edge of the electrostatic chuck located on a first straight line. The first fixed point is any point within the electrostatic chuck on the first straight line, which is a virtual straight line passing through the center of the electrostatic chuck. The coordinates of the wafer edge are determined by measuring the distance from the first fixed point on the first straight line to the edge of the wafer. Using the coordinates determined by each laser distance sensor, the center coordinates of the electrostatic chuck and the wafer are calculated and compared to guide the wafer.

[0014] As a second aspect of the present invention, a wafer guidance method is provided to adjust the position of a wafer disposed on an electrostatic chuck. The wafer guidance method includes: a first measurement step, measuring the position of the electrostatic chuck using a laser distance sensor; and a second measurement step, measuring the position of the wafer disposed on the electrostatic chuck using the laser distance sensor, and guiding the position of the wafer using the position of the electrostatic chuck measured in the first measurement step and the position of the wafer measured in the second measurement step.

[0015] Preferably, the first measurement step measures the distance from a first fixed point to the edge of the electrostatic chuck located on a first straight line, where the first fixed point is any point on the first straight line located inside the electrostatic chuck, and the first straight line is a virtual straight line passing through the center of the electrostatic chuck. The second measurement step measures the distance from the first fixed point on the first straight line to the edge of the wafer when the wafer is positioned on the electrostatic chuck, and the position of the wafer is guided by the difference between the distance between the first fixed point and the edge of the electrostatic chuck and the distance from the first fixed point to the edge of the wafer.

[0016] Preferably, the first measurement step repeatedly measures the distance between each point of the line segment extending from the first fixed point to the second fixed point and the laser distance sensor, wherein the second fixed point is any point on the first straight line and outside the electrostatic chuck.

[0017] Preferably, the second measurement step repeatedly measures the distance between each point of the line segment extending from the first fixed point to the third fixed point and the laser distance sensor, wherein the third fixed point is any point on the first straight line and outside the wafer.

[0018] Preferably, the laser distance sensor is configured as a module comprising multiple laser distance sensors.

[0019] As a solution to the aforementioned problem, the present invention provides a wafer guiding device for adjusting the position of a wafer disposed on an electrostatic chuck. The wafer guiding device includes: a laser distance sensor disposed above the electrostatic chuck; and a control unit for controlling a robot that transfers the wafer. The control unit uses the laser distance sensor to confirm the relative position of the electrostatic chuck and the wafer disposed on it, and uses the confirmed relative position to determine the position of the wafer, so that the wafer can be moved to a predetermined position. The laser distance sensor comprises three or more sensors, each measuring the distance from a first fixed point to the edge of the electrostatic chuck located on a first straight line and the distance from the first fixed point on the first straight line to the edge of the wafer when the wafer is disposed on the electrostatic chuck, and calculating the difference between these distances. The fixed point is any point located inside the electrostatic chuck on the first straight line, which is a virtual straight line passing through the center of the electrostatic chuck. The difference between the distances measured by each laser distance sensor is compared. Alternatively, three or more laser distance sensors are provided to measure the distance from the first fixed point to the edge of the electrostatic chuck located on the first straight line to determine the coordinates of the edge of the electrostatic chuck. The first fixed point is any point located inside the electrostatic chuck on the first straight line, which is a virtual straight line passing through the center of the electrostatic chuck. The coordinates of the wafer edge are determined by measuring the distance from the first fixed point on the first straight line to the edge of the wafer. The center coordinates of the electrostatic chuck and the wafer are calculated and compared using the coordinates determined by each laser distance sensor to guide the position of the wafer. The laser distance sensor is configured as a module combining multiple distance sensors.

[0020] According to the present invention, a wafer guiding device and a wafer guiding method thereof can be provided that can accurately guide the position of the wafer even when the wafer has an area wider than that of an electrostatic chuck. Attached Figure Description

[0021] Figure 1 This is a block diagram of a wafer guidance device according to an embodiment of the present invention.

