Grinding head retaining ring, grinding assembly and grinding equipment

Abstract

The utility model provides a grinding head retaining ring, a grinding assembly and grinding equipment. The grinding head retaining ring comprises a ring body, a measuring device and a plurality of water retaining pieces, a plurality of grooves are formed in the ring body, a plurality of water retaining pieces are detachably arranged in any groove, and a liquid supply groove allowing grinding liquid to circulate is formed between each water retaining piece and an opening of the corresponding groove; the measuring device is arranged close to the groove and is used for measuring the depth of the liquid supply tank; on the basis of the real-time depth, measured by the measuring device, of the liquid supply groove, part of the water retaining pieces can be detached after the groove is abraded, so that the depth of the liquid supply groove is kept. According to the configuration, the depth of the groove in the prior art is increased, and the detachable water retaining piece is additionally arranged in the deepened groove, so that the grinding fluid can circulate between the water retaining piece and the opening of the groove, and after the groove is abraded, the depth of the fluid supply groove can be increased by removing the water retaining piece, and the influence on the flow field of the grinding fluid is reduced; the grinding parameter adjusting frequency is reduced, and the production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to semiconductor manufacturing equipment especially a grinding head retaining ring, grinding assembly and grinding equipment. BACKGROUND

[0002] Chemical mechanical polish (CMP) is an important step to realize wafer surface planarization, which is essentially a process of wafer interaction between polishing disc, polishing head and polishing liquid, and any deviation in the three will affect the polishing efficiency and then the product yield.

[0003] The retaining ring, as a component directly contacting with the wafer on the polishing head, is mainly used for fixing the wafer during polishing and pressing the polishing pad in contact with the wafer edge flat, at the same time, the edge of the retaining ring is provided with a groove for the flow of polishing liquid. However, during the polishing process, the retaining ring will be polished and worn together with the wafer, and the depth of the groove will gradually decrease with the progress of polishing, which will directly change the polishing liquid flow field and make it difficult to control the polishing rate and surface uniformity. The conventional method in the industry is to change the polishing parameters (such as polishing time and polishing pressure, etc.) to weaken the influence of retaining ring wear on the polishing liquid flow field, but the above method needs to frequently adjust the polishing parameters, which is complicated and affects the production efficiency.

[0004] Therefore, how to reduce the influence of retaining ring wear on the polishing liquid flow field and reduce the number of adjusting the polishing parameters has become a technical problem to be solved by those skilled in the art. SUMMARY

[0005] The utility model discloses a kind of grinding head retaining ring, grinding assembly and grinding equipment, to solve the problem that frequent adjustment of polishing parameters is needed in prior art, complicated and affects production efficiency.

[0006] To achieve the above purpose, the utility model provides a kind of grinding head retaining ring, comprising: ring body, measuring device and multiple water baffles of being set on the polishing head;

[0007] The ring body has multiple grooves arranged along the circumference thereof, and multiple water baffles are detachably arranged in any groove, and a liquid supply groove for the flow of polishing liquid is formed between the water baffles and the opening of the groove.

[0008] The measuring device is arranged close to the groove and is used to measure the depth of the liquid supply groove.

[0009] Based on the real-time depth of the liquid supply groove measured by the measuring device, part of the water baffles can be removed after the groove is worn, to maintain the depth of the liquid supply groove.

[0010] Optionally, the length and width of the water baffle are adapted to the size of the opening, and the thickness direction of the water baffle is parallel to the depth direction of the groove.

[0011] Optionally, the initial depth of the groove is H0, the preset depth of the liquid supply groove is H1, the thickness of one water baffle is h0, and the number n0 of the water baffles that can be accommodated in the groove satisfies: n0=(H0-H1) / h0.

[0012] Optionally, 2.9mm≤H1≤3.1mm.

[0013] Optionally, 0.5mm≤h0≤1.5mm.

[0014] Optionally, the real-time depth of the liquid supply groove after the groove is worn is H2, and the number n1 of the water baffles that need to be removed satisfies: n1=(H1-H2) / h0.

[0015] Optionally, when n1≤1, the number of the water baffles that need to be removed is 0; and when n1>1, the number of the water baffles that need to be removed is the maximum integer value in [1, n1].

