Etching machine chamber air balance characterization method, monitoring method and system
By monitoring and adjusting the exhaust pressure and pH of the etching machine chamber, the problem of air imbalance in single-wafer etching machines was solved, thus improving wafer etching yield.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SIEN (QINGDAO) INTEGRATED CIRCUITS CO LTD
- Filing Date
- 2024-11-06
- Publication Date
- 2026-05-12
AI Technical Summary
Existing single-wafer etching equipment cannot effectively define and monitor the air balance in the chamber, resulting in unstable etching effects and affecting wafer yield.
By acquiring the exhaust pressure and ambient pH during the etching process, the target exhaust pressure and pH are calibrated, and the exhaust equipment power is monitored and adjusted in real time to maintain the air balance in the chamber.
Effective monitoring and regulation of chamber air balance reduces etching defects and improves wafer yield.
Smart Images
Figure CN122028673A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of semiconductor manufacturing technology, and more specifically, relates to a method, monitoring method and system for characterizing air balance in the chamber of an etching machine. Background Technology
[0002] The back-side etching process primarily involves thinning the back of the wafer. After physical thinning, a single-wafer etching machine is typically used to chemically thin the back side. One of the key factors affecting the etching effect of a single-wafer etching machine is aerodynamics, specifically the air balance within the etching machine chamber. During the etching reaction, gaseous reaction products are typically generated. These products, along with solvent droplets sprayed onto the wafer surface, collide and form a mist-like droplet. To reduce the impact of evaporation of reaction products and solvent droplets, the machine chamber is designed with exhaust equipment. However, excessively high or low exhaust rates can disrupt the air balance within the chamber, leading to non-standard defects on the back side of the wafer, resulting in reduced wafer yield or even scrap.
[0003] Existing single-wafer etching equipment lacks an effective definition of air balance within the equipment chamber, making it impossible to characterize or accurately monitor the air balance within the chamber. Furthermore, it cannot systematically control the exhaust equipment, frequently leading to air imbalance and resulting in defects in the etched products. When the air balance is imbalanced, the etching equipment also becomes unresponsive. Summary of the Invention
[0004] The purpose of this invention is to provide a method, monitoring method and system for characterizing air balance in an etching chamber. This method, monitoring method and system can effectively define the air balance in the etching chamber, effectively monitor the chamber to achieve air balance, and improve wafer etching yield.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of the present invention provides a method for characterizing the air balance of an etching machine chamber, comprising: The exhaust pressure inside the machine chamber during the etching process and the pH level inside the machine chamber during the etching process are obtained. Obtain the wafer etching status after etching is completed; Repeat the above steps multiple times, and calibrate the target exhaust pressure and target environmental pH based on the exhaust pressure, environmental pH, and wafer etching status obtained from each etching process.
[0006] In one embodiment, the process of obtaining the exhaust pressure inside the machine chamber during the etching process and obtaining the pH value of the environment inside the machine chamber during the etching process, wherein the exhaust pressure is the average value of the exhaust pressure of the machine chamber at a preset position during the etching process obtained multiple times at a fixed frequency, and the pH value is the average value of the pH value of the environment inside the machine chamber during the etching process obtained multiple times at a fixed frequency.
[0007] In one embodiment, the target exhaust pressure and target environmental pH are calibrated based on the exhaust pressure, environmental pH, and wafer etching status obtained from each etching process, including: The wafer surface image obtained from each etching process is compared with a preset standard etched wafer surface image. The venting pressure and the ambient pH value corresponding to the wafer surface image with the smallest difference from the standard etched wafer surface image are the target venting pressure and the target ambient pH value.
[0008] A second aspect of the present invention provides a method for monitoring the air balance in the chamber of an etching machine, comprising: The exhaust pressure inside the machine chamber during the etching process and the pH level inside the machine chamber during the etching process are obtained. The exhaust pressure is compared with the target exhaust pressure, and the environmental pH is compared with the target environmental pH. When the difference between the exhaust pressure and the target exhaust pressure is greater than a first preset value, and the difference between the ambient pH and the target ambient pH is less than a second preset value, the power of the machine chamber exhaust equipment is adjusted.
[0009] In one embodiment, the exhaust pressure inside the machine chamber during the etching process and the pH value of the environment inside the machine chamber during the etching process are obtained. The exhaust pressure is the average value of the exhaust pressure of the machine chamber at a preset position during the etching process, which is obtained multiple times at a fixed frequency. The pH value is the average value of the pH value of the environment inside the machine chamber during the etching process, which is obtained multiple times at a fixed frequency.
