Polishing equipment, polishing method and polishing device

Abstract

The invention provides polishing equipment, a polishing method and a polishing device, and belongs to the technical field of semiconductor manufacturing. The polishing equipment comprises a polishing table; the polishing pad is arranged on the upper surface of the polishing table; the driving shaft is used for driving the polishing table to rotate; the polishing head is arranged in a space above the polishing table and is used for pressing the silicon wafer on a polishing pad for polishing; the polishing head comprises a main body head, a pressurizing cavity and a rubber pad, the pressurizing cavity and the rubber pad are arranged on the side, facing the polishing pad, of the main body head, compressed air can be supplied into the pressurizing cavity through the first pipeline to form working pressure, and the working pressure acts on the rubber pad and can be transmitted to a silicon wafer to be polished through the rubber pad; the polishing head further comprises at least one air bag arranged in the pressurizing cavity and a second pipeline for supplying compressed air into the air bag. And the controller is used for adjusting the amount of air applied to each air bag so as to adjust the working pressure applied to the silicon wafer by each air bag. The flatness of the surface of the silicon wafer can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to a polishing device, a polishing method and a polishing apparatus. Background Art

[0002] In the process of producing silicon wafers, the final polishing (FP) process is the last step to control the flatness and roughness parameters of the silicon wafer. The final polishing process is to remove a certain amount of silicon wafer surface to remove the defects of the front-end process and to mirror-polish the silicon wafer surface.

[0003] During the FP operation, the most commonly used implementation is the Chemical Mechanical Polishing (CMP) method, and in the CMP method, the silicon wafer needs to be pressed onto a vibrating polishing table with a polishing pad by a polishing head, and a slurry of abrasive particles is provided to the polishing pad. However, since the working pressure from the polishing head is often concentrated in the central area of ​​the polishing head, the distribution of the pressure transmitted to the surface of the silicon wafer to be polished is also uneven, wherein the force received by the central area of ​​the silicon wafer is greater than the force received by other areas, which results in the polishing removal amount of the central area of ​​the silicon wafer surface being greater than the polishing removal amount of the edge area of ​​the silicon wafer surface during the polishing process of the silicon wafer, thereby causing the surface flatness of the silicon wafer to deteriorate. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a polishing device, a polishing method and a polishing apparatus, which can improve the flatness of the silicon wafer surface.

[0005] In order to achieve the above object, the technical solution adopted by the embodiment of the present invention is:

[0006] A polishing device, comprising:

[0007] Polishing table;

[0008] a polishing pad disposed on the upper surface of the polishing table;

[0009] A driving shaft for driving the polishing table to rotate;

[0010] A polishing head is arranged in the space above the polishing table, and the polishing head is used to press the silicon wafer onto the polishing pad for polishing; the polishing head comprises a main body head, a pressurizing chamber and a rubber pad arranged on the side of the main body head facing the polishing pad, and compressed air can be supplied into the pressurizing chamber through a first pipeline to form a working pressure, and the working pressure acts on the rubber pad and can be transmitted to the silicon wafer to be polished through the rubber pad; the polishing head also comprises: at least one air bag arranged inside the pressurizing chamber and a second pipeline for supplying compressed air into the air bag;

[0011] The controller is used to adjust the amount of gas applied to each of the airbags to adjust the working pressure applied by each of the airbags to the silicon wafer.

[0012] In some embodiments, a plurality of airbags are disposed in the polishing head, the second pipelines of different airbags are independent of each other, and the plurality of airbags are disposed corresponding to different areas of the silicon wafer.

[0013] In some embodiments, the airbag is ring-shaped, and a plurality of the airbags are nested.

[0014] In some embodiments, the controller is specifically used to adjust the amount of gas applied to each airbag so that the working pressure applied by each airbag to the silicon wafer gradually increases along the radial direction from the center of the polishing head to the edge.

