Polishing device and wafer polishing method

Abstract

The invention provides a polishing device and a wafer polishing method. The polishing device comprises a bearing table, a polishing pad, at least one polishing head and a pressure applying unit. The at least one polishing head is uniformly arranged on the bearing table; the pressure applying unit is arranged on the bearing table, and the pressure applying unit is arranged on the edge of the bearing table; the polishing pad is arranged between the bearing table and the polishing head and between the bearing table and the pressure applying unit, and the center of the polishing pad and the center of the bearing table are both located on the axis of the polishing pad. According to the scheme, by arranging the pressure applying unit and the polishing head, pressure can be applied to the polishing pad at the same time, it is guaranteed that all the positions of the polishing pad are stressed in the operation process of the polishing device, and the pressure borne by all the positions of the polishing pad is balanced. The problem that in the prior art, as the service time is prolonged, the thickness difference is generated between the center area and the edge area of the polishing pad, and then the flatness of a wafer is affected is solved.

Description

Technical Field

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

[0002] The housekeeper material of the wafer polishing node is the polishing pad. Hot-pressed polishing pads are widely used in the wafer polishing process due to their good flatness and particle size. The specific polishing process is: the polishing head carries the wafer on the surface of the polishing pad for polishing, and the two move relative to each other to achieve the wafer polishing process. Due to mechanical hardware limitations, the edge area of ​​the polishing pad basically does not contact the wafer. As the use time increases, the thickness difference between the center area and the edge area of ​​the polishing pad will be caused, which will affect the flatness of the wafer and reduce the competitiveness of the product. Summary of the invention

[0003] The embodiments of the present invention provide a polishing device and a wafer polishing method, which are used to solve the problem in the prior art that as the use time increases, a thickness difference will be caused between the center area and the edge area of ​​the polishing pad, thereby affecting the flatness of the wafer.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] In a first aspect, an embodiment of the present invention provides a polishing device, comprising:

[0006] A carrier, a polishing pad, at least one polishing head and a pressure unit;

[0007] The at least one polishing head is evenly arranged on the carrying platform;

[0008] The pressure unit is disposed on the carrying platform, and the pressure unit is disposed on the edge of the carrying platform;

[0009] The polishing pad is arranged between the bearing platform, the polishing head and the pressure unit, and the centers of the polishing pad and the bearing platform are both located on the axis of the polishing pad.

[0010] Furthermore, the polishing head and the pressure unit are both circular; the first radius is smaller than the second radius, and the sum of the first radius and the third radius is greater than or equal to the second radius;

[0011] The first radius is the radius of the polishing head, the second radius is the radius of the polishing pad, and the third radius is the radius of the pressure unit.

[0012] Furthermore, in a direction perpendicular to the polishing pad, an orthographic projection of the pressure applying unit is inscribed in an orthographic projection of the supporting platform.

[0013] Furthermore, the pressure applying unit comprises:

[0014] Robotic arm, connecting rod and pressure plate;

[0015] The mechanical arm and the carrying platform are both arranged on a base, and the mechanical arm is arranged close to the carrying platform;

[0016] The pressure plate is connected to the mechanical arm through the connecting rod.

[0017] Furthermore, a rotating shaft is provided on the connecting rod;

[0018] The rotating shaft is connected to the pressure plate and is used to drive the pressure plate to rotate.

[0019] Furthermore, the pressure applying unit further includes a purge component;

[0020] A first through hole is provided along the direction of the central axis of the pressure plate;

[0021] The purge component is disposed in the first through hole and is used to purge impurities on the polishing pad.

[0022] Furthermore, the pressure applying unit further includes a liquid spraying component;

[0023] A second through hole is provided along the direction of the central axis of the pressure plate;

[0024] The liquid spraying component is arranged in the second through hole and is used for flushing impurities on the polishing pad.

[0025] Furthermore, the mechanical arm is a liftable mechanical arm;

[0026] The pressure applied by the pressure plate to the polishing pad is adjusted by lifting and lowering the mechanical arm.