[0016] Optionally, the grinding head retaining ring further comprises a fastener, one end of the groove away from the opening is provided with a connecting hole, the water baffles are provided with through holes, and the fastener is sequentially arranged in the through holes of the plurality of water baffles and connected with the connecting hole, so as to realize the detachable connection of the water baffles and the groove.

[0017] In order to achieve the above purpose, the utility model still provides a kind of grinding assembly, comprising: grinding disc, grinding pad and the grinding head with the grinding head retaining ring as described above;

[0018] The grinding disc is laid with the grinding pad, the grinding head is arranged above the grinding pad, the wafer to be ground is arranged between the grinding head and the grinding pad, and the grinding disc rotates around the shaft during the grinding process of the grinding assembly to cooperate with the grinding pad, the grinding head and grinding liquid to realize the grinding of the wafer.

[0019] While maintaining the grinding pad, the number of water baffles is adjusted based on the real-time depth of the liquid supply groove measured by the measuring device to maintain the depth of the liquid supply groove.

[0020] In order to achieve the above purpose, the utility model still provides a kind of grinding equipment, comprising the grinding assembly as described above.

[0021] Compared with the existing retaining ring, the grinding head retaining ring, the grinding assembly and the grinding equipment provided by the present application have the following advantages:

[0022] The polishing head retaining ring provided by the application deepens the groove depth in the prior art, and a detachable water baffle is additionally arranged in the deepened groove, so that the polishing liquid can flow between the water baffle and the opening of the groove. When the groove is worn during the polishing process, the depth of the liquid supply groove can be increased in time by removing the water baffle, the influence on the polishing liquid flow field is reduced, the frequency of adjusting the polishing parameters is reduced, and the production efficiency is improved.

[0023] The polishing assembly provided by the application can remove the corresponding number of water baffles based on the real-time depth of the liquid supply groove while maintaining the polishing pad when the groove is worn, thereby avoiding the suspension of machine production for removing the water baffles and reducing the production efficiency. At the same time, removing the water baffles can keep the depth of the liquid supply groove at a stable value, thereby reducing the influence of groove wear on the polishing liquid flow field, reducing the frequency of adjusting the polishing parameters, and being simple and efficient. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The figure is a schematic view of the groove before and after wear in the prior art;

[0025] Figure 2 The figure is a schematic view of the polishing head retaining ring provided by the embodiment of the application before and after wear of the groove;

[0026] Figure 3 The figure is a structural schematic view of the polishing head retaining ring provided by the embodiment of the application;

[0027] Figure 4 The figure is a partial sectional view of the polishing head retaining ring provided by the embodiment of the application;

[0028] Figure 5 The figure is a partial top view of the polishing head retaining ring provided by the embodiment of the application;

[0029] Figure 6 The figure is a structural schematic view of the water baffle provided by the embodiment of the application;

[0030] Figure 7 The figure is a flowchart of the method for adjusting the water baffle provided by the embodiment of the application;

[0031] Figure 8 The figure is a structural schematic view of the polishing assembly provided by the embodiment of the application.

[0032] Among them, the explanation of each reference sign is as follows:

[0033] 1-ring body; 10-groove; 100-opening; 101-connection hole;

[0034] 2 - water stop; 20 - through hole;

[0035] 3 - liquid supply groove; 4 - fastener; 5 - polishing disc; 6 - polishing pad; 7 - polishing head; 8 - wafer. DETAILED DESCRIPTION

[0036] To make the purposes, advantages and features of the present application clearer, the following will make further detailed description of the present application in combination with the drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn in proportion, and are only used to facilitate and clearly assist in the purpose of describing the embodiments of the present application. In addition, the structures shown in the drawings are often part of the actual structures. In particular, the emphasis of each drawing needs to be different, and sometimes different proportions are used.

