Wafer glue spreading device

Abstract

The present application provides a wafer coating device, which can improve the uniformity of wafer coating, comprising a substrate, a wafer, and a cover plate, wherein the wafer is adsorbed on one side of the substrate by vacuum adsorption, and the cover plate is coaxially arranged on a side away from the substrate and facing the wafer, and the diameter of the cover plate is larger than the diameter of the wafer; the rotation speed of the cover plate is controlled so that the rotation speed of the cover plate is less than or equal to the rotation speed of the substrate, and the rotation directions of the cover plate and the substrate are the same; during the operation of the device, the airflow on the upper surface of the wafer during the spin coating process can be controlled to change the influence of the airflow on the spin coating process, and the "wave"-shaped texture can be effectively solved by controlling its rotation speed so that the rotation speed of the cover plate is always less than or equal to that of the substrate, thereby significantly reducing the thickness of the film after coating, achieving spin coating of an imprinted adhesive film below 50nm, and having a good spin coating effect.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, in particular to a wafer glue spreading device. Background Art

[0002] During the wafer coating process of semiconductor devices, traditional glue spin coating machines rarely take into account the impact of air resistance on the wafer surface on the coating quality during the coating process. For some photoresists with a thickness reduced to less than 200nm, layered "wave" textures will be produced on the edge of the wafer after coating. This texture causes uneven distribution of glue within about 30mm of the wafer edge.

[0003] Spin coating (or spin coating) is a coating process that relies on the centrifugal force and gravity generated when the workpiece rotates to spread the material droplets that fall on the workpiece on the surface of the workpiece. Based on the existing wafer spin coating and glue spreading method, the existing technology has the following defects: 1) It is difficult to control the airflow interference problem on the upper surface of the wafer during the spin coating process. For certain specific glues, the airflow resistance during the spin coating process will cause "wave"-shaped patterns to form on the edge of the wafer. 2) For different glue spreading thicknesses, the existing technology mainly controls the thickness of the film after spin coating by the spin coating speed. The higher the spin coating speed, the smaller the thickness of the film after spin coating; when the thickness is below a certain level, increasing the spin coating speed can no longer obtain a film of this thickness.

[0004] Therefore, how to improve the edge quality of glue spreading and reduce the thickness of existing glue spreading so that the glue spreading thickness is lower and the glue spreading effect is better to meet the needs of different scenarios is important and needs to be solved for technical personnel in this field. Utility Model Content

[0005] The embodiment of the utility model provides a wafer glue spreading device, which can improve the uniformity of wafer glue spreading and solve the problems existing in the prior art.

[0006] A wafer coating device can improve the uniformity of wafer coating, comprising a substrate, a wafer, and a cover plate, wherein the wafer is adsorbed on one side of the substrate by vacuum adsorption, and the cover plate is coaxially arranged on a side away from the substrate and facing the wafer, and the diameter of the cover plate is larger than the diameter of the wafer; the rotation directions of the cover plate and the substrate are controlled to keep the rotation directions of the cover plate and the substrate the same.

[0007] Furthermore, the rotation speed of the cover plate is controlled so that the rotation speed of the cover plate is less than or equal to the rotation speed of the substrate.

[0008] In one embodiment, a controller is further included, and the cover plate is connected to the controller to control the rotation speed of the cover plate to be less than or equal to the rotation speed of the base.

[0009] Furthermore, the distance between the cover plate and the wafer is less than or equal to 5 mm.

[0010] In one embodiment, it also includes a lifting and rotating rod, and the cover plate is connected to the bracket via the lifting and rotating rod, and the lifting and rotating rod drives the lifting and / or rotation of the cover plate; the bracket is fixedly connected to the surface of the glue leveling machine platform.

[0011] In one embodiment, the cover plate has a truncated cone formed by a circular bottom surface adapted to the substrate, and the circular bottom surface is arranged opposite to the surface of the wafer.

[0012] Furthermore, the diameter of the cylindrical bottom surface is greater than the diameter of the wafer.

[0013] In one embodiment, the cover plate is a hollow cover plate having a cavity, and the wafer is placed in the cavity, so that the cover plate covers the wafer.

[0014] Furthermore, the inner diameter of the cover plate is larger than the diameter of the wafer.

