Wafer edge washing device and system

Abstract

The utility model provides a wafer edge washing device and a system adopting the device, the wafer edge washing device comprises a supporting table, a spray head and a connecting rod mechanism, the supporting table is used for supporting a wafer and driving the wafer to rotate, the spray head is connected to the connecting rod mechanism, and the spray head is configured to move to the position above the wafer under the control of the connecting rod mechanism during working. The liquid spraying direction of the nozzle and the plane where the wafer surface is located have an intersection point, and the liquid spraying direction comprises a tangential component of a wafer concentric circle where the intersection point is located. According to the invention, a vertical interface can be formed between the edge-washed area and the non-edge-washed area after edge washing, so that photoresist deformation is avoided; and meanwhile, the solvent is controlled near and on the outer side of a spraying point on the surface of the wafer, so that secondary defects caused by photoresist splashing can be reduced.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular to a wafer edge cleaning device and system. Background Art

[0002] In the integrated circuit manufacturing process, the wafer needs to undergo multiple photolithography steps. During the photoresist spin coating process, the excess glue will be pushed to the edge of the wafer by centrifugal force. Most of it will be thrown off the wafer, and some will remain on the edge of the wafer. Since the airflow at the edge of the wafer has a relatively high relative speed, the remaining glue will solidify quickly, forming a raised edge. This part of the glue is prone to residual impurities, causing pollution, reducing the number of effective chips, and may also cause abnormalities in the later process. Therefore, it needs to be removed immediately after the spin coating is completed.

[0003] Therefore, after the soft baking process, the photoresist at the edge of the wafer is removed by chemical or optical methods, which is called edge bead removal (EBR), or edge washing for short. Chemical EBR is to spray edge bead removal solvent to the edge of the wafer with a nozzle. The solvent is in close contact with the edge of the wafer to dissolve the photoresist at the edge. The commonly used edge washing method is to spray the solvent while the nozzle is kept at a fixed angle to the wafer surface while the wafer rotates at a constant speed. However, edge washing will produce more or less defects (such as photoresist deformation and splashing, etc.), which will affect subsequent processes, cause defects in the entire wafer, and thus affect the output yield. Utility Model Content

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a wafer edge cleaning device and system for solving the problems of photoresist deformation and splashing in the edge cleaning process of the prior art.

[0005] An embodiment of the present application provides a wafer edge cleaning device, including a support, a nozzle and a connecting rod mechanism, wherein the support is used to support the wafer and drive the wafer to rotate, the nozzle is connected to the connecting rod mechanism, and the nozzle is configured to move above the wafer under the control of the connecting rod mechanism when working, the direction of the nozzle spraying liquid has an intersection with the plane where the wafer surface is located, and the direction of the liquid spraying includes a tangential component of the concentric circle of the wafer where the intersection is located.

[0006] In some embodiments, the angle between the liquid spraying direction of the nozzle and the plane where the wafer surface is located is set to an acute angle or a right angle.

[0007] In some embodiments, the distance between the liquid spraying port of the nozzle and the surface of the wafer ranges from 5 mm to 20 mm.

[0008] In some embodiments, the distance between the intersection point and the center of the wafer is in a range of 97% to 99% of the radius of the wafer.

[0009] In some embodiments, the connecting rod mechanism includes a first connecting rod and a second connecting rod, the first connecting rod and the second connecting rod are rotatably connected, the first connecting rod rotates around the connection point between the first connecting rod and the second connecting rod, and the nozzle is fixedly connected to the first connecting rod.

[0010] In some embodiments, the second connecting rod is disposed parallel to and above the wafer, and the second connecting rod can move parallel to the surface of the wafer.

[0011] In some embodiments, the liquid inlet end of the spray head is connected to a solvent source of the edge washing solvent through a hose.

[0012] An embodiment of the present application also provides a wafer edge cleaning system, comprising a control unit and the wafer edge cleaning device described in the above embodiment, wherein the control unit is electrically connected to at least the support and nozzle of the wafer edge cleaning device to configure the rotation direction and rotation speed of the wafer and the spray speed of the nozzle.

[0013] In some embodiments, the rotation direction of the wafer is consistent with the direction in which the nozzle sprays liquid.

[0014] In some embodiments, the liquid spraying speed of the nozzle is configured such that the wafer rotation linear speed at the intersection is equal to the horizontal component of the liquid spraying speed.

