Wafer cleaning and drying method and wafer cleaning and drying device

Abstract

The present disclosure provides a wafer cleaning and drying method and a wafer cleaning and drying device. The wafer cleaning and drying method comprises the following steps: providing a cleaning tank storing cleaning liquid, immersing a wafer vertically in the cleaning liquid, continuously injecting cleaning liquid to allow excess cleaning liquid to flow out from an overflow port above the cleaning tank, allowing the cleaning liquid to be discharged from a lower drain port in a slow drainage mode, closing the drain port when the liquid level of the cleaning liquid drops to above the wafer, injecting a liquid volatile solvent into the liquid surface in a two-stage manner to form a two-liquid phase layer, opening the drain port again to discharge the cleaning liquid in a slow drainage mode, discharging the cleaning liquid in a fast drainage mode when the liquid level of the liquid volatile solvent is lower than the lowest position of the wafer, and introducing high-temperature nitrogen gas from the top of the cleaning tank to blow dry the wafer.

Description

[Technical field]

[0002] The present disclosure relates to a cleaning and drying method and a cleaning and drying device, and more particularly to a wafer cleaning and drying method and a wafer cleaning and drying device. [Background technology]

[0004] In the prior art, after a wafer is cleaned using a wet process, the wafer must be dried immediately to facilitate subsequent processes.

[0005] Specifically, since the finished products after wafer processing are all at the nanometer level, the particles or chemicals remaining on the surface of the wafer during the processing will seriously affect the yield of the finished wafer products and need to be effectively removed from the surface of the wafer.

[0006] When a wafer is cleaned using a wet process, the wafer is immersed in a cleaning solution in a cleaning tank, and the remaining particles or chemicals are removed by rinsing with the cleaning solution. The cleaned wafer also needs to be effectively dried before the subsequent process can be carried out.

[0007] Therefore, how to complete the cleaning and drying operations of the wafer in the shortest possible time is an urgent problem to be solved in the industry. [Summary of the invention]

[0009] An object of the present disclosure is to provide a wafer cleaning and drying method and a wafer cleaning and drying device, which can effectively remove particles or chemicals remaining on the wafer and shorten the working time of drying the wafer, thereby completing the wafer cleaning and drying operations in the shortest time.

[0010] To achieve the above-mentioned purpose, a wafer cleaning and drying method disclosed herein comprises the following steps:

[0011] Providing a cleaning tank storing a cleaning solution;

[0012] Immerse the wafer vertically into the cleaning solution;

[0013] Continuously inject cleaning liquid from the water inlet below the cleaning tank so that excess cleaning liquid flows out from the overflow port above the cleaning tank;

[0014] Close the water inlet and open the drain at the bottom of the cleaning tank to allow the cleaning liquid to drain in a slow drainage mode;

[0015] When the liquid level of the cleaning solution drops to above the wafer, the drain port of the cleaning tank is closed;

[0016] Injecting a liquid volatile solvent into the liquid surface of the cleaning liquid in a two-stage manner to form two liquid phase layers;

[0017] Open the drain again and drain the cleaning fluid in slow drain mode;

[0018] When the liquid level of the liquid volatile solvent is below the lowest position of the wafer, the cleaning solution is discharged in a fast drainage mode; and

[0019] High-temperature nitrogen is introduced from the top of the cleaning tank to dry the wafer;

[0020] The steps of injecting the liquid volatile solvent in two stages are:

[0021] Initially injecting the liquid volatile solvent so that the liquid volatile solvent has a first height;

[0022] Allowing the liquid volatile solvent to stand; and

[0023] The liquid volatile solvent is injected again to make the liquid volatile solvent reach a second height.

[0024] In the wafer cleaning and drying method disclosed in the present invention, the first height of the liquid volatile solvent is between 5 and 6 mm, and the second height of the liquid volatile solvent is between 10 and 15 mm.

[0025] In the wafer cleaning and drying method disclosed herein, the flow rate of the slow drainage mode is between 3.5 and 5 L / M.

[0026] In the wafer cleaning and drying method disclosed herein, when high-temperature nitrogen is introduced to dry the wafer, the flow rate of the high-temperature nitrogen is between 380 and 430 L / M.

