Electrostatic chuck

Abstract

The utility model discloses an electrostatic chuck, comprising an electrostatic chuck body which is provided with an electrostatic adsorption surface which is used for fixing a wafer and is provided with a mounting groove, and the mounting groove is communicated with the outside; the adsorption removing assembly is provided with a contact end, the contact end is arranged in the mounting groove and can move in the thickness direction of the electrostatic chuck body, and when the contact end abuts against a wafer, the contact end is used for removing the adsorption force between the electrostatic adsorption surface and the wafer. According to the utility model, when plasma ignition is abnormal, the contact end can move along the thickness direction of the electrostatic chuck body to directly abut against a wafer, so that charges on the wafer can be quickly led out, the wafer is prevented from staying in equipment for a long time, and the risk of wafer damage is reduced.

Description

Technical Field

[0001] This utility model relates to semiconductor wafer equipment, and more particularly to an electrostatic chuck. Background Technology

[0002] In semiconductor manufacturing, electrostatic chucks (ESCs) are commonly used to hold wafers in place during the fabrication of semiconductor devices. For example, ESCs can be used in plasma etching or plasma deposition processes to maintain the position of the wafer relative to a support surface using electrostatic attraction. Specifically, ESCs attract the wafer using Coulomb forces, or electrostatic forces, generated between the wafer and electrodes. These Coulomb forces are produced by the attraction between the positive and negative charges on the wafer and electrodes. In a unipolar ESC structure, the wafer needs to receive charge from the plasma for attraction, and after processing, the charge on the wafer needs to be removed via plasma to achieve de-attraction.

[0003] However, this process presents a potential technical challenge: if equipment malfunctions, such as power supply or gas supply issues preventing plasma generation, the charge on the wafer cannot be discharged. In this situation, the wafer cannot be quickly removed from the reaction chamber because wafer adsorption and release depend entirely on the presence of plasma. This not only leads to prolonged wafer waiting in the reaction chamber, increasing the risk of malfunctions during production, but may also impact the entire production process. Therefore, when equipment malfunctions and plasma ignition fails, determining how to remove the wafer adsorbed from the electrostatic chuck becomes extremely important. Utility Model Content

[0004] The purpose of this invention is to provide an electrostatic chuck to facilitate rapid wafer removal when the machine malfunctions and plasma ignition cannot be performed.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows:

[0006] An electrostatic chuck, characterized in that it comprises:

[0007] The electrostatic chuck body has an electrostatic adsorption surface for fixing the wafer, and a mounting groove is formed on the electrostatic adsorption surface, which is connected to the outside.

[0008] The de-adsorption component has a contact end, which is disposed in the mounting groove and can move along the thickness direction of the electrostatic chuck body. When the contact end abuts against the wafer, it can remove the charge on the wafer.

[0009] The electrostatic chuck has the beneficial effects that: in the traditional electrostatic chuck, the release of the wafer depends on the existence of the plasma, because the plasma is needed to help the charge on the wafer to be led out. However, in the present scheme, even in the absence of the plasma, the desorption assembly can quickly interrupt the electrostatic adsorption force through physical contact, so that the wafer is quickly released. Specifically, when the equipment is abnormal and the plasma cannot be ignited, the contact end can be moved along the thickness direction of the electrostatic chuck body, directly abuts against the wafer, and the charge on the wafer can be removed. This direct physical contact can be used to remove the charge between the wafer and the electrostatic adsorption surface, and then remove the adsorption force between the wafer and the electrostatic adsorption surface. Therefore, the long-time stay of the wafer in the equipment is avoided, the production efficiency is improved, and the risk of wafer damage is reduced.

[0010] Further, the desorption assembly comprises:

[0011] The fixed seat is fixedly connected with the electrostatic chuck body, an insulating layer is arranged on the electrostatic adsorption surface, and the insulating layer is used for blocking the charge on the electrostatic adsorption surface from being conducted to the fixed seat;

[0012] The conductive part is slidably connected in the mounting groove, one end of the conductive part away from the wafer is connected with a grounding wire, and the contact end is located on the side of the conductive part close to the wafer;

[0013] The driving part is fixedly connected with the side of the conductive part away from the wafer, and the driving part is used for driving the conductive part to move along the height direction of the mounting groove.

[0014] Further, the mounting groove has at least two first groove positions and second groove positions with decreasing sizes in the direction away from the mounting groove opening.

[0015] Further, the conductive part comprises:

[0016] The first column body is slidably connected in the first groove position;

[0017] The second column body is fixedly connected with the first column body, and the second column body is slidably connected in the second groove position.

