Wafer processing apparatus and method

Abstract

The application discloses a wafer processing device and method. The wafer processing device comprises a liquid tank for containing a mixed liquid composed of a cleaning liquid and a drying liquid, and a drying tank with a cavity and an air inlet hole connected with the cavity; the cavity is used for containing the soaked wafer; and the air inlet hole is used for transmitting the vaporized drying liquid to the cavity to dry the wafer in the cavity. The application can avoid the wafer structure from being damaged during the drying process and improve the performance of the wafer.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more particularly to a wafer processing apparatus and method. Background Technology

[0002] In the wafer fabrication process, after etching the film layer in the wafer, the wafer needs to be cleaned with a cleaning solution, and then a desiccant is used to remove the cleaning solution residue on the wafer surface.

[0003] However, the wafer contains a large number of fine nanosheet structures 10, and the surface tension difference between the desiccant and the cleaning solution is significant. This can easily cause the nanosheet structures 10 to bend due to stress differences during the drying process, and may even cause the nanosheet structures 10, which need to be spaced apart, to connect. Figure 1 As shown, this damages the wafer structure and affects wafer performance. Summary of the Invention

[0004] This invention provides a wafer processing apparatus and method that can prevent structural damage during wafer drying and improve wafer performance.

[0005] This invention provides a wafer processing apparatus, comprising:

[0006] A liquid tank contains a mixture of cleaning solution and drying solution for immersing wafers;

[0007] A drying tank having a chamber and an air inlet communicating with the chamber;

[0008] The chamber is used to contain the wafer after it has been soaked;

[0009] The air inlet is used to deliver vaporized drying liquid into the chamber to dry the wafer in the chamber.

[0010] More preferably, the concentration of the dried liquid in the mixture gradually increases in the direction from the bottom to the top of the liquid tank.

[0011] More preferably, the wafer processing apparatus further includes:

[0012] The first liquid inlet is used to transfer the cleaning fluid into the liquid tank;

[0013] At least one second liquid inlet is provided for transferring the drying liquid into the liquid tank;

[0014] The first liquid inlet and the second liquid inlet are distributed sequentially at the bottom of the liquid tank in the direction of facing the top.

[0015] More preferably, the flow rate of the second inlet gradually increases in the direction from the bottom to the top of the liquid tank.

[0016] More preferably, the wafer processing apparatus further includes:

[0017] A heating device is located on the side wall of the drying tank and is used to heat the chamber.

[0018] More preferably, the air inlet is also used to transmit carrier gas to the chamber;

[0019] The drying tank also has an exhaust port, which is used to discharge the vaporized drying liquid from the chamber through the carrier gas after the wafer is dried.

[0020] More preferably, the cleaning solution is deionized water and the drying solution is isopropanol.

[0021] This application also provides a wafer processing method, the method comprising:

[0022] The wafer is immersed in a mixture of cleaning solution and drying solution;

[0023] The soaked wafer is then removed into the chamber;

[0024] The wafer in the chamber is dried by vaporizing the drying liquid.

[0025] More preferably, in the wafer removal direction, the concentration of the drying liquid in the mixture gradually increases.

[0026] More preferably, the step of immersing the wafer in a mixture of cleaning solution and drying solution includes:

[0027] The wafer is immersed in the cleaning solution;

[0028] The cleaning solution and the drying solution are introduced into the cleaning solution, so that the wafer is immersed in the mixture composed of the cleaning solution and the drying solution.

[0029] More preferably, the input positions of the cleaning fluid and the input positions of the drying fluid are sequentially distributed in the wafer removal direction.

[0030] More preferably, the method further includes:

[0031] The chamber is heated during the drying process of the wafer.

[0032] More preferably, the method further includes:

[0033] After the wafer is dried, the vaporized drying liquid in the chamber is discharged by a carrier gas.

[0034] More preferably, the cleaning solution is deionized water and the drying solution is isopropanol.

[0035] The beneficial effects of this invention are as follows: by immersing the wafer in a mixture of cleaning liquid and drying liquid in a liquid tank, the wafer is then dried by vaporized drying liquid. During the drying process, the surface tension difference between the vaporized drying liquid and the cleaning liquid in the mixture on the wafer is reduced because the residual cleaning liquid on the wafer surface contains a certain concentration of drying liquid. This allows the vaporized drying liquid to effectively prevent the bending of the nanosheet structure in the wafer when removing the residual cleaning liquid from the wafer surface, thereby preventing damage to the wafer structure and improving the wafer performance. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments or prior art, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of a cross-section of a wafer after drying, as described in the prior art.

