Wafer photoresist defoaming device and method

Abstract

The invention relates to the technical field of semiconductor manufacturing, in particular to a wafer photoresist defoaming device and method.The wafer photoresist defoaming device comprises a container, and a bracket used for containing a wafer coated with photoresist is arranged in the container; volatile liquid is further contained in the container, the liquid level of the volatile liquid is located below the bracket, and the volatile liquid is used for fumigating to soften the photoresist, so that bubbles in the photoresist are squeezed to the surface of the photoresist. According to the device, the wafer coated with the photoresist is fumigated before soft baking, the volatile liquid can volatilize and soften the photoresist, bubbles in the photoresist are squeezed to the surface of the photoresist, then in the soft baking process, the volatile liquid can volatilize, the softened photoresist can level and fill the positions of the bubbles on the surface of the photoresist, and the bubbles on the surface of the photoresist are fully filled with the volatile liquid. Therefore, bubbles in the photoresist can be removed, the yield is improved, and the device is simple in structure, low in equipment investment, low in consumable cost and low in operation complexity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor manufacturing, in particular to a wafer photoresist bubble removing device and method. BACKGROUND

[0002] The existing wafer photoresist coating methods are mainly divided into spraying and spin coating, and the photoresist is prone to produce micro-bubbles in the coating process due to solvent volatilization, uneven coating speed, etc., especially the spraying method is prone to produce bubbles, which causes pattern defects after development to affect the subsequent process. At present, the method for reducing the bubbles of wafer photoresist is mainly realized by mechanical vibration method, ultrasonic treatment, chemical soaking method, vacuum degassing method or by adjusting the process parameters of the photoresist coating machine. SUMMARY

[0003] The purpose of the present application is to provide a wafer photoresist bubble removing device and method, which can realize wafer photoresist bubble removing without affecting the original photoetching process and improve the yield.

[0004] To achieve the above purpose, the technical scheme of the present application is a wafer photoresist bubble removing device, which comprises a container, a bracket for placing the wafer after coating photoresist is arranged in the container; a volatile liquid is also contained in the container, and the liquid level of the volatile liquid is below the bracket, which is used for fumigation to soften the photoresist, so as to squeeze the bubbles in the photoresist to the surface of the photoresist.

[0005] As one of the embodiments, the bracket has multiple layers and is arranged in vertical direction.

[0006] As one of the embodiments, a fixing frame is also arranged in the container, and the bracket is fixed on the fixing frame.

[0007] As one of the embodiments, an upper cover is arranged on the top of the container, and the fixing frame is fixed on the upper cover or the container.

[0008] As one of the embodiments, the volatile liquid is at least one of ketone, ester and alcohol ether.

[0009] As one of the embodiments, the volatile liquid is acetone.

[0010] As one of the embodiments, the container is made of a material which is transparent and resistant to corrosion of the volatile liquid.

[0011] As one of the embodiments, the container is provided with a liquid inlet and a liquid outlet.

[0012] The application also provides a wafer photoresist bubble removing method, comprising the following steps:

[0013] S1, providing a wafer coated with photoresist;

[0014] S2, fumigating the wafer coated with photoresist by using a volatile liquid capable of softening the photoresist;

[0015] S3, soft baking the fumigated wafer.

[0016] As one of the embodiments, in step S2, the fumigation time is determined according to the ambient temperature, the type of the photoresist and the thickness of the photoresist.

[0017] Compared with the prior art, the application has the following beneficial effects:

[0018] (1) The device of the application is used to fumigate the wafer coated with photoresist before soft baking, the volatile liquid can volatilize and soften the photoresist, so that the bubbles in the photoresist are squeezed to the surface of the photoresist, then in the soft baking process, the volatile liquid volatilizes, the softened photoresist flows flat and fills the bubble positions on the surface of the photoresist, so that the bubbles in the photoresist are removed, the yield is improved, and the device has simple structure, low equipment investment, low consumable cost and low operation complexity;

[0019] (2) The application can effectively eliminate the bubble defects in photoresists of different components (such as positive resist / negative resist), different thicknesses and different curing degrees by using the characteristic that the volatile liquid can soften the photoresist, and has wide applicability to various photoresist systems;

[0020] (3) The application does not need to make any adjustment to the existing photoetching process (including exposure, development, baking parameters and clean room environment), and can be directly implemented in the original production line after the photoresist coating process, so as to ensure the process stability and yield. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only constitute some embodiments of the application, and those skilled in the art can also obtain other drawings according to these drawings without creative effort.