[0027] In a second aspect, an embodiment of the present invention provides a wafer polishing method, which is applied to the polishing device as described above, comprising:

[0028] During the process of operating the polishing head to polish the wafer, the pressure applying unit is operated to apply pressure to the polishing pad.

[0029] Further, the pressure applied by the polishing head to the polishing pad is the same as the pressure applied by the pressure applying unit to the polishing pad.

[0030] The beneficial effects of the present invention are:

[0031] The polishing device of the embodiment of the present application can simultaneously apply pressure to the polishing pad by providing the pressure unit and the polishing head, so that the pressure can be applied to the part that the polishing head cannot apply pressure to, ensuring that the polishing pad is subjected to pressure at all locations during the operation of the polishing device, so that the pressure on each location of the polishing pad is relatively balanced, thereby effectively reducing the probability of thickness differences between different regions of the polishing pad. This solves the problem in the prior art that as the use time increases, a thickness difference between the center region and the edge region of the polishing pad will be caused, thereby affecting the flatness of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 One of the structural schematic diagrams showing the polishing device according to the embodiment of the present invention;

[0033] Figure 2 A second structural schematic diagram showing a polishing device according to an embodiment of the present invention;

[0034] Figure 3 A schematic diagram showing the structure of a pressure applying unit according to an embodiment of the present invention;

[0035] Figure 4 A schematic diagram showing the steps of a wafer polishing method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will be described in detail in conjunction with the accompanying drawings and specific embodiments. In the following description, specific details such as specific configurations and components are provided only to help fully understand the embodiments of the present invention. Therefore, it should be clear to those skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. In addition, for clarity and brevity, the description of known functions and structures is omitted.

[0037] It should be understood that the references to "one embodiment" or "an embodiment" throughout the specification mean that the specific features, structures, or characteristics associated with the embodiment are included in at least one embodiment of the present invention. Therefore, the references to "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0038] The present invention aims to solve the problem in the prior art that as the use time increases, a thickness difference will be generated between the central area and the edge area of ​​the polishing pad, thereby affecting the flatness of the wafer. A polishing device and a wafer polishing method are provided.

[0039] like Figure 1 and Figure 2 As shown, an embodiment of the present application provides a polishing device, comprising:

[0040] A carrier 1, a polishing pad 2, at least one polishing head 3 and a pressure unit 4;

[0041] The at least one polishing head 3 is evenly arranged on the supporting platform 1;

[0042] The pressure unit 4 is disposed on the carrying platform 1, and the pressure unit 4 is disposed at the edge of the carrying platform 1;

[0043] The polishing pad 2 is disposed between the supporting platform 1 , the polishing head 3 and the pressure unit 4 , and the centers of the polishing pad 2 and the supporting platform 1 are both located on the axis of the polishing pad 2 .

[0044] Optionally, the supporting platform is circular and is disposed on a base.

[0045] Optionally, the polishing device further comprises at least one driving unit;

[0046] The driving unit is used to drive the polishing head to rotate;

[0047] The driving unit corresponds to the polishing head one by one, or one driving unit controls a plurality of polishing heads.

[0048] Optionally, the polishing device further comprises a servo motor;

[0049] The servo motor is used to control the rotation of the supporting platform.

[0050] Optionally, the pressure applying unit is a micro polishing head.

[0051] The polishing device of the embodiment of the present application can simultaneously apply pressure to the polishing pad by providing the pressure unit and the polishing head, so that the pressure can be applied to the part that the polishing head cannot apply pressure to, ensuring that the polishing pad is subjected to pressure at all locations during the operation of the polishing device, so that the pressure on each location of the polishing pad is relatively balanced, thereby effectively reducing the probability of thickness differences between different regions of the polishing pad. This solves the problem in the prior art that as the use time increases, a thickness difference between the center region and the edge region of the polishing pad will be caused, thereby affecting the flatness of the wafer.

[0052] Optionally, the polishing head 3 and the pressure unit 4 are both circular; the first radius is smaller than the second radius, and the sum of the first radius and the third radius is greater than or equal to the second radius;

[0053] The first radius is the radius of the polishing head 3 , the second radius is the radius of the polishing pad 2 , and the third radius is the radius of the pressure unit 4 .