[0010] In one embodiment, after comparing the exhaust pressure with the target exhaust pressure and comparing the environmental pH with the target environmental pH, the method further includes: When the difference between the exhaust pressure and the target exhaust pressure is greater than a third preset value, and / or the difference between the ambient pH and the target ambient pH is greater than or equal to the second preset value, the etching machine is controlled to alarm.
[0011] In one embodiment, the first preset value is 0.1-0.2 kPa, and / or the second preset value is 0.1-0.2 kPa, and / or the third preset value is 0.8-1.2 kPa.
[0012] A third aspect of the present invention provides an air balance monitoring system for an etching machine chamber, comprising: Base, pressure sensor, droplet collector, pH meter, exhaust equipment, and controller; The pressure sensor is located on the chamber exhaust path and is used to detect the exhaust pressure. The droplet collector is used to collect mist-like droplets during the etching process inside the chamber. The pH meter is used to test the pH of the mist-like droplets to obtain the ambient pH. The controller is used for: The exhaust pressure inside the machine chamber during the etching process and the pH level inside the machine chamber during the etching process are obtained. The exhaust pressure is compared with the target exhaust pressure, and the environmental pH is compared with the target environmental pH. When the difference between the exhaust pressure and the target exhaust pressure is greater than a first preset value, and the difference between the ambient pH and the target ambient pH is less than a second preset value, the power of the machine chamber exhaust equipment is adjusted.
[0013] In one embodiment, the droplet collector includes a collection disk and a driving structure. The driving structure is used to drive the collection disk to a first state or a second state. When the collection disk is in the first state, it is used to collect mist-like droplets. When the pressure sensor is used to detect the exhaust pressure, the collection disk is in the second state.
[0014] In one embodiment, the first state is a horizontal state and the second state is a vertical state; or, the first state is an extended state and the second state is a contracted state.
[0015] In one embodiment, the collection tray is provided with a hydrophobic coating.
[0016] In one embodiment, an alarm is also included, which is signal-connected to the controller. The controller is further configured to control the etching machine to alarm when the difference between the exhaust pressure and the target exhaust pressure is greater than a third preset value, and / or when the difference between the ambient pH and the target ambient pH is greater than or equal to a second preset value.
[0017] In one embodiment, the external material of the pressure sensor is polyetheretherketone, the accuracy of the pressure sensor is less than 0.01 kPa, and the accuracy of the pH meter is 0.01 kPa.
[0018] The present invention provides a method for characterizing the air balance of an etching machine chamber, comprising: acquiring the exhaust pressure within the etching chamber during the etching process; acquiring the pH level of the environment within the etching chamber during the etching process; acquiring the wafer etching status after etching; repeating the above steps multiple times; and calibrating a target exhaust pressure and a target environmental pH level based on the exhaust pressure, the environmental pH level, and the wafer etching status acquired in each etching process. This method defines the air balance of the etching machine chamber by using the target exhaust pressure and the target environmental pH level, and characterizes the air balance by using the number of wafer defects after etching. This effectively defines and characterizes the air balance of the etching machine chamber, facilitating effective monitoring of the etching process.
[0019] The etching machine chamber air balance monitoring method provided by this invention includes acquiring the exhaust pressure and the ambient pH of the etching machine chamber during the etching process; comparing the exhaust pressure with a target exhaust pressure and comparing the ambient pH with a target ambient pH; when the difference between the exhaust pressure and the target exhaust pressure is greater than a first preset value, and the difference between the ambient pH and the target ambient pH is less than a second preset value, adjusting the power of the machine chamber exhaust equipment to bring the exhaust pressure closer to the target exhaust pressure. This etching machine chamber air balance monitoring method can effectively monitor the exhaust pressure and ambient pH of the etching machine chamber during the etching process. When the ambient pH is within a preset range, and the exhaust pressure decreases or exceeds the preset range, the exhaust pressure can be automatically adjusted to approach the target exhaust pressure. This etching machine chamber air balance monitoring method can effectively monitor the chamber air balance, reduce or avoid the phenomenon of etching defects on the wafer caused by air balance imbalance in the machine chamber, and improve the wafer etching yield. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of the etching machine chamber air balance characterization method provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the etching machine chamber air balance monitoring method provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the etching machine chamber air balance monitoring method provided in an embodiment of the present invention; Figure 4A schematic diagram of the air balance monitoring system for the etching machine chamber when the droplet collector is not in use, as provided in an embodiment of the present invention; Figure 5 A schematic diagram of the air balance monitoring system for the etching machine chamber in use, provided in an embodiment of the present invention; Figure 6 A schematic diagram of the collection tray of the etching machine chamber air balance monitoring system provided in an embodiment of the present invention in a horizontal state; Figure 7 This is a schematic diagram of the collection tray of the etching machine chamber air balance monitoring system provided in an embodiment of the present invention in a vertical state. Detailed Implementation
[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0023] In the description of this invention, it should be understood that the terms “comprising” and “having” as used herein, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.