[0022] Figure 1 The structure diagram of the wafer photoresist bubble removing device provided by the embodiment of the application;

[0023] Figure 2 The partial perspective view of the wafer photoresist bubble removing device provided by the embodiment of the application;

[0024] Figure 3The flow chart of the wafer photoresist bubble removing method provided by the embodiment of the present application;

[0025] Figure 4 The flow chart of the wafer photoresist bubble removing method provided by the embodiment of the present application, wherein a) is the wafer after photoresist coating, b) is the wafer after fumigation, and c) is the wafer after soft baking;

[0026] In the figure: 1, wafer; 2, photoresist; 3, bubble; 4, container; 5, upper cover; 6, volatile liquid; 7, bracket; 8, fixing frame; 9, liquid inlet; 10, liquid outlet; 11, scale. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0028] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0029] The terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features; in the description of the present application, unless otherwise specified, the meaning of "multiple" is two or more.

[0030] As Figures 1-2As shown, the embodiment provides a wafer photoresist bubble removing device, which comprises a container 4, wherein a bracket 7 for placing a wafer 1 coated with photoresist 2 is arranged in the container 4; a volatile liquid 6 is also arranged in the container 4, and the liquid level of the volatile liquid 6 is below the bracket 7, which is used for fumigation to soften the photoresist 2, so as to squeeze the bubbles in the photoresist 2 to the surface of the photoresist 2. The device of the embodiment is used for fumigation treatment of the wafer 1 coated with photoresist 2 before soft baking, the volatile liquid 6 can volatilize and soften the photoresist 2, so that the bubbles 3 in the photoresist 2 are squeezed to the surface of the photoresist 2, then in the soft baking process, the volatile liquid 6 volatilizes, the softened photoresist 2 flows flat and fills the bubble 3 position on the surface of the photoresist 2, so that the bubbles 3 in the photoresist 2 are removed, the yield is improved, and the device has simple structure, low equipment investment, low consumable cost and low operation complexity.

[0031] In some embodiments, the bracket 7 has multiple layers and is arranged in a vertical direction. As shown in Figure 1 and Figure 2 By arranging the multiple layers of brackets 7, multiple wafers 1 coated with photoresist 2 can be treated at the same time, the wafer photoresist bubble removing efficiency is improved, and batch production is realized; and the lowermost bracket 7 is also located above the liquid level of the volatile liquid 6, so that the volatile liquid 6 does not contact the wafer 1.

[0032] As shown in Figure 1 and Figure 2 Three layers of brackets 7 are arranged in the container 4 in a vertical direction, the spacing between adjacent brackets 7 is greater than the thickness of the wafer 1 coated with photoresist 2, and one wafer 1 coated with photoresist 2 can be placed on each bracket 7, so that three wafers 1 coated with photoresist 2 can be treated at the same time, and the fumigation treatment efficiency is greatly improved.

[0033] In some embodiments, the container 4 is further provided with a fixing frame 8, and the bracket 7 is fixed on the fixing frame 8. The fixing frame 8 is arranged in the container 4 to facilitate fixing the bracket 7; when the bracket 7 has multiple layers, each bracket 7 is connected with the fixing frame 8, so as to form an integral whole and facilitate placement.

[0034] Further, the top of the container 4 is provided with an upper cover 5, and the fixing frame 8 is fixed on the upper cover 5 or the container 4.

[0035] In some embodiments, the fixing frame 8 is fixed on the upper cover 5. As shown in Figure 1 and Figure 2As shown, the bracket 7 is fixed at the bottom of the fixing frame 8, and the top of the fixing frame 8 is fixed to the bottom surface of the upper cover 5, so that when the upper cover 5 is closed or opened, the bracket 7 and the wafer 1 to be fumigated thereon can be put into or taken out of the container 4 synchronously, which can simplify the operation process and improve the processing efficiency.

[0036] In some other embodiments, the fixing frame 8 is fixed to the container 4. Specifically, a step portion can be arranged on the inner wall of the top of the container 4, and a support portion is arranged on the top of the fixing frame 8. When fumigation is needed, the wafer 1 to be fumigated is first placed on the bracket 7, and then the fixing frame 8 is placed into the container 4, so that the support portion of the fixing frame 8 is just placed on the step portion on the inner wall of the container 4, thereby the fixing frame 8 is placed in the container 4, and then the upper cover 5 is closed. After fumigation, the upper cover 5 is opened, and then the fixing frame 8 is taken out of the container 4. The opening and closing of the upper cover 5 does not affect the placement of the fixing frame 8 and the bracket 7.