[0054] Optionally, the number of the polishing heads is 2.

[0055] In the present application embodiment, Figure 2 As shown, the centers of the two polishing heads and the center of the polishing pad are located on the same straight line, and the two polishing heads are symmetrically arranged relative to the center of the polishing pad; the pressure unit is arranged close to the edge of the polishing pad.

[0056] It should be noted that during the operation of the polishing equipment, the polishing head is driven to rotate and apply pressure to the polishing pad, and the pressure unit applies pressure to the polishing pad. In the process of the carrier platform driving the polishing pad to rotate, pressure is applied to all areas of the polishing pad.

[0057] The polishing device of the embodiment of the present application, by setting the sum of the first radius and the third radius to be greater than or equal to the second radius, can cover all areas of the polishing pad through the polishing head and the pressure unit during the operation of the polishing device, so that the pressure on each part of the polishing pad is more balanced, thereby effectively reducing the probability of thickness differences in different areas of the polishing pad. This solves the problem in the prior art that as the use time increases, a thickness difference will occur between the center area and the edge area of ​​the polishing pad, thereby affecting the flatness of the wafer.

[0058] Optionally, in a direction perpendicular to the polishing pad 2 , the orthographic projection of the pressure applying unit 4 is inscribed with the orthographic projection of the supporting platform 1 .

[0059] The polishing equipment of the embodiment of the present application, by arranging the orthographic projection of the pressure unit to be inscribed in the orthographic projection of the carrier platform, can cover the entire area including the edge of the polishing pad through the polishing head and the pressure unit during the rotation of the polishing pad, thereby avoiding the thickness difference between the edge and the center of the polishing pad and improving the flatness of the polished wafer.

[0060] Optionally, the pressure applying unit 4 comprises:

[0061] A mechanical arm 41, a connecting rod 42 and a pressure plate 43;

[0062] The mechanical arm 41 and the carrying platform 1 are both arranged on a base, and the mechanical arm 41 is arranged close to the carrying platform 1;

[0063] The pressure plate 43 is connected to the mechanical arm 41 through the connecting rod 42 .

[0064] Optionally, the pressure plate applies pressure to the polishing pad through the robotic arm.

[0065] Optionally, a rotating shaft is provided on the connecting rod 42;

[0066] The rotating shaft is connected to the pressure plate 43 and is used to drive the pressure plate 43 to rotate.

[0067] Optionally, the rotating shaft is connected to an edge of the pressure plate.

[0068] like Figure 3 As shown, the pressure applying unit 4 further includes a purge component 44;

[0069] A first through hole is provided along the direction of the central axis of the pressure plate 43;

[0070] The purge member 44 is disposed in the first through hole and is used to purge impurities on the polishing pad 2 .

[0071] In the embodiment of the present application, during the operation of the polishing device, the polishing head and the polishing pad polish the wafer, the pressure unit applies pressure to the polishing pad, and the purge component purges impurities or dust during the polishing process.

[0072] Optionally, the pressure applying unit 4 further includes a liquid spraying component 45;

[0073] A second through hole is provided along the direction of the central axis of the pressure plate 43;

[0074] The liquid spraying member 45 is disposed in the second through hole to flush impurities on the polishing pad 2 .

[0075] Optionally, the first through hole and the second through hole overlap, the purge member and the liquid spraying member are both arranged in the first pupil, and the purge member and the liquid spraying member are coaxial.

[0076] In the embodiment of the present application, during the operation of the polishing device, the polishing head and the polishing pad polish the wafer, the pressure unit applies pressure to the polishing pad, and the purge component purges impurities or dust during the polishing process.

[0077] Optionally, the mechanical arm is a liftable mechanical arm;

[0078] The pressure applied by the pressure plate to the polishing pad is adjusted by lifting and lowering the mechanical arm.