[0024] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present 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. Therefore, they should not be construed as limitations on the present invention.
[0025] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. It should be understood that the term "and / or" as used herein is merely a description of the relationship between related objects, indicating that three relationships may exist; for example, A and / or B can represent: A alone, A and B simultaneously, and B alone. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.
[0026] The following detailed description of the etching machine chamber air balance characterization method, monitoring method, and system provided by the present invention, with reference to specific embodiments, provides a detailed explanation.
[0027] Figure 1 Please refer to the schematic diagram of the etching machine chamber air balance characterization method provided in the embodiment of the present invention. Figure 1 The first aspect of this embodiment provides a method for characterizing the air balance in the chamber of an etching machine, comprising: S101. Obtain the exhaust pressure inside the machine chamber during the etching process, and obtain the pH level of the machine chamber environment during the etching process. Specifically, the etching machine chamber air balance characterization method of this embodiment is applied to an acid-base single-wafer etching machine. In this embodiment, the exhaust pressure is obtained by a pressure sensor installed within the machine chamber, located on the exhaust path within the chamber. For example, the pressure sensor is installed on the side of the wafer carrier within the machine chamber. The pH level of the machine chamber environment in this embodiment is obtained by collecting mist-like droplets at a preset location within a preset time period and measuring the pH value of the collected mist-like droplets.
[0028] S102. Obtain the wafer etching status after etching is completed; Specifically, the wafer etching status in this embodiment can be obtained by taking an image of the wafer surface after etching is completed, wherein the technology of reflecting the wafer etching status through an image of the wafer surface is an existing technology.
[0029] S103. Repeat the above steps multiple times, and calibrate the target exhaust pressure and target environmental pH based on the exhaust pressure, environmental pH and the etching status of the wafer obtained in each etching process.
[0030] Specifically, images of the wafer surface after each etching process are compared, and the image of the wafer surface with the best etching result is selected as the characterization image. The exhaust pressure and environmental pH corresponding to this characterization image during the etching process are defined as the target exhaust pressure and target environmental pH. Alternatively, the wafer surface image obtained from each etching process is compared with a preset standard etched wafer surface image. The exhaust pressure and environmental pH corresponding to the wafer surface image with the smallest difference from the standard etched wafer surface image are defined as the target exhaust pressure and target environmental pH.
[0031] Furthermore, in the process of obtaining the exhaust pressure in the machine chamber during the etching process and obtaining the pH value of the environment in the machine chamber during the etching process, the exhaust pressure is the average value of the exhaust pressure in the machine chamber at a preset position during the etching process obtained multiple times at a fixed frequency, and the pH value is the average value of the pH value of the environment in the machine chamber during the etching process obtained multiple times at a fixed frequency.
[0032] For example, during the wafer etching process, the exhaust pressure at a fixed location is collected every 10 seconds within a certain time period. The average of the exhaust pressure collected multiple times during the entire wafer etching process is the exhaust pressure required for each etching operation. The fixed location is a fixed position on the exhaust path of the equipment chamber; for example, the fixed location is at the side of the wafer substrate. In this embodiment, the environmental pH is the average value of the environmental pH within the equipment chamber during the etching process, obtained multiple times at a fixed frequency. In this embodiment, the environmental pH within the equipment chamber is obtained by collecting mist droplets at a preset location within a preset time period and measuring the pH value of the collected mist droplets. Collecting the mist droplets requires a certain amount of time. In this embodiment, the frequency of collecting the environmental pH is less than the frequency of collecting the exhaust pressure.