[0037] Specifically, as shown in the drawings, Figure 2 The fixing frame 8 includes four vertical connecting rods arranged in a circumferential direction, and each bracket 7 includes two horizontal rods arranged horizontally, wherein the two ends of one of the horizontal rods are connected to the bottom of two of the connecting rods, and the two ends of the other horizontal rod are connected to the bottom of the other two connecting rods. The distance between the two horizontal rods is less than the diameter of the wafer 1. When the fixing frame 8 is fixed to the upper cover 5, the top of the four connecting rods can be directly fixed to the bottom surface of the upper cover 5. When the fixing frame 8 is fixed to the container 4, a support portion can be arranged on the outside of the top of each of the four connecting rods, and a corresponding step portion can be arranged on the inner wall of the top of the container 4, and the support portion is placed on the corresponding step portion to fix the fixing frame 8 to the container 4.

[0038] In some embodiments, the volatile liquid is at least one of ketones, esters, and alcohol ethers. Specifically, the ketones can be acetone, the esters can be ethyl acetate, and the alcohol ethers can be ethylene glycol monomethyl ether. A compound solution of ketones, esters, and alcohol ethers can also be used to precisely control the evaporation speed and solubility, and adapt to different types of photoresist.

[0039] Preferably, the volatile liquid 6 is acetone. Acetone is a volatile organic solvent that can volatilize and effectively reduce the glass transition temperature of the photoresist 2, so that the photoresist 2 is temporarily softened at the process temperature. The bubbles 3 inside the photoresist 2 will be squeezed to the surface of the photoresist 2 during the softening process. Then, during the soft baking process, the acetone will volatilize, the softened photoresist 2 will flow and fill the position of the bubbles 3 on the surface of the photoresist 2, thereby removing the bubbles 3 in the photoresist 2. The acetone can be a standard laboratory grade acetone reagent.

[0040] In some embodiments, the container 4 is made of a material that is transparent and resistant to the volatile liquid 6. The container 4 made of a material that is transparent and resistant to the volatile liquid 6 is not only transparent, which is convenient for observing the injection depth of the volatile liquid 6 before fumigation, the relationship between the liquid level of the volatile liquid 6 and the height of the bracket 7, and the surface condition of the photoresist 2 on the wafer 1 during fumigation, but also resistant to the volatile liquid 6, which can effectively avoid the performance degradation of the container 4 due to long-term exposure to the volatile liquid 6 steam, and improve the long-term service life of the equipment. Preferably, the material that is transparent and resistant to the volatile liquid 6 can be quartz glass, or fluoroplastic such as fluorinated ethylene propylene, polytrifluorochloroethylene, etc.

[0041] Further, the outer wall of the container 4 is engraved with a capacity scale 11 for monitoring the capacity of acetone.

[0042] In this embodiment, the upper cover 5, the bracket 7, and the fixing frame 8 are also made of a material that is resistant to the volatile liquid 6, which can improve the long-term service life of the equipment.

[0043] In some embodiments, the container 4 is provided with a liquid inlet 9 and a liquid outlet 10. Specifically, the liquid inlet 9 is arranged on the side wall of the container 4 for injecting the volatile liquid 6, and the liquid outlet 10 is arranged on the bottom surface of the container 4 for discharging the volatile liquid 6. Further, the liquid inlet 9 and the liquid outlet 10 are both provided with a detachable composite rubber sealing body, so as to seal the liquid inlet 9 and the liquid outlet 10 by installing the composite rubber sealing body during fumigation treatment, open the liquid inlet 9 by detaching the composite rubber sealing body of the liquid inlet 9 when it is necessary to add the volatile liquid 6, and open the liquid outlet 10 by detaching the composite rubber sealing body of the liquid outlet 10 when it is necessary to discharge the volatile liquid 6. As shown in Figure 1 and Figure 2 When the fixing frame 8 is fixed to the upper cover 5 for use, the composite rubber sealing body of the liquid inlet 9 is first taken out, a certain amount of acetone is injected into the container 4, the capacity of the acetone is ensured not to be higher than the height of the bracket 7, the cover is taken out, the wafer 1 is placed on the bracket 7, the cover is placed on the container 4, the wafer 1 is taken out after fumigation for a certain time, and the wafer 1 after fumigation is transferred to the original position for soft baking.

[0044] As shown in Figure 3 The embodiment also provides a wafer photoresist bubble removing method, which comprises the following steps:

[0045] S1, providing a wafer 1 coated with a photoresist 2;

[0046] S2, fumigating the wafer 1 coated with the photoresist 2 with a volatile liquid 6 capable of softening the photoresist 2;

[0047] S3, soft baking the wafer 1 after fumigation.