[0018] Further, the grounding wire is connected with the side of the second column body away from the wafer.

[0019] Further, the driving part comprises a gas cylinder, the gas cylinder has an output end, and the output end is fixedly connected with the second column body.

[0020] Further, the first column body and the second column body are conductive ceramics.

[0021] Further, the electrostatic chuck body comprises a base, a fixed plate, a power supply and a plasma, the fixed plate is installed on the base, the power supply is connected to the fixed plate, an insulator is arranged on the side of the fixed plate close to the wafer, one electrode of the power supply is connected to the fixed plate, and the plasma is arranged on the side of the fixed plate away from the base, and the plasma is used for absorbing the electric charge on the wafer.

[0022] Further, a position sensor is connected to the output end of the cylinder, and the position sensor is used for measuring the stroke of the output end of the cylinder.

[0023] Further, a temperature control module is arranged on the fixed seat, and the temperature control module is used for controlling the temperature of the electrostatic chuck body. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a structural schematic view of the edge ring body in the embodiment of the utility model;

[0025] Figure 2 It is a structural schematic view of the wafer position correction device in the embodiment of the utility model;

[0026] Figure 3 It is a sectional view of the edge ring body in the embodiment of the utility model;

[0027] Figure 4 It is a structural schematic view of the heating piece in the embodiment of the utility model;

[0028] Figure 5 It is a structural schematic view of the mechanical arm in the embodiment of the utility model;

[0029] Figure 6 It is a plasma voltage state diagram in the embodiment of the utility model.

[0030] Mark: 1, electrostatic chuck body; 11, electrostatic adsorption surface; 12, installation groove; 13, base; 14, fixed plate; 15, plasma; 121, first slot; 122, second slot; 2, desorption assembly; 21, fixed seat; 22, conducting part; 221, first column; 222, second column; 223, ground wire; 3, wafer; 4, inner wall of isolation chamber; 5, power supply; 51, electrode. DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this utility model pertains. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, but does not exclude other elements or objects.

[0032] An electrostatic chuck is a device used to hold wafers in place during the manufacturing process of semiconductor devices. For example, in plasma etching or plasma deposition processes, an electrostatic chuck can be used to hold a wafer in position relative to a support surface using its binding force. Specifically, the wafer binding force is either a Coulomb force generated between the wafer and electrodes located within the electrostatic chuck, or a Jungian thermal back force generated between the wafer and electrodes located within the electrostatic chuck. During the holding process by the electrostatic chuck, the wafer acquires a charge. (See reference...) Figure 6 When the wafer begins to be adsorbed, the voltage needs to be increased, which simultaneously increases the amount of charge on the wafer, so that the wafer is adsorbed by the electrostatic force on the electrostatic chuck. During the etching process, the voltage remains constant, and the amount of charge on the wafer remains constant. When the wafer is desorbed, a reverse voltage is applied to remove the charge on the wafer.

[0033] The following is in conjunction with the appendix Figure 1 - Appendix Figure 6 The specific embodiments of this utility model will be further described in detail below.

[0034] Reference Figures 1-6 The present invention provides an electrostatic chuck comprising an electrostatic chuck body 1 and a de-adsorption component 2.

[0035] The electrostatic chuck body 1 is located in an isolation chamber, where plasma 15 is formed near the wafer. Plasma 15 is a state of matter composed of electrons, ions, neutral gas, and other particles. It exhibits collective behavior and macroscopically presents as a quasi-neutral mixed gas, i.e., a neutral clump-like gas. In semiconductor processes, plasma 15 ignition refers to using a high-energy pulse to generate a high-energy discharge, forming a localized high-temperature region and exciting a large number of active particles. This process is used in semiconductor manufacturing to generate plasma 15 for processes such as etching or deposition on the wafer. In this invention, plasma 15 is used to remove charge from the wafer. (See prior art) Figure 1If the machine appears abnormal and cannot ignite the plasma, the wafer cannot be discharged by the plasma, and the wafer cannot be quickly taken out of the isolation chamber.