[0033] The etching chamber air balance characterization method of this embodiment defines air balance by collecting environmental pH and exhaust pressure information within the chamber per unit area and time. It also characterizes air balance by collecting the number of wafer defects after etching, thus effectively defining air balance. For example, the target exhaust pressure in this embodiment is 2.5 ± 0.1 kPa, and the target environmental pH is 6.8 ± 0.1. When the exhaust pressure within the etching chamber is 2.5 ± 0.1 kPa and the environmental pH is 6.8 ± 0.1, the chamber is in an air balanced state. When the exhaust pressure exceeds 2.5 ± 0.1 kPa and / or the environmental pH exceeds 6.8 ± 0.1, the air balance within the chamber is unbalanced, facilitating effective monitoring of the etching process. Among them, the air balance imbalance in the machine chamber includes: exhaust pressure exceeding 2.5±0.1 kPa; or, the ambient pH value exceeding 6.8±0.1; or, the exhaust pressure exceeding 2.5±0.1 kPa and the ambient pH value exceeding 6.8±0.1.
[0034] The present invention provides a method for characterizing the air balance of an etching machine chamber, comprising: acquiring the exhaust pressure within the etching chamber during the etching process; acquiring the pH level of the environment within the etching chamber during the etching process; acquiring the wafer etching status after etching; repeating the above steps multiple times; and calibrating a target exhaust pressure and a target environmental pH level based on the exhaust pressure, the environmental pH level, and the wafer etching status acquired in each etching process. This method defines the air balance of the etching machine chamber by using the target exhaust pressure and the target environmental pH level, and characterizes the air balance by using the number of wafer defects after etching. This effectively defines and characterizes the air balance of the etching machine chamber, facilitating effective monitoring of the etching process.
[0035] Figure 2 This is a schematic diagram of the etching machine chamber air balance monitoring method provided in an embodiment of the present invention. Please refer to [link / reference]. Figure 2 The second aspect of this embodiment provides a method for monitoring the air balance in the chamber of an etching machine, comprising: S201. Obtain the exhaust pressure inside the machine chamber during the etching process, and obtain the pH level of the machine chamber environment during the etching process. Specifically, the etching chamber air balance characterization method of this embodiment is applied to an acid-base single-wafer etching machine. In this embodiment, the exhaust pressure is obtained by a pressure sensor installed inside the machine chamber. The pressure sensor is located on the exhaust path inside the machine chamber; exemplarily, the pressure sensor is located on the side of the base inside the machine chamber. The pH level of the machine chamber environment in this embodiment is obtained by collecting mist droplets at a preset location within a preset time period and measuring the pH value of the collected mist droplets.
[0036] S202. Compare the exhaust pressure with the target exhaust pressure, and compare the environmental pH with the target environmental pH. The target exhaust pressure and target environmental pH in this embodiment can be the target exhaust pressure and target environmental pH described in the first aspect embodiment above.
[0037] S203. When the difference between the exhaust pressure and the target exhaust pressure is greater than a first preset value, and the difference between the ambient pH and the target ambient pH is less than a second preset value, adjust the power of the machine chamber exhaust equipment.
[0038] For example, in this embodiment, the first preset value is 0.1 kPa and the second preset value is 0.1 kPa. When the difference between the exhaust pressure and the target exhaust pressure is greater than 0.1 kPa, and the difference between the ambient pH and the target ambient pH is less than 0.1 kPa, it indicates that the air balance in the machine chamber is unbalanced. At this time, the air balance in the chamber is restored by adjusting the power of the exhaust equipment. Specifically, when the exhaust pressure is greater than the target exhaust pressure, the power of the exhaust equipment is reduced; when the exhaust pressure is less than the target exhaust pressure, the power of the exhaust equipment is increased. (Here, the difference between the exhaust pressure and the target exhaust pressure represents the absolute value of the difference between the exhaust pressure and the target exhaust pressure, and the difference between the ambient pH and the target ambient pH represents the absolute value of the difference between the ambient pH and the target ambient pH.) After adjusting the power of the exhaust equipment, the difference between the exhaust pressure and the target exhaust pressure reaches within the preset range.
[0039] In this embodiment, adjusting the exhaust device power allows for adjustment of the airflow entering the machine chamber. Since the pH level within the machine chamber during etching is related to the etching solvent ratio and temperature, adjusting the exhaust device power only affects the number of collected droplets, not their pH level. Therefore, adjusting the exhaust device power does not affect the pH level within the machine chamber. In other words, when the difference between the ambient pH and the target pH level is within a preset range, but the difference between the exhaust pressure and the target exhaust pressure exceeds a preset range, adjusting the exhaust device power within the machine chamber can adjust the exhaust pressure back to the preset range without affecting the pH level, thus restoring air balance within the etching chamber.
