Cleaning method

Abstract

The application provides a cleaning method, which comprises a factory control system, a first pressure regulating valve, a gas pressure regulating system and a two-fluid nozzle; a first outlet end of the factory control system is connected with a first inlet end of the gas pressure regulating system through a first pipeline; a first outlet end of the gas pressure regulating system is connected with a first inlet end of the two-fluid nozzle through a second pipeline, and a first pressure regulating valve is arranged on the second pipeline; a second outlet end of the factory control system is used for conveying a chemical liquid to the two-fluid nozzle; and the two-fluid nozzle is used for spraying the mixed chemical liquid and gas to a wafer to clean the wafer. By arranging the first pressure regulating valve on the second pipeline, the two-fluid pressure borne by the wafer can be adjusted, so that the wafer is prevented from being damaged due to too large pressure borne in the cleaning process.

Description

Technical Field

[0001] This invention belongs to the field of microelectromechanical systems manufacturing, and specifically relates to a cleaning method. Background Technology

[0002] Microelectromechanical systems (MEMS) typically comprise tiny units such as microcantilevers, deep cavities, and deep holes, capable of sensing changes in the external environment. These structures are extremely fragile and easily damaged by external forces during wafer fabrication. The industry commonly employs two-fluid chromatography (2FC) technology for wafer cleaning. However, this technology has strict requirements regarding the gas-to-liquid ratio in the 2FC; otherwise, it can lead to damage to the MEMS structure or poor cleaning results.

[0003] In existing cleaning processes, the gas-liquid ratio is fixed under the same process parameters. According to common knowledge, in single-wafer cleaning processes, the linear velocity in the central region of the wafer is lower than that at the wafer edges. Therefore, the central region of the wafer is subjected to the impact of the two fluids for a relatively longer time than the edge region. Consequently, under excessive gas pressure, the structure of the central region is easily damaged.

[0004] Therefore, this invention proposes a cleaning method that ensures the wafer is clean while maintaining the integrity of the wafer structure. Summary of the Invention

[0005] This invention proposes a cleaning method that ensures the wafer is clean while maintaining the integrity of the wafer structure.

[0006] In a first aspect, the present invention provides a cleaning apparatus, comprising: a plant control system, a first pressure regulating valve, a gas pressure regulating system, and a two-fluid nozzle; the first outlet of the plant control system is connected to the first inlet of the gas pressure regulating system via a first pipeline, and gas is supplied to the gas pressure regulating system through the first outlet of the plant control system; the first outlet of the gas pressure regulating system is connected to the first inlet of the two-fluid nozzle via a second pipeline, and gas is supplied to the two-fluid nozzle through the first outlet of the gas pressure regulating system; a first pressure regulating valve is provided on the second pipeline for regulating the gas pressure in the second pipeline; the second outlet of the plant control system is connected to the second inlet of the two-fluid nozzle via a third pipeline, and a chemical solution is supplied to the two-fluid nozzle through the second outlet of the plant control system; the two-fluid nozzle is used to mix the chemical solution and gas, and sprays the mixed chemical solution and gas onto a wafer through its outlet to clean the wafer.

[0007] Its beneficial effects are as follows: By setting the first pressure regulating valve on the second pipeline, the present invention facilitates the adjustment of the pressure of the two fluids on the wafer, so as to prevent the wafer from being damaged due to excessive pressure during the cleaning process. That is, the present invention ensures the integrity of the wafer structure while ensuring that the wafer is clean.

[0008] Optionally, the cleaning device further includes a second pressure regulating valve; the second pressure regulating valve is disposed on the first pipeline and is used to regulate the gas pressure in the first pipeline. Its advantage is that the second pressure regulating valve can be used to pre-treat the gas pressure in the pipeline.

