Polishing head and polishing apparatus

Abstract

The invention provides a grinding head and a grinding device, the grinding head is used for removing a surface film on the surface of a substrate, the grinding head comprises a polishing pad provided with a grinding surface and a through hole penetrating through the polishing pad, and the area of the polishing pad is smaller than or equal to that of the substrate; the liquid supply pipeline is connected with the through hole and an external liquid supply device so as to provide polishing liquid for the surface of the substrate; radial guide grooves extending from the through holes to the edge of the grinding face are distributed in the grinding face, the polishing liquid flows to the edge of the grinding face from the through holes along the guide grooves, so that a liquid film is formed between the polishing pad and the substrate, and the liquid film between the polishing pad and the surface of the substrate is evenly distributed. And the substrate surface film is directionally ground by reducing the size of a polishing pad on the grinding head, so that the planarization of the substrate surface film is realized.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor technology and relates to a grinding head and grinding device for chemical mechanical polishing equipment. Background Technology

[0002] In the manufacturing process of semiconductor components, surface planarization is becoming increasingly important. The most important technology for surface planarization is chemical mechanical polishing (CMP). CMP supplies a polishing slurry (slurry) containing abrasive particles such as silicon dioxide (SiO2) to the polishing surface of the polishing pad, and causes the substrate, which is fixed to the polishing head, to rotate synchronously with the polishing head. As a result, the substrate comes into contact with the polishing surface and slides to be polished.

[0003] Existing polishing pads are typically larger than the substrate to be processed, allowing the pad to contact the substrate during polishing to grind the entire substrate surface. This method results in a uniform film thickness across the substrate surface. However, uneven film thickness distribution often leads to irregularities in the film profile, leaving the surface uneven even after polishing using the aforementioned method. Therefore, achieving planarization of the substrate surface is difficult.

[0004] In addition, in the prior art, the polishing slurry is supplied to the substrate surface through a separately set nozzle, which cannot be evenly distributed between the polishing head and the substrate surface, resulting in insufficient supply in some places and excessive supply in others.

[0005] Therefore, in view of the problems existing in the prior art, the designer of this case, based on years of experience in this industry, actively researched and improved, and thus the present application for a grinding head and grinding device was made. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a grinding head and grinding device to solve the problem that it is difficult to achieve substrate surface film planarization in the prior art.

[0007] To achieve the above and other related objectives, this application provides a grinding head for removing a film from a substrate surface, the grinding head comprising:

[0008] A polishing pad having a grinding surface and a through hole penetrating the polishing pad, wherein the area of ​​the polishing pad is less than or equal to the area of ​​the substrate;

[0009] A liquid supply line connects the through hole to an external liquid supply device to provide polishing liquid to the surface of the substrate;

[0010] The grinding surface is provided with radial guide grooves extending from the through holes to the edge of the grinding surface. The polishing liquid flows from the through holes along the guide grooves to the edge of the grinding surface to form a liquid film between the polishing pad and the substrate.

[0011] Optionally, the grinding head also includes a rotating shaft about which the polishing pad rotates.

[0012] Optionally, the center of the rotating shaft, the center of the polishing pad, and the center of the through hole overlap.

[0013] Optionally, the liquid supply line is located inside the rotating shaft.

[0014] Optionally, the guide groove is a straight line.

[0015] Optionally, the guide groove is an arc.

[0016] Optionally, the arc extends from the through hole to the edge of the grinding surface in the same direction as the rotation direction of the polishing pad.

[0017] Optionally, the arc extends from the through hole to the edge of the grinding surface in the opposite direction to the rotation direction of the polishing pad.

[0018] Optionally, the grinding head further includes an air bladder configured to change the pressure applied by the grinding head to the substrate surface by changing the magnitude of the air pressure in the air bladder, wherein the magnitude of the pressure applied by the grinding head to the substrate surface is positively correlated with the magnitude of the air pressure in the air bladder.

[0019] Optionally, it also includes a grinding head base, with the airbag installed between the grinding head base and the polishing pad.

[0020] To achieve the above and other related objectives, this application also provides a grinding apparatus, including the grinding head as described above.

