Pressing ring and sputtering equipment
By designing a clamping ring with an unshielded structure, increasing the inner diameter, and using the contact part to contact the wafer for sputtering shielding, the yield loss problem caused by the existing clamping ring was solved, and the yield was improved.
Patent Information
- Application Number
- CN202422912444.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-27
- Publication Date
- 2025-11-04
- Estimated Expiration
- 2034-11-27
AI Technical Summary
The existing clamping ring causes a high yield loss in the wafer back-side venting thin film sputtering process, mainly because the shielding part covers a large area of the wafer edge.
Design a clamping ring consisting only of a ring body and a contact part. Eliminate the shielding structure, increase the inner diameter and set symmetrical protrusions to reduce the coverage area of the wafer, and perform sputtering shielding by contacting the wafer through the contact part.
By reducing the area of the clamping ring covering the wafer, the yield rate is reduced and the product loss rate is increased.
Smart Images
Figure CN223509949U_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor technology, and more specifically to a clamping ring and sputtering equipment. Background Technology
[0002] Thin-film sputtering with back-side ventilation on the wafer requires clamping rings to press the wafer against the ventilation equipment.
[0003] The clamping ring has a through hole in the middle, which exposes most of the wafer surface. The part of the wafer covered by the clamping ring cannot be sputtered or can not be completely sputtered, resulting in yield loss.
[0004] However, using the existing clamping ring structure results in a high yield loss. Summary of the Invention
[0005] The problem this invention aims to solve is: how to reduce the yield loss of wafers in thin film sputtering processes.
[0006] To address the above problems, embodiments of the present invention provide a clamping ring, characterized in that it comprises:
[0007] A ring body having opposing first and second surfaces; the first surface of the ring body is used to contact a wafer.
[0008] The contact portion is located within the first surface of the ring body and on the inner side of the ring body, and is used to contact the wafer and to shield the wafer from sputtering.
[0009] In one possible embodiment, the clamping ring further includes two or more protrusions symmetrically arranged in pairs on the inner side of the ring body, the protrusions protruding from the inner side of the ring body toward the center of the ring body.
[0010] In one possible embodiment, the two or more protrusions include: a first protrusion and a second protrusion arranged symmetrically.
[0011] In one possible embodiment, the two or more protrusions further include: a third protrusion and a fourth protrusion arranged symmetrically.
[0012] In one possible embodiment, the distance between the first protrusion and the second protrusion, and the distance between the third protrusion and the fourth protrusion, are both greater than 142.9 mm.
[0013] In one possible embodiment, the maximum inner diameter of the inner side of the ring is greater than 144.0706 mm.
[0014] In one possible embodiment, the contact portion includes a plurality of contact structures distributed circumferentially along the inner side of the ring body.
[0015] In one possible embodiment, a fixing part is provided between adjacent contact structures for fixing the ring body.
[0016] In one possible embodiment, the contact structure includes: an inclined surface and a parallel surface; the inclined surface is inclined relative to a first surface of the ring; the parallel surface is parallel to the first surface of the ring.
[0017] In one possible embodiment, the maximum thickness of the ring is less than 5 mm.
[0018] In one possible embodiment, a chamfered connecting portion is provided on the second surface of the ring body, the chamfered connecting portion being used to connect the second surface of the ring body to the first surface of the ring body.
[0019] This invention also provides a sputtering apparatus, the sputtering apparatus comprising:
[0020] A coating cavity, wherein a ventilation component is provided within the coating cavity; the ventilation component provides a wafer placement surface;
[0021] And any of the above-mentioned clamping rings, the clamping rings being used to press the wafer against the wafer placement surface.
[0022] Compared with the prior art, the technical solution of the embodiments of the present invention has the following advantages:
[0023] The solution of the present invention only has a ring body and a contact portion. The contact portion contacts the wafer and performs sputtering shielding on the wafer. Instead of providing an additional shielding structure extending towards the center of the ring body inside the ring body, the inner diameter of the clamping ring can be increased, the coverage area of the clamping ring on the wafer can be reduced, and the finished product loss rate can be reduced. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the structure of the first surface of a ring body in an embodiment of the present invention;
[0025] Figure 2 yes Figure 1 A diagram showing the contact between the central ring and the first surface of the wafer.
[0026] Figure 3 This is a schematic diagram of the structure of the second surface of a ring body in an embodiment of the present invention;
[0027] Figure 4 This is a schematic diagram of the structure of the first surface of another ring in an embodiment of the present invention. Detailed Implementation
[0028] Currently, existing clamping rings not only have a contact part, but also a shielding part on the side of the contact part near the center of the clamping structure. The shielding part is used to shield the edge of the wafer to prevent deposits from accumulating at the edge during the thin film sputtering process.