[0022] Figure 2 This is a diagram used to illustrate the relationship between the electrostatic chuck and the laser distance sensor.

[0023] Figure 3 and Figure 4 This diagram illustrates the use of a laser distance sensor to measure the distance from a first fixed point to the edge of an electrostatic chuck.

[0024] Figure 5 and Figure 6 This diagram illustrates the use of a laser distance sensor to measure the distance from a first fixed point to the edge of the wafer.

[0025] Figure 7 This is a diagram illustrating a robot that transfers wafers.

[0026] (Explanation of reference numerals in the attached diagram)

[0027] 10: Laser distance sensor; 20: Control unit

[0028] 30: Electrostatic chuck; 40: Wafer Detailed Implementation

[0029] The following describes preferred embodiments of the present invention, thereby providing specific details for carrying out the invention. The terms or words used in this specification and claims should not be limited to their ordinary or dictionary meanings. In order to describe the invention in the best possible way, the inventors have appropriately defined the terms and concepts, and therefore they should be interpreted as meanings and concepts consistent with the technical concept of the present invention.

[0030] When describing the constituent elements of embodiments of the present invention, terms such as first, second, A, B, (a), (b) may be used. However, these terms are only used to distinguish their constituent elements from other constituent elements and are not limited by their terms to the nature, order, or sequence of the corresponding constituent elements.

[0031] First, an embodiment of the first form of the present invention, namely a wafer guiding device, will be described with reference to the accompanying drawings.

[0032] Figure 1 This is a block diagram of a wafer guidance device according to an embodiment of the present invention. Figure 2 This diagram illustrates the relationship between the electrostatic chuck and the laser distance sensor. Figure 3 and Figure 4 This diagram illustrates the use of a laser distance sensor to measure the distance from a first fixed point to the edge of the electrostatic chuck. Figure 5 and Figure 6 This diagram illustrates the use of a laser distance sensor to measure the distance from a first fixed point to the edge of the wafer. Figure 7 This is a diagram illustrating a robot that transfers wafers.

[0033] The wafer guiding device according to this embodiment is configured as a device for adjusting the position of a wafer disposed on an electrostatic chuck, and includes a laser distance sensor 10 and a control unit 20.

[0034] The laser distance sensor 10 is a sensor that uses laser light to measure the distance between two points. In this embodiment, the laser distance sensor 10 is a module consisting of multiple laser distance sensors, configured to simultaneously measure the distance between multiple points.

[0035] The laser distance sensor 10 is provided in three or more forms, as in this embodiment, such as... Figure 2 Three are set up as shown. The reason why more than three laser distance sensors 10 are needed is that at least the coordinate information of three points is required to determine a circle passing through these three points as a single entity.

[0036] The control unit 20 serves as a structure for controlling the position of the wafer 40 disposed on the electrostatic chuck 30. In this embodiment, it is configured to include a distance sensor control unit 21 and a robot control unit 22.

[0037] The distance sensor control unit 21 uses the laser distance sensor 10 to confirm the relative position of the electrostatic chuck 30 and the wafer 40 disposed on the electrostatic chuck 30. The confirmed relative position is used to confirm whether the wafer 40 is disposed in a specified position. If the wafer 40 is disposed in a position other than the specified position, the robot control unit 22 moves the position of the wafer 40 to the specified position.

[0038] like Figure 7 As shown, the robot control unit 22 controls the robot R that transfers the wafer 40.

[0039] The following describes an embodiment of a method for guiding the placement of a wafer using the aforementioned structure.

[0040] The basic principle of wafer guidance is to position wafer 40 in a location where the electrostatic chuck 30 and wafer 40 can form concentric circles. To this end, two embodiments are disclosed. The first embodiment involves measuring the distance from a specific point (first fixed point) on the electrostatic chuck to the edge of the electrostatic chuck and the distance to the edge of the wafer, and comparing the difference in these distances to determine whether the electrostatic chuck 30 and wafer 40 are concentric circles. The second embodiment involves using the values ​​of the distance from the specific point (first fixed point) on the electrostatic chuck to the edge of the electrostatic chuck and the distance to the edge of the wafer to determine the center coordinates of wafer 40, thereby confirming whether it coincides with the center of the electrostatic chuck 30.