[0038] Figure 2 A schematic cross-sectional view of a wafer before etching, provided in an embodiment of the present invention;

[0039] Figure 3 This is a schematic cross-sectional view of a wafer before drying, provided in an embodiment of the present invention.

[0040] Figure 4 A schematic diagram of the wafer processing apparatus provided in an embodiment of the present invention;

[0041] Figure 5 This is a schematic flowchart of a wafer processing method provided in an embodiment of the present invention. Detailed Implementation

[0042] The specific structural and functional details disclosed herein are merely representative and are intended to describe exemplary embodiments of the invention. However, the invention can be embodied in many alternative forms and should not be construed as being limited solely to the embodiments set forth herein.

[0043] In the description of this invention, it should be understood that the terms "center," "lateral," "upper," "lower," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. Additionally, the term "comprising" and any variations thereof are intended to cover non-exclusive inclusion.

[0044] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0045] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms “a” and “an” as used herein are also intended to include the plural. It should also be understood that the terms “comprising” and / or “including” as used herein specify the presence of the stated features, integers, steps, operations, units, and / or components, without excluding the presence or addition of one or more other features, integers, steps, operations, units, components, and / or combinations thereof.

[0046] See Figure 2 This is a schematic cross-sectional view of the wafer before etching, provided in an embodiment of the present invention.

[0047] like Figure 2As shown, prior to etching, wafer 100 may include a substrate 1 and a stacked layer 2 formed on the substrate 1. The stacked layer 2 includes multiple vertically alternating interlayer sacrificial layers 22 and interlayer insulating layers 21, where vertical refers to the direction perpendicular to the substrate 1. The number of stacked interlayer sacrificial layers 22 and interlayer insulating layers 21 is not limited, for example, 48 layers, 64 layers, etc. The substrate 1 is a semiconductor substrate, such as a silicon substrate, or a substrate including other elemental semiconductors or compound semiconductors. The interlayer insulating layer 21 includes, but is not limited to, silicon oxide, and the interlayer sacrificial layer 22 includes, but is not limited to, silicon nitride.

[0048] The stack layer 2 also has a memory string channel structure 23 that extends longitudinally through the stack layer 2 and into the interior of the substrate 1. The memory string channel structure 23 includes a longitudinally extending semiconductor channel layer (not shown in the figure) and a memory dielectric layer (not shown in the figure) disposed around the periphery of the semiconductor channel layer.

[0049] A vertically penetrating gate line slit 24 is also formed in stacked layer 2. Since the interlayer sacrificial layer 22 in stacked layer 2 needs to be replaced with the gate layer later, it is removed through the gate line slit 24. The interlayer sacrificial layer 22 is removed by a wet etching process, which has an easily adjustable etching rate and is inexpensive. Figure 3 As shown, the area after the interlayer sacrificial layer 22 is removed forms a sacrificial gap 25, that is, there is a sacrificial gap 25 between adjacent interlayer insulating layers 21.

[0050] After removing the interlayer sacrificial layer 22, the wafer 100 is cleaned with a cleaning solution. The wet cleaning process can remove various contaminants such as particles, organic matter, and metal ions from the wafer surface, which is crucial for good device performance, long-term reliability, and high yield.

[0051] After cleaning wafer 100, it needs to be dried to remove residual cleaning solution from its surface. Existing technology uses a vaporized drying liquid to dry wafer 100, leveraging the surface tension difference between the vaporized drying liquid and the cleaning liquid to peel off the residual cleaning solution. However, the surface tension difference between the vaporized drying liquid and the cleaning liquid is significant. Since the interlayer insulating layer 21 in wafer 100 has a nanosheet structure and sacrificial gaps 25 exist between the interlayer insulating layers 21, when using a vaporized drying liquid to peel off the residual cleaning solution from the surface of the interlayer insulating layer 21, the sacrificial layers 21 are prone to bending towards the sacrificial gaps 25, leading to the connection of adjacent interlayer insulating layers 21, damaging the structure of wafer 100 and affecting its performance.

[0052] Based on this, embodiments of the present invention provide a wafer processing apparatus.

