A focusing ring and etching machine

Abstract

The application relates to the field of semiconductors and discloses a focusing ring, which comprises a focusing ring body and a steering driving device used for driving the focusing ring body to rotate around an electrostatic chuck. In the application, the focusing ring body can rotate around the electrostatic chuck under the driving of the steering driving device. When plasma etching is carried out, the focusing ring body can be rotated to be alternately positioned at different positions in a reaction chamber to receive plasma etching, so that the loss of the focusing ring body in each direction is balanced, the consistency of the focusing ring in converging plasma in each direction is ensured, the service life of the focusing ring is prolonged, and the control ability of the etching uniformity of a wafer is improved. The application also provides an etching machine table with the above advantages.

Description

Technical Field

[0001] This application relates to the semiconductor field, and in particular to a focusing ring and an etching apparatus. Background Technology

[0002] A focusing ring is a component of a semiconductor etching machine. It is located within the reaction chamber of the etching machine and surrounds the electrostatic chuck. The electrostatic chuck supports the wafer, while the focusing ring extends the wafer surface to concentrate the plasma, thereby improving the uniformity of wafer etching.

[0003] During the etching process of a semiconductor reaction chamber, the top surface of the focusing ring is also etched. The etching rate at the edge of the wafer continuously accelerates, resulting in a significant difference in etching rate between the edge and center regions. This leads to a gradual deterioration in the uniformity of wafer etching, necessitating system shutdown for maintenance. The focusing ring typically has a lifespan of 200-500 hours.

[0004] To improve wafer etching uniformity and the lifespan of the focusing ring, the difference in etching uniformity between the wafer edge and center is currently adjusted by changing the vertical height of the focusing ring. At this point, the focusing ring's lifespan is typically 300-800 hours. However, adjusting the vertical height of the focusing ring cannot solve the problem of poor wafer edge uniformity caused by inconsistent plasma etching wear on the focusing ring itself. That is, the inconsistent wear of the focusing ring in different directions leads to inconsistent plasma focusing, ultimately resulting in the uniformity of the plasma processing at the wafer edge failing to meet process requirements. The focusing ring's lifespan remains relatively short, requiring replacement only during maintenance, resulting in shorter machine downtime for maintenance and consequently lower machine output.

[0005] Therefore, how to solve the above-mentioned technical problems should be a key focus for those skilled in the art. Summary of the Invention

[0006] The purpose of this application is to provide a focusing ring and an etching apparatus to improve the service life of the focusing ring and enhance the control over etching uniformity.

[0007] To address the aforementioned technical problems, this application provides a focusing ring, comprising: a focusing ring body and a steering drive device, wherein the steering drive device is used to drive the focusing ring body to rotate around an electrostatic chuck.

[0008] Optionally, the focusing ring body is a one-piece structure.

[0009] Optionally, a height adjustment device may also be included;

[0010] The focusing ring body includes a focusing ring base and a focusing ring cover, and the height adjustment device is used to adjust the position of the focusing ring cover.

[0011] The steering drive device is used to drive the focusing ring base to rotate.

[0012] Optionally, it may also include: a first unidirectional rotation limiting component and a first limiting groove;

[0013] The first limiting groove is disposed on the lower surface of the focusing ring cover, the first unidirectional rotation limiting component is disposed on the upper surface of the focusing ring base, and the top of the first unidirectional rotation limiting component extends to the first limiting groove, so that the focusing ring cover and the focusing ring base can rotate synchronously in the first direction.

[0014] The height adjustment device includes a second unidirectional rotation limiting component and a second limiting groove; the focusing ring upper cover and the focusing ring base are engaged by a threaded structure;

[0015] The second limiting groove is provided on the lower surface of the focusing ring cover. The bottom of the second unidirectional rotation limiting component is connected to the electrostatic chuck, and the top extends to the second limiting groove, so that when the focusing ring base rotates in the second direction, the focusing ring cover can be height adjusted in the direction away from the focusing ring base; the first direction and the second direction are opposite.

[0016] Optionally, the first unidirectional rotation limiting component and the second unidirectional rotation limiting component are elastic components.

[0017] Optionally, the number of the first unidirectional rotation limiting component and the second unidirectional rotation limiting component is two or more.