[0079] In the embodiment of the present application, during the operation of the polishing device, the pressure applied by the pressure plate on the polishing pad is adjusted by the liftable robotic arm, so that the pressure applied by the pressure plate and the polishing head on the polishing pad are consistent, ensuring that each area of ​​the polishing pad is subjected to the same pressure, avoiding thickness differences, and improving the flatness of the wafer.

[0080] like Figure 4 As shown, the embodiment of the present application also provides a wafer polishing method, which is applied to the polishing device as described above, comprising:

[0081] Step 401 : in the process of operating the polishing head to polish the wafer, operating the pressure applying unit to apply pressure to the polishing pad.

[0082] Optionally, the pressure applied by the polishing head to the polishing pad is the same as the pressure applied by the pressure applying unit to the polishing pad.

[0083] In the embodiment of the present application, the pressure applied by the pressure plate and the polishing head to the polishing pad is kept consistent to ensure that each area of ​​the polishing pad is subjected to the same pressure, avoid thickness differences, and improve the flatness of the wafer.

[0084] In addition, a specific embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored, and when the program is executed by a processor, the steps of the above-mentioned wafer polishing method are implemented. And the same technical effect can be achieved, so in order to avoid repetition, it will not be repeated here.

[0085] An embodiment of the present application also provides a computer program product, including computer instructions. When the computer instructions are executed by a processor, the various processes of the above-mentioned wafer polishing embodiment are implemented and the same technical effect can be achieved. To avoid repetition, they will not be repeated here.

[0086] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary personnel in this technical field, several improvements and modifications can be made without departing from the principles described in the present invention. These improvements and modifications are also within the scope of protection of the present invention.

Claims

1. A polishing device, characterized in that: include: A carrier, a polishing pad, at least one polishing head and a pressure unit; The at least one polishing head is evenly arranged on the carrying platform; The pressure unit is disposed on the carrying platform, and the pressure unit is disposed on the edge of the carrying platform; The polishing pad is arranged between the bearing platform, the polishing head and the pressure unit, and the centers of the polishing pad and the bearing platform are both located on the axis of the polishing pad.

2. The polishing device according to claim 1, characterized in that: The polishing head and the pressure unit are both circular; the first radius is smaller than the second radius, and the sum of the first radius and the third radius is greater than or equal to the second radius; The first radius is the radius of the polishing head, the second radius is the radius of the polishing pad, and the third radius is the radius of the pressure unit.

3. The polishing device according to claim 1, characterized in that: In a direction perpendicular to the polishing pad, an orthographic projection of the pressure-applying unit is inscribed with an orthographic projection of the supporting platform.

4. The polishing device according to claim 1, characterized in that: The pressure applying unit comprises: Robotic arm, connecting rod and pressure plate; The mechanical arm and the carrying platform are both arranged on a base, and the mechanical arm is arranged close to the carrying platform; The pressure plate is connected to the mechanical arm through the connecting rod.

5. The polishing device according to claim 4, characterized in that: The connecting rod is provided with a rotating shaft; The rotating shaft is connected to the pressure plate and is used to drive the pressure plate to rotate.

6. The polishing device according to claim 4, characterized in that: The pressure applying unit further includes a purge component; A first through hole is provided along the direction of the central axis of the pressure plate; The purge component is disposed in the first through hole and is used to purge impurities on the polishing pad.

7. The polishing device according to claim 4, characterized in that: The pressure applying unit further includes a liquid spraying component; A second through hole is provided along the direction of the central axis of the pressure plate; The liquid spraying component is arranged in the second through hole and is used for flushing impurities on the polishing pad.

8. The polishing device according to claim 4, characterized in that: The mechanical arm is a liftable mechanical arm; The pressure applied by the pressure plate to the polishing pad is adjusted by lifting and lowering the mechanical arm.

9. A wafer polishing method, applied to the polishing device according to any one of claims 1 to 8, characterized in that: include: During the process of operating the polishing head to polish the wafer, the pressure applying unit is operated to apply pressure to the polishing pad.

10. The wafer polishing method according to claim 9, characterized in that: The pressure applied by the polishing head to the polishing pad is the same as the pressure applied by the pressure applying unit to the polishing pad.

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