[0037] As used in this specification, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. The term "or" is generally employed in its sense including "and / or" unless the context clearly dictates otherwise. The term "and / or" means and or. The term "at least two" is generally employed in its sense including "two or more" unless the context clearly dictates otherwise. In addition, the terms "first," "second," "third," etc. are used only to describe the objects and do not indicate or imply relative importance or a number of the indicated technical features. Therefore, the features defined as "first," "second," "third" can explicitly or implicitly include one or at least two of the features. "One end" and "the other end" and "proximal end" and "distal end" generally refer to two parts corresponding to each other, which not only includes the end points, and the terms "mounting," "connecting," "connecting" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be directly connected, or indirectly connected through an intermediate medium; it can be the internal connection or interaction relationship of two elements. In addition, as used in this specification, an element disposed in another element generally only indicates that there is a connection, coupling, cooperation or transmission relationship between the two elements, and the connection, coupling, cooperation or transmission between the two elements can be direct or indirect through an intermediate element, and cannot be understood as indicating or implying the spatial positional relationship between the two elements, i.e. one element can be in any orientation inside, outside, above, below or one side of another element, unless the content is otherwise clearly indicated. The terms "up," "down," "top," "bottom" are generally arranged in the direction of gravity; the terms "vertical direction" generally refer to the direction along the gravity, which is generally perpendicular to the ground, and the terms "horizontal direction" generally refer to the direction parallel to the ground; for those skilled in the art, the specific meaning of the above terms in this specification can be understood according to the specific circumstances.

[0038] The utility model discloses a purpose at providing a kind of grinding head retaining ring, grinding assembly and grinding equipment, to solve the problem of frequent adjustment of grinding parameter in prior art, complicated and affect production efficiency.

[0039] Please refer to Figure 1 As can be understood by those skilled in the art, the retaining ring needs to be in direct contact with the wafer during the grinding process of the grinding equipment, which results in the retaining ring in contact with the wafer being worn due to the rotation of the wafer while the wafer is rotating driven by the grinding disc, and the most direct impact is that the groove 10 on the retaining ring is worn, thereby the depth is reduced, which results in the flow field of the grinding liquid circulating through the groove 10 changing, so that Figure 1 For example, before wearing, the abrasives in the grinding liquid can flow into or out of the wafer surface through the groove 10, while after wearing, due to the reduction of the depth of the groove 10, large-particle abrasives in the grinding liquid may be stuck at the groove 10 and unable to circulate, thereby affecting the grinding of the wafer surface by the grinding equipment, affecting the grinding efficiency as well as the uniformity of the wafer surface, and the grinding parameter needs to be frequently adjusted in the prior art, which is time-consuming and laborious and also affects the production efficiency. Based on this, the present embodiment provides a grinding head retaining ring, grinding assembly and grinding equipment, by additionally providing a water baffle in the groove, after the groove is worn, the depth of the liquid supply groove is kept in a stable state by removing part of the water baffle, to reduce the impact of wear on product yield, and the frequency of adjusting the grinding parameter can be reduced.

[0040] Please refer to Figures 2 to 6 The utility model provides a kind of grinding head retaining ring, comprising: ring body 1 being set on grinding head 7, measuring device (not shown in the figure) and multiple water baffles 2;Ring body 1 has multiple grooves 10 along the circumferential direction of itself, multiple water baffles 2 are detachably arranged in any groove 10, and water baffle 2 and the opening 100 of groove 10 form liquid supply groove 3 for the circulation of grinding liquid;Measuring device is close to groove 10 and is used to measure the depth of liquid supply groove 3;Based on the real-time depth of liquid supply groove 3 measured by measuring device, part of water baffle 2 can be removed after groove 10 is worn, to keep the depth of liquid supply groove 3.It needs to be explained that, in the present embodiment, the depth of liquid supply groove 3 refers to the shortest distance between the opening 100 of groove 10 and water baffle 2;Measuring device can be a range finder, which can be installed on grinding head 7, or can be held by operator to measure the depth of liquid supply groove 3 when needed, specifically can be laser range finder, and the structure and specific principle of range finder can be referred to prior art, and the present embodiment will not be repeated here;In other embodiments, measuring device can also be a member with scale, which can directly obtain the depth of liquid supply groove 3 by scale. Figure 2, multiple water baffle 2 placed in the groove 10, water baffle 2 and the opening 100 between the groove 10 form a liquid tank 3, at this time the liquid tank 3 has a preset depth H1, and after the grinding equipment is ground, the opening 100 of the groove 10 appears wear, at this time, the real-time depth H2 of the liquid tank 3 will be less than the preset depth H1, the prior art needs to be adjusted by adjusting the grinding parameters (grinding time, grinding pressure, etc.) to reduce the influence of the groove 10 wear on the product yield, and in this embodiment, only a certain number of water baffle 2 is removed, so that the real-time depth H2' of the liquid tank 3 is close to the preset depth H1, without the need to adjust the grinding parameters, reducing the operation difficulty.