[0053] like Figure 4 As shown, the wafer processing apparatus provided in this embodiment of the invention includes a liquid tank 200 and a drying tank 300. The drying tank 300 may be located above the liquid tank 200, and a movable plate 303 may be provided at the bottom of the drying tank 300. When the movable plate 303 is closed, the drying tank 300 is not connected to the liquid tank 200, and a sealed space can be formed in the drying tank 300; when the movable plate 303 is open, the drying tank 300 is connected to the liquid tank 200.

[0054] The liquid tank 200 contains a mixture 201 consisting of a cleaning solution and a drying solution, which is used to immerse the wafer 100. That is, after the wafer 100 is etched and cleaned, the wafer 100 is immersed in the mixture 201 in the liquid tank 200. Preferably, the cleaning solution is deionized water (DIW) and the drying solution is isopropanol (IPA).

[0055] The drying tank 300 has a chamber 301 for containing the immersed wafer 100, i.e., after the wafer 100 is immersed in the mixed solution 201, it is removed into the chamber 301. When the wafer 100 is removed from the mixed solution 201, the movable plate 303 opens, connecting the drying tank 300 to the liquid tank 200, so that the wafer 100 is placed in the chamber 301 of the drying tank 300. Then, the movable plate 303 closes, so that the wafer 100 is in the closed drying tank 300. At this time, the surface of the wafer 100 in the chamber 301 is still covered with the mixed solution 201, i.e., the surface of the wafer 100 is not only covered with cleaning solution but also with a certain concentration of drying solution.

[0056] The drying tank 300 also has an air inlet 302, which can be located on the side wall of the drying tank 300 and is connected to the chamber 301. The air inlet 302 is used to transfer vaporized drying liquid (vaporized drying liquid is a gaseous drying liquid that can be converted from liquid to gas by heating) to the chamber 301 to dry the wafer 100 in the chamber 301.

[0057] Since the surface of the wafer 100 in the chamber 301 is covered with a mixture 201, that is, the surface of the interlayer insulating layer 21 (nanosheet structure) in the wafer 100 is covered with a mixture 201, the residual cleaning liquid on the surface of the interlayer insulating layer 21 (nanosheet structure) is reduced, thereby reducing the surface tension difference between the vaporized drying liquid and the cleaning liquid in the mixture 201. This prevents the interlayer sacrificial layer 21 (nanosheet structure) from bending when the vaporized drying liquid peels off the residual cleaning liquid on the surface of the interlayer insulating layer 21 (nanosheet structure), thus avoiding damage to the structure of the wafer 100 and improving the performance of the wafer 100.

[0058] Preferably, the concentration of the drying solution in the mixture 201 gradually increases in the direction A from the bottom to the top of the liquid tank 200. An opening (not shown in the figure) may be provided at the top of the liquid tank 200, through which the wafer 100 is placed into and removed from the liquid tank 200. It should be noted that the liquid tank 200 may initially contain cleaning solution, with the wafer 100 placed at the bottom of the liquid tank 200 so that it is submerged in the cleaning solution. Then, drying solution is introduced into the liquid tank 200, forming a mixture 201 with the cleaning solution. The concentration of the drying solution in the mixture 201 gradually increases in the direction A from the bottom to the top of the liquid tank 200. The bottom of the liquid tank 200 may contain only cleaning solution or a mixture with a lower concentration of drying solution, while the concentration of drying solution in the mixture 201 at the top of the liquid tank 200 is the highest.

[0059] Then, wafer 100 is moved from the bottom to the top of liquid tank 200 and removed from the top of liquid tank 200, i.e., the removal direction of wafer 100 is direction A from the bottom of liquid tank 200 to the top of liquid tank 200. As the concentration of the drying liquid in the mixture 201 gradually increases in the removal direction of wafer 100, the concentration of the drying liquid that wafer 100 comes into contact with gradually increases and the concentration of the cleaning liquid that it comes into contact with gradually decreases during the removal process. This gradually reduces the surface tension difference between the drying liquid and the cleaning liquid on wafer 100, and avoids a sudden increase in the concentration of the drying liquid that wafer 100 comes into contact with, which would cause a sharp change in the surface tension of wafer 100 and thus cause the interlayer insulating layer 21 (nanosheet structure) to bend.