[0015] The wafer edge washing device and system of the present application have the following beneficial effects: by adjusting the relative position of the nozzle and the wafer, the direction of the nozzle spraying liquid and the plane where the wafer surface is located have an intersection point, and the direction of the liquid spraying includes the tangential component of the wafer concentric circle where the intersection point is located. The solvent on the surface of the wafer will not produce swirl, so that a vertical interface can be formed between the edge washing area and the non-edge washing area after edge washing, thereby avoiding deformation of the photoresist; at the same time, by configuring the rotation direction and rotation speed of the wafer and the liquid spraying speed of the nozzle, the solvent is controlled near and outside the injection point on the wafer surface, which can reduce the secondary defects caused by photoresist splashing and increase the number of effective chips produced by the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The following figures describe in detail the exemplary embodiments disclosed in this application. The same reference numerals represent similar structures in several views of the drawings. Those skilled in the art will understand that these embodiments are non-limiting, exemplary embodiments, and the drawings are only for the purpose of illustration and description, and are not intended to limit the scope of this application. Other embodiments may also accomplish the inventive intent in this application. It should be understood that the drawings are not drawn to scale.

[0017] in:

[0018] Figure 1is a schematic diagram of the position relationship between the showerhead and the wafer shown in some embodiments;

[0019] Figure 2 is a schematic diagram of a wafer edge cleaning device according to some embodiments of the present application;

[0020] Figure 3 yes Figure 2 An enlarged schematic diagram of the middle nozzle and the connecting rod mechanism;

[0021] Figure 4 Schematic diagram of the architecture of a wafer edge cleaning system according to some embodiments of the present application. DETAILED DESCRIPTION

[0022] The following description provides specific application scenarios and requirements of the present application, with the purpose of enabling those skilled in the art to make and use the content in the present application. It will be apparent to those skilled in the art that various local modifications to the disclosed embodiments are apparent, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present application. Therefore, the present application is not limited to the embodiments shown, but to the widest scope consistent with the claims.

[0023] In some embodiments, reference Figure 1 As shown, the nozzle 2 is perpendicular to the surface of the wafer 5', and the spray direction of the nozzle 2 intersects with the plane where the surface of the wafer 5' is located at point A'. In other words, the spray direction of the nozzle 2 is perpendicular to any straight line on the plane where the surface of the wafer 5' is located, including two special straight lines: the radial line 6' and the tangent line 7' of the concentric circle of the wafer 5' passing through point A'. In other words, the spray direction of the nozzle 2 is perpendicular to both the radial line 6' of the concentric circle of the wafer 5' passing through point A' and the tangent line 7' of the concentric circle of the wafer 5' passing through point A'.

[0024] according to Figure 1 , there may be the following embodiments:

[0025] In the first embodiment, the shower head 1 is radially arranged along the surface of the wafer 5 ′, pointing to the edge of the wafer 5 ′ and forming an acute angle with the surface of the wafer 5 ′.

[0026] In the second embodiment, the nozzle 2 is perpendicular to the surface of the wafer 5 ′ and points to the edge of the wafer 5 ′.

[0027] In Example 1 and Example 2, both nozzle forms with two angles have certain shortcomings, and will cause additional defects to a certain extent during the edge washing process. In Example 1, impurities are thrown out during the edge washing process under the combined action of centrifugal force and solvent thrust, and fewer impurities remain on the wafer; however, the swirl of the solvent during the edge washing process will cause the photoresist at the edge of the wafer to deform, affecting the edge profile of the wafer, and then causing a series of deteriorating effects. The nozzle in Example 2 is perpendicular to the surface of the wafer, which can avoid the deformation of the photoresist at the edge of the wafer caused by the swirl of the solvent, but this method is prone to sputtering of the solvent, and secondary defects will be generated.

[0028] The present application makes changes based on the above-mentioned positional relationship between the nozzle 2 and the wafer 5': maintain the perpendicular relationship between the nozzle and the radial line of the concentric circles on the wafer, and change the right angle (i.e., perpendicular) relationship between the nozzle and the tangent line of the concentric circles on the wafer to an acute angle relationship. Therefore, an embodiment of the present application provides a wafer edge washing device, including a support, a nozzle, and a connecting rod mechanism. Among them, the support is used to support the wafer and drive the wafer to rotate; the nozzle is connected to the connecting rod mechanism; the nozzle is configured to move to the top of the wafer under the control of the connecting rod mechanism when working, and the direction of the nozzle spray has an intersection with the plane where the wafer surface is located, and the direction of the spray includes the tangential component of the concentric circle of the wafer where the intersection is located.

[0029] The technical solution of the present invention is described in detail below in conjunction with the embodiments and drawings.

