Electrostatic chuck and semiconductor etching equipment
By integrating pressure detection and optical detection mechanisms into the electrostatic chuck, the wafer is separated only after the electrostatic attraction force is completely removed. This solves the problem that the electrostatic chuck cannot completely remove the electrostatic attraction force, avoids wafer breakage, and improves production efficiency and yield.
Patent Information
- Application Number
- CN202511142138.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-14
- Publication Date
- 2025-11-21
AI Technical Summary
Existing electrostatic chucks cannot completely eliminate electrostatic attraction during de-chuck operations, leading to wafer breakage and low production efficiency.
Design an electrostatic chuck equipped with a pressure detection mechanism and an optical detection mechanism. By combining multiple pressure detection points and optical detection signals, ensure that the electrostatic adsorption force is completely removed before driving the wafer to separate from the chuck.
It effectively prevents wafers from cracking due to residual electrostatic adsorption, thus improving production efficiency and product yield.
Smart Images
Figure CN120998858A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of semiconductor manufacturing equipment technology, and more specifically, relates to an electrostatic chuck and semiconductor etching equipment. Background Technology
[0002] An electrostatic chuck is a clamping device designed based on the principle of electrostatic adsorption. It is primarily used to hold wafers in semiconductor etching processes and is one of the core components of etching equipment. After the etching process is complete, the wafer needs to be released through a de-chuck operation (i.e., releasing the electrostatic adsorption). Specific methods include applying a negative voltage to the electrostatic chuck or directly grounding the electrostatic chuck to eliminate the electrostatic attraction between the wafer and the chuck.
[0003] However, in actual production, abnormal conditions on the wafer backside or the surface of the electrostatic chuck (such as residual charge) may lead to incomplete de-chuck operations, leaving some electrostatic adsorption on the wafer. In this case, directly lifting the wafer may cause it to break (fragment) due to uneven stress, affecting not only product yield but also reducing production efficiency. Summary of the Invention
[0004] The purpose of this application is to provide an electrostatic chuck and a semiconductor etching apparatus to solve the technical problem in the prior art that the electrostatic chuck cannot detect whether the electrostatic adsorption on the wafer caused by the electrostatic chuck has been completely eliminated.
[0005] To achieve the above objectives, a first aspect of this application is to provide an electrostatic chuck for use in a semiconductor etching apparatus, comprising: The chuck body has a bearing end face for carrying the target wafer, and a plurality of first receiving holes and second receiving holes that penetrate the chuck body along the axial direction of the chuck body, the plurality of first receiving holes being spaced apart circumferentially along the chuck body. A pressure detection mechanism is slidably connected in each of the first receiving holes. The pressure detection mechanism is used to lift the target wafer and detect the pressure applied to the target wafer thereon. An optical inspection mechanism, connected within the second receiving aperture, is used to generate a detection signal corresponding to the light beam reflected by the target wafer; When the target wafer is raised to the detection position, if the pressure values detected by the multiple pressure detection mechanisms are equal and the value of the detection signal generated by the optical detection mechanism is within a preset value range, the pressure detection mechanism drives the target wafer to separate from the chuck body.
[0006] Optionally, the plurality of first receiving holes are evenly spaced along the circumference of the chuck body, and a first circular path is formed between the lines connecting the plurality of first receiving holes, the first path being concentrically arranged with the chuck body.
[0007] Optionally, there are multiple second receiving holes, which are evenly spaced along the circumference of the chuck body. A circular second path is formed between the lines connecting the multiple second receiving holes. The second path is concentrically arranged with the chuck body, and the diameter of the second path is smaller than the diameter of the first path.
[0008] Optionally, the pressure detection mechanism includes: The first ejector pin is slidably connected within the first receiving hole; A pressure sensor is connected to the side of the first ejector pin near the target wafer, and is used to abut against the target wafer to detect the pressure applied to it by the target wafer; The first drive seat is connected to the end of the first ejector pin that is furthest from the pressure sensor; A first drive motor is connected to the first drive seat and is used to drive the first drive seat to move the first ejector pin and the pressure sensor within the first receiving hole.
[0009] Optionally, the pressure detection mechanism further includes: The first drive screw extends axially along the first receiving hole and is connected to the shaft of the first drive motor. The first drive seat is provided with a first threaded through hole, and the first drive screw is threadedly connected to the first threaded through hole.