[0029] However, due to the presence of the shielding part, the clamping ring covers a large area of the wafer edge, resulting in a high yield loss.
[0030] To address this problem, the present invention provides a clamping ring consisting of a ring body and a contact portion, without additional shielding structures extending towards the center of the ring body. This reduces the area of the clamping ring covering the wafer, thereby lowering the yield loss rate.
[0031] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
[0032] This invention provides a clamping ring, which includes a ring body and a contact portion. Wherein:
[0033] The ring body has a first surface and a second surface facing each other; the first surface of the ring body is used to contact the wafer.
[0034] The contact portion is located within the first surface of the ring body and on the inner side of the ring body, and is used to contact the wafer and to shield the wafer from sputtering.
[0035] Since no additional shielding structure is provided on the side of the contact area near the center of the clamping ring to shield the wafer edge, the inner diameter of the clamping ring can be increased, the coverage area of the clamping ring on the wafer can be reduced, thereby reducing the wafer loss rate.
[0036] Figure 1 This is a schematic diagram of the structure of the first surface of the ring 10 in one embodiment of the present invention. Figure 2 This is a schematic diagram showing the contact between wafer 20 and the first surface of ring 10. Figure 3 This is a schematic diagram of the structure of the second surface of the ring 10 in one embodiment of the present invention.
[0037] Reference Figure 1 and Figure 2 The ring body 10 has a through hole 11 in the middle, and the wafer 20 is located at the through hole 11. The edge of the wafer 20 can contact the first surface of the ring body 10. The ring body 10 presses the edge of the wafer 20 tightly, so that thin film sputtering can be performed on the exposed part of the wafer 20 on the second surface of the ring body 20. At this time, the edge of the wafer 20 is not sputtered or is not completely sputtered because it is covered by the pressing ring.
[0038] In specific implementation, refer to Figure 1 and Figure 2A contact portion 12 is provided on the first surface of the ring body 10. The contact portion 12 is located on the inner side of the ring body 10. The wafer 20 contacts the contact portion 12, and the contact portion 12 can extend towards the center of the ring body 10, thereby partially shielding the surface of the contacted wafer 20 to prevent deposits from accumulating at the edge of the wafer 10 and causing die sticking.
[0039] In one embodiment, reference is made to Figure 1 and Figure 2 The contact portion 12 may include a plurality of contact structures 121, which are distributed circumferentially along the inner side of the ring body 10. The edge of the wafer 20 contacts the contact structures 121.
[0040] In one embodiment, the contact structure 121 may include an inclined surface and a parallel surface. The inclined surface and the parallel surface are continuous, and the parallel surface is closer to the center of the clamping ring than the inclined surface. The thickness of the ring body 10 containing the inclined surface gradually decreases from the end furthest from the center of the clamping ring to the end closer to the center of the clamping ring. The parallel surface is located at the end of the inclined surface near the center of the clamping ring, and the thickness of the ring body 10 containing the parallel surface is equal to the thickness of the inclined surface at the end near the center of the clamping ring. The edge of the wafer 20 contacts the inclined surface, and the inclined surface makes the wafer 20 more stable. In addition, the portion of the inclined surface covering the wafer 20 and the parallel surface can both cover but not contact the wafer surface, thereby shielding the surface of the wafer 20 and preventing deposits from accumulating at the edge of the wafer 20 and causing die sticking.
[0041] In a specific implementation, a plurality of fixing parts 13 may be provided on the first surface of the ring body 10, and these fixing parts are distributed circumferentially along the inner side of the ring body 10. Specifically, in order to better connect with the ventilation equipment under the wafer, the fixing parts 13 may be provided between adjacent contact structures 121, so as to be aligned and connected with the ventilation equipment under the wafer.
[0042] In specific implementations, the structure of the fixing part 13 can be set according to the connecting component on the ventilation device below the wafer that is adapted to the clamping ring. For example, when the connecting component on the ventilation device below the wafer that is adapted to the clamping ring is a protrusion, the fixing part 13 can be a fixing hole that accommodates the protrusion. The protrusion on the ventilation device can extend into the fixing hole of the clamping ring, thereby fixing the clamping ring.
[0043] In one embodiment of the present invention, the maximum inner diameter r1 of the ring 10 is greater than 144.0706 mm, but should be less than the minimum outer diameter of the wafer. For example, the maximum inner diameter r1 of the ring 10 can be set to 146.02 mm. In this way, the inner diameter is increased from 144.0706 mm to 146.02 mm, which can further reduce the finished product loss rate of the entire edge.