[0021] As described above, in this application, the polishing slurry supply pipeline is integrated into the grinding head, and through holes and guide grooves are provided on the grinding surface of the polishing pad. This allows the polishing slurry in the supply pipeline to flow from the supply pipeline through the through holes and then along the guide grooves to the edge of the grinding surface. This enables the polishing slurry to be supplied directionally between the polishing pad and the substrate surface, eliminating the need for a separate polishing slurry supply pipeline, simplifying the equipment. The liquid film distribution between the polishing pad and the substrate surface is uniform, and by reducing the size of the polishing pad on the grinding head, the substrate surface film is directionally ground, achieving substrate surface film planarization. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the grinding device in one embodiment of this application.

[0023] Figure 2 This is a schematic diagram of the structure of the grinding pad in one embodiment of this application.

[0024] Figure 3 This is a schematic diagram of the structure of the abrasive pad in another embodiment of this application. Detailed Implementation

[0025] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0026] In the detailed description of embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged and not to scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0027] For ease of description, spatial relation terms such as “below,” “under,” “lower,” “below,” “below,” “above,” “upper,” and “above” may be used herein to describe the relationship between an element or feature shown in the accompanying drawings and other elements or features. It will be understood that these spatial relation terms are intended to include directions other than those depicted in the drawings for devices in use or operation. Furthermore, when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or there may be one or more layers in between. The phrase “between” as used herein includes both endpoint values.

[0028] In the context of this application, the structure described above the first feature may include embodiments in which the first and second features are formed in direct contact, or embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0029] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0030] This application provides a grinding head for use in a grinding apparatus to remove a film from the surface of a substrate. For example... Figure 1As shown, the polishing apparatus includes a polishing table 3 that can rotate about axis Z1. When polishing the substrate surface film on the polishing table 3 using the polishing head 2 of this application, the polishing table 3 holds and rotates the substrate W, and the polishing head 2 performs directional polishing on the substrate surface to achieve substrate surface planarization.

[0031] like Figure 1 As shown, the polishing head 2 includes a polishing pad 21, a polishing head base 24, and a rotating shaft 25. The polishing head base 24 rotates around the rotating shaft 25, causing the polishing pad 21 to rotate synchronously around the rotating shaft 25. The polishing head 2 also includes an air bladder 6 located between the polishing head base 24 and the polishing pad 21. The pressure applied by the polishing head to the substrate W is changed by altering the air pressure within the air bladder. An air supply unit 7 is connected to the air bladder 6 to supply gas to it. The air supply unit 7 includes an air supply pipe 72 connected to and supplying gas to the air bladder 6, and a pressure regulating valve 71 located within the air supply pipe 72 and used to control the pressure within the air bladder 6. Furthermore, the pressure applied by the polishing head 2 to the substrate surface is positively correlated with the air pressure within the air bladder 6. The polishing head 2 also includes an air passage 23 connecting the air supply unit 7 and the air bladder 6. In some embodiments, to prevent the air passage 23 from becoming entangled during the rotation of the polishing head 2, the air passage 23 is disposed within the rotating shaft 25.

[0032] like Figure 2 As shown, the polishing pad 21 includes a grinding surface 210 and a through hole 211 penetrating the polishing pad 21. The grinding surface 210 is provided with radial guide grooves 212 extending from the through hole 211 to the edge of the grinding surface 210. (Refer to...) Figure 2 and combined Figure 1 The through-hole 211 communicates with the liquid supply line 22, which connects the through-hole 211 to an external liquid supply device, allowing polishing slurry to be supplied from the liquid supply device to the liquid supply line 22 and flow from the through-hole 211 along the guide groove 212 to the edge of the grinding surface 210. Therefore, the polishing slurry is supplied through the guide groove 212 to the space between the polishing pad and the substrate for the grinding process. Simultaneously, the polishing slurry mixed with particulate matter after grinding is discharged from the guide groove 212 between the polishing pad 21 and the substrate. In one embodiment, the liquid supply line 22 is disposed within the rotating shaft 25 to prevent it from becoming entangled during the rotation of the grinding head 2. Both the liquid supply line 22 and the air passage 23 are independently configured as channels within the rotating shaft 25.

[0033] In one embodiment, the center of the rotating shaft 25, the center of the polishing pad 21, and the center of the through hole 211 overlap, allowing the polishing slurry to be delivered to the substrate surface more evenly.