[0040] Specifically, in step S201, the exhaust pressure inside the machine chamber during the etching process and the pH value of the environment inside the machine chamber during the etching process are obtained. The exhaust pressure is the average value of the exhaust pressure inside the machine chamber at a preset position during the etching process, which is obtained multiple times at a fixed frequency. The pH value is the average value of the pH value inside the machine chamber during the etching process, which is obtained multiple times at a fixed frequency.
[0041] For example, during the wafer etching process, the exhaust pressure at a fixed location is collected every 10 seconds within a certain time period. The average of the exhaust pressure collected multiple times during the entire wafer etching process is the exhaust pressure required for each etching operation. The fixed location is a fixed position on the exhaust path of the equipment chamber; for example, the fixed location is at the side of the wafer substrate. In this embodiment, the environmental pH is the average value of the environmental pH within the equipment chamber during the etching process, obtained multiple times at a fixed frequency. In this embodiment, the environmental pH within the equipment chamber is obtained by collecting mist droplets at a preset location within a preset time period and measuring the pH value of the collected mist droplets. Collecting the mist droplets requires a certain amount of time. In this embodiment, the frequency of collecting the environmental pH is less than the frequency of collecting the exhaust pressure.
[0042] Figure 3 This is a schematic diagram of the etching machine chamber air balance monitoring method provided in an embodiment of the present invention. Please refer to [link / reference]. Figure 3 Furthermore, after comparing the exhaust pressure with the target exhaust pressure and the environmental pH with the target environmental pH, the process further includes: S204. When the difference between the exhaust pressure and the target exhaust pressure is greater than a third preset value, and / or the difference between the ambient pH and the target ambient pH is greater than or equal to the second preset value, the etching machine is controlled to alarm.
[0043] Specifically, in this embodiment, when the difference between the exhaust pressure and the target exhaust pressure exceeds a preset range, and / or the difference between the ambient pH and the target ambient pH exceeds a preset range, the etching machine alarms and stops working to prevent serious product defects. For example, in this embodiment, the third preset value is 1 kPa, and the second preset value is 0.1. When the difference between the exhaust pressure and the target exhaust pressure exceeds 1 kPa, and the difference between the ambient pH and the target ambient pH exceeds 0.1, the etching machine alarms and stops working; when the difference between the exhaust pressure and the target exhaust pressure exceeds 1 kPa, the etching machine alarms and stops working; when the difference between the ambient pH and the target ambient pH exceeds 0.1, the etching machine alarms and stops working.
[0044] The etching machine chamber air balance monitoring method of this embodiment can effectively monitor the air pressure and ambient pH within the etching machine chamber, and provide feedback on the air balance status within the chamber during etching machine operation. When the difference between the exhaust pressure and the target exhaust pressure during etching exceeds a first preset value, and the difference between the ambient pH and the target ambient pH is less than a second preset value, the power of the machine chamber exhaust equipment can be adjusted to maintain air balance within the chamber. This avoids excessive or insufficient exhaust power affecting the chamber air balance, which could lead to non-standard defects on the back side of the wafer during etching, resulting in reduced wafer yield or even scrap. When the difference between the exhaust pressure and the target exhaust pressure exceeds a third preset value, and / or the difference between the ambient pH and the target ambient pH is greater than or equal to a second preset value, the etching machine generates an alarm signal, preventing serious etching defects caused by excessive air imbalance within the machine chamber.
[0045] In this embodiment, the first preset value, the second preset value, and the third preset value can be preset in advance by technicians. The first preset value is 0.1-0.2 kPa, and / or the second preset value is 0.1-0.2 kPa, and / or the third preset value is 0.8-1.2 kPa.
[0046] Optionally, the first preset value is 0.1-0.2 kPa, the second preset value is 0.1-0.2 kPa, and the third preset value is 0.8-1.2 kPa. Wherein, the first preset value of 0.1-0.2 kPa indicates that the first preset value is greater than or equal to 0.1 kPa and less than or equal to 0.2 kPa; the second preset value of 0.1-0.2 indicates that the second preset value is greater than or equal to 0.1 kPa and less than or equal to 0.2 kPa; and the third preset value of 0.8-1.2 kPa indicates that the third preset value is greater than or equal to 0.8 kPa and less than or equal to 1.2 kPa.