[0060] Specifically, the wafer processing apparatus further includes a first liquid inlet 202 and at least one second liquid inlet 203. The first liquid inlet 202 is used to transfer the cleaning solution to the liquid tank 200, and the second liquid inlet 203 is used to transfer the drying solution to the liquid tank 200, so as to ensure that the liquid tank 200 contains a mixture of cleaning solution and drying solution.

[0061] The first liquid inlet 202 and at least one second liquid inlet 203 can be located on the side wall of the liquid tank 200, and the first liquid inlet 202 and the second liquid inlet 203 are sequentially distributed in direction A from the bottom to the top of the liquid tank 200, that is, the first liquid inlet 202 is located at the bottom of the liquid tank 200, and the second liquid inlet 203 is located above the first liquid inlet 202 and close to the top of the liquid tank 200. The input direction of the cleaning liquid into the liquid tank 200 through the first liquid inlet 202 can be towards the top of the liquid tank 200, and the input direction of the drying liquid into the liquid tank 200 through the second liquid inlet 203 can be horizontal, so as to ensure that the concentration of drying liquid in the mixture at the bottom of the liquid tank 200 is the lowest, the concentration of drying liquid in the mixture at the top of the liquid tank 200 is the highest, and the drying liquid input from the top of the liquid tank 200 will not sink to the bottom of the liquid tank 200.

[0062] Preferably, there are multiple second inlet holes 203 (two or more), and the first inlet hole 202 and the multiple second inlet holes 203 are evenly distributed at intervals along direction A from the bottom to the top of the liquid tank 200. The flow rates of the drying liquid transmitted into the liquid tank 200 by the multiple second inlet holes 203 can be different. Along direction A from the bottom to the top of the liquid tank 200, the flow rate of the second inlet holes 203 gradually increases, that is, the flow rate of the second inlet holes 203 closer to the bottom of the liquid tank 200 is smaller, and the flow rate of the second inlet holes 203 closer to the top of the liquid tank 200 is larger, thereby ensuring that the concentration of the drying liquid in the mixture 201 changes in a gradient along direction A from the bottom to the top of the liquid tank 200.

[0063] The more second inlet holes 203 there are, the more precise the concentration change of the drying liquid in the mixture 201, but the higher the requirements for the device. Therefore, the number of second inlet holes 203 is preferably four, and the four second inlet holes 203 and the first inlet hole 202 are evenly distributed on the side wall of the liquid tank 200. Drying liquid of different flow rates is introduced into the liquid tank 200 through the four second inlet holes 203, ensuring that the concentration difference of the drying liquid at any two adjacent inlet holes does not exceed 20%, thus avoiding excessive changes in the concentration of the drying liquid.

[0064] Furthermore, the wafer processing apparatus also includes a heating device 400, which is located on the side wall of the drying tank 300, i.e., the heating device 400 can be arranged around the periphery of the chamber 301. The heating device 400 is used to heat the chamber 301 to increase the temperature in the chamber 301. Preferably, the heating temperature range of the heating device 400 is 200 degrees to 280 degrees.

[0065] In existing technologies, after the vaporized drying liquid removes the residual cleaning liquid from the wafer surface, it liquefies into a drying liquid on the wafer surface (where the wafer temperature is relatively low). This drying liquid is then vaporized and evaporated by high-temperature gas, resulting in low wafer drying efficiency. In contrast, this application incorporates a heating device 400 on the side wall of the drying tank 300 to heat the chamber 301, increasing the temperature of the wafer 100 within the chamber. This prevents the vaporized drying liquid from liquefying on the wafer 100 surface after removing the residual cleaning liquid, ensuring the drying liquid in the chamber 301 remains in a gaseous state. This accelerates the evaporation rate, improves drying efficiency, and further reduces the risk of structural damage to the wafer 100.

[0066] Furthermore, the air inlet 302 is also used to transmit carrier gas to the chamber 301, that is, while transmitting vaporized drying liquid to the chamber 301, the air inlet 302 also transmits carrier gas to the chamber 301. The carrier gas refers to an inert gas, such as nitrogen (N2).

[0067] The drying tank 300 also has an exhaust port 304, which can be located at the bottom of the drying tank 300. The exhaust port 304 is used to discharge the vaporized drying liquid from the chamber 301 through the carrier gas after the wafer 100 is dried. That is, after the wafer 100 is dried, the air inlet 302 stops transmitting vaporized drying liquid to the chamber 301, and only transmits carrier gas to the chamber 301, so that the carrier gas discharges the vaporized drying liquid to the outside of the chamber 301 through the exhaust port 304.

