Wafer drying method and device

Abstract

Provided in the embodiments of the present application are a wafer drying method and device. After a wafer is cleaned with a cleaning solution, the surface of the wafer has a residue of the cleaning solution. The method comprises: spraying a first liquid mutually soluble with the cleaning solution onto the wafer until the cleaning solution on the surface of the wafer is cleaned, resulting in the surface of the wafer having a residue of the first liquid; introducing a set amount of a first drying gas into a cavity, and spraying a modifying chemical solution onto the wafer at the same time, wherein the modifying chemical solution is mutually soluble with the first liquid and changes the surface of the wafer into a hydrophobic surface; and spraying a second drying gas onto the wafer. The wafer drying method and device of the present application can dry a wafer.

Description

Substrate drying method and apparatus TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor technology, and in particular, to a substrate drying method and apparatus. BACKGROUND

[0002] With the rapid development of semiconductor manufacturing technology, in order to achieve faster operation speed, larger data storage capacity and more functions, semiconductor chips develop towards higher integration. The higher the integration of semiconductor chips, the smaller the feature size (CD) of semiconductor devices, that is, the larger the aspect ratio of the chip interstitial trench formed after etching.

[0003] In the prior art, when manufacturing chips, the etched substrate needs to be cleaned and dried. Because the aspect ratio of the chip interstitial trench is large, the capillary action of the cleaning liquid between the trenches during the drying process causes the chips to easily stick together, which can easily cause damage to the substrate. SUMMARY

[0004] Embodiments of the present application provide a substrate drying method and apparatus, which can reduce the sticking during substrate drying.

[0005] In one aspect, the present application provides a substrate drying method, wherein the substrate surface has residual cleaning liquid after cleaning with a cleaning liquid, and the method comprises: spraying a first liquid that is miscible with the cleaning liquid onto the substrate until the cleaning liquid on the substrate surface is cleaned, and the first liquid remains on the substrate surface; introducing a first drying gas into the cavity, and spraying a modification liquid onto the substrate, wherein the modification liquid is miscible with the first liquid and makes the substrate surface a hydrophobic surface; and spraying a second drying gas onto the substrate.

[0006] Specifically, during the execution of the substrate drying method, the substrate is kept rotating around the center of the substrate.

[0007] Specifically, before the step of spraying the modification liquid onto the substrate, the method further comprises: introducing a set amount of the first drying gas into the cavity.

[0008] Specifically, the step of introducing a set amount of the first drying gas into the cavity is performed simultaneously with the step of spraying the first liquid that is miscible with the cleaning liquid onto the substrate.

[0009] Specifically, before the step of spraying the second drying gas onto the substrate, the method further comprises: spraying a second liquid that is miscible with the modification liquid onto the substrate until the modification liquid is cleaned, and the second liquid remains on the substrate surface, wherein the boiling point of the second liquid is lower than the boiling point of the modification liquid.

[0010] Specifically, the second liquid is the same as the first liquid.

[0011] Specifically, the first liquid is isopropyl alcohol.

[0012] Specifically, the first dry gas is high-purity clean dry air, dry compressed air or nitrogen.

[0013] Specifically, when the first dry gas is high-purity clean dry air, the flow rate of the first dry gas is 400 L / min-1000 L / min.

[0014] Specifically, when the second dry gas is nitrogen, the flow rate of the second dry gas is greater than 5 L / min.

[0015] In another aspect, the application provides a substrate drying device, comprising: a cavity provided with a tray for carrying a substrate; a nozzle assembly comprising a first liquid nozzle, a modification liquid nozzle and a dry gas nozzle, the first liquid nozzle is used to spray a first liquid to the substrate, the modification liquid nozzle is used to spray a modification liquid to the substrate to make the substrate surface into a hydrophobic surface, and the dry gas nozzle is used to spray a second dry gas to the substrate, wherein the first liquid is miscible with the cleaning liquid of the substrate surface, and the modification liquid is miscible with the first liquid; a dry gas inlet for introducing a first dry gas into the cavity.

