Wafer grinding equipment and grinding method

Abstract

The invention relates to the field of semiconductors, and discloses wafer grinding equipment and a grinding method.The wafer grinding equipment comprises a wafer bearing transfer part used for bearing a to-be-ground wafer; the image acquisition device is arranged at the side end of the wafer bearing transfer part and is used for acquiring an image of the edge of the wafer to be ground; the image processing device is connected with the image acquisition device and is used for determining whether the edge of the wafer to be ground has an abnormal area or not according to the image; and the grinding part is arranged at the side end of the wafer bearing transfer part and used for grinding the abnormal area of the edge of the wafer to be ground. In the wafer grinding equipment, the image acquisition device can acquire the image of the edge area of the to-be-ground wafer, the image processing device can judge whether the edge area of the wafer is abnormal or not according to the acquired image of the edge area, and when the edge area of the to-be-ground wafer is abnormal, the grinding component grinds the abnormal area. The state of the edge area is improved, and the yield loss caused by particle peeling during subsequent formal grinding due to the abnormal edge area is improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductors, and in particular to a wafer grinding device and a grinding method. Background Art

[0002] When processing a wafer, in order to provide a good foundation for subsequent manufacturing processes, it is usually necessary to perform global planarization on the wafer surface. The CMP (Chemical Mechanical Polishing) process can be used to polish and grind the wafer.

[0003] Wafer scratches are an important factor in the loss of yield during the grinding process. Currently, the CMP process is usually improved to improve the yield of wafer grinding. However, since the edge state of some wafers is relatively poor, such as burrs, pits, or steps that harbor dirt and dirt, scratches may also be a source of scratches. Improving the CMP process itself cannot solve the problem of abnormalities in the wafer edge area, which causes CMP scratches to jump, thereby causing yield loss.

[0004] Therefore, how to identify the state of the wafer edge and perform pretreatment before the CMP process should be a technical problem that technical personnel in this field need to solve urgently. Summary of the invention

[0005] The purpose of the present application is to provide a wafer grinding device and a grinding method to solve the problem of yield loss caused by poor wafer edge condition.

[0006] In order to solve the above technical problems, the present application provides a wafer grinding device, comprising:

[0007] Wafer carrying transfer piece, used for carrying the wafer to be ground;

[0008] An image acquisition device, disposed at a side end of the wafer carrying transfer member, for acquiring an image of the edge of the wafer to be ground;

[0009] An image processing device, connected to the image acquisition device, for determining whether there is an abnormal area at the edge of the wafer to be ground according to the image;

[0010] The grinding component is arranged at the side end of the wafer carrying transfer component and is used for grinding the abnormal area on the edge of the wafer to be ground.

[0011] Optionally, also include:

[0012] The positioning device is arranged at the side end of the wafer carrying transfer member and is used to position the grinding component so that the grinding component can grind the abnormal area on the edge of the wafer to be ground.

[0013] Optionally, the grinding component includes a blade and a first rotating component, and the first rotating component is used to drive the blade to rotate.

[0014] Optionally, also include:

[0015] The second rotating component is used to rotate the blade so that the blade rotates from a horizontal direction to a vertical direction.

[0016] Optionally, also include:

[0017] A grinding head, wherein the grinding head is used to drive the wafer to be ground to rotate.

[0018] Optionally, the image acquisition device is further used to acquire a new image of the edge of the wafer to be ground after grinding;

[0019] Correspondingly, the image processing device is also used to determine whether there is an abnormal area on the edge of the wafer after grinding based on the new image.

[0020] Optionally, also include:

[0021] The grinding disc is used to grind the surface of the wafer to be ground when there is no abnormal area at the edge of the wafer to be ground.

[0022] Optionally, also include:

[0023] A water pipeline is provided with a water outlet, and the water outlet direction is away from the grinding disc.

[0024] The present application also provides a wafer grinding method, comprising:

[0025] When the wafer to be ground is placed on the wafer carrying transfer member, an image of the edge of the wafer to be ground is acquired;

[0026] Determining whether there is still an abnormal area at the edge of the wafer to be ground according to the image;

[0027] When the abnormal area still exists at the edge of the wafer to be ground, the grinding component grinds the abnormal area at the edge of the wafer to be ground.

[0028] Optionally, after the grinding component grinds the abnormal area on the edge of the wafer to be ground, the method further includes:

[0029] Acquire a new image of the edge of the wafer to be ground after grinding;

[0030] Determining whether there is an abnormal area at the edge of the ground wafer according to the new image;

[0031] When the abnormal area exists on the edge of the ground wafer, the grinding component grinds the abnormal area on the edge of the ground wafer.