[0015] The embodiment of the present invention further provides a polishing method, which is applied to the polishing device as described above, and the method comprises:

[0016] A polishing table with a polishing pad disposed on its upper surface is driven to rotate by a driving shaft;

[0017] Supplying compressed air into the pressurizing chamber through a first pipeline to form a working pressure, the working pressure acts on the rubber pad and can be transmitted to the silicon wafer to be polished via the rubber pad, so as to press the silicon wafer onto the polishing pad for polishing;

[0018] The amount of gas applied to each of the airbags is adjusted by a controller to adjust the working pressure applied by each of the airbags to the silicon wafer.

[0019] In some embodiments, the method further comprises:

[0020] Obtaining flatness data of polished silicon wafers;

[0021] The amount of gas applied to each of the airbags is adjusted according to the flatness data to adjust the working pressure applied by each of the airbags to the silicon wafer.

[0022] In some embodiments, when the polishing removal amount of the silicon wafer area corresponding to the target airbag in the at least one airbag is less than a preset threshold value, the controller increases the amount of gas applied to the target airbag; when the polishing removal amount of the silicon wafer area corresponding to the target airbag is greater than the preset threshold value, the controller reduces the amount of gas applied to the target airbag.

[0023] In some embodiments, the controller adjusts the amount of gas applied to each of the airbags to adjust the working pressure applied by each of the airbags to the silicon wafer.

[0024] An embodiment of the present invention also provides a polishing device, which includes: a processor and a memory; the processor is used to execute instructions stored in the memory to implement the above-mentioned polishing method.

[0025] An embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores at least one instruction, and the at least one instruction is used to be executed by a processor to implement the above-mentioned polishing method.

[0026] The beneficial effects of the present invention are:

[0027] In this embodiment, at least one inflatable and pressurized airbag is arranged inside the pressurized chamber of the polishing head. Each airbag is individually connected to a pipeline. The pressure of the airbag can be adjusted according to actual processing requirements to compensate for the shortcoming that the pressure at the edge of the pressurized chamber of the polishing head is insufficient, resulting in a low amount of silicon wafer removal in the corresponding area, thereby achieving uniform grinding of the entire silicon wafer surface, controlling the uniformity of the silicon wafer removal amount, and thereby improving the flatness of the silicon wafer surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram showing the structure of an existing polishing device;

[0029] Figure 2 A schematic diagram showing the structure of a polishing device according to an embodiment of the present invention;

[0030] Figure 3 A schematic diagram showing a multi-loop airbag according to an embodiment of the present invention.

[0031] Reference numerals

[0032] 1 Pipeline

[0033] 2 Airbags

[0034] 3 Rubber pads

[0035] 4 Silicon wafer

[0036] 5 Pressurized chamber

[0037] 11 First pipeline

[0038] 12 Second pipeline DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0040] Figure 1 A schematic diagram showing the structure of an existing polishing device is shown in FIG. Figure 1 As shown, the polishing head of the polishing equipment is used to press the silicon wafer 4 onto the polishing pad for polishing; the polishing head includes a main body head, a pressurizing chamber 5 and a rubber pad 3 arranged on the side of the main body head facing the polishing pad, and compressed air can be supplied to the pressurizing chamber 5 through the first pipeline 11 to form a working pressure, and the working pressure acts on the rubber pad 3 and can be transmitted to the silicon wafer 4 to be polished through the rubber pad 3. Because the pressurizing chamber 5 is a single chamber, when the pressure is applied to the silicon wafer 4 through the rubber pad 3, the pressure at the edge of the pressurizing chamber 5 is insufficient, which inevitably leads to the problem that the protruding deformation amount of the center position of the rubber pad 3 is large and the protruding deformation amount of the edge position is small, which directly leads to the difference in the amount of removal on the surface of the silicon wafer 4, affecting the flatness of the silicon wafer 4.

[0041] The invention provides a polishing device, a polishing method and a polishing apparatus, which can improve the flatness of the silicon wafer surface.