[0027] In the wafer cleaning and drying method disclosed herein, when high-temperature nitrogen is introduced from the top of the cleaning tank to blow dry the wafer, an exhaust step is further included, in which the high-temperature nitrogen is simultaneously exhausted through an exhaust system at the bottom of the cleaning tank, and the exhaust pressure of the exhaust system is between 60 and 90 Pa.

[0028] In the wafer cleaning and drying method disclosed in the present invention, the cleaning liquid is heated deionized water, and the liquid volatile solvent is liquid isopropyl alcohol.

[0029] To achieve the above-mentioned purpose, a wafer cleaning and drying device disclosed in the present invention comprises a cleaning tank, a support, and a liquid volatile solvent introduction pipeline. The cleaning tank stores cleaning liquid, and the cleaning tank has a water inlet arranged at the bottom, an overflow port arranged at the top, and a drain port arranged at the bottom. The support is arranged in the cleaning tank to vertically support the wafer. The liquid volatile solvent introduction pipeline is used to introduce the liquid volatile solvent from the periphery above the cleaning tank.

[0030] In the wafer cleaning and drying device disclosed in the present invention, a guide plate is further arranged above the cleaning tank. When the liquid volatile solvent flows out of the liquid volatile solvent inlet pipeline, the guide plate is used to guide the liquid volatile solvent to be directly injected into the liquid surface of the cleaning liquid.

[0031] The wafer cleaning and drying device disclosed in the present invention further includes an exhaust system disposed at the bottom of the cleaning tank.

[0032] In the wafer cleaning and drying device disclosed in the present invention, the cleaning liquid is heated deionized water, and the liquid volatile solvent is liquid isopropyl alcohol.

[0033] In order to make the above contents of the present disclosure more clearly understandable, the following is a detailed description of the preferred embodiments in conjunction with the accompanying drawings as follows:

Brief Description of the Drawings

[0035] Figure 1 FIG. 1 is a step diagram of the wafer cleaning and drying method disclosed herein.

[0036] Figure 2 This is a diagram showing the steps of injecting a liquid volatile solvent in a two-stage manner in the wafer cleaning and drying method disclosed herein.

[0037] Figures 3 to 11 To correspond to Figure 1 Schematic diagram of the process.

[0038] Figure 12 to Figure 13 It is a schematic diagram of a guide plate disposed above a cleaning tank in the wafer cleaning and drying device disclosed herein. [Specific implementation method]

[0040] In order to make the above and other purposes, features, and advantages of the present disclosure more clearly understood, the preferred embodiments of the present disclosure are specifically cited below, and are described in detail in conjunction with the accompanying drawings. Furthermore, the directional terms mentioned in the present disclosure, such as up, down, top, bottom, front, back, left, right, inside, outside, side layer, periphery, center, horizontal, lateral, vertical, longitudinal, axial, radial, topmost or bottommost, etc., are only referenced to the directions of the attached drawings. Therefore, the directional terms used are used to illustrate and understand the present disclosure, but are not used to limit the present disclosure.

[0041] In the figures, structurally similar elements are denoted by the same reference numerals.

[0042] The present invention discloses a wafer cleaning and drying method and a wafer cleaning and drying device, which can effectively remove particles or chemicals remaining on the wafer and shorten the working time of drying the wafer, thereby completing the cleaning and drying operation of the wafer in the shortest time.

[0043] In the diagram, Figure 1 FIG. 1 is a step diagram of the wafer cleaning and drying method disclosed herein. Figures 2 to 11 Corresponding to Figure 1 Schematic diagram of the steps.

[0044] In detail, Figure 1 As shown, a wafer cleaning and drying method disclosed herein comprises the following steps:

[0045] S1: Provide a cleaning tank containing cleaning fluid.

[0046] like Figure 3 As shown, a cleaning tank 110 containing cleaning liquid 200 is provided, and the cleaning liquid 200 is injected from a water inlet 112 at the bottom of the cleaning tank 110 .

[0047] S2: Immerse the wafer vertically into the cleaning solution.

[0048] like Figure 4 As shown, after the cleaning liquid 200 in the cleaning tank 110 is injected to a certain height, the wafer 300 is vertically immersed in the cleaning liquid 200 so that the wafer 300 is supported by the support 120 and the wafer 300 is completely immersed in the cleaning liquid 200 .