[0036] Referring to Figures 2-4 The electrostatic chuck body 1 has an electrostatic adsorption surface 11, which is located on the side of the electrostatic chuck body 1 close to the wafer and is used to fix the wafer. The electrostatic chuck body 1 includes a base 13 at the bottom, a fixed plate 14 mounted on the base 13, and a power supply 5 connected to the fixed plate 14. The electrode 51 of the power supply 5 is connected to the fixed plate 14, and the power supply 5 is used to deliver electric charge to the fixed plate 14. The side of the fixed plate 14 close to the wafer is provided with an insulator. The insulator is a special insulating control, mainly used in power systems, installed between conductors of different potentials or conductors and ground potential components, and can withstand voltage and mechanical stress. In the embodiment, the insulator is used for electrical insulation to prevent the charge from flowing to the wafer through the upper surface of the fixed plate 14, thereby ensuring the stable operation of the electrostatic chuck. In the embodiment, the insulator includes but is not limited to porcelain insulator, glass insulator and composite insulator.

[0037] In addition, the electrostatic chuck body 1 is provided with a mounting groove 12 in the thickness direction, and the mounting groove 12 is in communication with the outside. The desorption assembly 2 has a contact end, which is arranged in the mounting groove 12 and can move in the thickness direction of the electrostatic chuck body 1, and is used to desorb the wafer on the electrostatic adsorption surface 11 when abutting against the wafer. The moving contact end of the desorption assembly 2 can directly contact the wafer 3 in the isolation chamber, and the charge on the wafer is transmitted to the contact end through the contact, and then transmitted and discharged to the outside, thereby realizing the desorption of the wafer on the electrostatic chuck.

[0038] In some embodiments of the utility model, the desorption assembly 2 includes a fixed seat 21 fixedly connected with the electrostatic adsorption surface 11, a conductive part 22 slidingly connected in the mounting groove 12 and a driving part. An insulating layer is arranged between the fixed seat 21 and the contact surface of the fixed plate 14, and the insulating layer is used to block the conduction of the charge on the electrostatic adsorption surface 11 to the fixed seat 21. The end of the conductive part 22 away from the wafer is connected with a grounding wire 223, and the contact end is located on the side of the conductive part 22 close to the wafer. The driving part is fixedly connected with the side of the conductive part 22 away from the wafer, and the driving part is used to drive the conductive part 22 to move in the height direction of the mounting groove 12.

[0039] In some embodiments of the utility model, installation groove 12 has at least two first slot positions 121 and second slot positions 122 with decreasing sizes in the direction away from the slot opening of installation groove 12. The conductive part 22 includes a first cylinder 221 close to the outlet direction of installation groove 12 and a second cylinder 222 away from the outlet, and the first cylinder 221 is slidingly connected in the first slot position 121. In the case of normal ignition of the plasma 15, the first cylinder 221 is located at the bottom of the first slot position 121 and does not contact the wafer. In the case of abnormal ignition of the plasma 15, the first cylinder 221 is located at the top of the first slot position 121, contacts the wafer and conducts electricity, avoiding abnormality of the wafer waiting in the isolation chamber for a long time. The second cylinder 222 is fixedly connected with the first cylinder 221, and the second cylinder 222 is slidingly connected in the second slot position 122. Specifically, the second cylinder 222 is integrally formed with the first cylinder 221. In other embodiments of the utility model, the first cylinder 221 and the second cylinder 222 are conductive ceramics. Specifically, by arranging the first cylinder 221 and the second cylinder 222, and the cross-sectional area of the second cylinder 222 being smaller than that of the first cylinder 221, two effects are achieved: on the one hand, the top of the first cylinder 221 has more cross-sectional area to contact the wafer to conduct electricity, and on the other hand, the first cylinder 221 is slidingly connected in the first slot position 121, which plays a role in limiting the first cylinder 221.

[0040] In some embodiments of the utility model, the grounding wire 223 is connected to the side of the second cylinder 222 away from the wafer. The grounding wire 223 is directly connected to the side of the second cylinder 222 away from the wafer, ensuring that the electricity can be effectively discharged from the wafer through the conductive part 22, the second cylinder 222 and the grounding wire 223. This design improves the efficiency of electricity discharge and reduces the residence time of the wafer on the electrostatic chuck. Moreover, the grounding wire 223 is connected to the bottom of the second cylinder 222, reducing the length of the wire in the installation groove 12 and saving wire material.

[0041] In some embodiments of the utility model, the driving part includes a pneumatic cylinder, and the output end of the pneumatic cylinder is fixedly connected with the second cylinder 222. Using the pneumatic cylinder as the driving part provides a simple and effective driving method. The output end of the pneumatic cylinder is fixedly connected with the second cylinder 222, so that the conductive part 22 can move along the height direction of the installation groove 12 to realize contact with and desorption of the wafer. The use of the pneumatic cylinder provides stable driving force, ensures that the contact end can accurately reach the predetermined position, and improves the reliability of the desorption process.

