Chuck of wafer holding device and wafer holding device

Abstract

A chuck (100) of a wafer holding device and a wafer holding device. The chuck comprises a chuck frame (110); a plurality of contact members (120), wherein the plurality of contact members (120) are evenly distributed on the chuck frame (110), each of the contact members (120) comprises a fixing portion (121), a connecting portion (122) and a contact portion (123), one end of the fixing portion (121) is connected to an upper end of the connecting portion (122), and a lower end of the connecting portion (122) is connected to the contact portion (123); and a limiting member (400) fixed to the chuck frame (110), wherein the limiting member (400) is used for limiting the connecting portion (122) of each of the contact members (120) so as to reduce the moment arm of the connecting portion (122). By means of providing the limiting member (400), the moment arm of the connecting portion (122) of each of the contact members (120) is reduced, so that the deformation of the connecting portion (122) is within an elastic limit thereof. After a wafer leaves the chuck, an applied external force is removed, so that the connecting portion (122) automatically returns to an original shape. When the next wafer enters the wafer holding device for electroplating, the connecting portion (122) has returned to the original shape and can come into uniform contact with the wafer, thereby ensuring uniform electrical conduction and improving process quality.

Description

Chuck of wafer holding device and wafer holding device TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor equipment, in particular to a chuck of wafer holding device and wafer holding device. BACKGROUND

[0002] In the process of wafer electroplating, the wafer needs to be fixed in the wafer holding device and then enters the electroplating cavity for electroplating process.

[0003] Please refer to FIG. 1 and FIG. 2, the wafer holding device includes a chuck 100 for holding a wafer, and the chuck 100 includes a chuck skeleton 110. A plurality of contact pieces 120 for conducting electricity to the seed layer of the wafer are arranged in the chuck skeleton 110. The contact pieces 120 are usually made of conductive metal with certain elasticity, such as multi-element alloy, stainless steel and the like. The contact pieces 120 include a fixed part 121, a connecting part 122 and a contact part 123. Adjacent contact parts 123 are spaced apart by a gap. One end of the contact part 123 is fixedly connected with the connecting part 122, and the other end of the contact part 123 is a free end. During the electroplating process, the free end of the contact part 123 contacts the edge of the wafer with the seed layer to conduct electricity to the seed layer of the wafer. The fixed part 121 is fixed on the chuck skeleton 110 to install and fix the contact pieces 120 in the chuck skeleton 110, and the fixed part 121 is connected with the contact part 123 through the connecting part 122. As shown in FIG. 3, the fixed part 121 of the contact piece 120 is fixed, and a gap 130 is formed between the connecting part 122 and the inner circumferential side of the chuck skeleton 110. The edge of the wafer needs to contact all the contact parts 123 to achieve the effect of uniform conduction of electricity to the seed layer on the edge of the wafer. However, in fact, the end of the contact part 123 contacting the wafer is a free end, and the material of the contact piece 120 is relatively soft and is prone to deformation. Therefore, not all the contact parts 123 are at the same height. Therefore, when the wafer enters the wafer holding device, it will first contact part of the contact parts 123. However, in order to enable all the contact parts 123 to contact the wafer, the wafer needs to be continuously pressed downward until the contact part 123 at the lowest level is reached. The gap 130 is the deformation space of the contact piece 120 when the wafer is pressed downward to contact the contact part 123. If the gap 130 is cancelled, the wafer is prone to breakage when changing from the transmission state to the static state, resulting in loss. Therefore, the gap 130 is necessary, that is, the end of the connecting part 122 connected with the contact part 123 must have a certain distance from the inner circumferential side of the chuck skeleton 110.

[0004] In the prior art, due to the size of the chuck skeleton 110, the length of the connecting portion 122 is relatively long, so that when one end of the connecting portion 122 is fixed by the fixing portion 121 and the other end of the connecting portion is connected with the opposite free contact portion 123, the force arm is relatively long, and because the material of the contact piece 120 is generally an elastic conductive metal, in the actual process, the connecting portion 122 only needs a small force to cause a large deformation, especially when the electroplating process of the wafer is completed and the wafer needs to be taken out, due to the adhesion of the wafer, the wafer moves upward and is separated from the wafer holding device, which will directly act on the contact portion 123 of the contact piece 120, driving the contact portion 123 and the connecting portion 122 to move upward and deform, because the force arm of the connecting portion 122 in the prior art is relatively long, a small adhesion force can also cause a large deformation of the connecting portion 122, when the deformation exceeds the elastic limit, it cannot be restored to the original state, and when the next wafer enters the wafer holding device for electroplating, the contact portion 123 on the deformed connecting portion 122 may be raised due to exceeding the elastic limit, and cannot be in contact with the wafer above the wafer, as shown in FIG. 4, which causes the conductive effect of each region of the seed layer of the wafer to be uneven, thereby affecting the processing of the wafer. SUMMARY