[0032] A wafer grinding device provided in the present application includes: a wafer carrying transfer member, used to carry a wafer to be ground; an image acquisition device, arranged at a side end of the wafer carrying transfer member, used to acquire an image of an edge of the wafer to be ground; an image processing device, connected to the image acquisition device, used to determine whether there is an abnormal area on the edge of the wafer to be ground based on the image; and a grinding component, arranged at a side end of the wafer carrying transfer member, used to grind the abnormal area on the edge of the wafer to be ground.

[0033] It can be seen that the wafer grinding equipment in the present application includes a wafer carrying transfer part, an image acquisition device, an image processing device and a grinding component. The image acquisition device can acquire images of the edge area of ​​the wafer to be ground, and the image processing device can determine whether there is an abnormality in the edge area of ​​the wafer based on the acquired edge area image. When there is an abnormality in the edge area of ​​the wafer to be ground, the grinding component grinds the abnormal area, thereby improving the state of the edge area and improving the yield loss caused by the abnormality in the edge area.

[0034] In addition, the present application also provides a wafer grinding method having the above advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions of the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 A schematic diagram of the structure of a wafer grinding device provided in an embodiment of the present application;

[0037] Figure 2 for Figure 1 A magnified schematic diagram of the local area A;

[0038] In the figure, 1. wafer carrying transfer member, 2. image acquisition device, 3. image processing device, 4. blade, 5. positioning device, 6. grinding disc, 7. main rod, 8. water outlet, 9. wafer to be ground. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0040] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0041] As described in the background technology section, when the wafer edge condition is relatively poor, it will bring about scratches. Improving the CMP process itself cannot solve the yield loss caused by abnormalities in the wafer edge area.

[0042] In view of this, the present application provides a wafer grinding device, please refer to Figure 1 and Figure 2 ,include:

[0043] The wafer carrying transfer member 1 is used to carry the wafer 9 to be ground;

[0044] An image acquisition device 2, disposed at a side end of the wafer carrying transfer member 1, for acquiring an image of an edge of the wafer 9 to be ground;

[0045] An image processing device 3, connected to the image acquisition device 2, for determining whether there is an abnormal area at the edge of the wafer 9 to be ground according to the image;

[0046] The grinding component is arranged at the side end of the wafer carrying transfer member 1 and is used for grinding the abnormal area on the edge of the wafer 9 to be ground.

[0047] The wafer loading and transfer component 1 (Load Cup) has the functions of loading and transferring the wafer 9 to be ground. Before the surface of the wafer 9 to be ground is polished, the wafer 9 to be ground is placed on the wafer loading and transfer component 1.

[0048] The shape of the wafer carrying transfer member 1 can be the same as the shape of the wafer 9 to be ground.

[0049] It should be noted that the image acquisition device 2 is not limited in this embodiment and depends on the situation. For example, the image acquisition device 2 can be a camera or a webcam.

[0050] In order to improve the clarity of the image captured by the image acquisition device 2 on the edge area of ​​the wafer 9 to be ground, the image acquisition device 2 may be a high-magnification optical image acquisition device.

[0051] The image of the edge of the wafer 9 to be ground is an image of all edges of a whole circle of the front side of the wafer 9 to be ground.

[0052] When capturing the image of the edge of the wafer 9 to be ground, the position of the image capture device 2 can be fixed at the side end of the wafer carrying transfer member 1, and the wafer 9 to be ground can be rotated, thereby capturing images of all areas of the edge of the wafer 9 to be ground. Alternatively, the position of the wafer 9 to be ground is fixed, and the image capture device 2 rotates around the wafer 9 to be ground, thereby capturing images of all areas of the edge of the wafer 9 to be ground.

[0053] When the image acquisition device 2 acquires images, the image acquisition device 2 is located below the wafer 9 to be ground, and acquires images of the front edge area of ​​the wafer 9 to be ground from bottom to top.

[0054] The wafer grinding device may further include a main rod 7 , and the image acquisition device 2 may be fixed on the main rod 7 , and the main rod 7 is arranged at a side end of the wafer carrying transfer member 1 .

[0055] The wafer grinding device may also include a grinding head. In one embodiment of the present application, when the position of the image acquisition device 2 is fixed and the wafer 9 to be ground is rotating,

[0056] The grinding head is used to drive the wafer 9 to be ground to rotate, so that the image acquisition device 2 can perform image acquisition during the rotation process.

[0057] The grinding head grabs the wafer 9 to be ground, and the speed at which the wafer 9 to be ground is driven to rotate can be adjusted, which is very convenient.