[0041] So configured, by deepening the depth of the prior art groove 10, and adding removable water baffle 2 inside the deepened groove 10, so that the grinding liquid can flow between the water baffle 2 and the opening 100 of the groove 10, and during the grinding process, the groove 10 appears wear, which can be timely removed by removing the water baffle 2, thereby increasing the depth of the liquid tank 3, reducing the influence on the flow field of the grinding liquid, reducing the frequency of adjusting the grinding parameters, and improving the production efficiency.

[0042] Please refer to Figures 4 to 6 In an optional embodiment, the grinding head retaining ring further comprises a fastener 4, the end of the groove 10 away from the opening 100 is provided with a connecting hole 101, the water baffle 2 is provided with a through hole 20, the fastener 4 is sequentially threaded through the through holes 20 on the plurality of water baffles 2 and connected with the connecting hole 101, so as to realize the detachable connection between the water baffle 2 and the groove 10. In this embodiment, the fastener 4 is a bolt, and the detachable connection between the water baffle 2 and the groove 10 is achieved by sequentially threading the bolt through the through holes 20 of the plurality of water baffles 2 and finally screwing it into the connecting hole 101 at the bottom of the groove 10. In other embodiments, the end of the groove 10 away from the opening 100 can be provided with a clamping groove, the end of the water baffle 2 away from the opening 100 is provided with a protrusion matched with the clamping groove, the end of the water baffle 2 close to the opening 100 is provided with a clamping groove, and the plurality of water baffles 2 are sequentially connected by the protrusions and the clamping grooves, and the water baffles 2 and the groove 10 are also connected by the protrusions and the clamping grooves, thereby realizing the detachable connection between the water baffles 2 and the groove 10.

[0043] Further, as an optional embodiment, please refer to Figure 2 and Figure 5 The length and width of the water baffle 2 are matched with the size of the opening 100, and the thickness direction of the water baffle 2 is parallel to the depth direction of the groove 10. In this embodiment, the cross-sectional shape of the groove 10 is rectangular, and the water baffle 2 is also a rectangular member, the length of the water baffle 2 is the long side in Figure 5 , and the width of the water baffle 2 is the short side in Figure 5The short side in the length direction of the groove 10 is the short side in the length direction of the opening 100; the side wall of the groove 10 and the side wall of the water baffle 2 are both planes, and the length and width of the water baffle 2 are both adapted to the size of the opening 100. In some other embodiments, the width of the water baffle 2 can also be adapted to the size of the opening 100, and the length can be smaller than the length of the opening 100, which can also achieve the blocking of the polishing liquid; at the same time, the side wall of the groove 10 and the side wall of the water baffle 2 can also be inclined planes or curved surfaces, as long as they can cooperate with each other to control the depth of the liquid supply groove 3.

[0044] Please refer to Figures 1 to 2 and Figure 6 In an alternative example, the initial depth of the groove 10 is H0, the preset depth of the liquid supply groove 3 is H1, and the thickness of a water baffle 2 is h0, then the number n0 of water baffles 2 that can be accommodated in the groove 10 satisfies: n0=(H0-H1) / h0. Further, 2.9mm≤H1≤3.1mm. Further, 0.5mm≤h0≤1.5mm. It should be noted that in this embodiment, n0≥1, and the number of water baffles 2 is the maximum integer value in [1, n0], that is, if n0=1.5, the number of water baffles 2 is 1; if n0=3.2, the number of water baffles 2 is 3. For example, Figure 1 and Figure 2 The initial depth H0' of the groove 10 in the prior art is equal to the preset depth H1 of the liquid supply groove 3 in this embodiment, that is, once the depth of the groove 10 in the prior art is reduced due to wear, it cannot be adjusted by other means, and only the polishing parameters can be adjusted; the initial depth H0 of the groove 10 in this application is greater than H0', and part of the depth is filled by the water baffles 2, so that the depth of the liquid supply groove 3 is reduced to the preset depth H1, and after the subsequent wear of the groove 10, the depth of the groove 10 can be restored by removing a certain number of water baffles 2, reducing the impact of the wear of the groove 10 on the yield, further improving the service life of the retaining ring, reducing the replacement frequency of the retaining ring, and also improving the working efficiency of the polishing assembly. Of course, in some other embodiments, H1 and n0 can also be other reasonable values, and those skilled in the art can flexibly configure them according to the actual situation, and this embodiment does not limit them.