[0049] S3: Continuously inject cleaning liquid from the water inlet below the cleaning tank, so that excess cleaning liquid flows out from the overflow port above the cleaning tank.

[0050] Please also read Figure 5 When the wafer 300 is vertically immersed in the cleaning liquid 200 and the wafer 300 is completely immersed in the cleaning liquid 200, the cleaning liquid 200 is still continuously injected from the water inlet 112 below the cleaning tank 110 to rinse the wafer 300. In this way, the cleaning liquid 200 with particles or chemicals after rinsing the wafer 300 will be pushed by the newly injected cleaning liquid 200 below the cleaning tank 110 and become redundant cleaning liquid 200, and then flow out from the overflow port 114 above the cleaning tank 110.

[0051] That is, particles or chemicals remaining on the surface of the wafer 300 during the wafer processing process can be effectively removed at this stage.

[0052] After the wafer 300 is cleaned, there are other subsequent processing steps. Therefore, the cleaned wafer 300 needs to be dried quickly to ensure that the subsequent related processing steps can proceed smoothly. Therefore, the subsequent drying steps are described below:

[0053] S4: Close the water inlet and open the drain port at the bottom of the cleaning tank to allow the cleaning liquid to be discharged in a slow drainage mode.

[0054] like Figure 6 As shown, since the particles or chemicals remaining on the surface of the wafer 300 have been effectively removed in the previous steps, after closing the water inlet 112, the drain port 116 at the bottom of the cleaning tank 110 will be opened to allow the cleaning liquid 200 to be discharged from the bottom of the cleaning tank 110 in a slow drainage mode.

[0055] S5: When the liquid level of the cleaning solution drops to above the wafer, the drain port of the cleaning tank is closed.

[0056] Then, if Figure 7 As shown, when the cleaning liquid 200 is discharged from the bottom of the cleaning tank 110 in a slow drainage mode and the liquid level of the cleaning liquid 200 drops to above the wafer 300 , the drain port 116 of the cleaning tank 110 is closed.

[0057] S6: Injecting a liquid volatile solvent into the liquid surface of the cleaning liquid in a two-stage manner to form two liquid phase layers.

[0058] like Figure 8 As shown, when the liquid level of the cleaning solution 200 drops to above the wafer 300 and the drain port 116 of the cleaning tank 110 is closed, the liquid volatile solvent 400 is injected into the liquid level of the cleaning solution 200 in two stages to form two liquid phase layers.

[0059] S7: Open the drain port again and drain the cleaning fluid in slow drainage mode.

[0060] like Fig. 9 As shown, after the two liquid phase layers are formed, the drain port 116 is opened again, and the cleaning liquid 200 is discharged in the slow drainage mode. In this way, during the slow discharge of the cleaning liquid 200, the liquid volatile solvent 400 will be able to completely contact the wafer 300 from top to bottom and gradually evaporate. Since the liquid volatile solvent 400 will also take away the moisture and impurities remaining on the wafer 300 during the volatilization process, this step will effectively complete the drying operation of the wafer 300.

[0061] S8: When the liquid level of the liquid volatile solvent is lower than the lowest position of the wafer, the cleaning liquid is discharged in a fast drainage mode.

[0062] Then, if Fig.10 As shown, when the liquid level of the liquid volatile solvent 400 is lower than the lowest position of the wafer 300, it means that the liquid volatile solvent 400 has covered the entire surface of the wafer 300 and is no longer affected by the cleaning liquid 200. Therefore, the cleaning liquid 200 can be discharged from the cleaning tank 110 in a fast drainage mode to facilitate the subsequent operation of removing the wafer 300 from the cleaning tank 110.

[0063] S9: Introduce high-temperature nitrogen gas from the top of the cleaning tank to dry the wafer.

[0064] Finally, if Fig.11 As shown, after the cleaning liquid 200 is completely discharged from the cleaning tank 110 , high-temperature nitrogen 500 may be introduced from the top of the cleaning tank 110 to accelerate the volatilization of the liquid volatile solvent 400 to dry the wafer 300 .

[0065] Among them, in S6: the step of injecting the liquid volatile solvent 400 in a two-stage manner, the following steps may be further included:

[0066] S61: initially injecting the liquid volatile solvent so that the liquid volatile solvent has a first height.