[0030] Figure 2 Schematic diagram of a wafer edge cleaning device 100 according to some embodiments of the present application. In some embodiments, the wafer edge cleaning device 100 includes a support table (not shown), a nozzle 3 and a connecting rod mechanism 4. The support table is used to support the wafer 5 and drive the wafer 5 to rotate; the nozzle 3 is connected to the connecting rod mechanism 4; the nozzle 3 is configured to move above the wafer 5 under the control of the connecting rod mechanism 4 when working, and the direction of the nozzle 3 spraying liquid has an intersection A with the plane where the surface of the wafer 5 is located, and the direction of the liquid spraying includes a tangential component of the concentric circle 8 of the wafer 5 where the intersection A is located.

[0031] When the nozzle and the radial direction of the wafer surface are at an acute angle, the solvent will swirl, causing the photoresist at the edge of the wafer to deform, affecting the edge profile of the wafer. In the embodiment of the present application, the nozzle 3 is perpendicular to the radial line 6 of the concentric circle 8 of the wafer 5 (i.e., at a right angle), which can avoid the swirl of the solvent, and the photoresist and impurities dissolved by the solvent can leave the wafer 5 under the action of centrifugal force. After edge washing, a vertical interface is formed between the edge washing area and the non-edge washing area, which can avoid deformation of the photoresist.

[0032] Preferably, in some embodiments, the angle α between the spray direction of the nozzle 3 and the plane where the surface of the wafer 5 is located is set to an acute angle, which can avoid secondary defects caused by photoresist sputtering when the angle α is a right angle.

[0033] refer to Figure 2 As shown, the solvent is sprayed at the intersection A by the nozzle 3. The solvent power is related to the injection speed of the solvent. When the solvent reaches the intersection A, the solvent power can be decomposed into horizontal power and vertical power. Among them, the vertical power of the solvent helps to dissolve the photoresist and makes the photoresist and impurities dissolved by the solvent separate from the surface of the wafer 5 under the action of the rebound force. During the rotation of the wafer 5, the external force on the solvent at the intersection A also includes the tangential friction force of the concentric circles 8 of the wafer 5 and the radial centrifugal force. Among them, the radial centrifugal force will throw the photoresist and impurities dissolved by the solvent out of the wafer 5. The friction force on the surface of the wafer 5 that the solvent is subjected to is related to the rotation speed of the wafer 5 and the speed of the nozzle 3 spraying liquid.

[0034] At the intersection point A on the surface of the wafer 5, the horizontal power of the solvent and the tangential component of the friction force exerted on the solvent by the surface of the wafer 5 are on a straight line. Their directions may be the same or opposite.

[0035] In some embodiments, the rotation direction of the wafer 5 is set so that the rotation direction of the wafer 5 is consistent with the solvent injection direction of the nozzle 3, that is, the wafer 5 rotates along the direction of the nozzle 3 spraying liquid. At the same time, the solvent injection speed of the nozzle 3 and / or the rotation speed of the wafer 5 are further adjusted. When the wafer rotation linear velocity at the intersection A is equal to the horizontal component of the injection speed, the solvent is stationary relative to the surface of the wafer 5 in the tangential direction, and there is no friction in the tangential direction. At this time, the centrifugal force becomes the main force controlling the movement of the solvent, and the solvent is taken away from the wafer 5 by the centrifugal force. Therefore, the solvent is controlled near and outside the injection point on the surface of the wafer 5, which can reduce secondary defects caused by photoresist splashing.

[0036] The distance between the liquid spraying port of the nozzle 3 and the surface of the wafer 5, and the width of the edge of the wafer 5 cleaned by the nozzle 3 can be adjusted according to different process requirements. In some embodiments, the distance between the liquid spraying port of the nozzle 3 and the surface of the wafer 5 ranges from 5mm to 20mm. In some embodiments, the distance between the intersection A and the center of the wafer is in the range of 97% to 99% of the radius of the wafer 5. For example, when washing the edge of a 12-inch wafer, the distance between the nozzle 3 and the surface of the wafer 5 is 10mm, and the position where the nozzle 3 sprays liquid onto the wafer 5 is 2mm to 3mm from the edge of the wafer 5. Since each process is different, the edge washing width is formulated according to different process requirements, and is usually not more than 3mm.

[0037] refer to Figure 3The enlarged schematic diagram of the spray head 3 and the connecting rod mechanism 4 is shown. In some embodiments, the connecting rod mechanism 4 includes a first connecting rod 41 and a second connecting rod 42. The first connecting rod 41 is rotatably connected to the second connecting rod 42, and the first connecting rod 41 rotates around the connection point between the first connecting rod 41 and the second connecting rod 42. The other end of the spray head 3 relative to the liquid spraying port is fixedly connected to the first connecting rod 41. The second connecting rod 42 includes a driving mechanism (not shown).

