Wafer chuck device and wafer clamping state detection method

Abstract

A wafer chuck device and a wafer clamping state detection method. In a wafer chuck device (100), a first rotating member (120) is coaxial with a base (110), and a driving electric motor (101) is used for driving the base (110) and the first rotating member (120) to rotate relative to each other; a first end (131) of an elastic member (130) is fixedly connected to the base (110), a second end (132) thereof is fixedly connected to the first rotating member (120), and when the base (110) and the first rotating member (120) rotate relative to each other, the elastic member (130) generates a stress to cause a change in the torque of the driving electric motor (101); and a second rotating member (140) is provided on the base (110), a clamping member (150) is provided on the second rotating member (140), the second rotating member (140) is in transmission connection with the first rotating member (120), and when the base (110) and the first rotating member (120) rotate relative to each other, the second rotating member (140) self-rotates, and drives the clamping member (150) to rotate between an open position, a clamping position and a closed position, wherein the clamping position indicates the position of the clamping member (150) when a wafer (W) is clamped. The wafer chuck device (100) is configured to output the relationship between the rotation angle and the torque of the driving electric motor (101) during a process of loading the wafer (W) and / or unloading the wafer (W).

Description

Wafer chuck device and wafer clamping state detection method Technical Field

[0001] The present application relates to the field of semiconductor manufacturing, and in particular to a wafer chuck device and a method for detecting a wafer clamping state. Background Art

[0002] In a wafer processing chamber, a wafer clamping device (also known as a chuck) is typically used to hold the wafer and rotate it for various processes. If the clamping device does not properly clamp the wafer and then starts operating, it can damage the wafer. To detect the wafer's clamping status, one or more sensors can be installed in the wafer processing chamber to detect whether the wafer is properly clamped. If not, the process is shut down to prevent damage.

[0003] Patent CN115458471A proposes a chuck device and a method for detecting the status of a wafer. This patent sets a position detection component in the chuck device to detect the relative position parameters of the chuck base and the drive disk, and uses the relative position parameters to determine whether the chuck device is clamping the wafer. However, in addition to increasing costs, setting up a sensor will also reduce the maintainable space in the cavity. In addition, in wafer liquid processing chambers, such as cleaning machines, the splash protection design of the sensor must be considered, which brings difficulties to the design. In addition, in high-process chambers with high requirements for cavity sealing, holes must be opened in the cavity to meet the lead-out of the sensor circuit, which brings difficulties to the sealing design.

[0004] Summary of the Invention

[0005] The present application provides a wafer chuck device that directly obtains the wafer clamping state according to the relationship between the rotation angle and torque of the driving motor of the chuck device, so as to solve the problem that the wafer clamping state is difficult to detect.

[0006] To solve the above technical problems, one aspect of the present application provides a wafer chuck device, comprising: a base, a drive motor, a first rotating member, a second rotating member, a clamping member, and an elastic member, wherein the first rotating member is coaxial with the base, and the drive motor is used to drive the base and the first rotating member to rotate relative to each other; the elastic member has a first end and a second end, the first end is fixedly connected to the base, and the second end is fixedly connected to the first rotating member, when the base and the first rotating member rotate relative to each other, the elastic member generates stress to cause the drive motor to generate a torque change; the second rotating member is arranged on the base, and the clamping member is arranged on the second rotating member, and the second rotating member is transmission-connected to the first rotating member, when the base and the first rotating member rotate relative to each other, the second rotating member rotates and drives the clamping member to rotate between an open position, a clamping position, and a closed position, wherein the clamping position represents the position of the clamping member when the wafer is clamped; wherein the wafer chuck device is configured to output the relationship between the rotation angle and torque of the drive motor during the process of loading and / or unloading wafers.

[0007] Another aspect of the present application provides a method for detecting the wafer clamping state, comprising: obtaining the relationship between the rotation angle and torque of the drive motor during the process of loading and / or unloading the wafer; and judging whether the wafer clamping is normal based on the relationship.

[0008] The wafer chuck device and monitoring method of the present application utilize the relationship between the rotation angle and torque that can be obtained by the driving motor of the wafer chuck device itself during the process of loading and unloading wafers, and judge whether the wafer clamping is normal or abnormal based on the corresponding rotation angle when the torque suddenly changes. It does not require the aid of additional sensor devices, sealing devices, etc., and has the advantages of simple structure and low cost, and is suitable for any type of wafer processing chamber.

