Wafer retaining ring and bearing disc
By designing an inclined first slope and support platform structure on the wafer retaining ring, the problems of short maintenance cycles and particle defects are solved, achieving a longer service life and higher coating quality.
Patent Information
- Application Number
- CN202421729740.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-19
- Publication Date
- 2025-07-29
- Estimated Expiration
- 2034-07-19
AI Technical Summary
The maintenance cycle and service life of existing wafer retaining rings are relatively short, and particle defects are prone to occur during coating, affecting the quality of wafer coating.
A wafer retention ring is designed, and the inclined first slope and support platform structure is used to replace the original horizontal and right-angle structure, increasing the surface area and reducing particle entry, and blocking particles into the wafer through inclined design.
The maintenance cycle and service life of the retaining ring are extended, the probability of particles entering the wafer is reduced, the coating quality is improved, and the risk of wafer damage is reduced.
Smart Images
Figure CN223163476U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of semiconductor coating, and particularly relates to a wafer retaining ring and a carrier plate. Background Art
[0002] The coating process is an extremely widely used and extremely important part in industries such as semiconductors, optics, and nano materials. It includes, but is not limited to: fields such as substrate epitaxy, chip pattern fabrication, electrode fabrication, optical material preparation, and two-dimensional material growth, etc. The large-scale and mass-production coating process forms basically adopt wafer coating.
[0003] During the wafer coating process, it is necessary to position and limit the wafer through a limiting structure. Most of them use a structure in which the wafer tray and the Ring (retaining ring) are separated or an integrated structure of the wafer tray and the Ring to achieve the above purpose. Currently, the general structure of the Ring is a ring structure with horizontal sides perpendicular, as shown in Figure 1 and Figure 2 This structure has the following problems:
[0004] 1. During the wafer coating process, in order to reduce the negative impact on the coating, the Ring needs to be maintained or scrapped and replaced with a new one after growing to a certain thickness. The deposition thickness on the top horizontal side 101 of the existing retaining ring 100 is generally the same as the coating thickness of the wafer. The maintenance period and service life are generally short, resulting in an increase in the maintenance and consumption costs of the accessories; frequent Ring maintenance also wastes the production time of the coating. These are not conducive to the industrialization and large-scale production of wafer coating.
[0005] 2. A large amount of loose and protruding deposits are easily attached to the top horizontal side 101 and the right-angle 102 structure of the existing retaining ring 100. When the growth temperature and flow field change, there is a certain probability that these loose and protruding deposits will move onto the wafer to form fatal defects, greatly affecting the quality of the wafer coating. Furthermore, the protruding deposits at the right-angle 102 structure will also affect the picking and placing of the wafer, causing the wafer to get stuck or even crack.
[0006] It should be noted that the information disclosed in the background art part of this utility model is only intended to deepen the understanding of the general background art of this utility model, and should not be regarded as an admission or any form of suggestion that this information constitutes the prior art known to those skilled in the art. Summary of the Utility Model
[0007] The purpose of the utility model is to provide a wafer retaining ring and a carrier plate to solve the problem that the maintenance period and service life of the existing retaining ring are generally short, reduce the particles from entering the wafer to form defects, and improve the quality of the wafer coating.
[0008] To solve the above technical problems, the present utility model provides a wafer holding ring, comprising:
[0009] An annular body;
[0010] A first ramp formed on the top of the annular body along a height direction, and the inner height of the first ramp is higher than the outer height; and
[0011] A supporting platform formed on the inner side of the annular body along a radial direction for supporting a wafer, the top surface of the supporting platform is lower than the inner height of the first ramp, and a first inner edge is provided on the inner side of the first ramp to connect with the supporting platform.
[0012] Preferably, it further comprises a second ramp, one side of the second ramp is connected to the first ramp, the other side is connected to the first inner edge, and the height of one side of the second ramp is higher than that of the other side.
[0013] Preferably, the other side of the second ramp and the first inner edge are connected by a fillet.
[0014] Preferably, one side of the first ramp and the second ramp are connected by a fillet.
[0015] Preferably, teeth are protrudingly provided at the bottom of the annular body.
[0016] Preferably, the ratio of the length of the first ramp to the length of the second ramp is 2:1 to 10:1.