[0016] Specifically, the device further comprises a rotating unit connected to the tray for driving the substrate to rotate around the center of the substrate.

[0017] Specifically, the device further comprises a rectifier plate arranged between the dry gas inlet and the nozzle assembly.

[0018] Specifically, the dry gas inlet has a plurality of dry gas inlets.

[0019] Specifically, the device further comprises a fan filter unit for filtering the first dry gas through the fan filter unit before entering the dry gas inlet.

[0020] Specifically, the nozzle assembly further comprises a second liquid nozzle for spraying a second liquid to the substrate, and the boiling point of the second liquid is lower than that of the modification liquid.

[0021] Specifically, the device further comprises an exhaust port arranged at the bottom of the cavity, and the exhaust port is provided with an adjustable angle adjusting baffle.

[0022] In the substrate drying method of the present application, the humidity in the cavity is reduced by introducing the first drying gas into the cavity to avoid the modified liquid from deteriorating due to water, so that the modified liquid can better treat the surface of the substrate, and thus the surface of the substrate can obtain better hydrophobic effect, which is beneficial to the drying of the substrate.

[0023] Other features and advantages of the present application will become apparent from the following detailed description, or will be learned by practice of the present application.

[0024] It should be understood that the general description above and the following detailed description are only exemplary and explanatory, and are not limiting to the present application.

[0025] SUMMARY

[0026] The features, benefits and attributes of the present application will become apparent by reference to the following detailed description and accompanying drawings, which illustrate a few embodiments of the present application.

[0027] The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, explain the principles of the present application. It is clear that the accompanying drawings, which are described below, are only some embodiments of the present application, and other drawings can be obtained from these drawings without creative labor for those skilled in the art. In the drawings:

[0028] Figure 1 shows a schematic diagram of the structure of a substrate drying device according to an embodiment of the present application;

[0029] Figure 2 shows a schematic diagram of the process of a substrate drying method according to an embodiment of the present application.

[0030] Preferred embodiments of the present application

[0031] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations may, however, be implemented in many different forms and should not be construed as limited to the implementations set forth herein; rather, these implementations are provided so that this disclosure will be thorough and complete, and will fully convey the scope of example implementations to those skilled in the art. Like reference numerals refer to like elements throughout.

[0032] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the application. One skilled in the relevant art will recognize, however, that the application can be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, devices, implementations, and operations have not been shown or described in detail to avoid obscuring aspects of the application.

[0033] The present embodiment provides a substrate processing device for quickly drying a substrate.

[0034] As shown in FIG. 1, the substrate drying device comprises a cavity 1 and a tray 2 arranged in the cavity 1, the tray 2 is used to carry the horizontally placed substrate, wherein the substrate is processed by a cleaning process, and the surface of the substrate is covered with cleaning liquid. The tray 2 is connected with a rotating member, and the rotating member drives the substrate to rotate along the center of the substrate.

[0035] A nozzle assembly is arranged in the cavity 1, and the nozzle assembly is arranged above the tray 2 and has a distance of 1-3 cm from the tray 2. The nozzle assembly comprises a first liquid nozzle 3, a modified chemical liquid nozzle 4 and a second liquid nozzle 5, and the heights of the first liquid nozzle 3, the modified chemical liquid nozzle 4 and the second liquid nozzle 5 can be the same or different. The first liquid nozzle 3 is used to spray a first liquid to the substrate, and the first liquid is miscible with the cleaning liquid, so as to replace the cleaning liquid on the surface of the substrate with the first liquid. The modified chemical liquid nozzle 4 is used to spray a modified chemical liquid to the substrate, and the modified chemical liquid is miscible with the first liquid, so as to replace the first liquid on the surface of the substrate with the modified chemical liquid, and the modified chemical liquid is also used to change the surface of the substrate into a hydrophobic surface. The second liquid nozzle 5 is used to spray a second liquid to the substrate, and the second liquid is miscible with the modified chemical liquid and has a lower boiling point than the modified chemical liquid, so as to replace the modified chemical liquid on the surface of the substrate with the second liquid which is easy to dry. In other embodiments of the present application, the first liquid and the second liquid share the same nozzle, that is, the first liquid nozzle 3 and the second liquid nozzle 5 are the same nozzle.