[0009] Summary of the Figures

[0010] The accompanying drawings are included to provide a further understanding of the present application. They are incorporated into and constitute a part of this application. The accompanying drawings illustrate embodiments of the present application and, together with this specification, serve to explain the principles of the present application. In the accompanying drawings:

[0011] 1 and 2 are schematic diagrams of the three-dimensional structure of a wafer chuck device according to an embodiment of the present application;

[0012] 3 and 4 are front cross-sectional views of the wafer chuck device according to the embodiment shown in FIG. 1 ;

[0013] FIG5 is a schematic diagram of a wafer chuck device according to an embodiment of the present application when normally clamping a wafer;

[0014] FIG6 is an enlarged schematic diagram of area A in FIG5 ;

[0015] FIG7 is a top view of a wafer chuck device according to another embodiment of the present application;

[0016] FIG8 is a top view of a wafer chuck device according to another embodiment of the present application;

[0017] FIG9 is a schematic diagram of a wafer chuck device according to an embodiment of the present application when the wafer is not clamped;

[0018] FIG10 is an enlarged schematic diagram of area B in FIG9 ;

[0019] FIG11 is a schematic diagram showing a relationship curve between the rotation angle and torque of the drive motor during wafer unloading when the wafer is clamped normally;

[0020] FIG12 is a schematic diagram showing a relationship curve between the rotation angle and torque of the drive motor during wafer unloading when wafer clamping is abnormal;

[0021] FIG13 is a schematic diagram showing a relationship curve between the rotation angle and torque of the drive motor during wafer loading when the wafer is normally clamped;

[0022] FIG14 is a schematic diagram showing a relationship curve between the rotation angle and torque of the drive motor during wafer loading when wafer clamping is abnormal;

[0023] 15A-15C are schematic diagrams showing the process of unloading a wafer when the wafer is clamped normally;

[0024] 16A-16C are schematic diagrams showing the process of unloading a wafer when wafer clamping is abnormal.

[0025] Preferred embodiment of this application

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the following is a brief introduction to the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0027] As used herein, unless the context clearly indicates otherwise, the terms "a," "an," "an," and / or "the" are not intended to refer to the singular but may include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0028] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to actual proportional relationships. The techniques, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values ​​should be interpreted as being merely exemplary and not as limitations. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0029] In the description of this application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of this application; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0030] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0031] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is solely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. Furthermore, while the terms used in this application are selected from commonly known and commonly used terms, some terms mentioned in this specification may have been selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant sections of this description. Furthermore, this application should be understood not only by the actual terms used, but also by the meaning implied by each term.

[0032] Flowcharts are used in this application to illustrate the operations performed by systems according to embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the various steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0033] The wafer chuck device of the present application can be used in various wafer processing chambers, including but not limited to dry process chambers, wet process chambers, etc. In addition to being suitable for various applicable wafer processing processes, the wafer chuck device of the present application is also suitable for detecting the clamping state of the wafer when needed, without the need for additional sensor devices.

[0034] Figures 1 and 2 are schematic diagrams of the three-dimensional structure of a wafer chuck device according to an embodiment of the present application, and the two have different perspectives. Figures 3 and 4 are front cross-sectional views of the wafer chuck device according to the embodiment shown in Figure 1. Figure 5 is a top perspective view of the wafer chuck device in Figure 1. As shown in Figures 1 to 5, the wafer chuck device 100 of this embodiment includes a base 110, a drive motor 101, a first rotating member 120, an elastic member 130, a second rotating member 140 and a clamping member 150. Among them, the drive motor 101 is used to drive the base 110 and / or the first rotating member 120 to rotate, so as to drive the wafer W to perform various process steps. This application does not limit the driving principle of the drive motor 101.

[0035] In some embodiments, as shown in Figures 1 and 2, the wafer chuck device 100 further includes a rotating shaft 210 disposed below the base 110. The drive motor 101 is used to drive the rotating shaft 210 to rotate, thereby driving the base 110 and / or the first rotating member 120 to rotate. The drive motor 101 can be installed in the rotating shaft 210 or externally connected to the wafer chuck device 100 and connected to the rotating shaft 210 to control the rotation of the rotating shaft 210.

[0036] In some embodiments, as shown in FIG3 , the base 110 includes an integral upper base 111 and a lower base 112, as well as a hollow structure 113 located between the upper base 111 and the lower base 112. The first rotating member 120 and the second rotating member 140 are both disposed in the hollow structure 113. The lower base 112 has an upwardly protruding central axis 114 in the middle, and the first rotating member 120 is sleeved on the outer ring of the central axis 114. When the drive motor 101 drives the base 110 to rotate, the upper base 111 and the lower base 112 rotate simultaneously. In some embodiments, the drive motor 101 can simultaneously drive the first rotating member 120 and the base 110 to rotate synchronously.

[0037] In the wafer chuck device 100 of the present application, the drive motor 101 can drive the base 110 and the first rotating member 120 to rotate relative to each other. For example, the drive motor 101 can drive the first rotating member 120 to rotate while the base 110 is stationary; the drive motor 101 can drive the base 110 to rotate while the first rotating member 120 is stationary; or the drive motor 101 can drive the base 110 to rotate in a first direction while simultaneously driving the base 110 to rotate in a second direction, the first direction and the second direction being opposite. This application will be described using the example of the drive motor 101 driving the base 110 to rotate.

[0038] In conjunction with Figures 1 and 5 , the first rotating member 120 can be implemented as a large gear with gear teeth on its outer ring. The large gear is coaxial with the base 110, and its diameter is slightly smaller than that of the base 110. The second rotating member 140 is mounted on the base 110, for example, fixedly connected to the lower base 112. The second rotating member 140 can also rotate about its own axis. The diameter of the second rotating member 140 is smaller than the distance between the outer periphery of the large gear and the outer periphery of the base 110. As shown in Figure 5 , the second rotating member 140 can be implemented as a small gear with gear teeth on its outer ring, and the gear teeth of the large gear match those of the small gear. Therefore, when the base 110 and the first rotating member 120 rotate relative to each other, the second rotating member 140 is driven to rotate. It should be noted that although Figure 5 shows gear teeth on the outer ring of the large gear, in other embodiments, gear teeth may be present only in the portion of the outer ring of the large gear that mates with the second rotating member 140, while the remaining portion may be devoid of gear teeth.