[0042] The embodiment of the present invention provides a polishing device, such as Figure 2 and Figure 3 As shown, including:

[0043] Polishing table;

[0044] a polishing pad disposed on the upper surface of the polishing table;

[0045] A driving shaft for driving the polishing table to rotate;

[0046] A polishing head is arranged in the space above the polishing table, and the polishing head is used to press the silicon wafer 4 onto the polishing pad for polishing; the polishing head includes a main body head, a pressurizing chamber 5 and a rubber pad 3 arranged on the side of the main body head facing the polishing pad, and compressed air can be supplied to the pressurizing chamber 5 through a first pipeline 11 to form a working pressure, and the working pressure acts on the rubber pad 3 and can be transmitted to the silicon wafer 4 to be polished via the rubber pad 3; the polishing head also includes: at least one air bag 2 arranged inside the pressurizing chamber 5 and a second pipeline 12 for supplying compressed air to the air bag 2, wherein the first pipeline 11 and the second pipeline 12 constitute a pipeline 1;

[0047] The controller is used to adjust the amount of gas applied to each of the airbags 2 to adjust the working pressure applied by each of the airbags 2 to the silicon wafer 4.

[0048] In this embodiment, at least one inflatable and pressurized airbag 2 is arranged inside the pressurized chamber 5 of the polishing head. Each airbag 2 is individually connected to a pipeline, and the pressure of the airbag 2 can be adjusted according to actual processing requirements to compensate for the shortcoming that the pressure at the edge of the pressurized chamber 5 of the polishing head is insufficient, resulting in a low amount of silicon wafer 4 removed in the corresponding area, thereby achieving uniform grinding of the entire silicon wafer 4 surface, controlling the uniformity of the amount of silicon wafer 4 removed, and thereby improving the flatness of the surface of the silicon wafer 4.

[0049] In this embodiment, a plurality of airbags 2 may be provided in the polishing head, or one airbag 2 may be provided. When one airbag 2 is provided in the polishing head, the airbag 2 may be provided at the edge of the pressurizing chamber 5 to compensate for the shortcoming that the pressure at the edge of the pressurizing chamber 5 of the polishing head is insufficient, resulting in a low removal amount of the silicon wafer 4 in the corresponding area, so as to achieve uniform grinding of the entire surface of the silicon wafer 4, control the uniformity of the removal amount of the silicon wafer 4, and further improve the flatness of the surface of the silicon wafer 4.

[0050] When multiple airbags 2 are arranged in the polishing head, the second pipelines 12 of different airbags 2 are independent of each other, so that the pressure of each airbag 2 can be controlled individually. Multiple airbags 2 can be arranged corresponding to different areas of the silicon wafer 4. In this embodiment, the amount of gas applied to each airbag 2 can be adjusted by the controller to adjust the working pressure applied by each airbag 2 to the silicon wafer 4, thereby adjusting the overall pressure applied to the silicon wafer 4. The pressure applied to the silicon wafer 4 is proportional to the polishing removal amount of the silicon wafer 4. The greater the pressure applied to the silicon wafer 4, the greater the polishing removal amount of the silicon wafer 4. Therefore, the uniformity of the removal amount of the silicon wafer 4 can be controlled by adjusting the amount of gas applied to each airbag 2, thereby improving the flatness of the surface of the silicon wafer 4.

[0051] Specifically, the pressure of the corresponding airbag 2 can be adjusted according to the removal amount of each area of ​​the silicon wafer 4. When the removal amount of a certain area of ​​the silicon wafer 4 is low, the pressure of the corresponding airbag 2 can be increased to compensate for the shortcoming that the removal amount of the silicon wafer 4 in this area is low due to insufficient pressure in the pressurization chamber 5; when the removal amount of a certain area of ​​the silicon wafer 4 is high, the pressure of the corresponding airbag 2 can be reduced.

[0052] In some embodiments, Figure 2 and Figure 3 As shown, the airbag 2 can be annular, and multiple airbags 2 are nested, that is, multiple circles of airbags 2 that can be inflated and pressurized separately are distributed inside the pressurized chamber 5 of the polishing head, and each circle of airbags 2 is separately connected to its own air circuit interface. Among them, the pressurized chamber 5 can be inflated through the first pipeline 11, and the airbag 2 can be inflated through the second pipeline 12 corresponding to each airbag 2. The pressure of each airbag 2 can be adjusted according to actual processing requirements to achieve uniform grinding of the entire silicon wafer 4 surface and control the uniformity of the removal amount of the silicon wafer 4.