[0005] In order to improve the wafer processing yield and ensure the uniform conductivity of each region of the seed layer of the wafer, the present application provides a chuck for a wafer holding device and a wafer holding device.

[0006] In a first aspect, the present application provides a chuck for a wafer holding device, which is used for holding a wafer and comprises:

[0007] a chuck skeleton;

[0008] a plurality of contact pieces, which are uniformly distributed on the chuck skeleton, and each of the contact pieces comprises a fixing portion, a connecting portion and a contact portion, one end of the fixing portion is connected with the upper end of the connecting portion, and the lower end of the connecting portion is connected with the contact portion;

[0009] a limiting piece, which is fixed on the chuck skeleton and is used for limiting the connecting portion of the contact piece, so as to reduce the force arm of the connecting portion.

[0010] In a second aspect, the present application provides a wafer holding device, which comprises the chuck described above.

[0011] The chuck and wafer holding device of the present application reduce the force arm of the connecting part of the contact part by setting the limiting part, so that the deformation of the connecting part is within the elastic limit, and after the wafer leaves the chuck, the external force is removed, and the connecting part restores to the original state, and when the next wafer enters the wafer holding device for electroplating, the connecting part has restored to the original state, and can be in uniform contact with the wafer, ensuring uniform conduction and improving process quality.

[0012] Additional features and advantages of the application will be set forth in the description that follows, and in part will be apparent from the description, or can be learned by practice of the application. The objectives and other advantages of the application will be realized and attained by the structure particularly pointed out in the description and claims.

[0013] BRIEF DESCRIPTION OF DRAWINGS

[0014] The features and advantages of the present application are further described by the following examples and accompanying drawings. In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced as follows. Obviously, the accompanying drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative work based on these drawings.

[0015] Fig. 1 shows a schematic view of a chuck structure;

[0016] Fig. 2 shows a schematic view of a contact part structure;

[0017] Fig. 3 shows a partial sectional view of a chuck structure;

[0018] Fig. 4 shows a schematic view of the position structure of the wafer and the contact part when the deformation of the connecting part of the contact part exceeds the elastic limit;

[0019] Fig. 5 shows a partial sectional view of a chuck structure according to an embodiment of the present application; and

[0020] Fig. 6 shows a partial sectional view of a chuck structure according to another embodiment of the present application.

[0021] Preferred embodiments of the present application

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the protection scope of the present application.

[0023] Please refer to Fig. 5, the present application provides a wafer holding device, the wafer holding device includes a chuck 100 for holding a wafer, the chuck 100 includes a chuck skeleton 110, a plurality of contact pieces 120 and a limiting piece 400. The plurality of contact pieces 120 are uniformly distributed on the chuck skeleton 110. The contact piece 120 includes a fixed part 121, a connecting part 122 and a contact part 123. The fixed part 121 is horizontally arranged, and one end of the fixed part 121 extends downward at an angle to form the connecting part 122, and the lower end of the connecting part 122 extends outward at an angle to form the contact part 123. During installation, the contact piece 120 is fixed by fixing the fixed part 121 of the contact piece 120 on the upper end surface of the chuck skeleton 110.

[0024] It should be understood that, when setting, it is best to have all contact parts 123 at the same horizontal height, and the horizontal height error range of the contact parts 123 of the plurality of contact pieces 120 is less than 0.1 mm. In order to further ensure that all contact parts 123 can contact the wafer when contacting the wafer, the lower end of the connecting part 122 is arranged at a distance from the corresponding position of the inner circumferential side of the chuck skeleton 110, and the distance is greater than 0.1 mm, so as to form a gap 130 between the connecting part 122 and the inner circumferential side of the chuck skeleton 110. When the wafer is placed in the chuck 100, it can continue to move downward, so that the higher contact part 123 is compressed and moves downward, and the lower end of the connecting part 122 is pressed to move in the direction of the inner circumferential side of the chuck skeleton 110, close to the inner circumferential side of the chuck skeleton 110, and finally the higher contact part 123 and the lower contact part 123 are in contact with the wafer. When all contact parts 123 can uniformly contact the seed layer at the edge of the wafer, the stability of the electroplating of the wafer is ensured.