[0039] 5 , the plurality of second rotating members 140 are evenly spaced around the circumference of the first rotating member 120 , and each second rotating member 140 is provided with a clamping member 150 . In other embodiments, the plurality of second rotating members 140 may also be unevenly spaced.

[0040] In some embodiments, as shown in FIG1 , the clamping member 150 specifically includes a clamping column 151 and an eccentric cylinder 152. The clamping column 151 is coaxial with the second rotating member 140, and the eccentric cylinder 152 is eccentrically disposed on the upper surface of the clamping column 151. When clamping a wafer W, the wafer W is placed on the upper surface of the clamping column 151 and supported by the upper surface of the clamping column 151. At the same time, when the second rotating member 140 rotates, the eccentric cylinder 152 can rotate toward or away from the center of the wafer W, thereby changing the diameter of the circle formed by the multiple eccentric cylinders 152. Rotation of the eccentric cylinder 152 away from the center of the wafer W is denoted as opening the clamping member, and rotation of the eccentric cylinder 152 toward the center of the wafer W is denoted as closing the clamping member. It is understood that when unloading a wafer W, the clamping member 150 must first be opened to release the wafer W. When loading a wafer W, the clamping member 150 must also be opened first, and after the wafer W is placed on the upper surface of the clamping column 151, the clamping member 150 is closed. The rotation angle of the second rotating member 140 is adjusted according to the size of the wafer W so that the multiple eccentric cylinders 152 can clamp the wafer W together. The clamping member 150 simultaneously supports, clamps, and defines the position of the wafer W. When opened, the multiple clamping members 150 are in the open position, at which time the diameter of the enclosed circle is larger, and the wafer chuck device 100 is in the open state; when clamping the wafer normally, the multiple clamping members 150 are in the clamping position, at which time the diameter of the enclosed circle is smaller than the diameter in the open position, and the wafer chuck device 100 is in the clamping state; in the idle state without clamping the wafer, the multiple clamping members 150 can be in the closed position, at which time the diameter of the enclosed circle is smaller than the diameter in the clamping position, and the wafer chuck device 100 is in the closed state.

[0041] Figures 7 and 8 are schematic top views of wafer chuck devices according to two other embodiments, used to illustrate two other first and second rotating members, respectively. As shown in Figure 7, the first rotating member 710 is snowflake-shaped, with a central portion 711 sleeved around the periphery of the central axis 114. A plurality of support rods 712 are radially arranged outward from the central portion 711. The ends of each support rod 712 are movably connected to the second rotating member 720 via a connecting rod 730. In some embodiments, a multi-section connecting rod 730 can be used to movably connect the support rods 712 and the second rotating member 720. When the first rotating member 710 and the base 110 rotate relative to each other, the first rotating member 710 pushes the second rotating member 720 to rotate via the connecting rod 730, thereby causing the clamping member 150 located on the second rotating member 720 to rotate between an open position, a clamped position, and a closed position.

[0042] As shown in FIG8 , the first rotating member 810 is also snowflake-shaped, with a central portion 811 sleeved around the periphery of the central axis 114. Several support rods 812 are radially arranged outward from the central portion 811, with the end 813 of each support rod 812 abutting against the second rotating member 820. The second rotating member 820 is a cam having two protrusions 831 and 832, with the end 813 of the support rod 812 abutting against the area between the two protrusions 831 and 832. When the first rotating member 810 and the base 110 rotate relative to each other, the end 813 of the first rotating member 810 pushes the second rotating member 820 to rotate within a certain range. This rotation causes the clamping member 150 located on the second rotating member 820 to rotate between an open position, a clamped position, and a closed position.

[0043] Other structures in the embodiments shown in FIG. 7 and FIG. 8 are similar to those in the embodiment shown in FIG. 5 , and may be explained with reference to the description of FIG. 5 .