[0010] Optionally, the optical inspection mechanism includes: The second ejector pin is connected to the second receiving hole; A light source emitter, connected to the side of the second pin near the target wafer, is used to emit a detection beam toward the target wafer; A light source receiver is connected to the side of the second pin near the target wafer, for receiving the reflected light beam reflected by the target wafer and converting the received reflected light beam into the detection signal.
[0011] Optionally, the light source emitter and the light source receiver are spaced apart on the second pin; The light source emitter emits a detection beam at an angle to the radial direction of the target wafer.
[0012] Optionally, the second ejector pin is slidably connected within the second receiving hole; The pressure detection mechanism also includes: The second drive seat, the second ejector pin is connected to the second drive seat; The second drive motor is connected to the drive base and is used to drive the second drive base to move the second ejector pin within the second receiving hole.
[0013] Optionally, the pressure detection mechanism further includes: The second drive screw extends axially along the second receiving hole and is connected to the shaft of the second drive motor. The second drive seat has a second threaded through hole, and the second drive screw is threadedly connected to the second threaded through hole.
[0014] The beneficial effects of the electrostatic chuck provided in this application are as follows: Compared with the prior art, the electrostatic chuck provided in this application includes a chuck body, a pressure detection mechanism, and an optical detection mechanism. The chuck body has a bearing end face for carrying the target wafer, and a first receiving hole and a second receiving hole penetrating the chuck body axially. The pressure detection mechanism is slidably connected in the first receiving hole and is used to lift the target wafer and detect the pressure applied to it by the target wafer. The optical detection mechanism is connected in the second receiving hole and is used to generate a detection signal corresponding to the light beam reflected by the target wafer. After the target wafer is lifted to the detection position, if the pressure values detected by the multiple pressure detection mechanisms are equal and the value of the detection signal generated by the optical detection mechanism is within a preset value range, the electrostatic adsorption force applied to the target wafer by the chuck body is completely removed. At this time, the pressure detection mechanism drives the target wafer to separate from the chuck body to prevent the residual electrostatic adsorption force of the chuck body from breaking the target wafer.
[0015] Secondly, this application provides a semiconductor etching apparatus, comprising: An electrostatic chuck, wherein the electrostatic chuck is any one of the electrostatic chucks described above.
[0016] The beneficial effects of the semiconductor etching apparatus provided in this application are as follows: Compared with the prior art, the semiconductor etching apparatus provided in this application includes the above-mentioned electrostatic chuck. The electrostatic chuck includes a chuck body, a pressure detection mechanism, and an optical detection mechanism. The chuck body is provided with a bearing end face for carrying the target wafer, and a first receiving hole and a second receiving hole that penetrate the chuck body along the axial direction of the chuck body. The pressure detection mechanism is slidably connected in the first receiving hole. The pressure detection mechanism is used to lift the target wafer and detect the pressure applied to it by the target wafer. The optical detection mechanism is connected in the second receiving hole and is used to generate a detection signal corresponding to the light beam reflected by the target wafer. After the target wafer is lifted to the detection position, if the pressure values detected by the multiple pressure detection mechanisms are equal and the value of the detection signal generated by the optical detection mechanism is within a preset value range, the electrostatic adsorption force applied to the target wafer by the chuck body is completely removed. At this time, the pressure detection mechanism drives the target wafer to separate from the chuck body to prevent the target wafer from being broken by the residual electrostatic adsorption force of the chuck body. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of the structure of the electrostatic chuck provided in the embodiments of this application; Figure 2 This is a structural schematic diagram of the electrostatic chuck provided in an embodiment of this application from another perspective; Figure 3 This is a schematic diagram of the structure when the target wafer is located at the detection position after the static charge on the chuck body has been completely removed; Figure 4 This is a schematic diagram of the optical inspection mechanism inspecting the wafer after the static charge on the chuck body has been completely removed. Figure 5 This is a schematic diagram of the structure when the target wafer is located at the detection position after the static charge on the chuck body has not been completely removed; Figure 6 A schematic diagram of the optical inspection mechanism inspecting a wafer after the static charge on the chuck body has not been completely removed. Figure 1 ; Figure 7 A schematic diagram of the optical inspection mechanism inspecting a wafer after the static charge on the chuck body has not been completely removed. Figure 2 .
[0019] The following are the labeling elements in the figure: 10. Chuck body; 11. First receiving hole; 12. Second receiving hole; 13. Bearing end face; 20. Pressure detection mechanism; 21. First ejector pin; 22. Pressure sensor; 23. First drive base; 24. First drive motor; 25. First drive screw; 30. Optical inspection mechanism; 31. Second ejector pin; 32. Light source emitter; 33. Light source receiver; 34. Second drive base; 35. Second drive motor; 36. Second drive screw; 40. Target wafer; L1, detection beam; L2, reflected beam; S1, the first path; S2, the second path. Detailed Implementation
[0020] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.