[0058] It should be noted that, in this embodiment, the image processing device 3 is not specifically limited, as long as it has the performance of processing and analyzing. Exemplarily, the image processing device 3 can be a central processing unit or a single-chip microcomputer.

[0059] The abnormal area at the edge of the wafer 9 to be ground refers to an area that may bring particle sources when the wafer is ground. For example, the abnormal area may be an area where burrs, pits, or steps are present and dirt is collected.

[0060] It should also be pointed out that in this embodiment, the method for the image processing device 3 to determine whether there is an abnormal area at the edge of the wafer 9 to be ground is not limited and can be set by the user.

[0061] As an implementable embodiment, the image processing device 3 can compare the image of the edge of the wafer 9 to be ground obtained from the image acquisition device 2 with the edge of a wafer without abnormal areas on the edge, so as to determine whether there are abnormal areas on the edge of the wafer 9 to be ground.

[0062] It should be pointed out that the grinding component is not limited in this embodiment, as long as it can grind the edge area of ​​the wafer 9 to be ground.

[0063] As an implementation method, the grinding component includes a blade 4 and a first rotating component, and the first rotating component is used to drive the blade 4 to rotate. During the rotation of the blade 4, the abnormal edge area of ​​the wafer 9 to be ground is ground. Among them, the rotation of the blade 4 is to rotate around the center of the blade 4 itself. When the blade 4 grinds the wafer 9 to be ground, the blade 4 can grind the surface of the edge area of ​​the wafer 9 to be ground in a tangential manner to the wafer 9 to be ground.

[0064] The blade 4 is fixed on the main body rod 7.

[0065] When the blade 4 grinds the edge of the wafer 9 to be grinded, the rotation speed of the blade 4 can be ≤100 rpm, so as to better control the grinding accuracy. Exemplarily, the rotation speed of the blade 4 can be 100 rpm, 90 rpm, 80 rpm, 60 rpm, etc.

[0066] It should be noted that when the blade 4 is grinding the edge of the wafer 9 to be ground, if there are abnormalities in the edge area of ​​the wafer 9 to be ground, in order to improve the working efficiency, the blade 4 and the wafer 9 to be ground can rotate synchronously, and the wafer 9 to be ground rotates one circle to complete the processing of the abnormal area of ​​the wafer edge.

[0067] The blade 4 can be fixed on the main body rod 7. The shape of the blade 4 can be circular.

[0068] The wafer grinding device in this embodiment includes a wafer carrying transfer member 1, an image acquisition device 2, an image processing device 3 and a grinding component. The image acquisition device 2 can acquire an image of the edge area of ​​the wafer 9 to be ground, and the image processing device 3 can determine whether there is an abnormality in the edge area of ​​the wafer based on the acquired edge area image. When there is an abnormality in the edge area of ​​the wafer 9 to be ground, the grinding component grinds the abnormal area, thereby improving the state of the edge area and improving the yield loss caused by the abnormality in the edge area.

[0069] Based on the above embodiments, in one embodiment of the present application, the wafer grinding equipment may further include:

[0070] The positioning device 5 is disposed at the side end of the wafer carrying transfer member 1 and is used to position the grinding component so that the grinding component can grind the abnormal area at the edge of the wafer 9 to be ground.

[0071] The positioning device 5 can be fixed on the main rod 7. The positioning device 5 can be a distance measuring sensor or other devices, which is not limited in this embodiment.

[0072] In this embodiment, the positioning device 5 can be provided to locate the position of the movable blade 4, so as to grind the abnormal area on the edge of the wafer 9 to be ground very quickly and accurately without manual intervention.

[0073] Based on any of the above embodiments, in one embodiment of the present application, the wafer grinding equipment may further include:

[0074] The second rotating component is used to rotate the blade 4 so that the blade 4 rotates from a horizontal direction to a vertical direction.

[0075] For example, for a circular blade 4, when viewed from a top view, the blade 4 is in a horizontal state, the shape is circular. When the blade 4 is rotated vertically by a certain angle, the shape of the blade 4 changes from circular to elliptical.

[0076] When the blade 4 is not grinding the edge of the wafer 9 to be ground, the blade 4 is placed in a parallel horizontal direction. Figure 2 In order to prevent the blade 4 from contacting the retainer ring of the grinding head during the grinding process, the blade 4 is deflected laterally (rotated from the horizontal direction to the vertical direction).

[0077] It should be pointed out that in this embodiment, after the blade 4 is rotated in the vertical direction, there is no limitation on the angle between the blade 4 and the edge of the wafer 9 to be ground.