[0018] Optionally, the thread height is not less than the maximum thickness consumed by the focusing ring cover during etching.

[0019] Optionally, when the steering drive device drives the focusing ring body to rotate, each rotation is a preset angle, and any integer multiple of the preset angle is not 360°.

[0020] Optionally, the number of steering drive devices is two or more.

[0021] This application also provides an etching apparatus, including any of the focusing rings described above.

[0022] The present application provides a focusing ring, comprising: a focusing ring body and a steering drive device, wherein the steering drive device is used to drive the focusing ring body to rotate around an electrostatic chuck.

[0023] As can be seen, in this application, the focusing ring body can rotate around the electrostatic chuck under the drive of the steering drive device. During plasma etching, the focusing ring body can be rotated to receive plasma etching at different positions in the reaction chamber, thereby balancing the loss of the focusing ring body in various directions, ensuring the consistency of the focusing ring's plasma focusing effect in various directions, extending the service life of the focusing ring, reducing etching costs, and improving the control capability of wafer etching uniformity.

[0024] In addition, this application also provides an etching apparatus that has the above-mentioned advantages. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this application or the prior art, 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.

[0026] Figure 1 A bottom view of a focusing ring provided in an embodiment of this application;

[0027] Figure 2 for Figure 1 A cross-sectional view of the central focusing ring along section AA;

[0028] Figure 3 A top view of another focusing ring provided in an embodiment of this application;

[0029] Figure 4 for Figure 3 A cross-sectional view of the central focusing ring along section BB;

[0030] Figure 5 for Figure 4 A cross-sectional view of the central focusing ring along the CC section;

[0031] Figure 6 for Figure 4 A cross-sectional view of the central focusing ring along section DD;

[0032] In the figure, 1 is the focusing ring body, 2 is the steering drive device, 3 is the electrostatic chuck, 4 is the first one-way rotation limiting component, 5 is the second one-way rotation limiting component, 6 is the threaded structure, 11 is the focusing ring top cover, 12 is the focusing ring base, 111 is the first limiting tooth, and 112 is the second limiting tooth. Detailed Implementation

[0033] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0035] As described in the background section, to improve wafer etching uniformity and the lifespan of the focusing ring, the difference in etching uniformity between the wafer edge and the wafer center is currently adjusted by changing the vertical height of the focusing ring. However, adjusting the vertical height of the focusing ring cannot solve the problem of poor wafer edge uniformity caused by inconsistent etching wear of the focusing ring itself due to plasma, and the lifespan of the focusing ring is still relatively short.

[0036] In view of this, this application provides a focusing ring, please refer to... Figures 1 to 2 It includes: a focusing ring body 1 and a steering drive device 2, wherein the steering drive device 2 is used to drive the focusing ring body 1 to rotate around the electrostatic chuck 3.

[0037] The steering drive unit 2 can be a motor.

[0038] Optionally, as one possible implementation, the focusing ring body 1 is a one-piece structure, such as... Figure 1 and Figure 2 As shown. However, this application does not impose specific limitations on this, and the focusing ring body 1 can also be a split structure, the specific scheme of which is described in the following embodiments.

[0039] It should be noted that this application does not limit the rotation period of the steering drive device 2 driving the focusing ring body 1. For example, it can be set to rotate once after processing a certain number of wafers (e.g., processing 100 or 150 wafers, etc.), or it can be set to rotate once after the focusing ring has been used for a certain period of time.

[0040] Each rotation of the focusing ring body 1 allows it to rotate to different positions within the reaction chamber to receive plasma etching. This ensures that the wear on the focusing ring body 1 is consistent in all directions, guaranteeing uniform plasma focusing around the wafer circumference. This results in superior etching uniformity control and extends the focusing ring's lifespan, thus extending the etching equipment's maintenance cycle. In this embodiment, the expected maintenance time is over 800 hours.

[0041] It should be noted that this application does not limit the angle of rotation of the focusing ring body 1 driven by the steering drive device 2 each time, and it can be set by the user. For example, the rotation angle of the focusing ring body 1 driven by the steering drive device 2 each time can be 20°, 30°, 40°, 50°, etc.