[0068] As described above, the wafer processing apparatus provided in this embodiment of the invention can immerse the wafer in a mixture of cleaning liquid and drying liquid in a liquid tank, and then dry the wafer with a vaporized drying liquid. During the drying process, since the mixture remaining on the wafer surface contains a certain concentration of drying liquid, the surface tension difference between the vaporized drying liquid and the cleaning liquid in the mixture is reduced. This allows the vaporized drying liquid to effectively prevent the bending of the nanosheet structure in the wafer when removing the cleaning liquid remaining on the wafer surface, thereby preventing the wafer structure from being damaged and improving the wafer performance.

[0069] Accordingly, this embodiment of the invention also provides a wafer processing method that can be applied to the wafer processing apparatus in the above embodiments.

[0070] See Figure 5 This is a schematic flowchart of the wafer processing method provided in an embodiment of the present invention.

[0071] like Figure 5 As shown, this embodiment provides a wafer processing method, including steps 101 to 103:

[0072] Step 101: Immerse the wafer in a mixture of cleaning solution and drying solution.

[0073] For example Figure 4 As shown, a mixture 201 consisting of a cleaning solution and a drying solution is formed in the liquid tank 200. After etching and cleaning the wafer 100, the wafer 100 is immersed in the mixture 201 in the liquid tank 200. Preferably, the cleaning solution is deionized water (DIW) and the drying solution is isopropanol (IPA).

[0074] Wafer 100 can be immersed in the bottom of liquid tank 200. Then, wafer 100 is moved from the bottom to the top of liquid tank 200 and removed from the top. That is, the removal direction of wafer 100 is direction A from the bottom to the top of liquid tank 200. In the removal direction of wafer 100, the concentration of the drying liquid in the mixture 201 gradually increases. During the removal process of wafer 100, the concentration of the drying liquid in contact with wafer 100 gradually increases, while the concentration of the cleaning liquid in contact with wafer 100 gradually decreases. This gradually reduces the surface tension difference between the drying liquid and the cleaning liquid on wafer 100, avoiding a sudden increase in the concentration of the drying liquid in contact with wafer 100 that would cause a sharp change in the surface tension of wafer 100, which could lead to bending of the nanosheet structure in wafer 100.

[0075] Specifically, step 101, which involves immersing the wafer in a mixture of cleaning solution and drying solution, includes:

[0076] The wafer is immersed in the cleaning solution;

[0077] The cleaning solution and the drying solution are introduced into the cleaning solution, so that the wafer is immersed in the mixture composed of the cleaning solution and the drying solution.

[0078] For example, before immersing the wafer 100, cleaning fluid is introduced into the liquid tank 200 only through the first inlet port 202, so that the wafer 100 is only immersed in the cleaning fluid. When the wafer 100 is immersed at the bottom of the liquid tank 200, while the cleaning fluid is introduced into the liquid tank 200 through the first inlet port 202, a drying fluid is introduced into the liquid tank 200 through at least one second inlet port 203, so that the liquid tank 200 contains a mixture of cleaning fluid and drying fluid.

[0079] The input positions of the cleaning fluid and the input positions of the drying fluid are sequentially distributed in the take-out direction of the wafer 100, that is, the first liquid inlet 202 and at least one second liquid inlet 203 are sequentially distributed in the take-out direction of the wafer 100, and the transmission flow rate of the second liquid inlet 203 gradually increases in the direction A from the bottom to the top of the liquid tank 200, so as to ensure that the concentration of the drying fluid in the mixture 201 changes in a gradient in the direction A from the bottom to the top of the liquid tank 200.

[0080] Step 102: Remove the soaked wafer into the chamber.

[0081] For example, after the soaked wafer 100 is removed, the surface of the wafer 100 is left with a mixture 201. The wafer 100 with the remaining mixture 201 is placed in the chamber 301 of the drying tank 300 for subsequent drying.

[0082] Step 103: Dry the wafer in the chamber using a vaporized drying liquid.

[0083] For example, when vaporizing drying liquid is transferred into chamber 301, the concentration of cleaning liquid in the mixture 201 remaining on the surface of wafer 100 is low, and the surface tension difference between the vaporizing drying liquid and the cleaning liquid in the mixture 201 on wafer 100 becomes smaller. This allows the vaporizing drying liquid to quickly peel off the cleaning liquid from the surface of wafer 100, preventing the nanosheet structure in wafer 100 from bending and thus damaging the structure of wafer 100.