[0041] Before describing the method for guiding wafers, several terms to be used in the description are defined.

[0042] The first straight line l is any straight line passing through the center of the electrostatic chuck 30. For example... Figure 3 and Figure 5 As shown, three first straight lines l are used to guide the wafer. a l b l c .

[0043] The first fixed point P1 is a point located inside the electrostatic chuck 30 among the points on the first straight line l. The first fixed point P1 is also defined as three first fixed points P. 1a P1b P 1c Three first fixed points P 1a P 1b P 1c The distance between the center O of the electrostatic chuck and the chuck can be the same or different.

[0044] The second fixed point P2 is a point located outside the electrostatic chuck 30 among the points on the first straight line l. Similarly, three second fixed points P are defined. 2a P 2b P 2c Three second fixed points P 2a P 2b P 2c The distance between the center O of the electrostatic chuck and the center O can be the same or different.

[0045] The third fixed point P3 is a point located outside wafer 40 among the points on the first straight line l. The third fixed point P3 also defines three third fixed points P. 3a P 3b P 3c Three third fixed points P 3a P 3b P 3c The distance between the center O of the electrostatic chuck and the center O can be the same or different.

[0046] The first line segment S1 is defined as the line segment connecting the first fixed point P1 and the second fixed point P2. Three segments are defined for each of the first and second fixed points P1 and P2, therefore three first line segments S1 are also defined. 1a S 1b S 1c .

[0047] The second line segment S2 is defined as the line segment connecting the first fixed point P1 and the third fixed point P3. Since three segments are defined for each of the first and third fixed points P1, three second line segments S2 are also defined. 2a S 2b S 2c .

[0048] The reason why the first straight line, first fixed point, second fixed point, third fixed point, first line segment, and second line segment are each defined in threes is that three laser distance sensors are used in this embodiment. If the number of laser distance sensors increases, the number of defined first straight line, first fixed point, second fixed point, third fixed point, first line segment, and second line segment should also increase by the same amount.

[0049] The wafer guidance method includes a first metrology step and a second metrology step. The wafer is guided by determining whether it is in a specified position by using the relative position of the electrostatic chuck and the wafer measured in the first and second metrology steps.

[0050] The first metrology step is to measure the position of the electrostatic chuck 30 using the laser distance sensor 10, and the second metrology step is to measure the position of the wafer 40 positioned on the electrostatic chuck 30 using the laser distance sensor 10. The position of the electrostatic chuck 30 does not change; therefore, if the first metrology step is performed once to measure the position of the electrostatic chuck 30, it does not need to be performed every time the wafer 40 enters the process chamber. However, the first metrology step can be performed when it is determined that the position of the electrostatic chuck 30 needs to be checked periodically.

[0051] like Figure 3 As shown, the first measurement step measures the distance from a first fixed point P1 on the first straight line l to the edge of the electrostatic chuck. It uses a method that repeatedly measures the distance from the laser distance sensor 10 to each point on the first line segment S1 using the laser distance sensor 10. Figure 4 The measurement results of the laser distance sensor 10 are shown. The x-axis is the distance from the first fixed point P1 to the measurement point, and the y-axis is the distance between the laser distance sensor 10 and the measurement point on the first line segment S1. Figure 4 As shown in the graph, if the distance passes through the edge of the electrostatic chuck 30, the distance between the laser distance sensor 10 and the measurement point on the first line segment S1 increases, as shown in the graph. This graph can be used to find the edge of the electrostatic chuck from the first fixed point P1 and calculate the distance d from the first fixed point P1 to the edge of the electrostatic chuck.