[0044] As shown in Figure 5, the elastic member 130 has a first end 131 and a second end 132. The first end 131 is fixedly connected to the base 110, and the second end 132 is fixedly connected to the first rotating member 120. In this embodiment, the elastic member 130 is implemented as a spring. When the first rotating member 120 and the base 110 rotate synchronously, the elastic member 130 is in a predetermined tension state. This predetermined tension state is different when a wafer is present and when no wafer is present. More specifically, the first rotating member 120 also includes a plurality of radially extending spokes 510. Specifically, the first rotating member 120 includes an inner ring 501 and an outer ring 502, which are connected by the spokes 510. The first end 131 of the elastic member 130 can be positioned anywhere on the base 110, for example, on the lower surface of the upper base 111 or the upper surface of the lower base 112. Thus, when the base 110 rotates, the first end 131 moves. The second end 132 of the elastic member 130 is specifically arranged on the spoke 510. When the first rotating member 120 rotates, the second end 132 is also driven to move. FIG5 is only an example. In other embodiments, the first rotating member 120 does not include spokes but other frame structures, and the second end 132 of the elastic member 130 can be set at any position on the frame structure. When the base 110 or the first rotating member 120 is driven to rotate, since the base 110 and the first rotating member 120 are connected by the elastic member 130 and have a linkage relationship, when the stress meets certain conditions, the base 110 and the first rotating member 120 rotate together, and maintain a certain relative position relationship between the two. At this time, the length of the elastic member 130 is maintained at a certain length, and the torque output by the drive motor 101 is a smaller torque. The inventors of the present application discovered that when the base 110 and the first rotating member 120 rotate relative to each other, the elastic member 130 generates a large stress, which causes the torque of the drive motor 101 to change suddenly. The rotation angle corresponding to the sudden change is different when the wafer is clamped normally and when the wafer is clamped abnormally. Therefore, the wafer chuck device 100 of the present application is configured to output the relationship between the rotation angle and torque of the drive motor 101 during the process of loading and / or unloading wafers. In this way, it can be judged whether the wafer clamping is normal or abnormal based on this relationship. Among them, the rotation angle and corresponding torque of the drive motor 101 are parameters that can be obtained by the drive motor 101 itself and can be selectively output. According to the working principle of the drive motor 101, its rotation angle can be obtained according to the encoder, and its torque can be obtained according to the current.

[0045] The wafer chuck device 100 of the present application has a simple structure and does not require the installation of additional, specific sensors. By outputting the relationship between the rotation angle and torque of the drive motor 101, it can be used to judge whether the wafer clamping is normal or abnormal during the process of loading and unloading wafers. It has the advantages of low cost, high feasibility and strong practicality.

[0046] Furthermore, in some embodiments, the wafer chuck device 100 is configured to determine whether wafer clamping is normal based on the relationship between the rotation angle and torque of the drive motor 101, wherein the corresponding rotation angle when the torque of the drive motor 101 undergoes a sudden change is different when the wafer clamping is normal and when the wafer clamping is abnormal. A sudden change in torque indicates a sudden increase or decrease in torque, which can be determined by the rate of change of torque with the rotation angle. For example, a torque sudden change is determined by setting the rate of change of torque to a threshold value, and the threshold value can be a positive or negative number.

[0047] Furthermore, the inventors of the present application have discovered in practice that the relationship between the rotation angle and the torque has different rules when unloading the wafer, loading the wafer, and when the wafer is clamped normally or abnormally, thereby obtaining different configuration methods of the wafer chuck device 100. One method is: in the process of unloading the wafer, the clamping member 150 is switched to the open position. During this process, the rate of change of the torque is obtained. When the rate of change reaches a first preset value, it is determined that the torque of the drive motor 101 has a sudden change and the corresponding rotation angle is recorded as the unloading angle. When the unloading angle is within the first angle range, it indicates that the wafer is clamped normally. When the unloading angle is not within the first angle range, it indicates that the wafer is clamped abnormally. Furthermore, a second angle range can also be set. When the unloading angle is within the second angle range, it indicates that the wafer is clamped abnormally, wherein the first angle range is greater than the second angle range, that is, the angles within the first angle range are all greater than the angles within the second angle range.

[0048] Another method is as follows: during wafer loading, the clamping member 150 performs a wafer clamping action from the open position. During this process, the rate of change of the torque is obtained. When the rate of change reaches a second preset value, it is determined that a sudden change has occurred in the torque of the drive motor 101 and the corresponding rotation angle is recorded as the loading angle. When the loading angle is within a third angle range, it indicates that the wafer is clamped normally. When the loading angle is not within the third angle range, it indicates that the wafer is clamped abnormally. Furthermore, a fourth angle range can be set. When the loading angle is within the fourth angle range, it indicates that the wafer is clamped abnormally. The third angle range is smaller than the fourth angle range, that is, all angles within the third angle range are smaller than the angles within the fourth angle range.

[0049] The first angle range, the second angle range, the third angle range, and the fourth angle range can be set by setting the first limiting member and the second limiting member and the positional relationship between the first limiting member and the first rotating member 120 .

[0050] As shown in Figures 5 and 6, in this embodiment, the wafer chuck device 100 also includes a first limiter 160 for preventing the first rotating member 120 or the base 110 from rotating, so that the first rotating member 120 and the base 110 change from synchronous rotation to relative rotation. As shown in Figures 1 and 2, in some embodiments, the wafer chuck device 100 includes a fixed seat 220, which is set independently of the rotating shaft 210. During the process, the position of the fixed seat 220 remains unchanged. Furthermore, a cylinder 230 is set on the fixed seat 220, and the first limiter 160 is a limit column set on the cylinder 230. The cylinder 230 is used to control the extension and contraction of the first limiter 160 in the vertical direction. Figure 2 shows two cylinders 230 and two first limiters 160, and the two first limiters 160 are respectively located on both sides of the rotating shaft 210 and are symmetrically distributed. Figure 2 is merely an example. This application does not limit the number or position of the first position-limiting members 160. This application does not limit how the first position-limiting members 160 are extended or retracted. Other methods besides a pneumatic cylinder can be used to control the position of the first position-limiting members 160. It will be appreciated that when multiple first position-limiting members 160 are provided, these multiple first position-limiting members 160 will collectively extend and retract to prevent the first rotating member 120 or the base 110 from rotating. The following description uses the example of the first position-limiting member 160 preventing the first rotating member 120 from rotating.