[0009] Optionally, the gas pressure regulating system includes N branch pipelines, where N is a positive integer; each branch pipeline is equipped with a switching valve and a third pressure regulating valve, the switching valve being electrically connected to a switching control unit, and the third pressure regulating valve being electrically connected to a pressure control unit. The switching control unit controls the opening and closing of the switching valve, and the pressure control unit controls the third pressure regulating valve to regulate the gas pressure in the branch pipeline. The first outlet of the plant control system is connected to the first inlet of the gas pressure regulating system via a first pipeline, and the first outlet of the gas pressure regulating system is connected to the first inlet of the two-fluid nozzle via a second pipeline. This includes: the first outlet of the plant control system being connected to one end of each of the N branch pipelines via a first pipeline, and the other end of each of the N branch pipelines being connected to the first inlet of the two-fluid nozzle via a second pipeline.

[0010] Alternatively, when N is greater than or equal to 3 and N is less than 5, the spacing between adjacent branch pipes is equal.

[0011] Alternatively, when N is greater than or equal to 5 and N is less than or equal to 9, the branch pipeline has a circle with the port of one of the branch pipelines as the center, and the center line connecting the ports of the remaining branch pipelines is circular and evenly distributed around the center.

[0012] Further optionally, when N is greater than 9, the branch pipes are divided into i circles with the port of one of the branch pipes as the center, and the center line connecting the ports of the branch pipes in each circle is circular and evenly distributed around the center, with equal spacing between adjacent circles, where i is a positive integer; and the number of branch pipes in the j-th circle is: The j is a positive integer, and the value of j is less than or equal to i.

[0013] Optionally, the two-fluid nozzle is disposed at one end of the swing arm, and the other end of the swing arm is fixed to the support point through a movable connection structure. The swing arm swings around the support point through the movable connection structure so that the two-fluid nozzle can clean the wafer surface according to a preset trajectory.

[0014] In a second aspect, the present invention provides a cleaning method applied to a cleaning apparatus as described in any one of the first aspects, comprising: supplying gas to a gas pressure regulating system through a first outlet end of the plant control system, and supplying gas to a two-fluid nozzle through a first outlet end of the gas pressure regulating system; supplying a chemical solution to the two-fluid nozzle through a second outlet end of the plant control system; mixing the chemical solution and gas in the two-fluid nozzle; spraying the mixed chemical solution and gas onto a wafer according to a set trajectory to clean the wafer; during the cleaning of the wafer by the two-fluid nozzle, adjusting the pressure of the gas supplied to the two-fluid nozzle by the gas pressure regulating system and the first pressure regulating valve, such that the gas pressure in the middle region of the wafer is less than the gas pressure in the edge region of the wafer.

[0015] Optionally, the two-fluid nozzle sprays the mixed liquid and gas onto the wafer according to a set trajectory, including: obtaining a trajectory circle with the distance from the two-fluid nozzle to the support point as the radius and the support point as the center; taking the intersection points of the trajectory circle and the edge of the wafer, and recording them as the first intersection point and the second intersection point, the set trajectory being the part of the trajectory circle between the first intersection point and the second intersection point that intersects with the wafer; the two-fluid nozzle sprays the mixed liquid and gas onto the wafer along the set trajectory, with the first intersection point or the second intersection point as the starting point and the other of the first intersection point and the second intersection point as the ending point.

[0016] Further optionally, during the process of cleaning the wafer with the two-fluid nozzle, the pressure of the gas supplied to the two-fluid nozzle is adjusted by the gas pressure regulating system and the first pressure regulating valve so that the gas pressure in the middle region of the wafer is less than the gas pressure in the edge region of the wafer. This includes: selecting X points along the set trajectory from the first intersection point and the second intersection point, with equal spacing between adjacent points, where X is an odd number; when the two-fluid nozzle starts spraying the mixed liquid and gas onto the wafer from the first intersection point or the second intersection point, the pressure of the gas supplied to the two-fluid nozzle is adjusted by the gas pressure regulating system and the first pressure regulating valve so that the gas pressure from the starting point to the edge region is less than the gas pressure in the middle region of the wafer. The gas pressure in the two-fluid nozzle gradually decreases between points, and from the first point... The pressure of the gas in the two-fluid nozzle gradually increases between the point and the endpoint. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of an embodiment of a cleaning device provided by the present invention;

[0018] Figure 2 This is a schematic diagram of an embodiment of a cleaning device provided by the present invention;