[0021] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.
[0022] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0024] Please refer to the following: Figures 1 to 7 The electrostatic chuck provided in the embodiments of this application will now be described.
[0025] The first aspect of this application is to provide an electrostatic chuck for use in a semiconductor etching apparatus, comprising a chuck body 10, a pressure detection mechanism 20, and an optical detection mechanism 30.
[0026] like Figure 2 As shown, the chuck body 10 has its axial direction parallel to the vertical direction. The chuck body 10 has a support end face 13 for supporting the target wafer 40, located on the upper end face of the chuck body 10. It also has a plurality of first receiving holes 11 and second receiving holes 12 extending through the chuck body 10 along its axial direction, with the plurality of first receiving holes 11 spaced circumferentially around the chuck body 10. The chuck body 10 generates electrostatic attraction force to attract the target wafer 40 onto the support end face 13.
[0027] like Figure 1 and Figure 2 As shown, a pressure detection mechanism 20 is slidably connected within each first receiving hole 11. Initially, the pressure detection mechanism 20 is separated from the target wafer 40, and the pressure detection mechanism 20 moves vertically relative to the chuck body 10 to lift the target wafer 40. During the process of the pressure detection mechanism 20 lifting the target wafer 40, since the target wafer 40 is supported on multiple pressure detection mechanisms 20, the target wafer 40 applies pressure to the pressure detection mechanism 20 so that the pressure detection mechanism 20 can detect the pressure applied by the target wafer 40. The multiple pressure detection mechanisms 20 transmit the detected pressure values to the controller in the device where the chuck body 10 is located.
[0028] By setting multiple pressure detection mechanisms 20, the target wafer 40 is supported at multiple points, thereby preventing the pressure detection mechanism 20 from damaging the target wafer 40 during the lifting process. At the same time, by setting multiple pressure detection mechanisms 20, the stress on the target wafer 40 can be detected at multiple points.
[0029] The optical inspection mechanism 30 is connected to the second receiving hole 12 and is used to generate a detection signal corresponding to the reflected light beam L2 reflected by the target wafer 40.
[0030] like Figure 3 As shown, when the target wafer 40 is in the detection position, the optical detection mechanism 30 emits a detection beam L1 towards the target wafer 40. The target wafer 40 reflects the detection beam L1 to form a reflected beam L2, and reflects the reflected beam L2 back to the optical detection mechanism 30. After receiving the reflected beam L2, the optical detection mechanism 30 generates a detection signal corresponding to the light intensity of the reflected beam L2, and transmits the detection signal to the controller in the device where the chuck body 10 is located. The controller compares the value of the detection signal with a preset value range to determine whether the target wafer 40 is deformed when in the detection position.
[0031] It should be noted that the portion of the detection beam L1 that illuminates the target wafer 40 is set radially apart from the center of the target wafer 40.
[0032] When the target wafer 40 is lifted to the detection position, if the pressure values detected by the multiple pressure detection mechanisms 20 are equal, and the value of the detection signal generated by the optical detection mechanism 30 is within the preset value range, the pressure detection mechanism 20 drives the target wafer 40 to separate from the chuck body 10.
[0033] Specifically, in this application, after the chuck body 10 completes the release of static charge, the controller controls the pressure detection mechanism 20 to slide toward the target wafer 40 in the first receiving hole 11. After contacting the target wafer 40, the controller pushes the target wafer 40 to move in the vertical direction so that the target wafer 40 is lifted to the detection position. At this time, the target wafer 40 and the bearing end face 13 are spaced apart in the vertical direction.
[0034] The pressure values applied to the target wafer 40 at multiple first detection sites include a preset pressure value and a non-preset pressure value range. The pressure values within the non-preset pressure value range are all greater than the preset pressure value.
[0035] The following explanation uses the example of the target wafer 40 being subjected to multiple pressure detection mechanisms 20, all of which are preset pressure values.
[0036] like Figure 3 and Figure 4 As shown, if the static charge on the chuck body 10 is completely removed, the adsorption force of the chuck body 10 on the target wafer 40 is zero. The pressure applied to the target wafer 40 by the first pressure detection mechanism 20 is the weight of the target wafer 40 itself, and the weight of the target wafer 40 itself is shared by the multiple pressure detection mechanisms 20. That is, at this time, the pressure value detected by each pressure detection mechanism 20 is a preset pressure value.