[0067] S62: allowing the liquid volatile solvent to stand; and

[0068] S63: injecting the liquid volatile solvent again to make the liquid volatile solvent reach a second height.

[0069] In detail, Fig.12 As shown, in the initial process of injecting the liquid volatile solvent 400 into the liquid surface of the cleaning liquid 200 , the liquid surface of the cleaning liquid 200 will present an uneven turbidity phenomenon, so only a small amount of the liquid volatile solvent 400 with a first height H1 will be injected in the stage S61 .

[0070] Next, as shown in step S62, the liquid volatile solvent 400 is left to stand for a first time so that the cleaning liquid 200 and the liquid volatile solvent 400 present an initial two-phase layer, and then Fig.13 As shown in step S63, the liquid volatile solvent 400 is injected again to make the liquid volatile solvent 400 reach the second height H2.

[0071] At this time, since the liquid volatile solvent 400 is already above the initial two liquid phase layers after standing in step S62, the liquid volatile solvent 400 injected again in step S63 will not come into contact with the liquid surface of the cleaning liquid 200, thereby avoiding the occurrence of turbidity and shortening the waiting time for the standing liquid volatile solvent 400.

[0072] In other words, in the present disclosure, the step of injecting the liquid volatile solvent 400 in two stages is used to shorten the waiting time required for the liquid volatile solvent to be left standing after being injected to the liquid surface of the cleaning liquid in the prior art, thereby improving the working efficiency of the wafer cleaning and drying device method.

[0073] In the wafer cleaning and drying method disclosed in the present invention, the first height H1 of the liquid volatile solvent 400 injected in the first stage is between 5 and 6 mm. This height prevents the liquid volatile solvent 400 injected in the second stage from contacting the cleaning solution 200, thereby effectively avoiding turbidity. After the liquid volatile solvent 400 is injected in the second stage, the second height H2 (i.e., the total height) of the liquid volatile solvent 400 is between 10 and 15 mm, so as to ensure that the liquid volatile solvent 400 is not in contact with the cleaning solution 200. Fig. 9In step S7 shown, when the liquid volatile solvent 400 contacts the wafer 300 from top to bottom and gradually evaporates, a sufficient amount of the liquid volatile solvent 400 can contact the wafer 300 .

[0074] In the wafer cleaning and drying method disclosed herein, the flow rate of the slow drainage mode is between 3.5 and 5 L / M. This flow rate can ensure that the liquid levels of the cleaning liquid 200 and the liquid volatile solvent 400 maintain a gentle decline during the drainage process, so that the liquid volatile solvent 400 can contact the wafer 300 and evaporate accordingly.

[0075] In the wafer cleaning and drying method disclosed herein, when the high temperature nitrogen gas 500 is introduced to dry the wafer 300, the flow rate of the high temperature nitrogen gas 500 is between 380 and 430 L / M. Furthermore, when the high temperature nitrogen gas 500 is introduced from the top of the cleaning tank 110 to dry the wafer 300, an exhaust step may be further included, wherein the high temperature nitrogen gas 500 is simultaneously exhausted through the exhaust system 140 at the bottom of the cleaning tank 110, and the exhaust pressure of the exhaust system 140 is between 60 and 90 Pa.

[0076] The introduction of high-temperature nitrogen 500 can accelerate the drying process of the wafer 300 , and the use of the exhaust system 140 helps to quickly discharge the gas containing moisture or other impurities after the liquid volatile solvent 400 evaporates, thereby avoiding contamination of the wafer 300 again.

[0077] In a preferred embodiment of the wafer cleaning and drying method disclosed herein, the cleaning liquid 200 is heated deionized water, and the liquid volatile solvent 400 is liquid isopropyl alcohol.

[0078] Please refer again Figures 3 to 11 The present disclosure also discloses a wafer cleaning and drying device 100, which includes a cleaning tank 110, a support 120 and a liquid volatile solvent introduction pipeline 130, for performing the above-mentioned Figure 1 The wafer cleaning and drying method is shown.

[0079] The cleaning tank 110 contains cleaning liquid 200, and has a water inlet 112 disposed at the bottom, an overflow port 114 disposed at the top, and a drain port 116 disposed at the bottom. The support 120 is disposed in the cleaning tank 110 to vertically support the wafer 300. The liquid volatile solvent introduction pipeline 130 is used to introduce the liquid volatile solvent 400 from the periphery of the top of the cleaning tank 110.