[0025] The limiting piece 400 includes a first limiting part 401 and a second limiting part 402, the first limiting part 401 fixes the fixed part 121 of the contact piece 120 on the chuck skeleton 110. For example, the first limiting part 401 in the embodiment is a fixed block, which presses the fixed part 121 of the contact piece 120 on the upper end surface of the chuck skeleton 110. In the actual installation process, the fixed block can be fixed again by using a fixed bolt, to further ensure the fixing effect. The second limiting part 402 is arranged on the side of the connecting part 122 of the contact piece 120 away from the inner circumferential side of the chuck skeleton 110, and limits the connecting part 122. For example, the second limiting part 402 can be a strip-shaped annular structure, or a plate-shaped annular structure.

[0026] In one embodiment, please continue to refer to FIG. 5, the second limiting part 402 is a plate-shaped annular structure, and is arranged along the arrangement direction of the connecting part 122 of the contact piece 120. In this embodiment, the distance between the end of the second limiting part 402 close to the one end of the contact part 123 and the corresponding position of the inner circumferential side of the chuck skeleton 110 is h1, the distance between the upper end of the connecting part 122 and the corresponding position of the inner circumferential side of the chuck skeleton 110 is h2, and the distance between the lower end of the connecting part 122 and the corresponding position of the inner circumferential side of the chuck skeleton 110 is h3, wherein h2 < h1 < h3. By fixing the fixed part 121 of the contact piece 120 through the limiting piece 400, the connecting part 122 can be limited, and the fulcrum of the connecting part 122 is shifted from the connecting part 122 and the fixed part 121 before limiting to the lower end of the second limiting part 402, thereby reducing the force arm of the connecting part 122. Even if the wafer leaves the chuck 100 and exerts an upward force on the contact piece 120, the deformation of the contact piece 120 can be limited under the limitation of the second limiting part 402, thereby preventing the connecting part 122 from deforming beyond the elastic deformation amount and affecting the electroplating effect, ensuring the electroplating safety and improving the electroplating quality. The second limiting part 402 of this embodiment has a plate-shaped structure and has a wider limiting range, can have a stronger limiting strength, and has a better limiting effect.

[0027] In another embodiment, please refer to FIG. 6, when the structure of the second limiting part 402 is a plate-shaped structure, a plurality of through holes 4021 are arranged on the second limiting part 402. When the contact piece 120 is cleaned after the electroplating process is completed, the through holes 4021 can reduce the residual cleaning liquid between the second limiting part 402 and the inner circumferential side of the chuck skeleton 110.

[0028] Preferably, the through holes 4021 are arranged between the connecting parts 122 of adjacent contact pieces 120, so as to facilitate the flow of the cleaning liquid and further avoid the residual cleaning liquid.

[0029] Further, the cross-sectional area of the through holes 4021 along the arrangement direction of the second limiting part 402 is 1 / 3-2 / 3 of the cross-sectional area of the second limiting part 402, so that the cleaning liquid can quickly pass through the through holes 4021, the residual cleaning liquid between the second limiting part 402 and the inner circumferential side of the chuck skeleton 110 is avoided, and the limiting piece 400 has sufficient limiting strength and ensures the limiting effect.

[0030] In another embodiment, the second limiting part 402 is a strip-shaped annular structure, i.e., a limiting ring (not shown in the figure), and the second limiting part 402 can be fixedly arranged on the inner circumferential side of the chuck skeleton 110 through a fixing structure, or can be fixedly connected with the first limiting part 401 through a fixing structure to achieve the purpose of fixing the second limiting part 402. The connecting part 122 of the contact piece 120 is located between the limiting ring and the inner circumferential side of the chuck skeleton 110. In this embodiment, the distance between the one end of the second limiting part 402 close to the contact part 123 and the corresponding position of the inner circumferential side of the chuck skeleton 110 is h1, the distance between the upper end of the connecting part 122 and the corresponding position of the inner circumferential side of the chuck skeleton 110 is h2, and the distance between the lower end of the connecting part 122 and the corresponding position of the inner circumferential side of the chuck skeleton 110 is h3, wherein h2 < h1 < h3.