[0037] As the target wafer 40 is lifted to the detection position and spaced apart from the bearing end face 13, multiple pressure detection mechanisms 20 are spaced circumferentially along the chuck body 10. Since the middle part of the target wafer 40 is not supported and under the action of the target wafer 40's own gravity, the target wafer 40 undergoes a first deformation. The first deformation is an elastic deformation, that is, in the vertical direction, the height of the target wafer 40 at its center is less than the height of its edge. The angle between the cross-section of the part of the detection beam L1 illuminating the target wafer 40 and the horizontal direction is set as the first angle.
[0038] For ease of explanation, when the static charge on the chuck body 10 is completely removed, the degree of deformation corresponding to the first deformation of the target wafer 40 is negligible, and the section where the detection beam L1 irradiates the target wafer 40 is parallel to the horizontal direction, that is, the magnitude of the first angle is zero.
[0039] At this time, the controller controls the optical inspection mechanism 30 to emit a detection beam L1. The target wafer 40 reflects the detection beam L1 to form a reflected beam L2. The reflected beam L2 is reflected back to the optical inspection mechanism 30 and received by the optical inspection mechanism 30. The optical inspection mechanism 30 converts the light intensity of the reflected beam L2 into a detection signal corresponding to the light intensity and transmits the detection signal to the controller. The value corresponding to the detection signal is within the preset detection signal range.
[0040] Subsequently, the controller drives the pressure detection mechanism 20 to continue to start, so as to separate the target wafer 40 from the chuck body 10.
[0041] The following example illustrates the situation where the pressure applied to multiple first detection sites on the target wafer 40 is located in a non-preset pressure value range.
[0042] Please see Figures 5 to 7 If the static charge on the chuck body 10 is not completely removed, the chuck body 10 has an electrostatic attraction force on the target wafer 40. At this time, the pressure applied by the target wafer 40 to the multiple pressure detection mechanisms 20 is the sum of the weight of the target wafer 40 itself and the attraction force of the chuck body 10 on the target wafer 40. At this time, the pressure value of the target wafer 40 applied to it detected by the multiple pressure detection mechanisms 20 is within the non-preset pressure value range, that is, the pressure value of the target wafer 40 applied to it detected by the multiple pressure detection mechanisms 20 is greater than the preset pressure value.
[0043] When the static charge on the chuck body 10 is not completely removed and the static charge is uniformly distributed on the chuck body 10, the pressure values applied to the target wafer 40 detected by the multiple pressure detection mechanisms 20 are equal. When the static charge on the chuck body 10 is not completely removed and the static charge is not uniformly distributed on the chuck body 10, the pressure values applied to the target wafer 40 detected by the multiple pressure detection mechanisms 20 are unequal.
[0044] Because the target wafer 40 is lifted to the detection position and spaced from the bearing end face 13, the multiple pressure detection mechanisms 20 are spaced circumferentially along the chuck body 10, and the chuck body 10 has an electrostatic attraction force on the target wafer 40, the target wafer 40 undergoes a second deformation under the action of its own gravity and electrostatic attraction force. The degree of deformation corresponding to the second deformation of the target wafer 40 is greater than the degree of deformation corresponding to the first deformation, and in the vertical direction, the height of the target wafer 40 at its center is less than the height of its edge.
[0045] In the vertical direction, the height difference between the target wafer 40 and its edge during the second deformation is greater than the height difference between the target wafer 40 and its edge during the first deformation. The angle between the cross-section of the portion of the detection beam L1 illuminating the target wafer 40 and the horizontal direction is defined as the second angle, where the second angle is greater than the first angle.
[0046] At this time, the controller controls the optical inspection mechanism 30 to emit the inspection beam L1. Since the angle between the plane where the inspection beam L1 illuminates the target wafer 40 and the horizontal direction is the second angle, the reflected beam L2 will be reflected to the edge of the optical inspection mechanism 30, or the reflected beam L2 will be reflected to the outside of the optical inspection mechanism 30, thereby causing the value of the inspection signal generated by the optical inspection mechanism 30 to be outside the preset inspection signal range.
[0047] Subsequently, the controller releases the static charge on the chuck body 10 again and continues the above operation until the static charge on the chuck body 10 is completely released.