[0017] Preferably, the length of the second ramp is 0.1 mm to 0.8 mm.
[0018] Preferably, a first included angle is formed between the first ramp and the height direction, and the first included angle is 10° to 85°.
[0019] Preferably, a second included angle is formed between the second ramp and the height direction, and the second included angle is 10° to 85°.
[0020] Based on the same technical concept, the present disclosure also provides a wafer carrier, comprising the wafer holding ring as described above.
[0021] The wafer holding ring provided by the present utility model has the following beneficial effects:
[0022] 1. The original horizontal edge is replaced by the first ramp inclined outward. The first ramp is provided on the top of the annular body to replace the original right-angle structure. A first included angle θ is formed between the first ramp and the height direction, and also S 第一斜坡 = S 水平边 / sinθ. The top area of the first slope is larger than that of the horizontal side, and the top area of the wafer holding ring is greatly increased. During the wafer coating process, most of the growth sources diffuse from the vertical direction. The total amount of growth sources coming from the vertical direction is roughly the same for the hypotenuse and the horizontal side. Here, that is, the product of the coating thickness and the area of the first slope is equivalent to the product of the coating thickness of the flat side and the area of the hypotenuse. Denoted as: h 第一斜坡 S 第一斜坡 = h 平边 S 水平边 , and because S 第一斜坡 sinθ = S 水平边 , the growth thickness h 第一斜坡 = h 水平边 sinθ; that is, under the same growth conditions, when the existing holding ring reaches the maintenance or scrapping thickness h, the thickness of the growth on the first slope is h 第一斜坡 sinθ, and it can continue to grow by h - h 第一斜坡 sinθ. Therefore, the hypotenuse design method improves the maintenance cycle and service life of the Ring.
[0023] 2. By the above structure, the introduction of wafer particles is also reduced, and the quality of the grown wafer is improved. Specifically as follows:
[0024] First, the surface deposition rates of the first slope and the flat side of the present disclosure can be expressed as: v 第一斜坡 = h 第一斜坡 / t, v 平边 = h 平边 / t. According to the above thickness relationship between the two, we can get: v 第一斜坡 = v 水平边 sinθ. Therefore, the surface growth deposition rate of the newly designed holding ring is slower, the coverage on the surface of the Ring is more stable and dense, and the probability of particles entering the wafer is smaller.
[0025] Second, compared with the right-angle structure of the horizontal side, the slope and rounded chamfer of the holding ring of the present disclosure make it difficult for overly loose and protruding deposits to adhere to the Ring and are more likely to be carried away by the gas, reducing the introduction of particles to the coated wafer.
[0026] Finally, the first slope structure of the new wafer holding ring is inclined outward. When particles brought from other places pass through the Ring and enter the wafer, they are blocked by the slope, causing them to tend to move outside the wafer and making it difficult to enter the wafer.
[0027] The above description enables the new holding ring Ring to reduce the number of particles entering the wafer, reduce the number of fatal defects on the wafer, and improve the quality of wafer coating.
[0028] 3. The ramp and round chamfer structure near the inner side of the ring is not prone to forming inwardly protruding sediments compared with the existing horizontal edge right-angle structure, making the vicinity of the wafer and the ring smoother; reducing the probability of wafer jamming and cracking during wafer picking and placing.
[0029] The wafer carrier provided by the present utility model and the wafer retaining ring provided by the present utility model belong to the same inventive concept. Therefore, the wafer carrier provided by the present utility model has at least all the advantages of the wafer retaining ring provided by the present utility model, which will not be elaborated herein. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Those of ordinary skill in the art will understand that the provided drawings are used to better understand the present utility model and do not constitute any limitation to the scope of the present utility model. Among them:
[0031] Figure 1 is a top view structural schematic diagram of an existing retaining ring;
[0032] Figure 2 is a partial cross-sectional structural schematic diagram of an existing retaining ring;
[0033] Figure 3 is a top view structural schematic diagram of a wafer retaining ring according to an embodiment of the present utility model;
[0034] Figure 4 is a partial cross-sectional structural schematic diagram of a wafer retaining ring according to an embodiment of the present utility model;
[0035] Figure 5 is a cross-sectional structural schematic diagram of a wafer retaining ring according to another embodiment of the present utility model;
[0036] Figure 6 is a cross-sectional structural schematic diagram of a wafer retaining ring according to an embodiment of the present utility model.