[0036] A drying gas inlet 11 is arranged on the top wall of the cavity 1, and is used to introduce a first drying gas into the cavity 1 to reduce the humidity in the cavity 1. In some embodiments, the drying gas inlet 11 has a plurality of drying gas inlets, so that the first drying gas is more uniformly distributed in the cavity 1. Further, a flow regulation plate 6 is arranged between the drying gas inlet 11 and the nozzle assembly, and a plurality of flow regulation holes are uniformly arranged on the flow regulation plate 6, which is used to make the first drying gas uniformly fill the cavity below the flow regulation plate 6, so that the first drying gas uniformly fills the cavity 1 below the modified chemical liquid nozzle 4, and ensures that the humidity of the cavity 1 below the modified chemical liquid nozzle 4 is uniformly reduced, thereby avoiding the deactivation of the modified chemical liquid due to water. The drying gas inlet 11 is connected with a drying gas supply device, and a fan filter unit (FFU) 7 is arranged between the drying gas supply device and the drying gas inlet 11, so as to filter the first drying gas, and the filtered first drying gas has a better drying effect. The fan filter unit (FFU) 7 can also adjust the flow of the first drying gas into the cavity 1. In other embodiments of the present application, the drying gas inlet 11 is arranged on the top of the side wall of the cavity 1.

[0037] A drying gas nozzle 8 is further arranged in the cavity 1, and the drying gas nozzle 8 is arranged above the tray 2 and is used to spray a second drying gas to the substrate to accurately dry the substrate.

[0038] The bottom of the cavity 1 is further provided with a discharge port 12 for discharging the cleaning liquid, the first dry liquid, the modified liquid, the second dry liquid, the first dry gas and the second dry gas. In some embodiments, an adjusting baffle is arranged at the discharge port 12, and the discharge amount of the discharge port is controlled by adjusting the angle of the adjusting baffle, so as to adjust the humidity of the cavity by adjusting the flow of the first dry gas and the discharge amount of the discharge port.

[0039] The application further provides a substrate drying method, which is executed by the substrate drying device and used for drying a substrate.

[0040] As shown in FIG. 2, the substrate drying method specifically comprises the following steps:

[0041] S110: Keep the substrate horizontally rotating, and the substrate is covered with the cleaning liquid.

[0042] The substrate is etched and cleaned in sequence, and the cleaning liquid on the surface of the substrate can be deionized water or other cleaning liquid.

[0043] S120: Spray the first liquid that is miscible with the cleaning liquid to the surface of the substrate until the cleaning liquid on the substrate is completely replaced by the first liquid.

[0044] When the cleaning liquid is deionized water, the first liquid is an organic substance that is miscible with the deionized water, for example, isopropyl alcohol (IPA).

[0045] While the first liquid is being introduced, the cleaning liquid and the first liquid are continuously discharged out of the cavity until the cleaning liquid on the substrate is completely dissolved by the first liquid, and the liquid on the surface of the substrate is changed into the first liquid.

[0046] S130: Introduce a set amount of the first dry gas into the cavity.

[0047] The first dry gas is extra clean dry air (XCDA), compressed dry air (CDA), nitrogen or other gas that can reduce the humidity of the cavity. The dry gas has better flowability than liquid and other substances, can more uniformly fill the cavity, and has better drying effect.

[0048] The set amount is set according to process requirements. For example, if the first dry gas is XCDA, the flow of the introduced first dry gas can be 400 L / min to 1000 L / min, for example, 500 L / min, and the time for introducing the first dry gas is set according to process requirements.

[0049] S140: continue to introduce the first dry gas and spray the modification liquid to the substrate surface, the modification liquid is miscible with the first liquid and modifies the substrate surface until the modification liquid changes the hydrophilic surface of the substrate surface to a hydrophobic surface.