[0042] To prevent a certain position on the focusing ring body 1 from returning to the same position in the reaction chamber and being etched again after several rotations, thus extending the service life of the focusing ring, preferably, when the steering drive device 2 drives the focusing ring body 1 to rotate, each rotation is a preset angle, and any integer multiple of the preset angle is not 360°. For example, the preset angle can be 25°, 50°, etc.

[0043] In this application, the focusing ring body 1 can rotate around the electrostatic chuck 3 under the drive of the steering drive device 2. During plasma etching, the focusing ring body 1 can be rotated to receive plasma etching at different positions in the reaction chamber, thereby balancing the loss of the focusing ring body 1 in various directions, ensuring the consistency of the focusing ring's plasma focusing effect in various directions, extending the service life of the focusing ring, reducing etching costs, and improving the control capability of wafer etching uniformity.

[0044] Based on the above embodiments, in one embodiment of this application, the focusing ring further includes a height adjustment device;

[0045] The focusing ring body 1 includes a focusing ring base 12 and a focusing ring upper cover 11, and the height adjustment device is used to adjust the position of the focusing ring upper cover 11;

[0046] The steering drive device 2 is used to drive the focusing ring base 12 to rotate.

[0047] The focusing ring cover 11 is located above the focusing ring base 12. On the one hand, the focusing ring cover 11 can rotate together with the focusing ring base 12, and on the other hand, the height of the focusing ring cover 11 can be adjusted by the height adjustment device.

[0048] The height of the focusing ring cover 11 is adjusted by a height adjustment device, thereby correcting the difference in uniformity between the wafer edge and the wafer center caused by plasma etching wear. In this embodiment, the height adjustment of the focusing ring cover 11 combined with rotation provides better control over etching uniformity, meeting higher process requirements, while maximizing the lifespan of the focusing ring and extending the machine maintenance cycle. In this embodiment, the expected maintenance time is over 1200 hours.

[0049] It should be noted that this application does not limit the height adjustment device and can be set by the user.

[0050] Optionally, as one possible implementation, the height adjustment device may include a protruding structure and a recessed structure that cooperate with each other, disposed between the focusing ring cover 11 and the focusing ring base 12. When the focusing ring cover 11 needs to rotate, the protruding structure and the recessed structure come together and rotate together with the focusing ring base 12; when the height of the focusing ring cover 11 needs to be adjusted, the protruding structure and the recessed structure separate, lifting the focusing ring cover 11 up, thereby achieving upward height adjustment of the focusing ring cover 11.

[0051] Alternatively, as another possible implementation, please refer to Figures 3 to 6 The height adjustment device includes a second unidirectional rotation limiting component 5 and a second limiting groove. At this time, the focusing ring also includes:

[0052] The first unidirectional rotation limiting component 4 and the first limiting groove; the first limiting groove and the second limiting groove are provided on the lower surface of the focusing ring cover 11;

[0053] The first unidirectional rotation limiting component 4 is disposed on the upper surface of the focusing ring base 12, and the top of the first unidirectional rotation limiting component 4 extends to the first limiting groove, so that the focusing ring upper cover 11 and the focusing ring base 12 can rotate synchronously in the first direction.

[0054] The focusing ring upper cover 11 and the focusing ring base 12 are fitted together by a threaded structure 6;

[0055] The bottom of the second unidirectional rotation limiting component 5 is connected to the electrostatic chuck 3, and the top extends to the second limiting groove, so that when the focusing ring base 12 rotates in the second direction, the focusing ring cover 11 can be height adjusted in the direction away from the focusing ring base 12; the first direction and the second direction are opposite.

[0056] The steering drive device 2 is accurate enough to ensure that the rotation angle error of the focusing ring is within 1°, so as to improve the rotation accuracy of the focusing ring.

[0057] The first direction and the second direction are respectively counterclockwise and clockwise.

[0058] like Figure 5 and Figure 6 As shown, the first limiting groove is formed by two first limiting teeth 111, and the second limiting groove is formed by two second limiting teeth 112. The first limiting teeth 111 and the second limiting teeth 112 are inclined in opposite directions.

[0059] The first unidirectional rotation limiting component 4 and the second unidirectional rotation limiting component 5 are elastic components, for example, the elastic components can be spring sheets.