[0015] The wafer coating device provided in the present application can improve the uniformity of coating on the wafer. During the operation of the device, the airflow on the upper surface of the wafer during the spin coating process can be controlled to change the influence of the airflow on the spin coating process as much as possible, thereby achieving the effect of removing the wave pattern. By controlling its rotation speed so that the rotation speed of the cover plate is always less than or equal to the substrate, the "wave" pattern can be effectively solved, and the thickness of the film after coating can be significantly reduced, so as to achieve spin coating of an imprinted adhesive film below 50nm, and have a good spin coating effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 A schematic diagram of a wafer coating device provided by the utility model Figure 1 ;

[0018] Figure 2 A schematic diagram of the structure of a wafer glue spreading device provided by the utility model Figure 2 ;

[0019] Figure 3 A schematic diagram of a wafer coating device provided by the utility model Figure 3 ;

[0020] Figure ID:

[0021] 10: cover plate; 20: wafer; 30: substrate; 40: bracket. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0023] The utility model provides a wafer glue spreading device, which can improve the uniformity of glue spreading. Figures 1 to 3 As shown, it includes a substrate 30, a wafer 20 and a cover plate 10. The wafer 20 is adsorbed on one side of the substrate 30 by vacuum adsorption. The cover plate 10 is coaxially arranged on a side away from the substrate 30 and facing the wafer 20. The diameter of the cover plate 10 is larger than the diameter of the wafer 20. The rotation directions of the cover plate 10 and the substrate 30 are controlled so that the rotation directions of the cover plate and the substrate remain the same.

[0024] Furthermore, the rotation speed of the cover plate 10 is controlled so that the rotation speed of the cover plate 10 is less than or equal to the rotation speed of the substrate 30 , and the cover plate 10 and the substrate 30 rotate in the same direction.

[0025] The term "coaxial" means that the central axes of the cover plate 10 , the base 30 , and the wafer 20 coincide with each other coaxially.

[0026] On the one hand, the structure of the cover plate 10 is adapted to the structure of the base 30 .

[0027] In one embodiment, a controller (not shown) is further included, and the cover plate 10 is connected to the controller to control the rotation speed of the cover plate 10 to be less than or equal to the rotation speed of the base 30 .

[0028] In one embodiment, the controller is a drive motor.

[0029] In another embodiment, the cover plate 10 is driven by a rotation mechanism of the base 20 .

[0030] Furthermore, in one embodiment, the substrate 30 may be a vacuum chuck to achieve adsorption of the wafer 20 , or close adsorption.

[0031] like Figure 1As shown, the cover plate 10 is arranged on one side of the wafer 20, and in order to solve the "wave" texture problem pointed out in the background technology part of this application, the rotation speed of the cover plate 10 is limited to be less than or equal to the rotation speed of the base 30, and further, the distance between the cover plate 10 and the wafer 20 is limited to be less than or equal to 1cm, 0.5cm, 5mm, etc., so as to further improve the air fluidity at the edge of the wafer 20. In this way, the air flow rate on the upper surface of the wafer 20 is always greater than the rotation speed of the wafer 20 itself, so as to achieve the effect of reducing the air resistance of the wafer, thereby reducing the generation of "wave" texture and improving the effect of wafer glue spreading, which is beneficial compared with the prior art and has certain beneficial technical effects.

[0032] During the process of glue spreading, the cover plate 10 and the base 30 are controlled to rotate, thereby driving the wafer 20 and the base 30 to rotate synchronously, and the rotation speed is controlled so that the rotation speed of the cover plate 10 is always less than or equal to the base 30, and the air resistance is changed by changing the air flow state above the wafer, so as to overcome the problem that the prior art cannot control the glue spreading of lower thickness by changing the rotation speed. In particular, in the present application, for a film with a thickness of less than 50nm, the method of the present application can prepare a glue spreading layer with a thickness of less than 100nm, even less than 80nm, or less than 50nm; especially for a glue spreading layer with a thickness of less than 50nm, the present application can significantly improve the glue spreading effect, and to a certain extent, improve the "wave" texture. Compared with the prior art, the thickness of the film after glue spreading can be significantly reduced, and a glue spreading layer with a thickness of less than 100nm, even less than 80nm, or less than 50nm can be prepared.

[0033] In the first embodiment, Figure 2 As shown, the cover plate 10 is connected to the bracket 40 via a lifting and rotating rod, which is controlled by a controller to drive the cover plate 10 to lift and / or rotate around an axis. The controller controls the rotation rate of the cover plate 10, as well as the distance between the cover plate 10 and the wafer 20, to achieve control of the rotation speed and the distance between the two; the rotation speed is controlled so that the rotation speed of the cover plate 10 is always less than or equal to the substrate 30.