[0050] Since the modification liquid is miscible with the first liquid, the modification liquid replaces the first liquid on the substrate surface. The remaining modification liquid chemically reacts with the substance containing the hydrophilic group on the substrate surface to obtain a product with a hydrophobic group, so that the substrate with a hydrophilic surface becomes a substrate with a hydrophobic surface. When the modification of the substrate surface is completed and the surface becomes hydrophobic, stop spraying the modification liquid to the substrate surface.

[0051] The modification liquid is a SMT (surface modification treatment) liquid, which is not miscible with the cleaning liquid, and the hydrophilic group on the substrate surface is a silicon hydroxyl group. The SMT liquid combines with the silicon hydroxyl group to form a hydrophobic silyl group, thereby making the substrate surface hydrophobic.

[0052] The continuously introduced first dry gas can continuously reduce the humidity in the cavity, which is beneficial to the drying of the substrate.

[0053] S150: spray the second liquid to the substrate surface, the second liquid is miscible with the modification liquid and the boiling point of the second liquid is lower than that of the modification liquid, until the modification liquid is cleaned and the second liquid remains on the substrate surface.

[0054] Since the modification liquid generally has a high boiling point and is not easy to dry, the second liquid is sprayed to the substrate surface covered with the modification liquid. The second liquid is an organic substance that is easier to dry than SMT and can dissolve SMT, such as IPA / HFE (hydrofluoroether), so as to replace the modification liquid on the substrate surface with the second liquid, so that the substrate with a hydrophobic surface is easy to dry.

[0055] In other embodiments of the present application, the second liquid is the same as the first liquid, which is an organic substance miscible with water and SMT and easier to dry than SMT. For example, the second liquid and the first liquid are both IPA. In other embodiments of the present application, the second liquid is different from the first liquid.

[0056] In other embodiments of the present application, during the execution of step S150, the first dry gas continues to be introduced.

[0057] S160: spray the second dry gas to the substrate to dry the substrate.

[0058] The second dry gas is extra clean dry air (XCDA), compressed dry air (CDA), nitrogen or other gases that can dry the substrate.

[0059] When the second dry gas is nitrogen, the flow rate of the second dry gas is set to be greater than 5 L / min to dry the substrate quickly. For example, the flow rate of the second dry gas can be 8 L / min, 10 L / min, or other flow rates.

[0060] In other embodiments of the present application, the amount set in step S130 can be zero, i.e., step S140 is directly performed after step S120 to simultaneously supply the first dry gas and the modified liquid, which can alleviate the problem of denaturation of the modified liquid. In other embodiments of the present application, step S130 is performed simultaneously with step S120 to save time. In other embodiments of the present application, the first dry gas is simultaneously supplied during the performance of step S160, which continuously reduces the humidity in the cavity and is beneficial to the drying of the substrate.

[0061] In this embodiment, the substrate is modified by using the modified liquid, which changes the hydrophilic surface of the substrate into a hydrophobic surface, thereby avoiding the residue of liquid in the grooves of the substrate, preventing the sticking of the substrate, avoiding the damage of the substrate, and making the substrate be dried faster and achieve better drying effect. The modified liquid is miscible with the cleaning liquid and the modified liquid itself is not easy to dry. Therefore, for the substrate just finished cleaning, the cleaning liquid on the surface of the substrate is replaced by the dry liquid first, and then the substrate is modified. After the modification is finished, the modified liquid on the surface of the substrate is replaced by the dry liquid, which can better dry the substrate. In addition, before the modified liquid is sprayed onto the surface of the substrate, the dry gas is sprayed into the cavity first, which can reduce the humidity in the cavity, further accelerate the drying speed of the substrate, and avoid the inactivation of the modified liquid due to water, thereby saving the amount of the modified liquid. In addition to the dry gas itself reducing the moisture in the cavity, the dry gas has good fluidity, and the airflow of the dry gas can quickly take away the moisture in the cavity, so that the cavity is uniformly and quickly dried, avoiding the influence of the moisture in the cavity on the modified liquid and the substrate, thereby achieving better drying effect. Finally, since the substrate is always kept horizontal rotation during the drying process, the various liquids in the substrate drying method can uniformly cover the surface of the substrate, thereby uniformly drying the substrate.