[0060] For example, the first limiting tooth 111 and the first one-way rotation limiting member 4 can be tilted in the counterclockwise direction, and the second limiting tooth 112 and the second one-way rotation limiting member 5 can be tilted in the clockwise direction; or, the first limiting tooth 111 and the first one-way rotation limiting member 4 can be tilted in the clockwise direction, and the second limiting tooth 112 and the second one-way rotation limiting member 5 can be tilted in the counterclockwise direction.

[0061] When the first limiting tooth 111 and the first unidirectional rotation limiting component 4 tilt in the counterclockwise direction (e.g.) Figure 5 As shown), the second limiting tooth 112 and the second unidirectional rotation limiting component 5 are tilted in a clockwise direction (as shown). Figure 6 When the focusing ring base 12 is driven by the steering drive device 2 to rotate counterclockwise, the first one-way rotation limiting component 4 located on the focusing ring base 12 moves against the first limiting tooth 111, that is, the top tooth of the first one-way rotation limiting component 4. Therefore, the focusing ring upper cover 11 and the focusing ring base 12 rotate synchronously. At this time, the second one-way rotation limiting component 5 moves along the second limiting tooth 112, that is, the second one-way rotation limiting component 5 moves along the tooth, and has no effect. The focusing ring upper cover 11 and the focusing ring base 12 are relatively stationary, thereby realizing the rotation action of the focusing ring upper cover 11. When the focusing ring base 12 is driven to rotate clockwise by the steering drive device 2, the first one-way rotation limiting component 4 located on the focusing ring base 12 moves along the first limiting tooth 111, that is, the first one-way rotation limiting component 4 moves along the tooth and has no effect. At this time, the second one-way rotation limiting component 5 pushes the tooth, limiting the focusing ring cover 11 to rotate counterclockwise. Due to the existence of the threaded structure between the focusing ring cover 11 and the focusing ring base 12, the rotational motion is converted into linear motion through the lead screw principle, thereby realizing the upward height adjustment of the focusing ring cover 11.

[0062] Similarly, when the first limiting tooth 111 and the first one-way rotation limiting component 4 are tilted clockwise, and the second limiting tooth 112 and the second one-way rotation limiting component 5 are tilted counterclockwise, the focusing ring base 12 is driven by the steering drive device 2 to rotate clockwise, and the focusing ring upper cover 11 can achieve synchronous rotation with the focusing ring base 12. When the focusing ring base 12 is driven by the steering drive device 2 to rotate counterclockwise, the focusing ring upper cover 11 can achieve height adjustment.

[0063] It should be noted that the number of the first unidirectional rotation limiting component 4 and the second unidirectional rotation limiting component 5 is not limited in this application; there can be one or more.

[0064] Preferably, in order to ensure the smooth realization of the focusing ring rotation and height adjustment performance, the number of the first unidirectional rotation limiting component 4 and the second unidirectional rotation limiting component 5 is more than two.

[0065] When there are two or more first unidirectional rotation limiting components 4 and second unidirectional rotation limiting components 5, the first unidirectional rotation limiting components 4 and the second unidirectional rotation limiting components 5 are evenly distributed to further improve the stability of the rotation and height adjustment of the focusing ring cover 11.

[0066] Combination Figures 3 to 6 The rotation and height adjustment of the focusing ring cover 11 are explained using the first direction as counterclockwise and the second direction as clockwise as an example. Figure 3 When the focusing ring base 12 is driven by the steering drive device 2 to rotate counterclockwise, that is, in Figure 5 When the focusing ring base 12 moves to the right, the first one-way rotation limiting component 4 moves along with the focusing ring base 12. The movement direction of the first one-way rotation limiting component 4 is the same as the top tooth of the first limiting tooth 111, that is, the top of the first one-way rotation limiting component 4 is pressed into the first limiting groove. Therefore, the first one-way rotation limiting component 4 drives the focusing ring upper cover 11 and the focusing ring base 12 to rotate synchronously. At this time, the corresponding Figure 6 The second one-way rotation limiting component 5 slides out of the second limiting groove along the second limiting tooth 112, that is, the second one-way rotation limiting component 5 does not work, and the focusing ring upper cover 11 and the focusing ring base 12 are relatively stationary, thereby realizing the rotation of the focusing ring.