[0034] Furthermore, both sides of the bracket 40 are fixed to one side of the glue machine frame (the glue machine frame is not shown in the figure) to achieve the fixation of the bracket. Of course, the bracket 40 can be connected to one end of the glue machine platform through a connecting rod, such as the bracket 40 is connected to the glue machine platform on the side of the base 30 through a connecting rod; on the other hand, the frame 40 is connected to the glue machine platform surface on the upper part of the frame 40 through a connecting rod to achieve the fixation of the bracket 40.

[0035] In this embodiment, the controller is connected to the cover plate 10 and is used to drive the cover plate to rotate and / or lift. The controller is such as a motor, or a controller with the same function, etc., mainly to achieve the ability to drive the cover plate. To this end, technicians in this field can make appropriate improvements, all of which are within the scope of the controller of this application.

[0036] In one embodiment, if Figure 2 As shown, the bottom surface of the cover plate 10 is a circular plane, and a truncated cone structure adapted to the base is formed by the circular bottom surface. For example, the truncated cone structure has a stepped shape, which is the same as the structure of the base. The circular bottom surface of the cover plate 10 is opposite to the surface of the wafer 20, and the wafer 20 is located below the bottom surface of the cover plate 10. The diameter of the cylindrical bottom surface is greater than the diameter of the wafer; further, the spacing between the cover plate 10 and the wafer 20 is limited to be less than or equal to 5 mm;

[0037] In another embodiment, the cover plate 10 is a hollow cover plate with a cavity, and the wafer 20 can be placed in the cavity. The cover plate 10 covers the wafer 20 to form an integrally rotating mechanism, so that the wafer 20 is accommodated in the cover plate. Furthermore, it is defined that the inner diameter of the cover plate 10 is greater than the diameter of the wafer 20.

[0038] The device based on the present application can control the airflow on the upper surface of the wafer during the spin coating process, reduce the influence of the airflow on the spin coating process, and achieve the effect of removing the wave pattern; by controlling its rotation speed so that the rotation speed of the cover plate is always greater than or equal to the substrate, the "wave" pattern can be effectively solved, thereby significantly reducing the thickness of the film after uniform coating, achieving spin coating of an imprinted adhesive film below 50nm, and having a good spin coating effect.

[0039] The above specific implementations do not constitute a limitation on the protection scope of the present utility model. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A wafer coating device capable of improving the uniformity of wafer coating, comprising a substrate and a wafer, characterized in that: It also includes a cover plate, the wafer is adsorbed on one side of the base by vacuum adsorption, the cover plate is coaxially arranged on a side away from the base and facing the wafer, and the diameter of the cover plate is larger than the diameter of the wafer; the rotation direction of the cover plate and the base is controlled so that the rotation directions of the cover plate and the base remain the same.

2. A wafer coating device according to claim 1, characterized in that: The rotation speed of the cover plate is controlled so that the rotation speed of the cover plate is less than or equal to the rotation speed of the substrate.

3. A wafer coating device according to claim 1 or 2, characterized in that: A controller is also included, and the cover plate is connected to the controller to control the rotation speed of the cover plate to be less than or equal to the rotation speed of the base.

4. A wafer coating device according to claim 1 or 2, characterized in that: The distance between the cover plate and the wafer is less than or equal to 5 mm.

5. A wafer coating device according to claim 1 or 2, characterized in that: It also includes a lifting and rotating rod, through which the cover plate is connected to the bracket, and the lifting and rotating rod drives the lifting and / or rotation of the cover plate; the bracket is fixedly connected to the surface of the glue leveling machine platform.

6. A wafer coating device according to claim 1 or 2, characterized in that: The cover plate is a truncated cone formed by a circular bottom surface adapted to the base, and the circular bottom surface is arranged opposite to the surface of the wafer.

7. The wafer coating device according to claim 6, characterized in that: The diameter of the cylindrical bottom surface is greater than the diameter of the wafer.

8. A wafer coating device according to claim 1 or 2, characterized in that: The cover plate is a hollow cover plate with a cavity, and the wafer is placed in the cavity so that the cover plate covers the wafer.

9. The wafer coating device according to claim 7, characterized in that: The inner diameter of the cover plate is greater than the diameter of the wafer.

10. The wafer coating device according to claim 3, characterized in that: The controller is a driving motor.

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