[0019] Figure 3 This is a schematic diagram of an embodiment of a gas pressure regulation system provided by the present invention;

[0020] Figure 4 This is a cross-sectional schematic diagram of an embodiment of a gas pressure regulating system provided by the present invention;

[0021] Figure 5 This is a schematic diagram of an embodiment of a two-fluid nozzle spraying path provided by the present invention;

[0022] Figure 6 This is a flowchart illustrating an embodiment of a cleaning method provided by the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of this application are described below with reference to the accompanying drawings. In the description of the embodiments of this application, the terminology used in the following embodiments is for the purpose of describing specific embodiments only and is not intended to limit the application. As used in the specification and appended claims of this application, the singular expressions "a," "the," "the," "the," and "this" are intended to also include expressions such as "one or more," unless the context clearly indicates otherwise. It should also be understood that in the following embodiments of this application, "at least one" and "one or more" refer to one or more (including two). The term "and / or" is used to describe the relationship between related objects, indicating that three relationships can exist; for example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0024] References to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized. The term "connection" includes direct connections and indirect connections, unless otherwise stated. "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 technical features indicated.

[0025] In the embodiments of this application, the words "exemplarily" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplarily" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of the words "exemplarily" or "for example" is intended to present the relevant concepts in a specific manner.

[0026] This invention provides a cleaning device that mitigates the two-fluid pressure pulse effect caused by periodic changes in gas pressure. For example... Figure 1 As shown, the cleaning device includes: a plant control system 101, a first pressure regulating valve 103, a gas pressure regulating system 102, and a two-fluid nozzle 104; the first outlet of the plant control system 101 is connected to the first inlet of the gas pressure regulating system 102 via a first pipeline, and gas is supplied to the gas pressure regulating system 102 through the first outlet of the plant control system 101; the first outlet of the gas pressure regulating system 102 is connected to the first inlet of the two-fluid nozzle 104 via a second pipeline, and gas is supplied to the gas pressure regulating system 104 through the first outlet of the plant control system 101. The first outlet of the 02 supply gas to the two-fluid nozzle 104. A first pressure regulating valve 103 is provided on the second pipeline to regulate the gas pressure in the second pipeline. The second outlet of the plant control system 101 is connected to the second inlet of the two-fluid nozzle 104 through a third pipeline, and a chemical solution is supplied to the two-fluid nozzle 104 through the second outlet of the plant control system 101. The two-fluid nozzle 104 is used to mix the chemical solution and gas, and sprays the mixed chemical solution and gas onto the wafer through its outlet to clean the wafer.

[0027] The present invention provides a first pressure regulating valve on the second pipeline to facilitate the adjustment of the pressure of the two fluids on the wafer, so as to prevent the wafer from being damaged due to excessive pressure during the cleaning process. In other words, the present invention ensures the integrity of the wafer structure while ensuring that the wafer is clean.

[0028] In one possible embodiment, such as Figure 2 As shown, the cleaning device further includes a second pressure regulating valve 201; the second pressure regulating valve 201 is disposed on the first pipeline, and is used to regulate the gas pressure in the first pipeline. The second pressure regulating valve can be used to pre-treat the gas pressure in the pipeline.

[0029] In another possible embodiment, the gas pressure regulating system includes N branch pipelines, where N is a positive integer; each branch pipeline is equipped with a switching valve and a third pressure regulating valve, the switching valve being electrically connected to a switching control unit, and the third pressure regulating valve being electrically connected to a pressure control unit. The switching control unit controls the opening and closing of the switching valve, and the pressure control unit controls the third pressure regulating valve to regulate the gas pressure in the branch pipelines. The first outlet of the plant control system is connected to the first inlet of the gas pressure regulating system via a first pipeline, and the first outlet of the gas pressure regulating system is connected to the first inlet of the two-fluid nozzle via a second pipeline. This includes: the first outlet of the plant control system being connected to one end of each of the N branch pipelines via a first pipeline, and the other end of each of the N branch pipelines being connected to the first inlet of the two-fluid nozzle via a second pipeline. For example, as... Figure 3 As shown, a second pressure regulating valve is installed at the first inlet end of the gas pressure regulating system. Gas, after pressure regulation, enters a plurality of branch pipelines of the gas pressure regulating system in a proportional manner. The gas from these branch pipelines is collected and then flows out from the first outlet end of the gas pressure regulating system, where it is pressure regulated by the first pressure regulating valve and supplied to the two-fluid nozzle. The gas pressure regulating system includes N branch pipelines, where N is greater than or equal to 25. Each branch pipeline is equipped with a switching valve and a third pressure regulating valve. Figure 3 As shown ( Figure 3 (Only some branch pipelines are shown). These switching valves include: valve K1, valve K2, ..., valve K25, ... These third pressure regulating valves include: valve V1, valve V2, ..., valve V25, ...