[0067] Figure 3 When the focusing ring base 12 is driven by the steering drive device 2 to rotate clockwise, corresponding to... Figure 5When the focusing ring base 12 moves to the left, the first one-way rotation limiting component 4 slides out of the first limiting groove along the first limiting tooth 111, that is, the first one-way rotation limiting component 4 does not work. At this time, the second one-way rotation limiting component 5 is stuck in the second limiting groove. The second one-way rotation limiting component 5 pushes the tooth, that is, the second one-way rotation limiting component 5 plays a limiting role. The focusing ring upper cover 11 and the focusing ring base 12 rotate relative to each other. Due to the threaded structure 6 between the focusing ring upper cover 11 and the focusing ring base 12, the rotational motion is converted into linear motion through the lead screw principle, thereby realizing the upward height adjustment of the focusing ring upper cover 11.

[0068] In this application, there is no limitation on the adjustment height of the focusing ring cover 11 relative to the rotation angle of the focusing ring base 12, and it can be set by the user. For example, if the focusing ring cover 11 rotates 50° relative to the focusing ring base 12, the height of the focusing ring cover 11 will increase by 0.1 mm.

[0069] In order to maximize the service life of the focusing ring cover 11, the height of the thread 6 is not less than the maximum thickness of the focusing ring cover 11 consumed during etching.

[0070] The maximum thickness consumed by the focusing ring cover 11 during etching is the maximum lifespan of the focusing ring cover 11. For example, for a focusing ring cover 11 with an overall thickness of 3mm, the maximum thickness that can be etched away during the etching process is 2mm, so the maximum lifespan of the focusing ring cover 11 is 2mm.

[0071] Based on any of the above embodiments, in one embodiment of this application, the number of steering drive devices 2 is two or more, so as to ensure that the focusing ring can be smoothly driven to rotate.

[0072] Preferably, the number of steering drive devices 2 is three or more, and the steering drive devices 2 are evenly distributed to ensure that the focusing ring rotates smoothly.

[0073] This application also provides an etching apparatus, including the focusing ring described in any of the above embodiments.

[0074] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0075] The focusing ring and etching apparatus provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A focusing ring, characterized in that, include: A focusing ring body and a steering drive device, wherein the steering drive device is used to drive the focusing ring body to rotate around an electrostatic chuck; It also includes a height adjustment device; The focusing ring body includes a focusing ring base and a focusing ring cover, and the height adjustment device is used to adjust the position of the focusing ring cover. The steering drive device is used to drive the focusing ring base to rotate; The height adjustment device includes a second unidirectional rotation limiting component and a second limiting groove; The second limiting groove is provided on the lower surface of the focusing ring cover. The bottom of the second unidirectional rotation limiting component is connected to the electrostatic chuck, and the top extends to the second limiting groove, so that when the focusing ring base rotates in the second direction, the height of the focusing ring cover can be adjusted in the direction away from the focusing ring base.

2. The focusing ring as described in claim 1, characterized in that, Also includes: First unidirectional rotation limiting component and first limiting groove; The focusing ring cover and the focusing ring base are engaged by a threaded structure; the first limiting groove is provided on the lower surface of the focusing ring cover, the first unidirectional rotation limiting component is provided on the upper surface of the focusing ring base, and the top of the first unidirectional rotation limiting component extends to the first limiting groove, so that the focusing ring cover and the focusing ring base can rotate synchronously in the first direction. The first direction and the second direction are opposite.

3. The focusing ring as described in claim 2, characterized in that, The first unidirectional rotation limiting component and the second unidirectional rotation limiting component are elastic components.

4. The focusing ring as described in claim 2, characterized in that, The number of the first unidirectional rotation limiting component and the second unidirectional rotation limiting component is two or more.

5. The focusing ring as described in claim 2, characterized in that, The thread height is not less than the maximum thickness consumed by the focusing ring cover during etching.

6. The focusing ring as described in claim 1, characterized in that, When the steering drive device drives the focusing ring body to rotate, each rotation is a preset angle, and any integer multiple of the preset angle is not 360°.

7. The focusing ring as described in any one of claims 1 to 6, characterized in that, The number of steering drive devices is two or more.

8. An etching machine, characterized in that, Includes the focusing ring as described in any one of claims 1 to 7.

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