[0051] As shown in FIG3 , the first stopper 160 is in a retracted state, with its end not extending into the base 110. In this state, the first stopper 160 cannot function as a stopper. During wafer processing, the wafer chuck assembly 100 rotates the wafer W, and the first stopper 160 is in a retracted state. As shown in FIG4 , the first stopper 160 is in an extended state, with its end extending into the base 110, thereby preventing the first rotating member 120 or the base 110 from rotating. More specifically, referring to FIG4 and FIG5 , the lower base 112 has a stopper hole 410. Furthermore, a hollow structure 420 is formed between the multiple spokes 510 of the first rotating member 120. The first stopper 160 extends into this hollow structure 420. When the first stopper 160 reaches an appropriate height, it contacts the spokes 510, thereby preventing the first rotating member 120 from rotating.

[0052] It will be understood that FIG5 is merely an example. In other embodiments, the first stopper 160 may be implemented in other specific embodiments. For example, if the first rotating member 120 does not include the spokes 510 but instead includes some other structure, such as an arbitrary frame structure, a stopper may be provided at any position on the first rotating member 120 as a stopper. During wafer processing, the stopper does not affect the normal rotation of the first rotating member 120. When wafers need to be loaded or unloaded, the first stopper 160 extends and contacts the stopper, thereby preventing the first rotating member 120 from rotating.

[0053] As shown in FIG5 , this embodiment further includes a second limiting member 170 disposed on the base 110 for limiting the relative position between the first rotating member 120 and the base 110. For example, the second limiting member 170 is a limiting post disposed on the lower surface of the upper base 111, or a limiting post disposed on the upper surface of the lower base 112.

[0054] Figure 5 shows the state in which the clamping member 150 is in the clamping position and clamping the wafer W. Figure 6 is an enlarged schematic diagram of area A in Figure 5. As shown in Figure 6, in this state, a first angle a is formed between a limiting spoke 511 among the spokes 510 and the first limiting member 160, and the first angle a is within a first angular range. The angle between the limiting spoke 511 and the first limiting member 160 represents the angle between the first rotating member 120 and the first limiting member 160. At the same time, a third angle m is formed between the limiting spoke 511 and the second limiting member 170. The angle between the limiting spoke 511 and the second limiting member 170 represents the angle between the first rotating member 120 and the base 110.

[0055] In this embodiment, the second limiting member 170 is disposed on the right side of the limiting spoke 511 to limit the maximum position that the first rotating member 120 can reach when rotating clockwise. In other embodiments, such as that shown in FIG6 , the second limiting member further includes a second limiting member 171 to limit the maximum position that the first rotating member 120 can reach when rotating counterclockwise.

[0056] FIG9 is a schematic diagram of the wafer chuck device according to an embodiment of the present application when the wafer is not clamped, and the clamping member 150 is in a closed position, wherein W′ is used to indicate the position where the wafer W should be. At this time, it is assumed that the angle between the base 110 and the first rotating member 120 is 0. FIG10 is an enlarged schematic diagram of area B in FIG9 . As shown in FIG10 , in this state, the limiting spoke 511 contacts the second limiting member 170, so that the first rotating member 120 is blocked and cannot rotate to the right relative to the base 110. At the same time, a second angle c is formed between the limiting spoke 511 and the first limiting member 160, and the second angle c is within the second angular range.