[0038] The connecting rod mechanism 4 can be manually controlled or electrically controlled.

[0039] In some embodiments, the connecting rod mechanism 4 is manually controlled. The first connecting rod 41 is rotatably connected to the second connecting rod 42 via a damping shaft, and the driving mechanism of the second connecting rod 42 is a manual combined slide rail.

[0040] In some embodiments, the connecting rod mechanism 4 is electrically controlled. The first connecting rod 41 is rotatably connected to the second connecting rod 42 via an electric rotating shaft (such as a servo motor), and the driving mechanism of the second connecting rod 42 is an electric combined slide rail to achieve electric control.

[0041] In some embodiments, any adjustable angle α between the nozzle 3 and the surface of the wafer 5 can be achieved by rotating the first connecting rod 41. The second connecting rod 42 is arranged parallel to the top of the wafer 5, and the second connecting rod 42 can move parallel to the surface of the wafer 5 under the drive mechanism thereof. Among them, the second connecting rod 42 moves parallel to the surface of the wafer 5, which means that the second connecting rod 42 always remains parallel to the surface of the wafer 5, and the moving direction can be vertical or horizontal, and the horizontal direction includes front, back, left and right. For example 1, it is assumed that the distance between the current nozzle 3 liquid spray port and the surface of the wafer 5 is h, and the angle between the nozzle 3 and the surface of the wafer 5 is β. If it is necessary to adjust the angle between the nozzle 3 and the surface of the wafer 5 to γ ​​(β≠γ), and the distance between the nozzle 3 and the surface of the wafer 5 remains unchanged (i.e., still h), it can be adjusted as follows: adjust the angle between the first connecting rod 41 and the surface of the wafer 5 to γ, and then vertically move the second connecting rod 42 to make the distance between the nozzle 3 and the surface of the wafer 5 h, and at the same time horizontally move the second connecting rod 42 so that the intersection of the nozzle 3 and the plane where the surface of the wafer 5 is located is still at point A. For example 2, if the distance between the nozzle 3 and the surface of the wafer 5 and the angle between the nozzle 3 and the surface of the wafer 5 remain unchanged, it is only necessary to adjust the horizontal distance of the nozzle 3 relative to the center of the wafer 5 (for example, replace a wafer of different size), and then it is only necessary to horizontally move the second connecting rod 42. As can be seen from the above, the cooperation of the first connecting rod 41 and the second connecting rod 42 can realize any preset position and three-dimensional angle relationship of the nozzle 3 relative to the surface of the wafer 5.

[0042] In some embodiments, the nozzle 3 can be installed on a three-dimensional platform or a robotic arm, and any preset position and three-dimensional angle relationship of the nozzle 3 relative to the surface of the wafer 5 can be achieved. The three-dimensional platform and the robotic arm belong to the prior art and will not be described in detail.

[0043] In some embodiments, the liquid inlet end of the nozzle 3 is connected to a solvent source through a hose, and the solvent matching different processes can be replaced as needed.

[0044] refer to Figure 4 As shown, the embodiment of the present application also provides a wafer edge cleaning system 200, including a control unit and the wafer edge cleaning device 100 described in the above embodiment. Among them, the control unit is electrically connected to at least the support table and the nozzle 3 of the wafer edge cleaning device 100 to configure the rotation direction and rotation speed of the wafer 5 and the spray speed of the nozzle 3. When the connecting rod mechanism 4 of the wafer edge cleaning device 100 is electrically controlled, the control unit is also electrically connected to the connecting rod mechanism 4 to configure the position and three-dimensional angle relationship of the nozzle 3 relative to the surface of the wafer 5.

[0045] In some embodiments, the rotation direction of the wafer 5 is set to be consistent with the spraying direction of the nozzle 3 , that is, the wafer 5 rotates along the direction in which the nozzle 3 sprays liquid.

[0046] In some embodiments, the rotation speed of the stage (ie, the rotation speed of the wafer 5 ) ranges from 2000 to 6000 rpm.

[0047] In some embodiments, the liquid spraying speed of the nozzle 3 is configured such that the wafer rotation linear speed at the intersection A is equal to the horizontal component of the liquid spraying speed. At this time, the solvent is stationary relative to the surface of the wafer 5 in the tangential direction, there is no friction in the tangential direction, and the centrifugal force becomes the main force controlling the movement of the solvent, and the solvent is carried away from the wafer 5 by the centrifugal force.