[0052] The first measurement step uses three laser distance sensors 10 a 10 b 10 c This can be achieved separately, thus allowing the calculation of the first fixed point P measured by each laser distance sensor. 1a P 1b P 1c The distance d between the chuck and the edge of the electrostatic chuck a d b d c .

[0053] like Figure 5 As shown, the second measurement step measures the distance from a first fixed point on the first straight line l to the edge of the wafer 40. Figure 6 The measurement results of the laser distance sensor 10 are shown, and for reference, the measurement results of the electrostatic chuck 30 are also shown.

[0054] The second measurement step uses three laser distance sensors 10a 10 b 10 c This can be achieved separately, thus allowing the calculation of the first fixed point P measured by each laser distance sensor. 1a P 1b P 1c Distance D between the wafer edge a D b D c The second measurement step utilizes the same mechanism as the first measurement step, therefore a detailed explanation is omitted.

[0055] The laser distance sensor 10 is configured as a module consisting of multiple laser distance sensors, which can simultaneously measure the distance from the laser distance sensor 10 to each point on the two line segments S1 and S2.

[0056] If the measurement is performed from the first fixed point P through the first and second measurement steps 1a P 1b P 1c Distance d to the edge of the electrostatic chuck a d b d c and from the first fixed point P 1a P 1b P 1c Distance D to the edge of the wafer a D b D c Then the difference D between each distance can be calculated. a -d a D b -d b D c -d c If the distance differences are all the same, it confirms that the centers of the electrostatic chuck 30 and the wafer 40 are the same. At this point, there is no need to move the wafer 40 to adjust its position.

[0057] If the distances between them are not all the same, the centers of the electrostatic chuck 30 and the wafer 40 are not the same. Therefore, it is necessary to perform a guidance operation to move the wafer 40. The robot R is used to move the wafer 40 and perform the second measurement step to confirm whether the electrostatic chuck 30 and the wafer 40 are concentric circles. If they are the same, the guidance ends. If they are different, the movement of the wafer 40 and the second measurement step are repeated.

[0058] A second embodiment of the wafer guidance method will be described.

[0059] The wafer guidance method in this embodiment is the same as that in the previously described embodiment, including a first measurement step and a second measurement step. The methods for performing the first measurement step and the second measurement step are substantially the same, and three laser distance sensors are used in the same way, so detailed descriptions are omitted.

[0060] The guidance method of this embodiment is implemented in the following manner: the center coordinates of the electrostatic chuck 30 and the wafer 40 are obtained and compared using the measurement results of the first measurement step and the second measurement step.

[0061] Alternatively, if the plane on which the electrostatic chuck 30 is placed and the plane on which the wafer 40 is placed are represented by an x ​​and y coordinate system, and a specific point (e.g., the center of the electrostatic chuck 30) is taken as the origin, then the three edge coordinates of the electrostatic chuck 30 on the first straight line can be obtained using the measurement results of the first measurement step, and the center coordinates of the electrostatic chuck 30 can be obtained using its three coordinates.

[0062] If the edge coordinates of the wafer 40 on the first straight line are obtained using the measurement results of the second measurement step in the same way, the center coordinates of the wafer 40 can be obtained using these three coordinates.

[0063] Finding the coordinates of the center of a circle using three coordinates on the circle is a simple geometric process, so a detailed explanation is omitted.

[0064] If the center coordinates of the electrostatic chuck 30 and the wafer 40 obtained in this way are the same, then no further guidance is needed. If the center coordinates of the electrostatic chuck 30 and the wafer 40 are different, the robot control unit 22 moves the robot R to move the wafer 40 and executes the second measurement step, thereby obtaining the center coordinates of the wafer 40 and performing the step of comparing it with the center of the electrostatic chuck 30. This process is repeated until the center of the electrostatic chuck 30 and the center of the wafer 40 are the same.

[0065] The preferred embodiments of the present invention have been described above, thereby providing specific content for implementing the present invention. However, the technical concept of the present invention is not limited to the described embodiments and can be embodied in various forms within the scope of the technical concept of the present invention.