[0042] In some embodiments of the utility model, a plasma 15 emitter is further included, the plasma emitter can emit the plasma 15, the formed plasma 15 is located on the side of the fixed plate 14 away from the base 13, and the plasma 15 is used for absorbing electricity on the wafer.

[0043] In some embodiments of the present application, a position sensor (not shown in the figure) is connected to the output end of the air cylinder, which is used to measure the stroke of the air cylinder output end. The addition of the position sensor enables the system to accurately control the position of the air cylinder output end, ensuring that the conductive part 22 can accurately contact the wafer surface. This precise position control helps to improve the accuracy of the desorption process, while reducing the risk of wafer damage caused by the first column 221 exceeding the stroke due to position deviation.

[0044] In some embodiments of the present application, a temperature control module is provided on the fixed seat 21, which is used to control the temperature of the electrostatic chuck body 1. By providing a temperature control module on the fixed seat 21, the temperature of the electrostatic chuck body 1 can be effectively controlled. This is crucial for maintaining temperature stability during wafer processing, as fluctuations in temperature can affect the processing quality of the wafer and the performance of the electrostatic chuck.

[0045] The implementation principle of the present application is that in the case that the plasma 15 cannot be ignited, the charge on the wafer 3 cannot be conducted out through the plasma, at which time the desorption assembly 2 works. Specifically, the driving part drives the conductive part 22 to move along the height of the mounting groove 12 until the contact end of the top of the first column contacts the wafer. Once the contact end contacts the wafer, the conductive part 22 conducts the charge on the wafer out through the first column, the second column 222, and the ground wire 223 to the outside, realizing the conduction of the charge on the wafer 3, and further realizing the rapid desorption of the wafer 3 on the electrostatic chuck.

[0046] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0047] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and connections within two components or interactions between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0048] Unless otherwise expressly specified and limited, "above" or "below" a second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of a second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" of a second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0049] Although the embodiments of this utility model have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of this utility model as described in the claims. Moreover, the utility model described herein may have other embodiments and can be implemented or realized in various ways.

Claims

1. An electrostatic chuck, comprising: include: The electrostatic chuck body has an electrostatic adsorption surface for fixing the wafer, and a mounting groove is formed on the electrostatic adsorption surface, which is connected to the outside. The de-adsorption component has a contact end, which is disposed in the mounting groove and can move along the thickness direction of the electrostatic chuck body. When the contact end abuts against the wafer, it can remove the charge on the wafer.

2. An electrostatic chuck as recited in claim 1, wherein, The desorption component includes: A fixed base is fixedly connected to the electrostatic chuck body. An insulating layer is provided on the electrostatic adsorption surface, which is used to block the conduction of charge on the electrostatic adsorption surface to the fixed base. A conductive component is slidably connected in the mounting groove. The end of the conductive component facing away from the wafer is connected to a grounding wire, and the contact end is located on the side of the conductive component closer to the wafer. A driving component is fixedly connected to the side of the conductive component opposite to the wafer, and the driving component is used to drive the conductive component to move along the height direction of the mounting groove.

3. An electrostatic chuck as recited in claim 2, wherein, The mounting groove has at least two first slots and second slots with decreasing dimensions in the direction away from the opening of the mounting groove.

4. An electrostatic chuck as recited in claim 3, wherein, The conductive element includes: The first column is slidably connected within the first slot; The second column is fixedly connected to the first column, and the second column is slidably connected within the second slot.

5. An electrostatic chuck as recited in claim 4, wherein, The grounding wire is connected to the side of the second pillar that is away from the wafer.

6. An electrostatic chuck as recited in claim 4, wherein, The driving component includes a cylinder, which has an output end that is fixedly connected to the second column.

7. An electrostatic chuck as recited in claim 4, wherein, The first column and the second column are made of conductive ceramic.

8. The electrostatic chuck of claim 1, wherein, The electrostatic chuck body includes a base, a fixing plate, and a plasma. The fixing plate is mounted on the base and a power supply component is connected to the fixing plate. An insulator is provided on the side of the fixing plate near the wafer. One electrode of the power supply component is connected to the fixing plate. The plasma is located on the side of the fixing plate away from the base and is used to absorb the charge on the wafer.

9. An electrostatic chuck as recited in claim 6, wherein, A position sensor is connected to the output end of the cylinder, and the position sensor is used to measure the stroke of the cylinder output end.

10. The electrostatic chuck of claim 2, wherein, The mounting base is equipped with a temperature control module, which is used to control the temperature of the electrostatic chuck body.

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