[0057] FIG11 is a diagram showing a relationship curve between the rotation angle of the drive motor 101 and the torque during the unloading process of the wafer when the wafer is clamped normally; FIG12 is a diagram showing a relationship curve between the rotation angle of the drive motor 101 and the torque during the unloading process of the wafer when the wafer is clamped abnormally. In FIG11 and FIG12, the horizontal axis is the rotation angle of the drive motor 101, and the unit is degree; the vertical axis is the torque output by the drive motor 101, and the unit is Nm. FIG15A-FIG15C are schematic diagrams showing the process of unloading the wafer when the wafer is clamped normally, wherein the states of FIG15A, FIG15B, and FIG15C occur sequentially when the wafer is unloaded. In this embodiment, it is assumed that the base 110 is rotated clockwise to open the clamping member 150, and the base 110 is rotated counterclockwise to close the clamping member 150. As shown in Figure 15A , base 110 is in the HOME position. Clamping member 150 is in the clamping position, raising first stopper 160. The positional relationship between stopper spokes 511 in first rotating member 120 and first and second stoppers 160, 170 is shown in Figures 5 and 6 . Stopper spokes 511 form a second angle a with first stopper 160 and a third angle m with second stopper 170. To unload wafers, drive motor 101 rotates base 110 clockwise. Base 110, first rotating member 120, and second rotating member 140 rotate together as a whole, while the stretched length of elastic member 130 remains unchanged. When the rotation angle between the base 110 and the first rotating member 120 reaches a value equal to a, the first rotating member 120 is blocked by the first stopper 160, as shown in Figure 15B . At this point, the base 110 continues to rotate clockwise, stretching the elastic member 130 and causing a sudden change in the torque of the drive motor 101. As shown in Figure 11 , when the rotation angle reaches a, the torque suddenly increases, as indicated by the vertical line segment 1111 in Figure 11 . A first preset value is set, and the rate of change of the torque with the rotation angle is compared with the first preset value. If the rate of change exceeds the first preset value, it indicates a sudden change in torque. According to Figure 11 , the torque sudden change occurs at a rotation angle near a. Thereafter, the base 110 continues to rotate clockwise. As the rotation angle increases, the torque continues to increase, but the rate of change decreases, as indicated by the oblique line segment 1112 in Figure 11 , until the clamping member 150 reaches the preset open position, as shown in Figure 15C . At this point, the rotation angle e of the drive motor 101 is equal to and the torque is equal to T. The rotation angle e corresponding to the open position can be preset. In the open position, the diameter of the circle formed by the multiple clamps 150 is larger than the diameter of the wafer W. At this point, the robot can unload the wafer or load one when no wafer is available. As shown in Figure 11, the first angle range is approximately a, e.g., [a - ε, a + ε], where ε is a tolerance. If the rotation angle is outside this first angle range when the torque suddenly changes during wafer unloading, it indicates a wafer clamping anomaly.

[0058] Figures 16A - 16C show schematic diagrams of the process of unloading a wafer when wafer clamping is abnormal. When wafer clamping is abnormal, the clamping state of the clamping member 150 is the same as the state of not clamping the wafer, being in the closed position. It is considered that abnormal wafer clamping is equivalent to not clamping the wafer. Figure 16A is used to represent the initial state in the process of unloading the wafer when wafer clamping is abnormal. At this time, the positional relationship between the limiting spoke 511 in the first rotating member 120 and the first limiting member 160 and the second limiting member 170 is as shown in Figures 9 and 10. The limiting spoke 511 contacts the second limiting member 170, and the first rotating member 120 is restricted by the second limiting member 170 at a limit position. At the same time, there is a first included angle c between the limiting spoke 511 and the first limiting member 160. In order to unload the wafer, the drive motor 101 drives the base 110 to rotate clockwise. The base 110, the first rotating member 120, and the second rotating member 140 rotate together as a whole, and the stretching length of the elastic member 130 remains unchanged. When the rotation angle of the base 110 and the first rotating member 120 together is equal to c, the first rotating member 120 is blocked by the first limiting member 160, as shown in Figure 16B. At this time, the base 110 continues to rotate clockwise, causing the elastic member 130 to be stretched, and the torque of the drive motor 101 undergoes a sudden change. As shown in Figure 12, when the rotation angle is equal to c, the torque suddenly rises. At this time, the unloading angle is c. In the second angle range, that is, [c - ε, c + ε], c < a < e. The second angle range has no intersection with the first angle range. It can be judged that wafer clamping is abnormal according to the unloading angle within the second angle range. Thereafter, as the rotation angle continues to increase, the torque keeps rising until the clamping member 150 reaches the preset open position, as shown in Figure 16C. At this time, the rotation angle is e and the torque is T.

[0059] Combined with Figures 6 and 10, the first included angle a is equal to the sum of the second included angle c and the third included angle m.

[0060] Figure 13 is a schematic diagram of the relationship between the rotation angle and torque of the drive motor 101 during wafer loading when wafer clamping is normal; Figure 14 is a schematic diagram of the relationship between the rotation angle and torque of the drive motor 101 during wafer loading when wafer clamping is abnormal. In Figures 13 and 14, the horizontal axis is the rotation angle of the drive motor 101, in degrees; the vertical axis is the torque output by the drive motor 101, in Nm. The process of loading a wafer when wafer clamping is normal in Figure 13 can be explained in conjunction with Figures 15C and 15A. The states of Figures 15C, 15B, and 15A occur sequentially during wafer loading. In this embodiment, Figure 15C represents the initial state when loading the wafer, that is, the clamping member 150 is in the open position. As the reverse process of unloading the wafer, from Figure 15C to Figure 15A, the total rotation angle of the drive motor 101 is e. Figure 15C is used to represent the initial state of loading the wafer. At this time, the rotation angle of the drive motor 101 is 0, and the clamping member 150 is in the open position. At this time, the angle between the limiting spoke 511 and the second limiting member 170 is the fourth angle d. Rotate the base 110 counterclockwise to close the clamping member 150. As shown in Figure 13, the stretched length of the elastic member 130 gradually shortens, and the torque gradually decreases from T. When the rotation angle reaches approximately b, b = dm, the clamping member 150 abuts the edge of the wafer, and the wafer is normally loaded and clamped. At this time, the base 110, the elastic member 130, and the first rotating member 120 are in a balanced state. The drive motor 101 no longer bears the stress generated by the elastic member 130, causing the torque of the drive motor 101 to suddenly decrease. As shown in Figure 13, when the rotation angle reaches b, the torque suddenly decreases, which is represented by the vertical line segment 1311 in Figure 13. By setting a second preset value, the rate of change of the torque with the rotation angle is compared with the second preset value. If the rate of change exceeds the second preset value, it indicates that the torque has suddenly changed. According to Figure 13, the corresponding rotation angle when the torque suddenly changes is near b. From angle b to angle e, the first rotating member 120 rotates synchronously with the base 110 under the action of the elastic member 130 until the state shown in Figure 15A is reached, at which point the base 110 returns to the home position. According to Figure 13 , the third angle range is approximately b, for example, [b - ε, b + ε], where ε is a tolerance. If the angle at which the torque suddenly changes during wafer loading is not within this third angle range, the wafer is properly clamped. In other words, the difference between the fourth angle d and the third angle m is within the third angle range.