[0048] Compared with the prior art, the electrostatic chuck provided in this application includes a chuck body 10, a pressure detection mechanism 20, and an optical detection mechanism 30. The chuck body 10 has a bearing end face 13 for carrying a target wafer 40, and a first receiving hole 11 and a second receiving hole 12 penetrating the chuck body 10 along its axial direction. The pressure detection mechanism 20 is slidably connected within the first receiving hole 11 and is used to lift the target wafer 40 and detect the pressure applied to it by the target wafer 40. The optical detection mechanism 30 is connected to the second receiving hole 11. Within 2, a detection signal corresponding to the light beam reflected by the target wafer 40 is generated. After the target wafer 40 is raised to the detection position, if the pressure values detected by the multiple pressure detection mechanisms 20 are equal and the value of the detection signal generated by the optical detection mechanism 30 is within a preset value range, the electrostatic adsorption force applied by the chuck body 10 to the target wafer 40 is completely removed. At this time, the pressure detection mechanism 20 drives the target wafer 40 to separate from the chuck body 10 to prevent the residual electrostatic adsorption force of the chuck body 10 from breaking the target wafer 40.
[0049] In some embodiments of this application, a plurality of first receiving holes 11 are evenly spaced along the circumference of the chuck body 10, and a circular first path S1 is formed between the lines connecting the plurality of first receiving holes 11, the first path S1 being concentrically arranged with the chuck body 10.
[0050] For details, please refer to Figure 1 By evenly spacing multiple first receiving holes 11 along the circumference of the chuck body 10 and concentrically arranging the first path S1 with the chuck body 10, multiple pressure detection mechanisms 20 are evenly spaced along the circumference of the chuck body 10. This allows the multiple pressure detection mechanisms 20 to uniformly support the target wafer 40 circumferentially, preventing damage to the target wafer 40 when driving its movement. At the same time, it ensures that the pressure applied by the target wafer 40 to each pressure detection mechanism 20 is equal, thereby improving the detection accuracy of the multiple pressure detection mechanisms 20.
[0051] In one embodiment of this application, there are four first receiving holes 11, and correspondingly, there are also four pressure detection mechanisms 20. The four pressure detection mechanisms 20 correspond one-to-one with the four first receiving holes 11, and each pressure detection mechanism 20 is slidably connected in the corresponding first receiving hole 11.
[0052] In one embodiment of this application, there are multiple second receiving holes 12, which are evenly spaced along the circumference of the chuck body 10. A circular second path S2 is formed between the lines connecting the multiple second receiving holes 12. The second path S2 is concentrically arranged with the chuck body 10, and the diameter of the second path S2 is smaller than the diameter of the first path S1.
[0053] For details, please refer to Figure 1 When the target wafer 40 is in the detection position, due to the effects of gravity and electrostatic adsorption, the degree of deformation of different parts of the target wafer 40 along the radial direction is not uniform. By uniformly spacing multiple second receiving holes 12 along the circumference of the chuck body 10 and setting a circular second path S2 between the connecting lines of multiple second receiving holes 12, the distance between the parts irradiated by multiple light source detection mechanisms and the center of the target wafer 40 is equal when the detection beams L1 emitted by multiple light source detection mechanisms irradiate the lower surface of the target wafer 40. This reduces the influence of the detection beams L1 irradiating different parts of the target wafer 40 and the different degrees of deformation of different parts on the reflection angle of the reflected beam L2, ensuring that the angle of the reflected beam L2 reflected by the target wafer 40 is the same, thereby improving the detection accuracy of the optical detection mechanism 30.
[0054] In one embodiment of this application, the pressure detection mechanism 20 includes a first pin 21, a pressure sensor 22, a first drive seat 23, and a first drive motor 24.
[0055] For details, please refer to Figure 3 In this embodiment, the first ejector pin 21 is a cylindrical structure with a circular cross-section, and is slidably connected within the first receiving hole 11. A pressure sensor 22 is connected to the side of the first ejector pin 21 closest to the target wafer 40, and is electrically connected to the controller. The pressure sensor 22 abuts against the target wafer 40 to detect the pressure applied to it by the target wafer 40, and transmits the detected pressure value to the controller. A first drive base 23 is connected to the end of the first ejector pin 21 furthest from the pressure sensor 22, and multiple first ejector pins 21 are connected to the first drive base 23. A first drive motor 24 is connected to the first drive base 23 and drives the first drive base 23 to slide the first ejector pin 21 and the pressure sensor 22 within the first receiving hole 11.