[0048] The embodiment fumigates the wafer 1 coated with photoresist 2 before soft baking, softens the photoresist 2 by using volatile liquid 6, and extrudes the bubbles 3 in the photoresist 2 to the surface of the photoresist 2, and then evaporates the excess volatile liquid 6 by soft baking, and levels the softened photoresist 2 and fills the bubble 3 position on the surface of the photoresist 2, thereby removing the bubbles 3 in the photoresist 2; and the embodiment can effectively eliminate the bubble 3 defects in the photoresist 2 of different components (such as positive resist / negative resist), different thicknesses and different curing degrees by using the characteristic that the volatile liquid 6 can soften the photoresist 2, has wide applicability to various photoresist 2 systems, and also does not need to make any adjustment to the existing photoetch process flow (including exposure, development, baking parameters and clean room environment), and can be directly embedded in the original production line after the photoresist 2 coating process, thereby ensuring process stability and yield.

[0049] In some embodiments, step S2 uses the wafer photoresist bubble removal device described in any one of the above embodiments, places the volatile liquid 6 capable of softening the photoresist 2 in the container, places the wafer 1 coated with photoresist 2 on the bracket in the container, and fumigates the wafer 1 coated with photoresist 2. The volatile liquid 6 and the simple wafer photoresist bubble removal device can realize defect repair through a simple gas phase treatment process, and have the advantages of less equipment investment, low consumable cost, and low operation complexity compared with traditional mechanical or chemical treatment schemes. The specific fumigation time can be changed according to the ambient temperature, the type of the photoresist 2, and the thickness of the photoresist 2.

[0050] Further, in step S2, the fumigation time is determined according to the ambient temperature, the type of the photoresist 2, and the thickness of the photoresist 2, to avoid incomplete bubble elimination due to insufficient fumigation time and photoresist peeling due to excessive fumigation time.

[0051] Further, in step S3, the temperature and time of soft baking can be adjusted according to the soft baking conditions of the original process, so that the excess solvent can be evaporated by high-temperature baking, and the softened photoresist 2 is leveled and filled in the bubble 3 position on the surface of the photoresist 2.

[0052] The method of the present application will be described in detail below through a specific embodiment.

[0053] A wafer photoresist bubble removal method, comprising the following steps:

[0054] S1, providing a wafer 1 coated with photoresist 2;

[0055] S2, using Figures 1-2The shown wafer photoresist bubble removing device first takes out the composite rubber sealing body of the liquid inlet 9, injects a certain amount of acetone into the container 4, ensures that the liquid level of the acetone is not higher than the height of the lowest bracket 7, then takes off the upper cover 5, places the wafer 1 on each layer of bracket 7 respectively, covers the container 4 with the upper cover 5, and carries out fumigation treatment; after the fumigation treatment, the upper cover 5 is taken off, and the wafer 1 is taken out;

[0056] S3, the wafer 1 after fumigation is soft-baked at 90℃ for 60s.

[0057] The above only describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A wafer photoresist debubbling device, characterized in that: The container is internally provided with a cradle for placing the wafer coated with photoresist; the container is also filled with volatile liquid, and the liquid level of the volatile liquid is below the cradle for fumigation to soften the photoresist and squeeze the air bubbles in the photoresist to the surface of the photoresist.

2. The wafer photoresist bubble removing device of claim 1, wherein: The cradle has multiple layers and is arranged in vertical direction.

3. The wafer photoresist bubble removing device of claim 1 or 2, wherein: The container is also internally provided with a fixing frame, and the cradle is fixed on the fixing frame.

4. The photoresist bubble removing apparatus for wafer as claimed in claim 3, wherein: The top of the container is provided with an upper cover, and the fixing frame is fixed on the upper cover or the container.

5. The wafer photoresist bubble removing device of claim 1, wherein: The volatile liquid is at least one of ketone, ester and alcohol ether.

6. The photoresist bubble removing apparatus for wafer as claimed in claim 5, wherein: The volatile liquid is acetone.

7. The wafer photoresist bubble removing device of claim 1, wherein: The container is made of transparent material resistant to corrosion of the volatile liquid.

8. The wafer photoresist bubble removing apparatus of claim 1, wherein: The container is provided with a liquid inlet and a liquid outlet.

9. A method for removing a bubble from a photoresist of a wafer, the method comprising: The method comprises the following steps: S1, providing a wafer coated with photoresist; S2, fumigating the wafer coated with photoresist with volatile liquid capable of softening the photoresist; S3, soft baking the wafer after fumigation.

10. The method of claim 9, wherein the method further comprises: determining a location of the bubble on the wafer; and determining a location of the bubble on the wafer. In step S2, the fumigation time is determined according to the ambient temperature, the type of photoresist and the thickness of photoresist.

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