Claims

1. A wafer guiding device that adjusts a position of a wafer having a wider area than an electrostatic chuck disposed above the electrostatic chuck, wherein, The wafer guidance device includes: A laser distance sensor is disposed on the upper side of the electrostatic chuck; and The control unit controls the robot that transfers the wafer. The laser distance sensor is set to three or more. Each laser distance sensor measures the distance from a first fixed point to the edge of the electrostatic chuck located on a first straight line, and the distance from a first fixed point on the first straight line to the edge of the wafer when the wafer is positioned on the electrostatic chuck. The first fixed point is any point on the first straight line located inside the electrostatic chuck, and the first straight line is a virtual straight line passing through the center of the electrostatic chuck. The control unit uses the laser distance sensor to determine the relative positions of the electrostatic chuck and the wafer disposed on the electrostatic chuck based on the measured distance from the first fixed point on the first straight line to the edge of the electrostatic chuck and the distance from the first fixed point on the first straight line to the edge of the wafer. The confirmed relative positions of the electrostatic chuck and the wafer are used to guide the position of the wafer so that the wafer can be moved to a specified position.

2. The wafer guiding device according to claim 1, wherein, Calculate the distance between the first fixed point and the edge of the electrostatic chuck, as well as the difference between the distance from the first fixed point to the edge of the wafer. The wafer is guided by comparing the differences in distances measured by various laser distance sensors.

3. The wafer guiding device according to claim 2, wherein, The distance from a first fixed point on the first straight line to the edge of the electrostatic chuck is obtained by repeatedly measuring the distances between each point on the line segment extending from the first fixed point to a second fixed point and the laser distance sensor. The second fixed point is any point on the first straight line and outside the electrostatic chuck.

4. The wafer guiding device according to claim 2 or 3, wherein, The distance from a first fixed point on the first straight line to the edge of the wafer is obtained by repeatedly measuring the distance between each point on the line segment extending from the first fixed point to a third fixed point and the laser distance sensor, wherein the third fixed point is any point on the first straight line outside the wafer.

5. The wafer guiding apparatus according to any one of claims 1 to 3, wherein, The laser distance sensor is configured as a module consisting of multiple laser distance sensors.

6. The wafer guiding device according to claim 4, wherein, The laser distance sensor is configured as a module consisting of multiple laser distance sensors.

7. The wafer guiding device according to claim 1, wherein, The coordinates of the edge of the electrostatic chuck are determined by the distance from the first fixed point on the first straight line to the edge of the electrostatic chuck. The coordinates of the wafer edge are determined by the distance from the first fixed point on the first straight line to the edge of the wafer. The wafer is guided by calculating and comparing the center coordinates of the electrostatic chuck and the wafer using the coordinates confirmed in each laser distance sensor.

8. The wafer guiding device according to claim 7, wherein, The distance is obtained by repeatedly measuring the distance between each point on the line segment extending from the first fixed point to the edge of the electrostatic chuck and the laser distance sensor, where the second fixed point is any point on the first line and outside the electrostatic chuck.

9. The wafer guiding apparatus according to claim 7 or 8, wherein, The distance from a first fixed point on the first straight line to the edge of the wafer is obtained by repeatedly measuring the distance between each point on the line segment extending from the first fixed point to a third fixed point and the laser distance sensor. The third fixed point is any point on the first straight line and outside the wafer.

10. The wafer guiding apparatus according to claim 7 or 8, wherein, The laser distance sensor is configured as a module consisting of multiple laser distance sensors.