[0045] Please refer to Figure 2 and Figure 7 In another embodiment, the embodiment also provides a method for adjusting the water baffles 2:

[0046] Step S1: while the polishing pad 6 is maintained, the real-time depth H2 of the liquid supply groove 3 is measured by using a measuring device;

[0047] Step S2: based on the real-time depth H2 of the liquid supply groove 3, the preset depth H1 and the thickness h0 of the water baffle 2, the number n1 of the water baffles 2 to be removed is calculated;

[0048] Step S3: compare the size of n1 and 1, when n1≤1, the number of the water baffles 2 is kept unchanged; when n1>1, the removal of the water baffles 2 is carried out;

[0049] Step S4: compare the size of the number of the remaining water baffles 2 and n1, when the number of the remaining water baffles 2>n1, n1 water baffles 2 are removed; when the number of the remaining water baffles 2≤n1, the grinding head 7 is replaced.

[0050] It should be noted that in step S2, the number n1 of the water baffles 2 to be removed satisfies: n1=(H1-H2) / h0; in step S3, when n1≤1, the number of the water baffles 2 to be removed is 0, that is, the number of the water baffles 2 is kept unchanged; when n1>1, the number of the water baffles 2 to be removed is the maximum integer value in [1, n1], that is, if n1=1.4, the number of the water baffles 2 to be removed is 1, and if n1=2.8, the number of the water baffles 2 to be removed is 2. In step S4, the number of the remaining water baffles 2 refers to the number of the water baffles 2 in the groove 10 when the current water baffles 2 are not removed, and when the number of the remaining water baffles 2 is less than the number of the water baffles 2 to be removed, it means that the groove 10 is seriously worn, that is, even if all the water baffles 2 are removed, the depth of the liquid supply groove 3 cannot reach the preset depth, therefore, at this time, the operation of replacing the grinding head 7 can be directly performed to ensure that the depth of the liquid supply groove 3 on the replaced ring body 1 meets the requirements, thereby ensuring that the grinding rate and the wafer 8 uniformity are not affected, and the yield of the product is improved.

[0051] Please refer to Figure 8 In another embodiment, the utility model also provides a grinding assembly, including: grinding disc 5, grinding pad 6 and grinding head 7 with the grinding head retaining ring as described above; The grinding disc 5 is laid with the grinding pad 6, and the grinding head 7 is arranged above the grinding pad 6, and the wafer 8 to be ground is arranged between the grinding head 7 and the grinding pad 6, and the grinding disc 5 rotates around the shaft during the grinding process of the grinding assembly to cooperate with the grinding pad 6, the grinding head 7 and the grinding liquid to realize the grinding of the wafer 8; while maintaining the grinding pad 6, the number of the water baffles 2 is adjusted based on the real-time depth of the liquid supply groove 3 measured by the measuring device to maintain the depth of the liquid supply groove 3.

[0052] With the above-mentioned grinding head retaining ring, after the groove 10 is worn, the corresponding number of water baffles 2 can be removed based on the real-time depth of the liquid supply groove 3 while the grinding pad 6 is maintained, so that the production efficiency is not reduced due to the suspension of the machine production for removing the water baffles 2; meanwhile, the depth of the liquid supply groove 3 can be maintained at a stable value by removing the water baffles 2, thereby reducing the influence of the groove 10 wear on the grinding liquid flow field and reducing the frequency of adjusting the grinding parameters.

[0053] In another embodiment, the utility model also provides a grinding equipment, including the above-mentioned grinding assembly. With the above-mentioned grinding assembly, after the groove 10 is worn, the corresponding number of water baffles 2 can be removed based on the real-time depth of the liquid supply groove 3 while the grinding pad 6 is maintained, so that the production efficiency is not reduced due to the suspension of the machine production for removing the water baffles 2; meanwhile, the depth of the liquid supply groove 3 can be maintained at a stable value by removing the water baffles 2, thereby reducing the influence of the groove 10 wear on the grinding liquid flow field.