[0056] Initially, the pressure sensor 22 is located below and spaced apart from the target wafer 40. After the chuck body 10 completes the release of static charge, the controller controls the first drive motor 24 to simultaneously drive multiple first ejector pins 21 to slide within the first receiving hole 11 via the first drive base 23. This causes the pressure sensor 22 to come into contact with the target wafer 40, driving the target wafer 40 to move to the detection position. When the pressure value detected by the pressure detection mechanism 20 and the value corresponding to the detection signal detected by the optical detection mechanism 30 are within the preset detection signal range, the controller controls the first drive motor 24 to drive the target wafer 40 to separate from the chuck body 10. Subsequently, the controller controls the first drive motor 24 to simultaneously drive multiple first ejector pins 21 and the pressure sensor 22 back to the initial position via the first drive base 23.
[0057] In one embodiment of this application, the pressure detection mechanism 20 further includes a first drive screw 25.
[0058] For details, please refer to Figure 3 The first drive screw 25 extends axially along the first receiving hole 11 and is connected to the shaft of the first drive motor 24. The first drive seat 23 is provided with a first threaded through hole, and the first drive screw 25 is threaded into the first threaded through hole. The controller controls the forward rotation of the first drive motor 24 so that the first drive motor 24 drives multiple first ejector pins 21 and pressure sensors 22 to move vertically upward in the first receiving hole 11 through the first drive screw 25 and the first drive seat 23. This causes the pressure sensors 22 to come into contact with the target wafer 40, thereby lifting the target wafer 40 to the detection position and subsequently separating the target wafer 40 from the chuck body 10.
[0059] Subsequently, the controller reverses the first drive motor 24, causing the first drive motor 24 to drive multiple first ejector pins 21 and pressure sensors 22 to move downward in the first receiving hole 11 in the vertical direction through the first drive screw 25 and the first drive seat 23, thereby returning the first ejector pins 21 and pressure sensors 22 to their initial positions.
[0060] In another embodiment of this application, the first drive motor 24 is a linear motor, which includes a first sliding seat that moves in a vertical direction. A first fixed seat is connected to the first sliding seat. The first drive motor 24 drives multiple first ejector pins 21 and pressure sensors 22 to move within the first receiving hole 11 through the first sliding seat and the first drive seat 23.
[0061] In this application, please refer to Figure 3 and Figure 4 The optical inspection mechanism 30 includes a second pin 31, a light source emitter 32, and a light source receiver 33.
[0062] Specifically, the second ejector pin 31 is a cylindrical structure with a circular cross-section, and is connected within the second receiving hole 12. A light source emitter 32 is connected to the side of the second ejector pin 31 near the target wafer 40, and is used to emit a detection beam L1 onto the lower surface of the target wafer 40. A light source receiver 33 is connected to the side of the second ejector pin 31 near the target wafer 40, and is used to receive the reflected beam L2 reflected by the target wafer 40, and convert the received reflected beam L2 into a detection signal. The light source emitter 32 is located outside the light source receiver 33 along the radial direction of the chuck body 10.
[0063] The light source receiver 33 is a photoelectric sensor. When the light beam shines on the photoelectric sensor at an angle, the photoelectric sensor will reflect the light beam, thereby reducing the photoelectric sensor's detection of the light beam intensity. In addition, the photosensitive surface of the photoelectric sensor does not have completely consistent response characteristics at every position. The central area of the photoelectric sensor is often the optimal receiving area in the design, while the response sensitivity of the edge area of the photoelectric sensor decreases.
[0064] When a light beam illuminates the center region of the photoelectric sensor, the sensor generates a first detection signal based on the light intensity of the beam. The light intensity value corresponding to the first detection signal is set to fall within a preset detection signal range. When the light beam illuminates the edge region of the photoelectric sensor, the sensor generates a second detection signal based on the light intensity of the beam. The light intensity value corresponding to the second detection signal is set to be less than a preset detection signal range. Specifically, the light intensity value corresponding to the second detection signal is less than the light intensity value corresponding to the first detection signal.
[0065] like Figure 7As shown, when the light beam shines on the area outside the photoelectric sensor, the photoelectric sensor generates a third detection signal, and the light intensity value corresponding to the third detection signal is set to zero.
[0066] In one embodiment of this application, a light source emitter 32 and a light source receiver 33 are spaced apart on the side of the second pin 31 near the target wafer 40. The light source emitter 32 emits a detection beam L1 at an angle to the radial direction of the target wafer 40, and the target wafer 40 reflects the detection beam L1 to form a reflected beam L2. The reflected beam L2 is reflected to the light source receiver 33 at an angle.