[0030] Optionally, when N is greater than or equal to 3 and less than 5, the spacing between adjacent branch pipes is equal. Further, optionally, when N is greater than or equal to 5 and less than or equal to 9, the branch pipes are arranged in a circle with the port of one branch pipe as the center, and the center lines connecting the ports of the remaining branch pipes are circular and evenly distributed around the center. Still further, optionally, when N is greater than 9, the branch pipes are divided into i loops with the port of one branch pipe as the center, and the center lines connecting the ports of the branch pipes in each loop are circular and evenly distributed around the center, with equal spacing between adjacent loops, where i is a positive integer; and the number of branch pipes in the j-th loop is: Here, j is a positive integer, and the value of j is less than or equal to i. For example, as shown... Figure 4 As shown, the branch pipes are evenly distributed in a circular mirror image at the first inlet and first outlet ends of the gas pressure regulating system. The branch pipes begin with one at the center of the outlet pipe, followed by eight in the first ring, sixteen in the second ring, and so on, up to the i-th ring. The root. The radius of the i-th cycle distribution is Where R is the radius of the first outlet pipe of the gas pressure regulating system, i is the total number of turns of the branch pipe at the outlet, and j is the j-th turn (j=1, 2, 3, ..., i). Within the same turn, the distance between two adjacent branch pipes is equal. The cross-sections of each branch pipe and the first outlet pipe of the gas pressure regulating system are as follows: Figure 4 As shown ( Figure 4 (Only a portion of the branch piping is shown).

[0031] Preferably, (0, If the first pipe in the i-th cycle is marked as , then the k-th pipe in the i-th cycle can be represented by coordinates ( , The ) represents the . The i-th loop of the pipeline can be divided into 2i+1 groups according to the mirror image of the center. (0, ) and (0, If the first group is marked as the first group, then the last group in the clockwise direction is the 2i+1 group. According to the process requirements, starting from the nth circle, the pressure of the two fluids is regulated by opening and closing several groups of branch pipes that are mirror-symmetrical to the center of the circle.

[0032] In one possible embodiment, the two-fluid nozzle is disposed at one end of a swing arm, and the other end of the swing arm is fixed to a support point via a movable connection structure. The swing arm swings around the support point via the movable connection structure, so that the two-fluid nozzle can clean the wafer surface according to a preset trajectory. For example, the path sprayed by the two-fluid nozzle on the wafer is divided into an odd number of points, S1, S2, S3, ..., S2m+1 (m is a positive integer greater than or equal to 1), with equal distances between each point. S1 and S2m+1 correspond to the outermost edge of the wafer, and Sm+1 corresponds to the center of the wafer. For convenience, this invention defines S1 as the starting point, S2m+1 as the ending point, and S2, S3, ..., S2m as intermediate points. It is further stipulated that when the two-fluid nozzle sprays, the path passing through S1, S2, S3, ..., S2m+1 in sequence is the outbound path; when the two-fluid nozzle returns from the endpoint, the path passing through S2m+1, S2m, ..., S3, S2, S1 in sequence is the return path.