[0078] As an implementable embodiment, the angle between the blade 4 and the edge of the wafer 9 to be ground after the blade 4 is rotated in the vertical direction can be in the range of 45° to 90°, so as to improve the grinding efficiency and speed.

[0079] For example, the angle between the blade 4 and the edge of the wafer 9 to be ground after the blade 4 is rotated in the vertical direction can be 45°, 50°, 60°, 70°, 80°, 90°, etc.

[0080] The image acquisition device 2, the blade 4, and the positioning device 5 are all fixed on the main rod 7. The spacing between the image acquisition device 2 and the positioning device 5 is fixed, and the spacing between the blade 4 and the positioning device 5 is fixed. When the image acquisition device 2 takes a picture of the edge of the wafer 9 to be ground, the image acquisition device 2 and the positioning device 5 are both located below the wafer 9 to be ground. When it is necessary to grind an abnormal area on the edge of the wafer 9 to be ground, since the blade 4 is fixed on the main rod 7, the position of the blade 4 is adjusted by swinging the main rod 7 at a certain angle, and the blade 4 is laterally deflected to adjust the angle. At the same time, the wafer 9 to be ground rotates, so that the blade 4 is tangent to the abnormal area on the edge of the wafer 9 to be ground, and the abnormal area is ground. During the grinding process, the main rod 7 is fixed.

[0081] Based on any of the above embodiments, in one embodiment of the present application, the image acquisition device is also used to acquire a new image of the edge of the wafer 9 to be ground after grinding; accordingly, the image processing device 3 is also used to determine whether there is an abnormal area on the edge of the wafer after grinding based on the new image.

[0082] After the grinding component grinds the abnormal area on the edge of the wafer 9 to be ground, in order to ensure the quality of grinding, image acquisition can be performed again after grinding, and the image processing device 3 makes a judgment again based on the newly acquired edge image to determine whether the abnormal area is ground into a non-abnormal area. When there is no abnormal area, the grinding is completed, and the wafer can be subjected to subsequent surface grinding processing; when there is still an abnormal area, the grinding component grinds the abnormal area again until all the edge areas of the wafer 9 to be ground are non-abnormal areas.

[0083] Based on any of the above embodiments, in one embodiment of the present application, the wafer grinding equipment may further include:

[0084] The grinding disc 6 is used to grind the surface of the wafer 9 to be ground when there is no abnormal area at the edge of the wafer 9 to be ground.

[0085] The grinding disc 6 performs polishing and grinding on the surface of the wafer, which is a conventional CMP process, so as to obtain a wafer with both the edge area and the surface being well ground.

[0086] As an implementation method, the wafer grinding equipment may further include:

[0087] The transfer component is used to transfer the wafer 9 to be ground to the grinding disk 6 after there is no abnormal area on the edge of the wafer 9 to be ground. There is no need for manual transfer, which is very convenient and fast.

[0088] The transfer component can be a robot or the like.

[0089] Based on any of the above embodiments, in one embodiment of the present application, the wafer grinding equipment may further include:

[0090] A water pipeline is provided with a water outlet 8 , and the water outlet direction is away from the grinding disc 6 .

[0091] The water pipeline can be arranged in the main rod 7.

[0092] When grinding the edge area of ​​the wafer 9 to be ground, grinding debris will be generated. The water in the water pipeline will be sprayed out from the water outlet 8 to flush the grinding debris to the side away from the grinding disk 6, avoiding the debris generated by the edge grinding from causing scratches on the wafer surface during grinding, thereby playing a role in improving scratches.

[0093] The water pipeline can be a hard pipeline, and the image acquisition device 2, the blade 4, and the positioning device 5 can be fixed on the water pipeline. Figure 1 and Figure 2 The position of the water pipe is adjustable, and when the edge area of ​​the wafer 9 to be ground needs to be ground, the water pipe can be deflected toward the direction close to the wafer 9 to be ground.

[0094] It should be pointed out that the wafer grinding equipment in the present application can be obtained by modifying the CMP equipment in the prior art, that is, a water pipe 7 is installed on the side end of the wafer carrying transfer part 1 in the existing CMP equipment, and components such as an image acquisition device 2, a blade 4, and a positioning device 5 are arranged on the water pipe 7, which will not have other effects on the structure of the CMP equipment. After identifying the abnormal area on the edge of the wafer 9 to be ground, cutting and grinding can remove the burrs on the edge of the wafer and the unstable particle sources in the pits in advance, so that the scratch performance of the CMP itself will not be affected by the state of the incoming wafer during the formal CMP process.