[0080] Please continue to read Fig.12 and Fig.13In the wafer cleaning and drying device 100 disclosed in the present invention, a guide plate 118 is further disposed above the cleaning tank 110. After the liquid volatile solvent 400 flows out of the liquid volatile solvent introduction pipeline 130, the guide plate 118 can be used to guide the liquid volatile solvent 400 to be directly injected into the liquid surface of the cleaning liquid 200. In this way, the use of the guide plate 118 can not only prevent the liquid volatile solvent 400 from being contaminated by flowing through the overflow port 114 above the cleaning tank 110, but also the liquid volatile solvent 400 guided by the guide plate 118 can reduce the turbidity generated when the liquid surface of the cleaning liquid 200 is injected, thereby shortening the waiting time required for the liquid volatile solvent to be left to stand after being injected into the liquid surface of the cleaning liquid in the prior art.

[0081] like Figures 3 to 11 As shown, the wafer cleaning and drying device disclosed in the present invention further includes an exhaust system 140, which is disposed at the bottom of the cleaning tank 110 to assist the drying operation of the wafer 300 and shorten the drying time.

[0082] In summary, through the two-stage liquid volatile solvent injection method of the wafer cleaning and drying method disclosed in the present invention, and the guide plate of the wafer cleaning and drying device, when the liquid volatile solvent is injected into the liquid surface of the cleaning liquid, it will be possible to effectively shorten the waiting time for the liquid volatile solvent and the cleaning liquid to form a stable two-liquid phase layer, and effectively remove the particles or chemicals remaining on the wafer, thereby completing the wafer cleaning and drying operations in the shortest time.

[0083] The above are only preferred implementations of the present disclosure. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principles of the present disclosure, and these improvements and modifications should also be regarded as within the scope of protection of the present disclosure.

Claims

1. A wafer cleaning and drying method, characterized in that: The following steps are involved: Providing a cleaning tank storing a cleaning solution; vertically immersing the wafer into the cleaning solution; Continuously injecting the cleaning liquid from the water inlet below the cleaning tank so that excess cleaning liquid flows out from the overflow port above the cleaning tank; The water inlet is closed, and the drain outlet at the bottom of the cleaning tank is opened to allow the cleaning liquid to be discharged in a slow drainage mode; When the liquid level of the cleaning liquid drops to above the wafer, closing the drain port of the cleaning tank; Injecting a liquid volatile solvent into the liquid surface of the cleaning liquid in a two-stage manner to form two liquid phase layers; opening the drain port again and discharging the cleaning fluid in the slow drainage mode; When the liquid level of the liquid volatile solvent is lower than the lowest position of the wafer, the cleaning liquid is discharged in a fast drainage mode; as well as Introducing high temperature nitrogen gas from above the cleaning tank to dry the wafer; Wherein, the steps of injecting the liquid volatile solvent in the two-stage manner are: Initially injecting the liquid volatile solvent so that the liquid volatile solvent has a first height; allowing the liquid volatile solvent to stand; and The liquid volatile solvent is injected again to make the liquid volatile solvent reach a second height.

2. The wafer cleaning and drying method according to claim 1, characterized in that: The first height of the liquid volatile solvent is between 5 and 6 mm, and the second height of the liquid volatile solvent is between 10 and 15 mm.

3. The wafer cleaning and drying method according to claim 1, characterized in that: The flow rate of the slow drainage mode is between 3.5 and 5 L / M.

4. The wafer cleaning and drying method according to claim 1, characterized in that: When the high temperature nitrogen gas is introduced to dry the wafer, the flow rate of the high temperature nitrogen gas is between 380 and 430 L / M.

5. The wafer cleaning and drying method according to claim 1, characterized in that: When the high-temperature nitrogen is introduced from the top of the cleaning tank to dry the wafer, a vacuum step is further included, in which the high-temperature nitrogen is simultaneously extracted through the vacuum system at the bottom of the cleaning tank, and the vacuum pressure of the vacuum system is between 60 and 90 Pa.

6. The wafer cleaning and drying method according to claim 1, characterized in that: The cleaning liquid is heated deionized water, and the liquid volatile solvent is liquid isopropyl alcohol.

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