[0067] like Figure 4 As shown, when the static charge on the chuck body 10 is completely removed, the target wafer 40 is lifted to the detection position and spaced from the bearing end face 13. Under the action of the target wafer 40's own gravity, the target wafer 40 undergoes a first deformation. At this time, when the detection beam L1 irradiates the target wafer 40, the cross-section of the part of the detection beam L1 irradiated on the target wafer 40 forms a first angle with the horizontal direction to reflect the detection beam L1 and form a reflected beam L2. The target wafer 40 reflects the reflected beam L2 at an angle to the light source receiver 33 and to the center position of the light source receiver 33. At this time, the light source receiver 33 generates a first detection signal based on the light intensity of the reflected beam L2.
[0068] like Figure 6 As shown, if the static charge on the chuck body 10 is not completely removed, the target wafer 40, being lifted to the detection position and spaced from the bearing end face 13, undergoes a second deformation under the combined effect of its own gravity and the adsorption force of the chuck body 10 on the target wafer 40. At this time, the angle between the section of the detection beam L1 illuminating the target wafer 40 and the horizontal direction is the second angle. Since the second angle is greater than the first angle, the target wafer 40 reflects the reflected beam L2 to the edge of the light source receiver 33. The light source receiver 33 then generates a second detection signal based on the intensity of the reflected beam L2.
[0069] Or, such as Figure 7 As shown, the target wafer 40 reflects the reflected beam L2 to the outside of the light source receiver 33. At this time, the light source receiver 33 generates a third detection signal based on the light intensity of the reflected beam L2.
[0070] In one embodiment of this application, the diameter of the second ejector pin 31 is larger than the diameter of the first ejector pin 21.
[0071] In some embodiments of this application, the second ejector pin 31 is slidably connected within the second receiving hole 12. By slidably connecting the second ejector pin 31 within the second receiving hole 12, the spacing between the light source emitter 32 and the light source receiver 33 and the target wafer 40 can be adjusted.
[0072] In one embodiment of this application, in order to enable the second ejector pin 31 to slide within the second receiving hole 12, the pressure detection mechanism 20 further includes a second drive seat 34 and a second drive motor 35.
[0073] For details, please refer to Figures 3 to 5 The ends of the multiple second ejector pins 31 furthest from the target wafer 40 are all connected to the second drive base 34. The second drive motor 35 is connected to the drive base and is used to drive the second drive base 34 to move the second ejector pins 31 within the second receiving hole 12.
[0074] When it is necessary to adjust the position of the light source emitter 32 and the light source receiver 33 relative to the target wafer 40, the controller controls the second drive motor 35 to start, so that the second drive base 34 simultaneously drives multiple second pins 31 to move the light source emitter 32 and the light source receiver 33 on them relative to the target wafer 40.
[0075] In one embodiment of this application, the optical detection mechanism 30 further includes a second drive screw 36.
[0076] The second drive screw 36 extends axially along the second receiving hole 12 and is connected to the shaft of the second drive motor 35. The second drive seat 34 has a second threaded through hole, and the second drive screw 36 is threadedly connected to the second threaded through hole.
[0077] The controller controls the forward or reverse rotation of the second drive motor 35 so that the second drive motor 35 drives the second ejector pin 31 and the light source emitter 32 and light source receiver 33 on the second ejector pin 31 to move relative to the target wafer 40 through the second drive screw 36 and the second drive seat 34.
[0078] In another embodiment of this application, the second drive motor 35 is also a linear motor. The second linear motor includes a second sliding seat that moves in a vertical direction. A second fixed seat is connected to the second sliding seat. The second drive motor 35 drives the light source emitters 32 and light source receivers 33 on a plurality of second pins 31 to move relative to the target wafer 40 through the second sliding seat and the second drive seat 34.
[0079] Secondly, this application provides a semiconductor etching apparatus, including an electrostatic chuck, wherein the electrostatic chuck is any one of the electrostatic chucks described above.