[0095] The present application also provides a wafer grinding method, which may include:

[0096] Step S101: When a wafer to be ground is placed on a wafer carrying transfer member, an image of an edge of the wafer to be ground is acquired.

[0097] The image in this step is an image of the entire edge of the wafer to be ground.

[0098] Step S102: determining whether there is an abnormal area at the edge of the wafer to be ground based on the image.

[0099] Step S103: When the abnormal area exists at the edge of the wafer to be ground, a grinding component grinds the abnormal area at the edge of the wafer to be ground.

[0100] The wafer grinding method in this embodiment can capture images of the edge area of ​​the wafer to be ground through an image acquisition device, and the image processing device can determine whether there is an abnormality in the edge area of ​​the wafer based on the captured edge area image. When an abnormality exists in the edge area of ​​the wafer to be ground, the grinding component grinds the abnormal area, thereby improving the state of the edge area and improving the yield loss caused by the abnormality in the edge area.

[0101] On the basis of the above embodiment, in one embodiment of the present application, after the grinding component grinds the abnormal area on the edge of the wafer to be ground, the method further includes:

[0102] Acquire a new image of the edge of the wafer to be ground after grinding;

[0103] Determining whether there is an abnormal area at the edge of the ground wafer according to the new image;

[0104] When the abnormal area exists on the edge of the ground wafer, the grinding component grinds the abnormal area on the edge of the ground wafer.

[0105] It is understandable that when there is no abnormal area at the edge of the wafer after grinding, the grinding component does not need to be ground again, and the grinding disc can perform subsequent surface grinding.

[0106] In this embodiment, after grinding the edge area of ​​the wafer to be ground, an image of the edge area is collected again and judged until the edge area of ​​the wafer is intact without abnormal areas, thereby avoiding the risk of scratches caused by abnormal areas on the edge in subsequent formal CMP grinding.

[0107] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0108] The above is a detailed introduction to the wafer grinding equipment and wafer grinding method provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the scheme and core ideas of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the present application.

Claims

1. A wafer grinding device, characterized in that: include: Wafer carrying transfer piece, used for carrying the wafer to be ground; An image acquisition device, disposed at a side end of the wafer carrying transfer member, for acquiring an image of the edge of the wafer to be ground; An image processing device, connected to the image acquisition device, for determining whether there is an abnormal area at the edge of the wafer to be ground according to the image; The grinding component is arranged at the side end of the wafer carrying transfer component and is used for grinding the abnormal area on the edge of the wafer to be ground.

2. The wafer grinding equipment according to claim 1, characterized in that: Also includes: The positioning device is arranged at the side end of the wafer carrying transfer member and is used to position the grinding component so that the grinding component can grind the abnormal area on the edge of the wafer to be ground.

3. The wafer grinding equipment according to claim 1, characterized in that: The grinding component includes a blade and a first rotating component, and the first rotating component is used for driving the blade to rotate.

4. The wafer grinding equipment according to claim 3, characterized in that: Also includes: The second rotating component is used to rotate the blade so that the blade rotates from a horizontal direction to a vertical direction.

5. The wafer grinding equipment according to claim 1, characterized in that: Also includes: A grinding head, wherein the grinding head is used to drive the wafer to be ground to rotate.

6. The wafer grinding equipment according to claim 1, characterized in that: The image acquisition device is also used to acquire a new image of the edge of the wafer to be ground after grinding; Correspondingly, the image processing device is also used to determine whether there is an abnormal area on the edge of the wafer after grinding based on the new image.

7. The wafer grinding equipment according to any one of claims 1 to 6, characterized in that: Also includes: The grinding disc is used to grind the surface of the wafer to be ground when there is no abnormal area at the edge of the wafer to be ground.

8. The wafer grinding equipment according to claim 7, characterized in that: Also includes: A water pipeline is provided with a water outlet, and the water outlet direction is away from the grinding disc.

9. A wafer grinding method, characterized in that: include: When the wafer to be ground is placed on the wafer carrying transfer member, an image of the edge of the wafer to be ground is acquired; Determining whether there is an abnormal area at the edge of the wafer to be ground according to the image; When the abnormal area exists at the edge of the wafer to be ground, the grinding component grinds the abnormal area at the edge of the wafer to be ground.

10. The wafer grinding method according to claim 9, wherein: After the grinding component grinds the abnormal area on the edge of the wafer to be ground, the method further includes: Acquire a new image of the edge of the wafer to be ground after grinding; Determining whether there is still an abnormal area on the edge of the wafer after grinding according to the new image; When the abnormal area still exists on the edge of the wafer after grinding, the grinding component grinds the abnormal area on the edge of the wafer after grinding.

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