[0033] For ease of understanding, this invention uses m = 2 for related technical descriptions, meaning the spray path of the two-fluid nozzle on the wafer is divided into five points: S1, S2, S3, S4, and S5. The relative positions of these five points are as follows: Figure 5 As shown, SO is the support point of the swing arm, and the two-fluid nozzle is installed at the other end of the swing arm. When the swing arm is at the origin position, the position of the two-fluid nozzle coincides with S1; when the swing arm is at the end position, the position of the two-fluid nozzle coincides with S5. The process of the two-fluid nozzle moving from the starting point S1 to the ending point S5 and then back from the ending point S5 to the starting point S1 is called one cycle. During the wafer cleaning process, the two-fluid nozzle needs to go through several cycles.

[0034] During the outward journey, when the two-fluid nozzle reaches S2, the gas pressure regulating system sends commands to the switch control unit and the pressure control unit. The switch control unit controls the opening and closing of the switch valve, and the pressure control unit controls the third pressure regulating valve to adjust the gas pressure in the branch pipeline. This reduces the pressure of the gas supplied by the gas pressure regulating system to the two-fluid nozzle by a set ratio, thereby reducing the pressure of the two fluids in the middle region. When the nozzle reaches S4, the gas pressure regulating system sends commands to the switch control unit and the pressure control unit. The switch control unit controls the opening and closing of the switch valve, and the pressure control unit controls the third pressure regulating valve to adjust the gas pressure in the branch pipeline. This increases the pressure of the gas supplied by the gas pressure regulating system to the two-fluid nozzle by a set ratio, thereby restoring the pressure of the two fluids in the edge region.

[0035] During the return stroke, when the two-fluid nozzle reaches S4, the gas pressure regulating system sends commands to the switch control unit and the pressure control unit. The switch control unit controls the opening and closing of the switch valve, and the pressure control unit controls the third pressure regulating valve to adjust the gas pressure in the branch pipeline. This reduces the pressure of the gas supplied by the gas pressure regulating system to the two-fluid nozzle by a set ratio, thereby reducing the pressure in the intermediate region. When the two-fluid nozzle reaches S2, the gas pressure regulating system sends commands to the switch control unit and the pressure control unit. The switch control unit controls the opening and closing of the switch valve, and the pressure control unit controls the third pressure regulating valve to adjust the gas pressure in the branch pipeline. This increases the pressure of the gas supplied by the gas pressure regulating system to the two-fluid nozzle by a set ratio, thereby restoring the pressure in the edge region.

[0036] For simplicity, this invention will be described with N equal to 25, meaning that the gas pressure regulating system has one branch pipe at the center of the first outlet, eight branch pipes in the first ring, and sixteen branch pipes in the second ring. The distribution of the 25 branch pipe outlets is as follows: Figure 4 As shown, the operating trajectory of the two-fluid nozzle is as follows: Figure 5 As shown, the relevant explanations are given by taking the example that the pressure of the two fluids in the middle region of the wafer is 8% and 72% lower than that in the edge region of the wafer.

[0037] Scenario 1: The fluid pressure in the central region of the wafer is 8% lower than that in the edge region.

[0038] 1) During the outward journey, when the two-fluid nozzle reaches S2, the gas pressure regulation system sends a command to the switch control unit and the pressure control unit to close a set of branch pipes that are mirror-symmetrical to the center of the second circle according to a set ratio, and supplies them to the two-fluid nozzle after pressure regulation, thereby reducing the pressure of the two fluid in the middle region of the wafer; when the two-fluid nozzle reaches S4, the system sends a command to open the closed branch pipes and supply them to the nozzle after pressure regulation, thereby restoring the pressure of the two fluid in the edge region of the wafer.

[0039] 2) During the return stroke, when the two-fluid nozzle reaches S4, the gas pressure regulating system sends a command to the switch control unit and the pressure control unit to close one set of branch pipes that are mirror-symmetrical to the center of the second circle according to a set ratio, and supplies them to the two-fluid nozzle after pressure regulation, thereby reducing the pressure in the middle region of the wafer; when the two-fluid nozzle reaches S2, the gas pressure regulating system sends a command to the switch control unit and the pressure control unit to open the closed branch pipes, and supplies them to the two-fluid nozzle after pressure regulation, thereby restoring the pressure in the edge region of the wafer.