[0031] The present application can fix the fixed part 121 of the contact piece 120 while limiting the connecting part 122 through the limiting piece 400, and can shift the fulcrum of the connecting part 122 from the connecting position between the connecting part 122 and the fixed part 121 before limiting to the one end of the second limiting part 402 close to the contact part 123, and can lower the fulcrum of the connecting part 122 to reduce the force arm of the connecting part 122, i.e., to exert an upward force on the contact piece 120 when the wafer leaves the chuck 100, and can limit the deformation degree of the contact piece 120 under the limitation of the second limiting part 402, prevent the deformation of the connecting part 122 from exceeding the elastic deformation amount, and be difficult to recover, and further affect the electroplating effect.

[0032] It should be understood that the first limiting part 401 and the second limiting part 402 can be integrally formed or integrated. The design of the first limiting part 401 and the second limiting part 402 can be selected according to actual needs.

[0033] When the electroplating process of the wafer is completed and the wafer needs to be removed, the adhesion of the wafer causes the contact part 123 of the contact piece 120 to move upward and deform, and at this time, the limiting effect of the second limiting part 402 of the limiting piece 400 on the connecting part 122 reduces the force arm of the connecting part 122, and under the action of the same force, the deformation degree of the connecting part 122 is reduced, and further ensures that the deformation amount of the connecting part 122 is within the elastic limit when the wafer is removed, and after the wafer leaves the chuck 100, the external force applied is eliminated, and the connecting part 122 restores to the original state. When the next wafer enters the wafer holding device for electroplating, the connecting part 122 has already restored to the original state, can uniformly contact the wafer, ensures uniform conduction, and improves the process quality.

[0034] Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood that modifications can be made to the foregoing embodiments, or additional implementations of the present application can be implemented, without departing from the spirit or scope of the application. Accordingly, the present application is not limited except as by the appended claims.

Claims

1. A chuck for a wafer holding apparatus, the chuck being used for holding a wafer, characterized by, The chuck comprises: a chuck skeleton; a plurality of contact pieces, which are uniformly distributed on the chuck skeleton, each of the contact pieces comprising a fixed part, a connecting part and a contact part, one end of the fixed part being connected to an upper end of the connecting part, and a lower end of the connecting part being connected to the contact part; a limiting piece fixed on the chuck skeleton, the limiting piece being used to limit the connecting part of the contact piece so as to reduce the moment arm of the connecting part.

2. The chuck of the wafer holding device according to claim 1, wherein: the limiting piece comprises a first limiting part and a second limiting part; the first limiting part is used to fix the fixed part of the contact piece on the chuck skeleton; the second limiting part is arranged on a side of the connecting part of the contact piece away from the inner circumferential side of the chuck skeleton, and is used to limit the connecting part.

3. The chuck of the wafer holding device according to claim 2, wherein: a distance between an end of the second limiting part close to an end of the contact part and a corresponding position on the inner circumferential side of the chuck skeleton is h1, a distance between an upper end of the connecting part and a corresponding position on the inner circumferential side of the chuck skeleton is h2, and a distance between a lower end of the connecting part and a corresponding position on the inner circumferential side of the chuck skeleton is h3, wherein h2 < h1 < h3.

4. The chuck of the wafer holding device according to claim 2, wherein: the first limiting part and the second limiting part are in an integral or integrated structure.

5. The chuck of the wafer holding device according to claim 2, wherein: the second limiting part is in a plate-like or strip-like structure.

6. The chuck of the wafer holding device according to claim 5, wherein: when the second limiting part is in a plate-like structure, a plurality of through holes are arranged on the second limiting part.

7. The chuck of the wafer holding device according to claim 6, wherein: the through holes are located between the connecting parts of adjacent contact pieces.

8. The chuck of the wafer holding device according to claim 6, wherein: a sectional area of the through holes along the arrangement direction of the second limiting part is 1 / 3-2 / 3 of a sectional area of the second limiting part.

9. The chuck of the wafer holding device according to claim 1, wherein: a horizontal height difference between the contact parts of the plurality of contact pieces is less than 0.1 mm.

10. The chuck of the wafer holding device according to claim 1, wherein: an end of the connecting part close to the contact part is arranged at a distance from a corresponding position on the inner circumferential side of the chuck skeleton, and the distance is greater than 0.1 mm.

11. A wafer holding device characterized by comprising: The chuck according to any one of claims 1-10.

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