[0054] In summary, in the grinding head retaining ring, the grinding assembly and the grinding equipment provided in the embodiments of the utility model, the grinding head retaining ring comprises: a ring body sleeved on the grinding head, a measuring device and a plurality of water baffles; the ring body has a plurality of grooves arranged along the circumferential direction of the ring body, a plurality of water baffles are detachably arranged in any groove, and a liquid supply groove for the flow of the grinding liquid is formed between the water baffles and the opening of the groove; the measuring device is arranged close to the groove and is used for measuring the depth of the liquid supply groove; based on the real-time depth of the liquid supply groove measured by the measuring device, part of the water baffles can be removed after the groove is worn, so as to maintain the depth of the liquid supply groove.

[0055] With the above configuration, by deepening the groove depth in the prior art and adding detachable water baffles inside the deepened groove, the grinding liquid can flow between the water baffles and the opening of the groove, and after the groove is worn during the grinding process, the depth of the liquid supply groove can be increased in time by removing the water baffles, thereby reducing the influence on the grinding liquid flow field and reducing the frequency of adjusting the grinding parameters, and improving the production efficiency.

[0056] The above description is only a description of the preferred embodiments of the utility model, and does not limit the scope of the utility model in any way, and any changes and modifications made by the ordinary skilled in the art based on the above disclosure are within the protection scope of the claims.

Claims

1. A polishing head retaining ring characterized by, The application relates to a grinding head holding ring, which comprises a ring body, a measuring device and a plurality of water baffles. The ring body is provided with a plurality of grooves arranged along the circumferential direction of the ring body, and a plurality of water baffles are detachably arranged in any groove. The measuring device is arranged close to the groove and used for measuring the depth of the liquid supply groove. Based on the real-time depth of the liquid supply groove measured by the measuring device, part of the water baffles can be removed after the groove is worn to maintain the depth of the liquid supply groove.

2. The polishing head retaining ring of claim 1, wherein, The length and width of the water baffles are matched with the size of the opening, and the thickness direction of the water baffles is arranged in parallel to the depth direction of the groove.

3. The polishing head retaining ring of claim 2, wherein, The initial depth of the groove is H0, the preset depth of the liquid supply groove is H1, and the thickness of one water baffle is h0, so that the number n0 of water baffles that can be accommodated in the groove satisfies n0=(H0-H1) / h0.

4. The polishing head retaining ring of claim 3, wherein, 2.9mm<=H1<=3.1mm.

5. The polishing head retaining ring of claim 3, wherein, 0.5mm<=h0<=1.5mm.

6. The polishing head retaining ring of claim 3, wherein, The real-time depth of the liquid supply groove after the groove is worn is H2, so that the number n1 of water baffles that need to be removed satisfies n1=(H1-H2) / h0.

7. The polishing head retaining ring of claim 6, wherein, When n1<=1, the number of water baffles that need to be removed is 0; and when n1>1, the number of water baffles that need to be removed is the maximum integer value in [1, n1].

8. The polishing head retaining ring of claim 1, wherein, The grinding head holding ring further comprises a fastener, one end of the groove away from the opening is provided with a connecting hole, the water baffles are provided with through holes, the fastener is sequentially arranged in the through holes of the plurality of water baffles and connected with the connecting hole, so that the detachable connection of the water baffles and the groove is realized.

9. A grinding assembly characterized by, The application relates to a grinding head holding ring, which comprises a ring body, a measuring device and a plurality of water baffles. The grinding disc is provided with the grinding pad, the grinding head is arranged above the grinding pad, a wafer to be ground is arranged between the grinding head and the grinding pad, and the grinding disc rotates around an axis during grinding of the grinding assembly to cooperate with the grinding pad, the grinding head and grinding liquid to grind the wafer. During maintenance of the grinding pad, the number of water baffles is adjusted based on the real-time depth of the liquid supply groove measured by the measuring device to maintain the depth of the liquid supply groove.

10. A grinding device comprising the grinding assembly according to claim 9. ​

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