[0048] The beneficial effects that may be brought about by the embodiments of the present application include but are not limited to: the present application provides a wafer edge washing device and system, by setting the position and three-dimensional angle relationship between the nozzle and the wafer, the solvent on the surface of the wafer will not swirl, and a vertical interface can be formed between the edge washing area and the non-edge washing area after edge washing, thereby avoiding deformation of the photoresist; at the same time, by configuring the rotation direction and rotation speed of the wafer and the spray speed of the nozzle, the solvent is controlled near and outside the injection point on the wafer surface, which can reduce secondary defects caused by photoresist splashing. The wafer edge washing device and system of the present application can increase the number of effective chips produced by wafers.

[0049] It should be noted that different embodiments may produce different beneficial effects. In different embodiments, the beneficial effects that may be produced may be any one or a combination of the above, or any other beneficial effects that may be obtained.

[0050] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of this specification. Although not explicitly stated here, those skilled in the art may make various modifications, improvements and corrections to this application. Such modifications, improvements and corrections are suggested in this specification, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of this application.

[0051] It should be noted that in the description of this application, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", and "fix" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a rotating connection or a sliding connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood in combination with specific circumstances.

[0052] In addition, when terms such as "first", "second", and "third" are used in the specification of this application to describe various features, these terms are only used to distinguish these features and cannot be understood as indicating or implying the relationship between the features, the relative importance, or implicitly indicating the number of features indicated.

[0053] In addition, the present specification describes exemplary embodiments by reference to idealized exemplary cross-sectional views and / or plan views and / or stereograms. Therefore, differences from the illustrated shapes due to, for example, manufacturing techniques and / or tolerances are foreseeable. Therefore, the exemplary embodiments should not be interpreted as being limited to the shapes of the regions shown herein, but should include deviations in shapes caused by, for example, manufacturing. Therefore, the regions shown in the figures are schematic in nature, and their shapes are not intended to illustrate the actual shapes of the regions of the device nor to limit the scope of the exemplary embodiments.

[0054] At the same time, the present application uses specific words to describe the embodiments of this specification. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in the present application does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0055] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0056] Finally, it should be understood that the embodiments described in this application are only used to illustrate the principles of the embodiments of the present application. Other variations may also fall within the scope of the present application. Therefore, as an example and not a limitation, the alternative configurations of the embodiments of the present application may be considered to be consistent with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to the embodiments explicitly introduced and described in the present application.

Claims

1. A wafer edge cleaning device, characterized in that: The invention comprises a support platform, a nozzle and a connecting rod mechanism, wherein the support platform is used for supporting a wafer and driving the wafer to rotate, the nozzle is connected to the connecting rod mechanism, and the nozzle is configured to move above the wafer under the control of the connecting rod mechanism when in operation, the direction of the nozzle spraying liquid has an intersection with the plane where the wafer surface is located, and the direction of the liquid spraying includes a tangential component of the concentric circle of the wafer where the intersection is located.

2. The wafer edge cleaning device according to claim 1, characterized in that: The angle between the liquid spraying direction of the nozzle and the plane where the wafer surface is located is set to be an acute angle or a right angle.

3. The wafer edge cleaning device according to claim 1, characterized in that: The distance between the liquid spraying port of the nozzle and the surface of the wafer ranges from 5 mm to 20 mm.

4. The wafer edge cleaning device according to claim 1, characterized in that: The distance between the intersection point and the center of the wafer is in a range of 97% to 99% of the radius of the wafer.

5. The wafer edge cleaning device according to claim 1, characterized in that: The connecting rod mechanism includes a first connecting rod and a second connecting rod, the first connecting rod is rotatably connected to the second connecting rod, the first connecting rod rotates around the connection point between the first connecting rod and the second connecting rod, and the nozzle is fixedly connected to the first connecting rod.

6. The wafer edge cleaning device according to claim 5, characterized in that: The second connecting rod is arranged parallel to the wafer, and the second connecting rod can move parallel to the surface of the wafer.

7. The wafer edge cleaning device according to claim 1, characterized in that: The liquid inlet end of the spray head is connected to a solvent source of the edge washing solvent through a hose.

8. A wafer edge cleaning system, characterized in that: It comprises a control unit and the wafer edge cleaning device according to any one of claims 1 to 7, wherein the control unit is electrically connected to at least a support table and a nozzle of the wafer edge cleaning device to configure the rotation direction and rotation speed of the wafer and the spraying speed of the nozzle.

9. The wafer edge cleaning system according to claim 8, characterized in that: The rotation direction of the wafer is consistent with the direction of the liquid spraying of the nozzle.

10. The wafer edge cleaning system according to claim 9, characterized in that: The liquid spraying speed of the nozzle is configured such that the wafer rotation linear speed at the intersection is equal to the horizontal component of the liquid spraying speed.

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