[0084] Furthermore, the method also includes:

[0085] The chamber is heated during the drying process of the wafer.

[0086] By heating the chamber 301, the temperature of the wafer 100 in the chamber 301 is increased, so that the vaporized drying liquid will not liquefy on the surface of the wafer 100 after stripping off the cleaning liquid remaining on the surface of the wafer 100. Even if the drying liquid in the chamber 301 is always in a gaseous state, the evaporation rate of the drying liquid is accelerated, the drying efficiency is improved, and the risk of damage to the structure of the wafer 100 is reduced.

[0087] Furthermore, the method also includes:

[0088] After the wafer is dried, the vaporized drying liquid in the chamber is discharged by a carrier gas.

[0089] While the vaporized drying liquid is being supplied to chamber 301, a carrier gas is also being supplied to chamber 301. After the wafer 100 has finished drying, the supply of vaporized drying liquid to chamber 301 is stopped, but the supply of carrier gas to chamber 301 continues, so that the carrier gas discharges the vaporized drying liquid from chamber 301.

[0090] The wafer processing method provided in this invention can immerse the wafer in a mixture of cleaning liquid and drying liquid in a liquid tank, and then dry the wafer with a vaporized drying liquid. During the drying process, the surface tension difference between the vaporized drying liquid and the cleaning liquid in the mixture is reduced because the residual cleaning liquid on the wafer surface contains a certain concentration of drying liquid. This allows the vaporized drying liquid to effectively prevent the bending of the nanosheet structure in the wafer when removing the residual cleaning liquid on the wafer surface, thereby preventing damage to the wafer structure and improving the wafer performance.

[0091] In summary, although the present invention has been disclosed above with reference to preferred embodiments, the above preferred embodiments are not intended to limit the present invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the claims.

Claims

1. A wafer processing apparatus, characterized in that, include: A liquid tank containing a mixture of cleaning solution and drying solution for immersing wafers, wherein the concentration of the drying solution in the mixture gradually increases from the bottom to the top of the liquid tank; A drying tank has a chamber and an air inlet communicating with the chamber. The chamber is used to contain the immersed wafer, and the air inlet is used to transfer vaporized drying liquid into the chamber to dry the wafer in the chamber. The first liquid inlet is used to transfer the cleaning fluid into the liquid tank; At least one second liquid inlet is provided for transferring the drying liquid into the liquid tank; The first liquid inlet and the second liquid inlet are distributed sequentially at the bottom of the liquid tank in the direction of facing the top.

2. The wafer processing apparatus according to claim 1, characterized in that, The flow rate of the second inlet gradually increases in the direction from the bottom to the top of the liquid tank.

3. The wafer processing apparatus according to claim 1, characterized in that, The wafer processing apparatus further includes: A heating device is located on the side wall of the drying tank and is used to heat the chamber.

4. The wafer processing apparatus according to claim 1, characterized in that, The air inlet is also used to transfer carrier gas into the chamber; The drying tank also has an exhaust port, which is used to discharge the vaporized drying liquid from the chamber through the carrier gas after the wafer is dried.

5. The wafer processing apparatus according to claim 1, characterized in that, The cleaning solution is deionized water, and the drying solution is isopropanol.

6. A wafer processing method, characterized in that, The method includes: The wafer is immersed in a cleaning solution; The cleaning solution and the drying solution are introduced into the cleaning solution, so that the wafer is immersed in the mixture of the cleaning solution and the drying solution. The input positions of the cleaning solution and the input positions of the drying solution are distributed sequentially in the wafer removal direction. The soaked wafer is removed into the chamber, and in the direction of wafer removal, the concentration of the drying solution in the mixture gradually increases; The wafer in the chamber is dried by vaporizing the drying liquid.

7. The wafer processing method according to claim 6, characterized in that, The method further includes: The chamber is heated during the drying process of the wafer.

8. The wafer processing method according to claim 6, characterized in that, The method further includes: After the wafer is dried, the vaporized drying liquid in the chamber is discharged by a carrier gas.

9. The wafer processing method according to claim 6, characterized in that, The cleaning solution is deionized water, and the drying solution is isopropanol.

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