[0044] In one embodiment of the present invention, in order to further shield the wafer 20, the clamping ring may further include two or more protrusions symmetrically arranged in pairs on the inner side of the ring body 10. The protrusions protrude from the inner side of the ring body 10 toward the center of the ring body 10.
[0045] For example, refer to Figure 4 Two protrusions, namely a first protrusion P1 and a second protrusion P2, can be provided on the inner side of the ring body 10. The first protrusion P1 and the second protrusion P2 are symmetrically distributed on the inner side of the ring body 10 with respect to the center of the clamping ring. Thus, the first protrusion P1 and the second protrusion P2 cover but do not contact the wafer surface, thereby achieving the shielding of the wafer 20.
[0046] For example, refer to Figure 1 In addition to the first protrusion P1 and the second protrusion P2, a third protrusion P3 and a fourth protrusion P4 can be provided inside the ring body 10. The third protrusion P3 and the fourth protrusion P4 are symmetrically distributed inside the ring body 10 with respect to the center of the clamping ring, thereby covering but not contacting the wafer surface by the third protrusion P3 and the fourth protrusion P4 to achieve further shielding of the wafer 20.
[0047] In a specific implementation, the protrusion can be set in the inner gap of the ring between adjacent structures. In this case, the length of the protrusion along the inner circumferential direction of the ring is greater than or equal to the length of the inner circumferential direction of the ring between adjacent structures. This can shield the exposed wafer surface between adjacent structures and prevent deposits from accumulating on the exposed wafer surface between adjacent structures and causing die sticking.
[0048] In practice, the clamping ring may have no protrusions, or it may have only two protrusions, or only four protrusions. The number of protrusions should not be too many to avoid affecting the sputtering effect.
[0049] In one embodiment of the present invention, the distance between the two symmetrically arranged protrusions is greater than 142.9 mm, thereby increasing the distance between the two symmetrically arranged protrusions and further reducing the coverage area on the wafer surface, thereby reducing the yield loss rate. For example, the distance between the first protrusion and the second protrusion, as well as the distance between the third protrusion and the fourth protrusion, can all be greater than 142.9 mm.
[0050] In specific implementation, refer to Figure 3The second surface of the ring body 10 has a chamfered connecting portion 14. The chamfered connecting portion 14 is used to connect the first surface and the second surface of the ring body 10. That is, the second surface of the ring body 10 is inclined relative to the chamfered connecting portion 14 near the first surface of the ring body 10 at the through hole 11. This inclination causes the thickness of the second surface of the ring body 10 to gradually decrease in the direction towards the center of the clamping ring, thereby exposing the surface of the wafer that needs to be sputtered as much as possible for more complete sputtering.
[0051] In a specific implementation, the maximum thickness of the ring 10 can be set to be less than 5 mm. Except for the chamfered connecting portion 14 and the contact portion 12, the thickness of the ring 10 is uniform, and can be the maximum thickness of the ring. In this case, setting the maximum thickness of the ring 10 to less than 5 mm is smaller than the maximum thickness of existing rings, which is equivalent to cutting the overall thickness of the existing ring, thereby reducing the weight of the clamping ring and preventing the wafer from being crushed. For example, the maximum thickness of the ring can be set to 3.15 mm.
[0052] In specific implementation, refer to Figures 1 to 3 The inner edge shape of the ring 10 matches the edge shape of the wafer 20.
[0053] For example, when the edge shape of wafer 20 includes both straight and curved portions, the corresponding edge shape of the inner side of ring 10 also includes both straight and curved portions. The contact structure containing the straight portion of the inner edge of ring 10 contacts and adheres to the straight portion of the edge of wafer 20. The contact structure containing the curved portion of the inner edge of ring 10 contacts and adheres to the curved portion of the edge of wafer 20.
[0054] In some embodiments, the edge shape of the wafer 20 can also be an arc shape, that is, an arc shape. Correspondingly, the edge shape of the inner side of the ring 10 can also be an arc shape, which facilitates the contact and bonding between the edge of the wafer 20 and the contact structure on the inner side of the ring 10.
[0055] In some embodiments, refer to Figure 1 The clamping ring may further include an edge portion 15, which is located on the outer side of the ring body 10, connected to the outer side of the ring body 10, and extends from the second surface of the ring body 10 towards the first surface of the ring body 10. The free end of the edge portion 15 extends beyond the first surface of the ring body 10. In practical applications, the edge portion 15 of the clamping ring can contact the bottom of the shielding barrel inside the coating cavity, thereby preventing deposits from entering the shielding barrel from the gap between the clamping ring and the shielding barrel, which would affect the sputtering effect.