[0062] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the embodiments disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the application being indicated by the following claims.

[0063] It should be understood that the application is not limited to the precise construction that has been described above and illustrated in the accompanying drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application. The scope of the application should be limited only by the appended claims.

Claims

1. A substrate drying method, the substrate being cleaned by a cleaning solution and having the cleaning solution remaining on the substrate surface, characterized by, The method comprises the following steps: spraying a first liquid immiscible with the cleaning liquid on the substrate until the cleaning liquid on the substrate surface is cleaned, and the first liquid remains on the substrate surface; introducing a first dry gas into the cavity, and spraying a modifying liquid on the substrate, the modifying liquid being immiscible with the first liquid and making the substrate surface become a hydrophobic surface; spraying a second dry gas on the substrate.

2. The substrate drying method according to claim 1, wherein During the execution of the substrate drying method, the substrate is kept rotating around the center of the substrate.

3. The method of drying a substrate of claim 1, wherein, Before the step of spraying the modifying liquid on the substrate, the method further comprises the step of introducing a set amount of the first dry gas into the cavity.

4. The method of drying a substrate of claim 3, wherein, The step of introducing the set amount of the first dry gas into the cavity is performed simultaneously with the step of spraying the first liquid immiscible with the cleaning liquid on the substrate.

5. The method of drying a substrate of claim 1 wherein, Before the step of spraying the second dry gas on the substrate, the method further comprises the step of spraying a second liquid immiscible with the modifying liquid on the substrate until the modifying liquid is cleaned, and the second liquid remains on the substrate surface, wherein the boiling point of the second liquid is lower than that of the modifying liquid.

6. The method of drying a substrate of claim 5, wherein, The second liquid is the same as the first liquid.

7. The substrate drying method according to claim 1 or 6, wherein The first liquid is isopropyl alcohol.

8. The method of drying a substrate of claim 1 wherein, The first dry gas and the second dry gas are high-purity clean dry air, dry compressed air or nitrogen.

9. The method of drying a substrate of claim 8, wherein, When the first dry gas is high-purity clean dry air, the flow rate of the first dry gas is 400 L / min-1000 L / min.

10. The method of drying a substrate of claim 8, wherein, When the second dry gas is nitrogen, the flow rate of the second dry gas is greater than 5 L / min.

11. A substrate drying apparatus characterized by comprising: The method comprises the following steps: a cavity provided with a tray for carrying a substrate; a nozzle assembly comprising a first liquid nozzle, a modifying liquid nozzle and a dry gas nozzle, the first liquid nozzle being used for spraying a first liquid on the substrate, the modifying liquid nozzle being used for spraying a modifying liquid on the substrate to make the substrate surface become a hydrophobic surface, and the dry gas nozzle being used for spraying a second dry gas on the substrate, wherein the first liquid is immiscible with the cleaning liquid on the substrate surface, and the modifying liquid is immiscible with the first liquid; a dry gas inlet for introducing a first dry gas into the cavity.

12. The substrate drying apparatus of claim 11, wherein A rotating unit is further provided, which is connected to the tray and used for rotating the substrate around the center of the substrate.

13. The substrate drying apparatus of claim 11, wherein A rectifier plate is further provided between the dry gas inlet and the nozzle assembly.

14. The substrate drying apparatus of claim 11, wherein The dry gas inlet has a plurality of inlets.

15. The substrate drying apparatus of claim 14, wherein A fan filter unit is further provided, which is used for filtering the first dry gas before the first dry gas enters the dry gas inlet.

16. The substrate drying apparatus of claim 15, wherein The nozzle assembly further comprises a second liquid nozzle, which is used for spraying a second liquid on the substrate, and the boiling point of the second liquid is lower than that of the modifying liquid.

17. The substrate drying apparatus of claim 16, wherein An exhaust port is further provided at the bottom of the cavity, and the exhaust port is provided with an adjustable angle adjusting baffle.

Images