[0047] The etching machine chamber air balance monitoring method provided in this invention includes acquiring the exhaust pressure and the ambient pH of the etching machine chamber during the etching process; comparing the exhaust pressure with a target exhaust pressure and comparing the ambient pH with a target ambient pH; when the difference between the exhaust pressure and the target exhaust pressure is greater than a first preset value and the difference between the ambient pH and the target ambient pH is less than a second preset value, adjusting the power of the machine chamber exhaust equipment to bring the exhaust pressure closer to the target exhaust pressure. This etching machine chamber air balance monitoring method can effectively monitor the exhaust pressure and ambient pH of the etching machine chamber during the etching process. When the ambient pH is within a preset range, and the exhaust pressure decreases or exceeds the preset range, the exhaust pressure can be automatically adjusted to approach the target exhaust pressure. This etching machine chamber air balance monitoring method can effectively monitor the chamber air balance, reduce or avoid the phenomenon of etching defects on the wafer caused by air balance imbalance in the machine chamber, and improve the wafer etching yield.
[0048] Figure 4 This is a schematic diagram of the air balance monitoring system for the etching machine chamber when the droplet collector is not in use, as provided in an embodiment of the present invention. Figure 5 Please refer to the schematic diagram of the air balance monitoring system of the etching machine chamber in the operating state of the droplet collector provided in this embodiment of the invention. Figure 4 and 5 The third aspect of this embodiment provides an air balance monitoring system for an etching machine chamber, including a base 1, a pressure sensor 2, a droplet collector 3, a pH meter 4, an exhaust device 5, and a controller 6. The pressure sensor 1 is located on the chamber exhaust path and is used to detect the exhaust pressure. The droplet collector 3 is located on the side of the base 1 and is used to collect mist-like droplets during the etching process in the chamber. The pH meter 4 is used to test the pH of the mist-like droplets to obtain the ambient pH. The controller 6 is used to obtain the exhaust pressure of the machine chamber at a preset position during the etching process and to obtain the ambient pH of the machine chamber during the etching process. The exhaust pressure is compared with the target exhaust pressure, and the ambient pH is compared with the target ambient pH. When the difference between the exhaust pressure and the target exhaust pressure is greater than a first preset value, and the difference between the ambient pH and the target ambient pH is less than a second preset value, the power of the machine chamber exhaust equipment is adjusted.
[0049] Existing traditional single-wafer etching machines lack an effective definition of air balance within the machine chamber, making it impossible to characterize or accurately monitor air balance. Furthermore, the power of the exhaust device 5 cannot be systematically controlled, frequently leading to air imbalance and product defects. Because the etching machine lacks monitoring capabilities, abnormal exhaust values also go unnoticed. This embodiment's etching machine chamber air balance monitoring system incorporates a pressure sensor 1 along the exhaust path within the chamber, a droplet collector 3 for collecting mist-like droplets during etching, and a pH meter 4 for testing the acidity and alkalinity of the mist-like droplets. A controller 6 monitors the exhaust pressure and ambient pH within the machine chamber. When the ambient pH is within a preset range, or when the exhaust pressure decreases or exceeds the preset range, the system automatically adjusts the power of the exhaust device 5 to bring the exhaust pressure closer to the target exhaust pressure, ensuring air balance within the machine chamber and reducing or preventing etching defects caused by air imbalance.
[0050] The etching machine chamber air balance monitoring system of this embodiment can effectively monitor the exhaust pressure and environmental pH in the machine chamber during the etching process. When the environmental pH is within the preset range, and the exhaust pressure decreases or exceeds the preset range, the exhaust pressure can be automatically adjusted to approach the target exhaust pressure, thereby reducing or avoiding the phenomenon of etching defects on the wafer caused by the imbalance of air in the machine chamber and improving the wafer etching yield.
[0051] Figure 6 This is a schematic diagram of the collection tray of the etching machine chamber air balance monitoring system provided in an embodiment of the present invention in a horizontal state. Figure 7 Please refer to the schematic diagram of the collection tray of the etching machine chamber air balance monitoring system provided in the embodiment of the present invention in the vertical state. Figure 6 and Figure 7 The droplet collector 3 in this embodiment includes a collection disk 31 and a driving structure. The driving structure drives the collection disk 31 to a horizontal or vertical position. When the collection disk 31 is in a horizontal position, it collects mist-like droplets. The droplet collector 3 in this embodiment is automatically controlled by the driving structure. In the state of collecting mist-like droplets, the driving structure drives the collection disk 31 to a horizontal position; in the state of not collecting droplets, the driving structure drives the collection disk 31 to a vertical position, ensuring that the collection disk 31 of the droplet collector 3 does not affect the exhaust situation inside the machine chamber.