[0037] In the drawings:
[0038] 100, existing retaining ring; 101, horizontal edge; 102, right angle.
[0039] 200, wafer retaining ring; 201, annular main body; 202, first ramp; 203, second ramp; 204, first inner edge; 205, supporting table; 206, second inner edge; 207, engaging teeth; 208, outer edge; 209, third inner edge. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0040] To make the objectives, advantages, and features of the present utility model clearer, the following further elaborates on the present utility model in conjunction with the accompanying drawings and specific embodiments. It should be noted that the accompanying drawings are in very simplified forms and not drawn to scale, only for conveniently and clearly assisting in explaining the objectives of the embodiments of the present utility model. In addition, the structures shown in the accompanying drawings are often part of the actual structures. Specifically, the accompanying drawings need to show different focuses and sometimes use different scales.
[0041] As used in the present utility model, the singular forms "a", "an", and "the" include plural objects. The term "or" is generally used in the sense of including "and / or". The term "several" is generally used in the sense of including "at least one". The term "at least two" is generally used in the sense of including "two or more". In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", "third" may explicitly or implicitly include one or at least two of such features. The term "proximal end" is usually the end close to the operator, and the term "distal end" is usually the end close to the patient. "One end" and "the other end", as well as "proximal end" and "distal end", usually refer to corresponding two parts, which include not only the endpoints. The terms "mount", "connect", "couple" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. In addition, as used in the present utility model, when an element is disposed on another element, it generally only indicates that there is a connection, coupling, cooperation, or transmission relationship between the two elements, and the two elements can be directly or indirectly connected, coupled, cooperated, or transmitted through an intermediate element, rather than being understood as indicating or implying the spatial position relationship between the two elements, that is, an element can be inside, outside, above, below, or on one side of another element, etc. in any orientation, unless otherwise explicitly stated in the content. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0042] The inventor of the utility model has found that in CVD and PVD coatings, specifically in the epitaxial layer coatings such as SiC and GaN, the PVD coatings such as Pt, Ni, and Au, and the CVD deposition of oxides, although the existing structure of the retaining ring can play a good role in positioning and restricting the wafers to be coated, during the coating process, a certain thickness of medium is likely to be deposited on its top along with the wafer coating, which poses certain requirements for production and maintenance. Moreover, the medium deposited on the top of the existing retaining ring is likely to move to the wafer surface, affecting the growth quality of the wafer coating.
[0043] Based on this, the core idea of the present utility model is to reduce the medium accumulated on the wafer holding ring by setting a first ramp, extend the maintenance period and service life of the wafer holding ring, and further, block external particles from reaching the growing wafer and reduce defects.
[0044] Specifically, please refer to Figures 3 - 6 , which is a schematic diagram of an embodiment of the present utility model. As Figure 3 shown, a wafer holding ring for wafer coating includes:
[0045] An annular main body 201;
[0046] A first ramp 202 formed on the top of the annular main body 201 along a height direction, and the inner height of the first ramp 202 is higher than the outer height; and
[0047] A supporting table 205 formed on the inner side of the annular main body 201 along a radial direction for supporting a wafer, the top surface of the supporting table 205 is lower than the inner height of the first ramp 202, and a first inner edge 204 is provided on the inner side of the first ramp 202 to connect with the supporting table 205.
[0048] As Figure 4 and Figure 6 shown, a first ramp 202 is provided on the top of the annular main body 201 to replace the original right-angle structure. There is a first included angle θ between the first ramp 202 and the height direction. Also, S 第一斜坡 =S 水平边 / sinθ. The top area of the first ramp 202 is larger than the area of the horizontal side, and the top area of the wafer holding ring 200 is greatly increased. During the film growth process, the total amount of growth sources coming in the vertical direction is approximately the same as that of the hypotenuse and the horizontal side. Therefore, under the same growth conditions, the relationship between the growth rates of the first ramp 202 and the horizontal side is v 第一斜坡 =v 水平边 sinθ, and the growth thickness h 第一斜坡 =h 水平边 sinθ. That is, under the same growth conditions, when the existing holding ring reaches the maintenance or scrapping thickness h, the thickness grown by the first ramp 202 is h 第一斜坡 sinθ, and it can continue to grow by h - h 第一斜坡 sinθ, greatly extending the maintenance period and service life of the holding ring.