[0080] Compared with the prior art, the semiconductor etching apparatus provided in this application includes the aforementioned electrostatic chuck. The electrostatic chuck includes a chuck body 10, a pressure detection mechanism 20, and an optical detection mechanism 30. The chuck body 10 has a bearing end face 13 for bearing a target wafer 40, and a first receiving hole 11 and a second receiving hole 12 penetrating the chuck body 10 along its axial direction. The pressure detection mechanism 20 is slidably connected within the first receiving hole 11 and is used to lift the target wafer 40 and detect the pressure applied to it by the target wafer 40. The optical detection mechanism 30 is connected within the second receiving hole 12 and is used to adjust the pressure according to the target wafer 40's position. The light beam reflected by the target wafer 40 generates a detection signal corresponding to the light beam. After the target wafer 40 is raised to the detection position, if the pressure values detected by the multiple pressure detection mechanisms 20 are equal and the value of the detection signal generated by the optical detection mechanism 30 is within the preset value range, the electrostatic adsorption force applied by the chuck body 10 to the target wafer 40 is completely removed. At this time, the pressure detection mechanism 20 drives the target wafer 40 to separate from the chuck body 10 to prevent the residual electrostatic adsorption force of the chuck body 10 from breaking the target wafer 40.
[0081] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. An electrostatic chuck, used in a semiconductor etching apparatus, characterized in that, include: The chuck body has a bearing end face for carrying the target wafer, and a plurality of first receiving holes and second receiving holes that penetrate the chuck body along the axial direction of the chuck body, the plurality of first receiving holes being spaced apart circumferentially along the chuck body. A pressure detection mechanism is slidably connected in each of the first receiving holes. The pressure detection mechanism is used to lift the target wafer and detect the pressure applied to the target wafer thereon. An optical inspection mechanism, connected within the second receiving aperture, is used to generate a detection signal corresponding to the light beam reflected by the target wafer; When the target wafer is raised to the detection position, if the pressure values detected by the multiple pressure detection mechanisms are equal and the value of the detection signal generated by the optical detection mechanism is within a preset value range, the pressure detection mechanism drives the target wafer to separate from the chuck body.
2. The electrostatic chuck as described in claim 1, characterized in that, The plurality of first receiving holes are evenly spaced along the circumference of the chuck body, and a circular first path is formed between the lines connecting the plurality of first receiving holes, the first path being concentrically arranged with the chuck body.
3. The electrostatic chuck as described in claim 2, characterized in that, The number of second receiving holes is multiple, and the multiple second receiving holes are evenly spaced along the circumference of the chuck body. A circular second path is formed between the lines connecting the multiple second receiving holes. The second path is concentrically arranged with the chuck body, and the diameter of the second path is smaller than the diameter of the first path.
4. The electrostatic chuck as described in claim 1 or 3, characterized in that, The pressure detection mechanism includes: The first ejector pin is slidably connected within the first receiving hole; A pressure sensor is connected to the side of the first ejector pin near the target wafer, and is used to abut against the target wafer to detect the pressure applied to it by the target wafer; The first drive seat is connected to the end of the first ejector pin that is furthest from the pressure sensor; A first drive motor is connected to the first drive seat and is used to drive the first drive seat to move the first ejector pin and the pressure sensor within the first receiving hole.
5. The electrostatic chuck as described in claim 4, characterized in that, The pressure detection mechanism also includes: The first drive screw extends axially along the first receiving hole and is connected to the shaft of the first drive motor. The first drive seat is provided with a first threaded through hole, and the first drive screw is threadedly connected to the first threaded through hole.
6. The electrostatic chuck as described in claim 1 or 3, characterized in that, The optical inspection mechanism includes: The second ejector pin is connected to the second receiving hole; A light source emitter, connected to the side of the second pin near the target wafer, is used to emit a detection beam toward the target wafer; A light source receiver is connected to the side of the second pin near the target wafer, for receiving the reflected light beam reflected by the target wafer and converting the received reflected light beam into the detection signal.
7. The electrostatic chuck as described in claim 6, characterized in that, The light source emitter and the light source receiver are spaced apart and arranged on the second pin; The light source emitter emits a detection beam at an angle to the radial direction of the target wafer.
8. The electrostatic chuck as described in claim 7, characterized in that, The second ejector pin is slidably connected to the second receiving hole; The pressure detection mechanism also includes: The second drive seat, the second ejector pin is connected to the second drive seat; The second drive motor is connected to the drive base and is used to drive the second drive base to move the second ejector pin within the second receiving hole.
9. The electrostatic chuck as described in claim 8, characterized in that, The pressure detection mechanism also includes: The second drive screw extends axially along the second receiving hole and is connected to the shaft of the second drive motor. The second drive seat has a second threaded through hole, and the second drive screw is threadedly connected to the second threaded through hole.
10. A semiconductor etching apparatus, characterized in that, include: An electrostatic chuck, wherein the electrostatic chuck is the electrostatic chuck according to any one of claims 1-9.