[0052] In this embodiment, the collecting tray 31 collects mist-like droplets when it is in a horizontal state, and is in a vertical state when the pressure sensor detects the exhaust pressure. In other embodiments, the collecting tray 31 can be configured to collect mist-like droplets when it is in an extended state, and to be in a retracted state when the pressure sensor detects the exhaust pressure. The droplet collector 3 is automatically controlled by a drive structure. When collecting mist-like droplets, the drive structure drives the collecting tray 31 to be in an extended state; when not collecting, the drive structure drives the collecting tray 31 to be in a retracted state, ensuring that the collecting tray 31 of the droplet collector 3 does not affect the exhaust situation inside the machine chamber.
[0053] Preferably, the collecting tray 31 is provided with a hydrophobic coating. By providing a hydrophobic coating in the collecting tray 31, the hydrophobic coating reduces the contact angle and contact angular tension between the surface and water, allowing water droplets formed on its surface to fall off quickly, making it easier for the collecting tray 31 to collect mist-like droplets.
[0054] Specifically, in this embodiment, multiple droplet collectors 3 are designed below the bearing surface of the base 1, i.e., on the side of the base 1, to collect mist-like droplets. In this embodiment, there are four droplet collectors; however, in other embodiments, the number of droplet collectors can be more or less than four. Each droplet collector 3 includes a collection tray 31 and a driving structure, wherein the driving structure is a motor. When collecting droplets, the driving structure moves the four collection trays 31 from a vertical state to a horizontal state. In this embodiment, the driving structure can be controlled by a controller 6. For example, the controller 6 controls the driving structure to drive the collection trays 31 to a horizontal state, and within a preset time, the driving structure drives the collection trays 31 back from a horizontal state to a vertical state. After the collection trays 31 are in a vertical state, the liquid collected in the collection trays 31 flows through pipes to the pH meter 4, allowing the determination of the pH level of the machine chamber environment. The pH meter 4 in this embodiment is the pH meter used in the prior art.
[0055] Furthermore, in this embodiment, the external material of the pressure sensor 2 is polyetheretherketone (PEEK), the accuracy of the pressure sensor 2 is less than 0.01 kPa, and the accuracy of the pH meter 4 is 0.01 kPa. The use of PEEK as the external material of the pressure sensor 2 in this embodiment, given its high temperature resistance and chemical corrosion resistance, is beneficial because the etching reagents inside the etching machine chamber are highly corrosive. Therefore, using PEEK as the external material of the pressure sensor 2 in this embodiment can improve its service life.
[0056] Furthermore, the etching machine chamber air balance monitoring system of this embodiment also includes an alarm, which is connected to the controller. The controller is also used to control the etching machine to alarm when the difference between the exhaust pressure and the target exhaust pressure is greater than a third preset value, and / or when the difference between the ambient pH and the target ambient pH is greater than or equal to the second preset value.
[0057] In this embodiment, when the difference between the exhaust pressure and the target exhaust pressure exceeds a preset range, and / or when the difference between the ambient pH and the target ambient pH exceeds a preset range, the etching machine will alarm and stop working, thus preventing serious defects in the etched products.
[0058] The etching machine chamber air balance monitoring system of this embodiment includes a pressure sensor, a droplet collector, a pH meter, an exhaust system, an alarm, and a controller. The pressure sensor detects the exhaust pressure along the exhaust path. The droplet collector collects mist-like droplets generated during the etching process within the chamber. The pH meter measures the pH of the mist-like droplets to obtain the ambient pH. When the ambient pH is within a preset range, and the exhaust pressure decreases or exceeds the preset range, the system automatically adjusts the exhaust pressure to approach the target exhaust pressure. This etching machine chamber air balance monitoring method effectively monitors the chamber air balance, reducing or preventing etching defects caused by chamber air imbalance, thus improving wafer etching yield. When the exhaust pressure and / or ambient pH decrease or exceed the warning range, the controller can trigger an alarm and stop the etching machine, preventing severe etching defects caused by excessive air imbalance.
[0059] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for characterizing the air balance in the chamber of an etching machine, characterized in that, include: The exhaust pressure inside the machine chamber during the etching process and the pH level inside the machine chamber during the etching process are obtained. Obtain the wafer etching status after etching is completed; Repeat the above steps multiple times, and calibrate the target exhaust pressure and target environmental pH based on the exhaust pressure, environmental pH, and wafer etching status obtained from each etching process.