[0061] In some embodiments, the first preset value and the second preset value have the same absolute value and opposite signs.

[0062] Combined with Figures 16C and 16A, the process of loading the wafer when the wafer clamping is abnormal in Figure 14 is explained. The states of Figures 16C, 16B, and 16A occur in sequence when loading the wafer. In this embodiment, Figure 16C represents the initial state when loading the wafer. At this time, the angle between the limiting spoke 511 and the second limiting member 170 is d, and d>b. As shown in Figure 14, when the rotation angle of the counterclockwise rotation base 110 is d, the torque of the drive motor 101 suddenly decreases, and the loading angle at this time is within the fourth range, that is, [d-ε, d+ε]. Comparing Figures 13 and 14, b is less than d, and [b-ε, b+ε] and [d-ε, d+ε] can be clearly distinguished. By setting reasonable b and d, it can be determined whether the wafer clamping is normal.

[0063] Based on the wafer chuck device 100 described above, a method for detecting a wafer clamping state according to an embodiment of the present application includes the following steps:

[0064] Step S01: obtaining a relationship between a rotation angle and torque of the drive motor 101 during a process of loading and / or unloading a wafer;

[0065] Step S02: judging whether the wafer clamping is normal based on the relationship.

[0066] The steps of the detection method have been described above in conjunction with the wafer chuck device 100, and the same contents will not be repeated here.

[0067] The application scenarios of this detection method include: judging whether the wafer clamping is normal in the previous process when the wafer is unloaded at the end of the previous process; judging whether the wafer clamping is normal in the next process when the wafer is loaded at the beginning of the next process.

[0068] The wafer chuck device 100 and the wafer clamping state detection method of the present application do not require the aid of additional sensor devices. Based on the relationship between the rotation angle and torque that can be obtained by the drive motor 101 itself, the normal or abnormal wafer clamping can be judged according to the corresponding rotation angle when the torque suddenly changes. It has the advantages of simple structure and low cost.

[0069] The basic concepts have been described above. It will be apparent to those skilled in the art that the above disclosures are merely examples and do not limit the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and revisions to the present application. Such modifications, improvements, and revisions are suggested in the present application and remain within the spirit and scope of the exemplary embodiments of the present application.

[0070] At the same time, this application uses specific terms to describe the embodiments of this application. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "one embodiment," "an embodiment," or "an alternative embodiment" mentioned twice or multiple times in different locations in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application may be appropriately combined.

[0071] Some aspects of the present application can be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software can be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". The processor can be one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors or combinations thereof. In addition, various aspects of the present application may be expressed as computer products located in one or more computer-readable media, which include computer-readable program code. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, tapes...), optical disks (e.g., compact disks CDs, digital versatile disks DVDs...), smart cards, and flash memory devices (e.g., cards, sticks, key drives...).

[0072] A computer-readable medium may include a propagated data signal embodying computer program code, for example, in baseband or as part of a carrier wave. The propagated signal may be in a variety of forms, including electromagnetic, optical, etc., or a suitable combination thereof. A computer-readable medium may be any computer-readable medium other than a computer-readable storage medium that can be connected to an instruction execution system, apparatus, or device to communicate, propagate, or transmit the program for use. The program code on the computer-readable medium may be transmitted via any suitable medium, including radio, cable, fiber optic cable, radio frequency signal, or similar medium, or any combination of the above.

[0073] Similarly, it should be noted that, in order to simplify the presentation of this application and thus facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this application sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not mean that the subject matter of this application requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single embodiment disclosed above.

[0074] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in this application are all approximate values, which may change according to the required characteristics of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0075] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions can be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the scope of the essential spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A wafer chuck device, characterized in that: include: A base, a driving motor, a first rotating member, a second rotating member, a clamping member and an elastic member, Wherein, the first rotating member is coaxial with the base, and the driving motor is used to drive the base and the first rotating member to rotate relative to each other; The elastic member has a first end and a second end, the first end is fixedly connected to the base, and the second end is fixedly connected to the first rotating member, and when the base and the first rotating member rotate relative to each other, the elastic member generates stress to make the driving motor generate torque changes; The second rotating member is arranged on the base, the clamping member is arranged on the second rotating member, the second rotating member is in transmission connection with the first rotating member, when the base and the first rotating member rotate relatively, the second rotating member rotates and drives the clamping member to rotate between an open position, a clamping position and a closed position, wherein the clamping position indicates the position of the clamping member when the wafer is clamped; Wherein, the wafer chuck device is configured to output the relationship between the rotation angle and torque of the drive motor during the process of loading and / or unloading the wafer.