[0053] In the related art, the pressure at the edge of the pressurized chamber 5 is insufficient, which inevitably leads to the problem that the protruding deformation amount at the center of the rubber pad 3 is large and the protruding deformation amount at the edge is small. In some embodiments, the controller is specifically used to adjust the amount of gas applied to each airbag 2, so that along the radial direction from the center of the polishing head to the edge, the working pressure applied by each airbag 2 to the silicon wafer 4 gradually increases, which can make up for the disadvantage that the removal amount of the silicon wafer 4 in the corresponding area is low due to the insufficient pressure at the edge of the pressurized chamber 5 of the polishing head, achieve uniform grinding of the entire silicon wafer 4 surface, control the uniformity of the removal amount of the silicon wafer 4, and thus improve the flatness of the surface of the silicon wafer 4.

[0054] The embodiment of the present invention further provides a polishing method, which is applied to the polishing device as described above, and the method comprises:

[0055] A polishing table with a polishing pad disposed on its upper surface is driven to rotate by a driving shaft;

[0056] Compressed air is supplied into the pressurizing chamber 5 through the first pipeline 11 to form a working pressure, and the working pressure acts on the rubber pad 3 and can be transmitted to the silicon wafer 4 to be polished via the rubber pad 3, so that the silicon wafer 4 is pressed on the polishing pad for polishing;

[0057] The amount of gas applied to each of the airbags 2 is adjusted by a controller to adjust the working pressure applied by each of the airbags 2 to the silicon wafer 4 .

[0058] In this embodiment, the pressure of the airbag 2 can be adjusted according to actual processing requirements to compensate for the shortcoming that the edge pressure of the polishing head pressurization chamber 5 is insufficient, resulting in a low amount of silicon wafer 4 removed in the corresponding area, thereby achieving uniform grinding of the entire silicon wafer 4 surface, controlling the uniformity of the amount of silicon wafer 4 removed, and thereby improving the flatness of the silicon wafer 4 surface.

[0059] In this embodiment, the controller can adjust the amount of gas applied to each of the airbags 2 to adjust the working pressure applied by each of the airbags 2 to the silicon wafer 4, thereby adjusting the overall pressure applied to the silicon wafer 4. The pressure applied to the silicon wafer 4 is proportional to the polishing removal amount of the silicon wafer 4. The greater the pressure applied to the silicon wafer 4, the greater the polishing removal amount of the silicon wafer 4. Therefore, the uniformity of the removal amount of the silicon wafer 4 can be controlled by adjusting the amount of gas applied to each airbag 2, thereby improving the flatness of the surface of the silicon wafer 4.

[0060] In some embodiments, the method further comprises:

[0061] Acquiring flatness data of the polished silicon wafer 4;

[0062] The amount of gas applied to each of the airbags 2 is adjusted according to the flatness data to adjust the working pressure applied by each of the airbags 2 to the silicon wafer 4 .

[0063] In this embodiment, when multiple airbags 2 are arranged in the polishing head, the second pipelines 12 of different airbags 2 are independent of each other, so that the pressure of each airbag 2 can be controlled individually. The multiple airbags 2 can be arranged corresponding to different areas of the silicon wafer 4. In this way, the pressure of the corresponding airbag 2 can be adjusted according to the flatness data of each area of ​​the silicon wafer 4 to compensate for the shortcoming that the pressure in the pressurized chamber 5 in some areas is insufficient, resulting in a low removal amount of the silicon wafer 4 in this area.

[0064] In some embodiments, when the polishing removal amount of the silicon wafer 4 area corresponding to the target airbag in the at least one airbag 2 is less than a preset threshold value, the controller increases the amount of gas applied to the target airbag so that the pressure of the target airbag becomes larger to compensate for the shortcoming of low silicon wafer 4 removal amount in this area due to insufficient pressure in the pressurization chamber 5; when the polishing removal amount of the silicon wafer 4 area corresponding to the target airbag is greater than the preset threshold value, the controller reduces the amount of gas applied to the target airbag so that the pressure of the target airbag becomes smaller to compensate for the shortcoming of high silicon wafer 4 removal amount in this area due to excessive pressure in the pressurization chamber 5.