2. The method for characterizing air balance in the etching machine chamber according to claim 1, characterized in that, The process involves acquiring the exhaust pressure within the machine chamber during etching and the pH level within the machine chamber during etching. The exhaust pressure is the average value of the exhaust pressure at a preset location during etching, acquired multiple times at a fixed frequency. The pH level is the average value of the pH level within the machine chamber during etching, acquired multiple times at a fixed frequency.
3. The method for characterizing air balance in the etching machine chamber according to claim 1, characterized in that, Based on the exhaust pressure, ambient pH, and wafer etching status obtained from each etching process, the target exhaust pressure and target ambient pH are calibrated, including: The wafer surface image obtained after each etching is compared with a preset standard etched wafer surface image. The venting pressure and the ambient pH value corresponding to the wafer surface image with the smallest difference from the standard etched wafer surface image are the target venting pressure and the target ambient pH value.
4. A method for monitoring air balance in the chamber of an etching machine, characterized in that, include: The exhaust pressure inside the machine chamber during the etching process and the pH level inside the machine chamber during the etching process are obtained. The exhaust pressure is compared with the target exhaust pressure, and the environmental pH is compared with the target environmental pH. When the difference between the exhaust pressure and the target exhaust pressure is greater than a first preset value, and the difference between the ambient pH and the target ambient pH is less than a second preset value, the power of the machine chamber exhaust equipment is adjusted.
5. The method for monitoring air balance in the etching machine chamber according to claim 4, characterized in that, The exhaust pressure inside the machine chamber during the etching process is obtained, and the pH value inside the machine chamber during the etching process is obtained. The exhaust pressure is the average value of the exhaust pressure inside the machine chamber at a preset position during the etching process, which is obtained multiple times at a fixed frequency. The pH value inside the machine chamber is the average value of the pH value inside the machine chamber during the etching process, which is obtained multiple times at a fixed frequency.
6. The method for monitoring air balance in the etching machine chamber according to claim 5, characterized in that, The step of comparing the exhaust pressure with the target exhaust pressure and comparing the environmental pH with the target environmental pH further includes: When the difference between the exhaust pressure and the target exhaust pressure is greater than a third preset value, and / or the difference between the ambient pH and the target ambient pH is greater than or equal to the second preset value, the etching machine is controlled to alarm.
7. The method for monitoring air balance in the etching machine chamber according to claim 6, characterized in that, The first preset value is 0.1-0.2 kPa, and / or the second preset value is 0.1-0.2 kPa, and / or the third preset value is 0.8-1.2 kPa.
8. An air balance monitoring system for an etching machine chamber, characterized in that, include: Base, pressure sensor, droplet collector, pH meter, exhaust equipment, and controller; The pressure sensor is located on the chamber exhaust path and is used to detect the exhaust pressure. The droplet collector is used to collect mist-like droplets during the etching process inside the chamber. The pH meter is used to test the pH of the mist-like droplets to obtain the ambient pH. The controller is used for: The exhaust pressure inside the machine chamber during the etching process and the pH level inside the machine chamber during the etching process are obtained. The exhaust pressure is compared with the target exhaust pressure, and the environmental pH is compared with the target environmental pH. When the difference between the exhaust pressure and the target exhaust pressure is greater than a first preset value, and the difference between the ambient pH and the target ambient pH is less than a second preset value, the power of the machine chamber exhaust equipment is adjusted.
9. The etching machine chamber air balance monitoring system according to claim 8, characterized in that, The droplet collector includes a collection disk and a driving structure. The driving structure is used to drive the collection disk to a first state or a second state. When the collection disk is in the first state, it is used to collect mist-like droplets. When the pressure sensor is used to detect the exhaust pressure, the collection disk is in the second state.
10. The etching machine chamber air balance monitoring system according to claim 9, characterized in that, The first state is a horizontal state and the second state is a vertical state; or, the first state is an extended state and the second state is a contracted state.
11. The etching machine chamber air balance monitoring system according to claim 9, characterized in that, The collection tray is equipped with a hydrophobic coating.
12. The etching machine chamber air balance monitoring system according to claim 8, characterized in that, It also includes an alarm, which is signal-connected to the controller. The controller is further configured to control the etching machine to alarm when the difference between the exhaust pressure and the target exhaust pressure is greater than a third preset value, and / or when the difference between the ambient pH and the target ambient pH is greater than or equal to a second preset value.
13. The etching machine chamber air balance monitoring system according to any one of claims 8-12, characterized in that, The external material of the pressure sensor is polyetheretherketone, the accuracy of the pressure sensor is less than 0.01 kPa, and the accuracy of the pH meter is 0.01 kPa.