[0040] The second scenario: The fluid pressure experienced in the central region of the wafer is 72% lower than that in the edge region.

[0041] 1) During the outward journey, when the two-fluid nozzle reaches S2, the gas pressure regulating system sends a command to the switch control unit and the pressure control unit to close all pipelines in the second circle and one set of branch pipelines that are mirror-symmetrical to the center of the first circle according to a set ratio, and supplies them to the two-fluid nozzle after pressure regulation, thereby reducing the pressure of the two fluids in the middle area; when the two-fluid nozzle reaches S4, the gas pressure regulating system sends a command to the switch control unit and the pressure control unit to open the aforementioned closed branch pipelines, and supplies them to the nozzle after pressure regulation, thereby restoring the pressure of the two fluids in the edge area.

[0042] 2) During the return stroke, when the two-fluid nozzle reaches S4, the gas pressure regulating system sends a command to the switch control unit and the pressure control unit to close all pipelines in the second loop and one set of branch pipelines that are mirror-symmetrical to the center of the first loop according to the set ratio, and supplies them to the two-fluid nozzle after pressure regulation, thereby reducing the pressure in the middle area; when the two-fluid nozzle reaches S2, the gas pressure regulating system sends a command to the switch control unit and the pressure control unit to open the aforementioned closed branch pipelines, and supplies them to the two-fluid nozzle after pressure regulation, thereby restoring the pressure in the edge area.

[0043] Based on the cleaning apparatus described in any of the above embodiments, the present invention provides a cleaning method, the process of which is as follows: Figure 5 As shown, it includes:

[0044] S501: Gas is supplied to the gas pressure regulating system through the first outlet end of the plant control system, and gas is supplied to the two-fluid nozzle through the first outlet end of the gas pressure regulating system;

[0045] S502: The liquid medicine is delivered to the two-fluid nozzle through the second outlet end of the plant control system;

[0046] S503: The two-fluid nozzle mixes the liquid medicine and gas;

[0047] S504: The two-fluid nozzle sprays the mixed liquid and gas onto the wafer according to a set trajectory to clean the wafer;

[0048] S505: During the process of cleaning the wafer with the two-fluid nozzle, the pressure of the gas delivered to the two-fluid nozzle is adjusted by the gas pressure regulating system and the first pressure regulating valve, so that the gas pressure in the middle region of the wafer is less than the gas pressure in the edge region of the wafer.

[0049] Optionally, the two-fluid nozzle sprays the mixed liquid and gas onto the wafer according to a set trajectory, including: obtaining a trajectory circle with the distance from the two-fluid nozzle to the support point as the radius and the support point as the center; taking the intersection points of the trajectory circle and the edge of the wafer, and recording them as the first intersection point and the second intersection point, the set trajectory being the part of the trajectory circle between the first intersection point and the second intersection point that intersects with the wafer; the two-fluid nozzle sprays the mixed liquid and gas onto the wafer along the set trajectory, with the first intersection point or the second intersection point as the starting point and the other of the first intersection point and the second intersection point as the ending point.

[0050] Further optionally, during the process of cleaning the wafer with the two-fluid nozzle, the pressure of the gas supplied to the two-fluid nozzle is adjusted by the gas pressure regulating system and the first pressure regulating valve so that the gas pressure in the middle region of the wafer is less than the gas pressure in the edge region of the wafer. This includes: selecting X points along the set trajectory from the first intersection point and the second intersection point, with equal spacing between adjacent points, where X is an odd number; when the two-fluid nozzle starts spraying the mixed liquid and gas onto the wafer from the first intersection point or the second intersection point, the pressure of the gas supplied to the two-fluid nozzle is adjusted by the gas pressure regulating system and the first pressure regulating valve so that the gas pressure from the starting point to the edge region is less than the gas pressure in the middle region of the wafer. The gas pressure in the two-fluid nozzle gradually decreases between points, and from the first point... The pressure of the gas in the two-fluid nozzle gradually increases between the point and the endpoint.

