Variable-pressure plasma etching system and method and etching equipment

Abstract

The invention relates to the technical field of plasma etching, and particularly provides a variable-pressure plasma etching system and method and etching equipment, and the system comprises an etching reaction chamber; an etching gas supply assembly; the voltage distribution adjusting assembly is arranged below the wafer to be etched and is used for adjusting the voltage of different etching areas; the etching rate acquisition assembly is arranged in the etching cavity and is used for acquiring the actual etching rate corresponding to each etching area; the controller is used for controlling the voltage distribution adjusting assembly to adjust the voltage of each etching area according to the preset etching rate and the actual etching rate, so that the difference value between the preset etching rate and the actual etching rate of each etching area is adjusted to be within a preset range; the system can effectively solve the problems that a device obtained by a plasma etching process is inconsistent with a target device, the performance of the device is affected and even waste products are generated due to the fact that the distribution uniformity of the etching rate is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of plasma etching, and in particular, to a variable voltage plasma etching system, method, and etching equipment. Background Art

[0002] In the field of semiconductor technology, related technologies need to form required devices on a wafer by etching the wafer through a plasma etching process. During the execution of the plasma etching process, the parameters of the plasma etching process are not adjustable. And during the execution of the plasma etching process, if there are situations such as uneven gas distribution, uneven temperature distribution, or uneven pressure distribution, the uniformity of the etching rate distribution will be affected. Therefore, related technologies have problems that the devices obtained by the plasma etching process are inconsistent with the target devices, the device performance is affected, and even defective products are produced due to the reduction of the uniformity of the etching rate distribution.

[0003] In view of the above problems, there is currently no effective technical solution. It should be noted that the above information disclosed in this part is only used to understand the background of the inventive concept of the present invention, and therefore may include information that does not constitute the prior art. Summary of the Invention

[0004] The purpose of the present application is to provide a variable voltage plasma etching system, method, and etching equipment, which can effectively solve the problems that the devices obtained by the plasma etching process are inconsistent with the target devices, the device performance is affected, and even defective products are produced due to the reduction of the uniformity of the etching rate distribution.

[0005] In a first aspect, the present application provides a variable voltage plasma etching system, which includes: An etching reaction chamber, which includes an etching chamber for placing a wafer to be etched, and the wafer to be etched is divided into multiple etching regions; An etching gas supply assembly, which is communicated with the etching chamber and is used to supply etching gas to the etching chamber; A voltage distribution adjustment assembly, which is arranged below the wafer to be etched and is used to adjust the voltage of different etching regions; An etching rate acquisition assembly, which is arranged in the etching chamber and is used to acquire the actual etching rate corresponding to each etching region; A controller, which is used to control the voltage distribution adjustment assembly to adjust the voltage of each etching region according to a preset etching rate and the actual etching rate, so as to adjust the difference between the preset etching rate and the actual etching rate of each etching region to be within a preset range.

[0006] A variable-pressure plasma etching system provided by the present application can adjust the difference between the preset etching rate and the actual etching rate of each etching region to within a preset range through the cooperation of a voltage distribution adjustment component and an etching rate acquisition component. That is, even in the event of unexpected situations such as uneven gas distribution, uneven temperature distribution, or uneven pressure distribution, the present application can stabilize the actual etching rate of each etching region near the preset etching rate. Therefore, the present application can effectively improve the uniformity of the etching rate distribution, thereby effectively solving the problems that the devices obtained by the plasma etching process are inconsistent with the target devices, the device performance is affected, and even waste products are generated due to the reduction of the uniformity of the etching rate distribution.

[0007] Optionally, the process of the controller controlling the voltage distribution adjustment component to adjust the voltage of each etching region according to the preset etching rate and the actual etching rate includes: A1. Generate a target voltage adjustment amount corresponding to each etching region according to the difference between the preset etching rate and the actual etching rate; A2. Control the voltage distribution adjustment component to adjust the voltage of the corresponding etching region according to the target voltage adjustment amount.

[0008] Optionally, step A1 includes: A11. Generate a preliminary voltage adjustment amount corresponding to each etching region according to the difference between the preset etching rate and the actual etching rate; A12. Calculate the coupling interference amount corresponding to the target etching region according to the preliminary voltage adjustment amount or the target voltage adjustment amount of the etching region adjacent to the target etching region and the preset coupling weight, and then calculate the corresponding target voltage adjustment amount according to the preliminary voltage adjustment amount and the coupling interference amount corresponding to the target etching region. The target etching region is the etching region for which the target voltage adjustment amount needs to be calculated; A13. Analyze whether there is an etching region for which the target voltage adjustment amount has not been calculated. If so, take any etching region for which the target voltage adjustment amount has not been calculated as the new target etching region, and return to step A12. If not, execute step A2.