[0049] It is understood that the inner side of the first slope 202 is the side closer to the axis of the annular body 201, while the outer side is the side farther from the axis. The design of the first slope 202, which is higher on the inside and lower on the outside, not only increases its surface area, but also slows the growth of sediments compared to the horizontal side, allowing for more stable and dense growth of deposits on the surface of the wafer retaining ring 200. Furthermore, the inclined first slope 202 prevents overly loose and protruding sediments from adhering to its surface, making them more likely to slide off the wafer retaining ring 200 along the first slope 202, thus preventing the wafer retaining ring 200 from becoming a source of particles during wafer growth.
[0050] The outward-inclined first slope 202 structure causes particles generated by other particle sources to tend to move outward from the ring when passing through the slope, making it difficult for them to enter the ring, thereby preventing the particles from reaching the growing wafer.
[0051] Specifically, it further includes a second slope 203 , one side of the second slope 203 is connected to the first slope 202 , and the other side is connected to the first inner edge 204 , and the height of one side of the second slope 203 is higher than the height of the other side.
[0052] like Figure 5 As shown, a second slope 203 connected to the first slope 202 facilitates wafer placement and placement, preventing wafer jamming even when thick deposits accumulate on top of the wafer retaining ring 200. Furthermore, the first slope 202 is longer than the second slope 203, creating a protrusion at the junction of the second slope 203 and the first slope 202, effectively blocking particles from the first slope 202.
[0053] The ratio of the length L of the first slope 202 to the length S of the second slope 203 is 2:1 to 10:1. Figure 5 As shown, the length S of the second slope 203 is 0.1 mm to 0.8 mm.
[0054] like Figure 5 As shown, a supporting platform 205 protrudes from the inner side of the annular body 201 for supporting the wafer, dividing the inner side of the annular body 201 into two discontinuous edges, namely a first inner edge 204 and a second inner edge 206. The first inner edge 204 and the second inner edge 206 are both vertical edges. The height h1 of the first inner edge 204 is, for example, 0.1mm to 1.2mm, and the height h2 of the second inner edge 206 is, for example, 0.1mm to 0.8mm.
[0055] Wherein, a latch tooth 207 is also convexly provided at the bottom of the annular body 201. The latch tooth 207 extends from the outer edge 208 of the annular body 201 and can be used to connect with a wafer carrier. The inner side edge of the latch tooth 207 is the third inner edge 209, and its height h3 is, for example, 0.15 mm to 0.8 mm.
[0056] Specifically, the other side of the second slope 203 is fillet-connected to the first inner edge 204. One side of the first slope 202 is fillet-connected to the second slope 203. The first slope 202 and the outer edge 208 are also fillet-connected, so as to avoid bumping the edges and corners when picking and placing the wafer, causing damage to the wafer. Even if the deposits on the wafer holder ring 200 are relatively thick, it is not easy to get stuck. Exemplarily, as Figure 6 shown, the radii of the fillets R are the same, all being 0.2 mm to 0.8 mm.
[0057] By designing the structures of the first slope 202, the second slope 203 and the round chamfer, the coverage of the deposits on the wafer holder ring is reduced, and the overly loose and protruding deposits are not easy to adhere to it and are easier to be carried away, so as to increase the maintenance period and service life of the wafer holder ring; the first slope structure inclined outward makes the particles generated by other particle sources block the particles outside the holder ring from entering the ring when passing through the slope, preventing the particles from reaching the growing sample and reducing the number of defects caused by the particles entering the wafer. The difficulty of picking and placing the wafer is reduced through the second slope 203, and the probability of wafer contamination, chipping and even cracking caused by picking and placing the wafer is reduced.
[0058] As Figure 6 shown, the first slope 202 has a first included angle θ with the height direction, and the first included angle θ is 10° to 85°. The second slope 203 has a second included angle α with the height direction, and the second included angle α is 10° to 85°. More preferably, the height of the first inner edge 204 and the second included angle α are set according to the mechanical structure for picking and placing the wafer to ensure that there is sufficient space between the second slope 203 and the side wall of the wafer for the mechanical structure to operate.