[0056] As can be seen from the above, the clamping ring in the embodiments of the present invention can reduce the area of the wafer covered by the clamping ring and reduce the wafer loss rate by completely removing the shielding structure set on the inner side of the ring body, increasing the inner diameter of the clamping ring, and increasing the spacing between the symmetrically arranged protrusions, without changing the area of the clamping ring in direct contact with the wafer.
[0057] This invention also provides a sputtering apparatus, which includes a coating cavity and the aforementioned clamping ring.
[0058] The coating cavity is equipped with a ventilation component, which provides a wafer placement surface. A clamping ring is used to press the wafer firmly against the wafer placement surface.
[0059] Specifically, the sputtering equipment may include a shielding barrel, which is installed and fixed at the bottom of the coating chamber. A clamping ring is installed inside the shielding barrel via a connector and can move up and down. A venting component is installed below the shielding barrel. In standby mode, the clamping ring rests at the bottom of the shielding barrel, with its edge in contact with the bottom of the barrel. After the wafer enters the chamber, it is placed on the wafer placement surface of the venting component. The venting component is controlled to rise, and as it rises, it enters the shielding barrel. Once the venting component reaches the height of the clamping ring, the clamping ring contacts the wafer, and the venting component pushes the clamping ring to continue rising until it reaches a set height, at which point it stops, and the clamping ring holds the wafer in place by its own weight.
[0060] At this point, one side of the wafer is in contact with the wafer placement surface, while the other side is exposed by the clamping ring, allowing sputtering to be performed on the exposed side. Specifically, the gas inside the coating chamber can be ionized to generate charged particles. These charged particles bombard the target material. When the accelerated charged particles bombard the target surface, they collide with the atoms on the target surface, resulting in energy and momentum transfer. This causes the target atoms to escape from the surface and deposit on the wafer surface, forming a thin film.
[0061] It should be noted that in low-temperature coating sputtering processes, the venting component can be a heating device. In high-temperature coating sputtering processes, the venting component can be a cooling device.
[0062] It should be noted that the coating cavity includes, but is not limited to, a high-temperature hot aluminum (HTHU) cavity. The clamping ring includes, but is not limited to, a clamping ring that matches the HTHU cavity.
[0063] By using the clamping ring in the embodiments of the present invention, when sputtering occurs, the coverage area of the clamping ring on the edge of the first surface of the wafer is reduced, thereby allowing more of the wafer edge to be sputtered, which can reduce the product loss rate.
[0064] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.
Claims
1. A clamping ring, characterized in that, include: A ring body having opposing first and second surfaces; the first surface of the ring body is used to contact a wafer. The contact portion is located within the first surface of the ring body and on the inner side of the ring body, and is used to contact the wafer and to shield the wafer from sputtering.
2. The clamping ring as described in claim 1, characterized in that, Also includes: Two or more protrusions are symmetrically arranged in pairs on the inner side of the ring body, and the protrusions protrude from the inner side of the ring body toward the center of the ring body.
3. The clamping ring as described in claim 2, characterized in that, The two or more protrusions include: a first protrusion and a second protrusion arranged symmetrically.
4. The clamping ring as described in claim 3, characterized in that, The two or more protrusions also include: a third protrusion and a fourth protrusion arranged symmetrically.
5. The clamping ring as described in claim 4, characterized in that, The distance between the first protrusion and the second protrusion, and the distance between the third protrusion and the fourth protrusion, are both greater than 142.9 mm.
6. The clamping ring as described in claim 3, characterized in that, The maximum inner diameter of the ring body is greater than 144.0706 mm.
7. The clamping ring according to any one of claims 1 to 6, characterized in that, The contact portion includes multiple contact structures, which are distributed circumferentially along the inner side of the ring.
8. The clamping ring as described in claim 7, characterized in that, A fixing part is provided between adjacent contact structures, and the fixing part is used to fix the ring body.
9. The clamping ring as described in claim 7, characterized in that, The contact structure includes an inclined surface and a parallel surface; the inclined surface is inclined relative to the first surface of the ring; the parallel surface is parallel to the first surface of the ring.
10. The clamping ring as described in claim 1, characterized in that, The maximum thickness of the ring is less than 5 mm.
11. The clamping ring as described in claim 1, characterized in that, A chamfered connecting portion is provided on the second surface of the ring body, which is used to connect the second surface of the ring body to the first surface of the ring body.
12. A sputtering apparatus, characterized in that, include: A coating cavity, wherein a ventilation component is provided within the coating cavity; the ventilation component provides a wafer placement surface; And a clamping ring according to any one of claims 1 to 11, the clamping ring being used to clamp the wafer onto the wafer placement surface.