[0034] The guide groove 212 provided by this invention can be distributed on the polishing surface 210 in various shapes, such as straight lines, broken lines, and arcs. Since different processes have different requirements, the shape of the guide groove affects the residence time of the polishing slurry between the substrate surface and the polishing pad. Therefore, the shape of the guide groove is selected according to the desired residence time of the polishing slurry between the substrate surface and the polishing pad in different processes. If the guide groove is straight, such as... Figure 2 As shown, the polishing slurry flows from the through-hole 211 along the guide groove 212 to the edge of the grinding surface 210, and is discharged from the edge of the grinding surface 210 under the centrifugal force generated by the rotation of the polishing pad 21. Therefore, the residence time of the polishing slurry on the substrate surface and the polishing pad is short, making it suitable for processes where a short residence time is desired. Figure 3 As shown, if the guide groove 213 is curved, compared to the straight guide groove 212, the polishing slurry, in addition to being subjected to the centrifugal force generated by the rotation of the polishing pad 21, also experiences a guiding force from the curved guide groove 213 itself. Therefore, when using the curved guide groove 213, the residence time of the polishing slurry on the substrate surface and the polishing pad is longer than that of the straight guide groove, making it suitable for processes requiring a longer desired residence time. Furthermore, when the guide groove 213 is curved, to better adjust the residence time of the polishing slurry between the polishing pad and the substrate, the residence time can be controlled by setting different rotation directions and speeds of the polishing pad 21. In one embodiment, the guide groove is curved, and the direction of the curve extending from the through hole to the edge of the grinding surface is opposite to the rotation direction of the polishing pad. In this case, the centrifugal force on the polishing slurry is different from the direction of the guiding force of the guide groove, resulting in a longer discharge time for the polishing slurry, which can further extend the residence time of the polishing slurry. In another embodiment, the guide groove is an arc, and the direction of the arc from the through hole to the edge of the grinding surface is the same as the rotation direction of the polishing pad. In this case, the centrifugal force on the polishing liquid is in the same direction as the guiding force on the polishing liquid by the guide groove, which is more conducive to the discharge of the polishing liquid and can further reduce the residence time of the polishing liquid.

[0035] In this application, the polishing slurry supply pipeline is integrated into the grinding head, and through holes and guide grooves are provided on the grinding surface of the polishing pad. This allows the polishing slurry in the supply pipeline to flow from the supply pipeline through the through holes and then along the guide grooves to the edge of the grinding surface. This enables the polishing slurry to be supplied directionally between the polishing pad and the substrate surface, eliminating the need for a separate polishing slurry supply pipeline, thus simplifying the equipment. The liquid film between the polishing pad and the substrate surface is controlled uniformly, and by reducing the size of the polishing pad on the grinding head, the substrate surface film is directionally ground, achieving substrate surface film planarization.

[0036] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A grinding head for removing a film from a substrate surface, characterized in that, The grinding head includes: A polishing pad having a grinding surface and a through hole penetrating the polishing pad, wherein the area of ​​the polishing pad is less than or equal to the area of ​​the substrate; A liquid supply line connects the through hole to an external liquid supply device to provide polishing liquid to the surface of the substrate; The grinding surface is provided with radial guide grooves extending from the through holes to the edge of the grinding surface. The polishing liquid flows from the through holes along the guide grooves to the edge of the grinding surface to form a liquid film between the polishing pad and the substrate.

2. The grinding head according to claim 1, characterized in that, It also includes a rotating shaft about which the polishing pad rotates.

3. The grinding head according to claim 2, characterized in that, The center of the rotating shaft, the center of the polishing pad, and the center of the through hole overlap.

4. The grinding head according to claim 2, characterized in that, The liquid supply line is located inside the rotating shaft.

5. The grinding head according to claim 1, characterized in that, The guide groove is a straight line.

6. The grinding head according to claim 1, characterized in that, The guide groove is curved.

7. The grinding head according to claim 6, characterized in that, The arc extends from the through hole to the edge of the grinding surface in the same direction as the rotation direction of the polishing pad.

8. The grinding head according to claim 6, characterized in that, The arc extends from the through hole to the edge of the grinding surface in the opposite direction to the rotation direction of the polishing pad.

9. The grinding head according to claim 1, characterized in that, The grinding head also includes an air bladder, which is configured to change the pressure applied by the grinding head to the substrate surface by changing the air pressure in the air bladder, the pressure applied by the grinding head to the substrate surface being positively correlated with the air pressure in the air bladder.

10. The grinding head according to claim 9, characterized in that, It also includes a grinding head base, and the airbag is installed between the grinding head base and the polishing pad.

11. A grinding apparatus comprising a grinding head as described in any one of claims 1-10.

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