2. The wafer chuck device according to claim 1, characterized in that: The wafer chuck device is configured to determine whether the wafer clamping is normal based on the relationship between the rotation angle and torque of the drive motor, wherein the corresponding rotation angle when the torque of the drive motor changes suddenly is different when the wafer clamping is normal and when the wafer clamping is abnormal.

3. The wafer chuck device according to claim 2, characterized in that: The wafer chuck device is also configured as follows: during the process of unloading the wafer, the clamping member is switched to an open position, and when the rate of change of the torque reaches a first preset value, it is determined that a sudden change has occurred in the torque of the drive motor and the corresponding rotation angle is recorded as the unloading angle, and when the unloading angle is within a first angle range, it indicates that the wafer is clamped normally, and when the unloading angle is not within the first angle range, it indicates that the wafer is clamped abnormally.

4. The wafer chuck device according to claim 3, characterized in that: The wafer chuck device is further configured to indicate wafer clamping abnormality when the unloading angle is within a second angle range, wherein the first angle range is greater than the second angle range.

5. The wafer chuck device according to claim 2, characterized in that: The wafer chuck device is also configured as follows: during the process of loading the wafer, the clamping member performs the wafer clamping action from the open position, and when the rate of change of the torque reaches a second preset value, it is determined that the torque of the drive motor has changed suddenly and the corresponding rotation angle is recorded as the loading angle, and when the loading angle is within a third angle range, it indicates that the wafer clamping is normal, and when the loading angle is not within the third angle range, it indicates that the wafer clamping is abnormal.

6. The wafer chuck device according to claim 5, characterized in that: The wafer chuck device is further configured to indicate wafer clamping abnormality when the loading angle is within a fourth angle range, wherein the third angle range is smaller than the fourth angle range.

7. The wafer chuck device according to claim 4, characterized in that: It also includes a first limiting member, which is used to prevent the first rotating member or the base from rotating, so that the first rotating member and the base change from synchronous rotation to relative rotation.

8. The wafer chuck device according to claim 7, characterized in that: When the clamping member is in the clamping position, a first angle is defined between the first rotating member and the first limiting member, and the first angle is within the first angle range.

9. The wafer chuck device according to claim 8, characterized in that: When the clamping member is in the closed position, a second angle (c) is formed between the first rotating member and the first limiting member, and the second angle is within the second angle range.

10. The wafer chuck device according to claim 9, characterized in that: The second angle is smaller than the first angle.

11. The wafer chuck device according to claim 6, wherein: It also includes a second limiting member, which is used to limit the relative position between the base and the first rotating member.

12. The wafer chuck device according to claim 11, wherein: When the clamp is in a closed position, the angle between the base and the first rotating member is 0; when the clamp is in a clamping position, the angle between the base and the first rotating member is a third angle; when the clamp is in an open position, the angle between the base and the first rotating member is a fourth angle, and the fourth angle is within the fourth angle range.

13. The wafer chuck device according to claim 12, wherein: When the wafer is clamped normally, the loading angle is equal to the difference between the fourth angle and the third angle, and the difference between the fourth angle and the third angle is within the third angle range.

14. A method for detecting a wafer clamping state, comprising: During the process of loading and / or unloading the wafer, obtaining the relationship between the rotation angle and the torque of the driving motor; Whether the wafer is clamped normally is determined based on the relationship.

15. The detection method according to claim 14, characterized in that: The step of judging whether the wafer clamping is normal according to the relationship includes judging whether the wafer clamping is normal or abnormal according to the corresponding rotation angle when the torque of the driving motor changes suddenly.

16. The detection method according to claim 15, characterized in that: The steps of judging whether the wafer clamping is normal according to the relationship include: During the process of unloading the wafer, the wafer chuck device is switched to the open state. When the rate of change of the torque reaches a first preset value, it is determined that the torque of the drive motor has changed suddenly and the corresponding rotation angle is obtained as the unloading angle. When the unloading angle is within the first angle range, it indicates that the wafer is clamped normally. When the unloading angle is not within the first angle range, it indicates that the wafer is clamped abnormally.

17. The detection method according to claim 16, characterized in that: Also includes: When the unloading angle is within a second angle range, it indicates that the wafer is clamped abnormally, wherein the first angle range is greater than the second angle range.

18. The detection method according to claim 15, characterized in that: The steps of judging whether the wafer clamping is normal according to the relationship include: During the process of loading the wafer, the wafer chuck device performs a wafer clamping action from an open state. When the rate of change of the torque reaches a second preset value, it is determined that the torque of the drive motor has changed suddenly and the corresponding rotation angle is obtained as the loading angle. When the loading angle is within a third angle range, it indicates that the wafer clamping is normal. When the loading angle is not within the third angle range, it indicates that the wafer clamping is abnormal.

19. The detection method according to claim 18, characterized in that: Also includes: When the loading angle is within a fourth angle range, it indicates that the wafer is clamped abnormally, wherein the third angle range is smaller than the fourth angle range.

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