[0059] Based on the same technical concept, the present disclosure also provides a wafer carrier, including the wafer holder ring as described above. The wafer holder ring is fixedly arranged on the wafer carrier, and the two can be of an integrated structure, and obviously can also be of a separable structure, which is not specifically limited herein.
[0060] In the wafer holding ring and carrier provided by the present disclosure, by providing a new holding ring structure, the existing horizontal edge and right-angle structure are replaced by the connected first slope and second slope. The original horizontal edge is replaced by the first slope that slopes outward, and a shorter second slope is designed on the inner side of the ring. Finally, rounded corners are respectively provided at the junctions of the edges on the surface of the holding ring where growth substances may be deposited and adhered.
[0061] Through the above structure, the maintenance cycle and service life of the holding ring are greatly extended. The top of the annular body 201 is provided with the first slope 202 to replace the original right-angle structure. The first slope 202 has a first included angle θ with the height direction, and S 第一斜坡 = S 水平边 / sinθ. The top area of the first slope 202 is larger than the area of the horizontal edge, and the top area of the wafer holding ring 200 is greatly increased. During the film growth process, the total amount of growth sources coming in the vertical direction is roughly the same for the hypotenuse and the horizontal edge. Therefore, under the same growth conditions, the relationship between the growth rates of the first slope 202 and the horizontal edge is v 第一斜坡 = v 水平边 sinθ, and the growth thickness h 第一斜坡 = h 水平边 sinθ. That is, under the same growth conditions, when the existing holding ring reaches the maintenance or scrapping thickness h, the thickness grown by the first slope 202 is h 第一斜坡 sinθ, and it can continue to grow by h - h 第一斜坡 sinθ.
[0062] Through the above structure, the introduction of wafer particles is reduced, and the quality of the grown wafers is improved. On the one hand, the growth rate of the deposits on the surface of the holding ring is slower than that of the horizontal edge, making the attachments on the surface of the holding ring more stable and dense; on the other hand, for the new holding ring, compared with the right-angle structure of the horizontal edge, the overly loose and protruding deposits are not easy to adhere to the inclined first slope with rounded corners and are easier to be carried away. Both of these aspects make the new holding ring not easily become a particle source. The first slope structure that slopes outward makes the particles generated by other particle sources tend to move out of the ring when passing through the slope, making it difficult to enter the ring and hindering the particles from reaching the growing samples.
[0063] In summary, through the above structure, the particles introduced on the wafer are reduced, thereby reducing fatal defects and improving the quality of the product.
[0064] The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of the present invention in any way. Any changes and modifications made by those of ordinary skill in the art of the present invention based on the above disclosure belong to the protection scope of the technical solution of the present invention.
Claims
1. A wafer holding ring for wafer coating, characterized in that, Comprising: A circular main body; A first slope formed on the top of the circular main body along a height direction, and the inner height of the first slope is higher than the outer height; And A supporting table formed on the inner side of the circular main body along a radial direction for supporting a wafer, the top surface of the supporting table is lower than the inner height of the first slope, and a first inner edge is provided on the inner side of the first slope to connect with the supporting table.
2. The wafer holding ring according to claim 1, wherein, It further includes a second slope, one side of the second slope is connected to the first slope, the other side is connected to the first inner edge, and the height of one side of the second slope is higher than that of the other side.
3. The wafer holding ring according to claim 2, characterized in that, The other side of the second slope is connected to the first inner edge by a fillet.
4. The wafer holding ring according to claim 2, characterized in that, One side of the first slope and the second slope are connected by a fillet.
5. The wafer holding ring according to claim 1, wherein Teeth are also protrudingly provided at the bottom of the circular main body.
6. The wafer holding ring according to claim 2, characterized in that, The ratio of the length of the first slope to the length of the second slope is 2:1 to 10:
1.
7. The wafer holding ring according to claim 2, characterized in that, The length of the second slope is 0.1 mm to 0.8 mm.
8. The wafer holding ring according to claim 1, characterized in that, A first included angle is formed between the first slope and the height direction, and the first included angle is 10° to 85°.
9. The wafer holding ring according to claim 2, wherein, A second included angle is formed between the second slope and the height direction, and the second included angle is 10° to 85°.
10. A wafer carrier, characterized in that, Comprising a wafer holding ring according to any one of claims 1-9.