11. A wafer guidance method, wherein the position of a wafer disposed on an electrostatic chuck and having an area wider than the electrostatic chuck is adjusted, wherein, The wafer guidance method includes: The first measurement step involves using a laser distance sensor to measure the position of the electrostatic chuck by measuring the distance from a first fixed point to the edge of the electrostatic chuck located on a first straight line. The first fixed point is any point within the electrostatic chuck along the first straight line, which is a virtual straight line passing through the center of the electrostatic chuck. The second measurement step involves using the laser distance sensor to measure the position of the wafer positioned on the electrostatic chuck by measuring the distance from a first fixed point on the first straight line to the edge of the wafer while the wafer is positioned on the electrostatic chuck. The position of the wafer is guided by the position of the electrostatic chuck measured in the first metering step and the position of the wafer measured in the second metering step.

12. The wafer guidance method according to claim 11, wherein, The wafer's position is guided by the difference between the distance between the first fixed point and the edge of the electrostatic chuck, and the distance from the first fixed point to the wafer edge.

13. The wafer guidance method according to claim 12, wherein, The first measurement step repeatedly measures the distance between each point of the line segment extending from the first fixed point to the second fixed point and the laser distance sensor, wherein the second fixed point is any point on the first straight line and outside the electrostatic chuck.

14. The wafer guidance method according to claim 12 or 13, wherein, The second measurement step repeatedly measures the distance between each point of the line segment extending from the first fixed point to the third fixed point and the laser distance sensor, wherein the third fixed point is any point on the first straight line and outside the wafer.

15. The wafer guidance method according to any one of claims 11 to 13, wherein, The laser distance sensor is configured as a module consisting of multiple laser distance sensors.

16. The wafer guidance method according to claim 14, wherein, The laser distance sensor is configured as a module consisting of multiple laser distance sensors.

17. The wafer guidance method according to claim 11, wherein, The laser distance sensor is set to three or more. The wafer is guided by calculating and comparing the center coordinates of the electrostatic chuck and the wafer using the measurement results of the first and second measurement steps performed in each of the laser distance sensors.

18. The wafer guidance method according to claim 17, wherein, The first measurement step repeatedly measures the distance between each point of the line segment extending from the first fixed point to the second fixed point and the laser distance sensor, wherein the second fixed point is any point on the first straight line and outside the electrostatic chuck.

19. The wafer guidance method according to claim 17 or 18, wherein, The second measurement step repeatedly measures the distance between each point of the line segment extending from the first fixed point to the third fixed point and the laser distance sensor, wherein the third fixed point is any point on the first straight line and outside the wafer.

20. A wafer guiding device for adjusting the position of a wafer disposed on an electrostatic chuck and having an area wider than the electrostatic chuck, wherein, The wafer guidance device includes: A laser distance sensor is disposed above the electrostatic chuck; and The control unit controls the robot that transfers the wafer. The control unit uses the laser distance sensor to confirm the relative position of the electrostatic chuck and the wafer disposed on the electrostatic chuck, and uses the confirmed relative position to determine the position of the wafer, so that the wafer can be moved to a predetermined position. in: The laser distance sensor is set to three or more. Each laser distance sensor measures the distance from a first fixed point to the edge of the electrostatic chuck located on a first straight line, and the distance from the first fixed point on the first straight line to the edge of the wafer when the wafer is positioned on the electrostatic chuck, and calculates the difference between these distances. The first fixed point is any point on the first straight line located inside the electrostatic chuck, and the first straight line is a virtual straight line passing through the center of the electrostatic chuck. Compare the differences in distance measured by each laser distance sensor; or, The laser distance sensor is set to three or more. The coordinates of the edge of the electrostatic chuck are determined by measuring the distance from a first fixed point to the edge of the electrostatic chuck located on a first straight line. The first fixed point is any point on the first straight line located inside the electrostatic chuck, and the first straight line is a virtual straight line passing through the center of the electrostatic chuck. The coordinates of the wafer edge are determined by measuring the distance from a first fixed point on the first straight line to the edge of the wafer. The wafer's position is guided by calculating and comparing the center coordinates of the electrostatic chuck and the wafer using the coordinates confirmed by each laser distance sensor. The laser distance sensor is configured as a module that combines multiple distance sensors.

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