[0065] An embodiment of the present invention also provides a polishing device, which includes: a processor and a memory; the processor is used to execute instructions stored in the memory to implement the above-mentioned polishing method.

[0066] An embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores at least one instruction, and the at least one instruction is used to be executed by a processor to implement the above-mentioned polishing method.

[0067] Those skilled in the art should be aware that in one or more of the above examples, the functions described in the embodiments of the present application can be implemented with hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein the communication media include any media that facilitates the transmission of a computer program from one place to another. The storage medium can be any available medium that a general or special-purpose computer can access.

[0068] It should be noted that each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the embodiments, since they are basically similar to the product embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the product embodiments.

[0069] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0070] It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” or “under” another element, it can be “directly on” or “under” the other element or intervening elements may be present.

[0071] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0072] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A polishing device, characterized in that: include: Polishing table; a polishing pad disposed on the upper surface of the polishing table; A driving shaft for driving the polishing table to rotate; A polishing head is arranged in the space above the polishing table, and the polishing head is used to press the silicon wafer onto the polishing pad for polishing; the polishing head comprises a main body head, a pressurizing chamber and a rubber pad arranged on the side of the main body head facing the polishing pad, and compressed air can be supplied to the pressurizing chamber through a first pipeline to form a working pressure, and the working pressure acts on the rubber pad and can be transmitted to the silicon wafer to be polished via the rubber pad; The polishing head further comprises: at least one air bag disposed inside the pressurized chamber and a second pipeline for supplying compressed air into the air bag; The controller is used to adjust the amount of gas applied to each of the airbags to adjust the working pressure applied by each of the airbags to the silicon wafer.

2. The polishing device according to claim 1, characterized in that: A plurality of airbags are arranged in the polishing head, the second pipelines of different airbags are independent of each other, and the plurality of airbags are arranged corresponding to different areas of the silicon wafer.

3. The polishing device according to claim 1, characterized in that: The airbag is ring-shaped, and a plurality of the airbags are nested.

4. The polishing device according to claim 1, characterized in that: The controller is specifically used to adjust the amount of gas applied to each airbag, so that along the radial direction from the center of the polishing head to the edge, the working pressure applied by each airbag to the silicon wafer gradually increases.

5. A polishing method, characterized in that: Applied to the polishing device according to any one of claims 1 to 4, the method comprises: A polishing table with a polishing pad disposed on its upper surface is driven to rotate by a driving shaft; Supplying compressed air into the pressurizing chamber through a first pipeline to form a working pressure, the working pressure acts on the rubber pad and can be transmitted to the silicon wafer to be polished via the rubber pad, so as to press the silicon wafer onto the polishing pad for polishing; The amount of gas applied to each of the airbags is adjusted by a controller to adjust the working pressure applied by each of the airbags to the silicon wafer.

6. The polishing method according to claim 5, characterized in that: The method further comprises: Obtaining flatness data of polished silicon wafers; The amount of gas applied to each of the airbags is adjusted according to the flatness data to adjust the working pressure applied by each of the airbags to the silicon wafer.

7. The polishing method according to claim 6, characterized in that: When the polishing removal amount of the silicon wafer area corresponding to the target airbag in at least one airbag is less than a preset threshold value, the controller increases the amount of gas applied to the target airbag; when the polishing removal amount of the silicon wafer area corresponding to the target airbag is greater than the preset threshold value, the controller reduces the amount of gas applied to the target airbag.

8. The polishing method according to claim 5, characterized in that: The amount of gas applied to each of the airbags is adjusted by the controller to adjust the working pressure applied by each of the airbags to the silicon wafer.

9. A polishing device, characterized in that: The device comprises: a processor and a memory; the processor is used to execute instructions stored in the memory to implement the polishing method according to any one of claims 1 to 4.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores at least one instruction, and the at least one instruction is used to be executed by a processor to implement the polishing method according to any one of claims 1 to 4.

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