[0051] The above description is merely a specific implementation of the embodiments of this application, but the protection scope of the embodiments of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the embodiments of this application should be covered within the protection scope of the embodiments of this application. Therefore, the protection scope of the embodiments of this application should be determined by the protection scope of the claims.

Claims

1. A cleaning method, characterized in that, The cleaning device is used in a cleaning apparatus, which includes: a plant control system, a first pressure regulating valve, a gas pressure regulating system, and a two-fluid nozzle. The gas pressure regulating system includes: N branch pipelines, where N is a positive integer; each branch pipeline is equipped with a switching valve and a third pressure regulating valve; the switching valve is electrically connected to a switching control unit, and the third pressure regulating valve is electrically connected to a pressure control unit. The cleaning method includes: Gas is supplied to the gas pressure regulating system through the first outlet end of the plant control system, and gas is supplied to the two-fluid nozzle through the first outlet end of the gas pressure regulating system. The liquid medicine is delivered to the two-fluid nozzle through the second outlet end of the plant control system. The two-fluid nozzle mixes the liquid medicine and gas; The two-fluid nozzle sprays the mixed liquid and gas onto the wafer according to a set trajectory to clean the wafer; During the process of cleaning the wafer with the two-fluid nozzle, the pressure of the gas delivered to the two-fluid nozzle is adjusted by the gas pressure regulating system and the first pressure regulating valve, so that the gas pressure in the middle region of the wafer is less than the gas pressure in the edge region of the wafer. When the two-fluid nozzle reaches the first position, the gas pressure regulating system sends commands to the switch control unit and the pressure control unit. The switch control unit controls the switch valve to close a portion of the branch pipeline, and the pressure control unit controls the third pressure regulating valve to regulate the gas pressure in the branch pipeline. This reduces the pressure of the gas supplied by the gas pressure regulating system to the two-fluid nozzle by a set ratio, thereby reducing the pressure of the two fluids in the middle region of the wafer. When the two-fluid nozzle continues to reach the second position, the gas pressure regulating system sends commands to the switch control unit and the pressure control unit. The switch control unit controls the switch valve to open the branch pipeline that was closed in the first position, and the pressure control unit controls the third pressure regulating valve to regulate the gas pressure in the branch pipeline. This increases the pressure of the gas supplied by the gas pressure regulating system to the two-fluid nozzle by a set ratio, thereby restoring the pressure of the two fluids in the edge region of the wafer. The first position is the point between the starting point of the spray path and the corresponding center of the wafer, and the second position is the point between the ending point of the spray path and the corresponding center of the wafer.

2. The cleaning method according to claim 1, characterized in that, The two-fluid nozzle sprays the mixed liquid and gas onto the wafer according to a set trajectory, including: Using the distance from the two-fluid nozzle to the support point as the radius, and the support point as the center, a trajectory circle is obtained; The intersection points of the trajectory circle and the edge of the wafer are taken and recorded as the first intersection point and the second intersection point. The set trajectory is the part of the trajectory circle between the first intersection point and the second intersection point that intersects with the wafer. The two-fluid nozzle starts at either the first intersection point or the second intersection point and ends at the other of the first and second intersection points, spraying the mixed liquid and gas onto the wafer along the set trajectory.

3. The cleaning method according to claim 2, characterized in that, During the process of cleaning the wafer using the two-fluid nozzle, the pressure of the gas supplied to the two-fluid nozzle is adjusted by the gas pressure regulating system and the first pressure regulating valve, so that the gas pressure in the middle region of the wafer is less than the gas pressure in the edge region of the wafer, including: Along the predetermined trajectory, X points are selected between the first intersection point and the second intersection point, with equal spacing between adjacent points, where X is an odd number; When the two-fluid nozzle begins spraying the mixed liquid and gas onto the wafer from the first intersection point or the second intersection point, the gas pressure regulating system and the first pressure regulating valve regulate the pressure of the gas supplied to the two-fluid nozzle, so that the pressure from the starting point to the second intersection point is adjusted. The gas pressure in the two-fluid nozzle gradually decreases between points, and from the first point... The pressure of the gas in the two-fluid nozzle gradually increases between the point and the endpoint.

Images