[0009] Since this technical solution first calculates the coupling interference amount of the target etching region, and then calculates the target voltage adjustment amount according to the coupling interference amount and the preliminary voltage adjustment amount corresponding to the target etching region, this technical solution can effectively avoid the situation that when adjusting the voltage of a certain etching region, it will cause coupling interference to the voltage of the adjacent etching region, resulting in the inability to adjust the difference between the preset etching rate and the actual etching rate to within the preset range even when adjusting the voltage according to the target voltage adjustment amount obtained based on the difference between the preset etching rate and the actual etching rate. That is, this technical solution can effectively improve the accuracy of the target voltage adjustment amount and the etching rate adjustment, thereby further improving the uniformity of the etching rate and the yield of the etching process.

[0010] Optionally, step A12 includes: A121. Obtain etching parameter information, and obtain a preset coupling weight according to the etching parameter information and a first preset conversion relationship; A122. Calculate a coupling interference amount corresponding to the target etching area according to a preliminary voltage adjustment amount or a target voltage adjustment amount of an etching area adjacent to the target etching area and the preset coupling weight; A123. Calculate a target voltage adjustment amount corresponding to the target etching area according to the preliminary voltage adjustment amount and the coupling interference amount corresponding to the target etching area.

[0011] Since the change of etching parameter information will cause the change of the state of the plasma and the etching reaction characteristics, thus resulting in the change of the coupling interference degree between adjacent etching areas, and this technical solution is equivalent to dynamically adjusting the preset coupling weight according to the etching parameter information, so this technical solution can effectively improve the accuracy of the coupling interference amount, and further improve the accuracy of the target voltage adjustment amount and the etching rate adjustment.

[0012] Optionally, the process of dividing the etching area includes: B1. Perform area division on the wafer to be etched based on a preset division rule, so as to obtain a plurality of preliminary areas on the premise of meeting the distribution accuracy of the voltage distribution adjustment component and the etching rate acquisition component; B2. Obtain the device density corresponding to each preliminary area according to the pre-determined wafer design layout; B3. Analyze whether all the device densities are within a preset density range. If so, each preliminary area is used as an etching area. If not, step B4 is executed; B4. Analyze whether the device density of the preliminary area adjacent to the preliminary area exceeding the preset density range is within the preset density range. If so, step B5 is executed. If not, step B8 is executed; B5. Perform random area division on the area where the preliminary area exceeding the preset density range and the preliminary area adjacent to it and having a device density within the preset density range are located on the premise of meeting the distribution accuracy of the voltage distribution adjustment component and the etching rate acquisition component; B6. Obtain the device density of the preliminary area obtained after the random area division according to the wafer design layout; B7. Analyze whether the device densities of the preliminary areas obtained after the random area division are all within the preset density range. If so, the preliminary areas obtained after the random area division are used as etching areas. If not, perform random area division again and return to step B5; B8. On the premise of meeting the distribution accuracy of the voltage distribution adjustment component and the etching rate acquisition component, randomly divide the wafer to be etched into regions, and return to step B2.

[0013] Since the device density in the etching region is related to the etching rate when the plasma density and plasma energy are the same in different regions, and this technical solution divides the wafer to be etched into multiple etching regions based on the device density, this technical solution can effectively avoid the situation that the etching rate adjustment accuracy difference in different etching regions is too large and the etching rate uniformity decreases due to the too large difference in device density in different etching regions.

[0014] Optionally, the etching gas includes multiple component gases, the etching gas supply component includes multiple gas delivery pipelines, each gas delivery pipeline is used to deliver a component gas, a flow rate adjustment component is provided on each gas delivery pipeline, a gas ratio acquisition component is further provided in the etching chamber, the gas ratio acquisition component is used to acquire gas ratio information, the gas ratio information is the ratio of different component gases, and the controller is further used to control the flow rate adjustment component to adjust the flow rate of the component gas in the delivery pipeline where it is located according to the gas ratio information and the preset gas ratio, so as to adjust the gas ratio information to be the same as the preset gas ratio.

[0015] Since this technical solution can accurately control the ratio of various component gases in the etching chamber by controlling the flow rate adjustment component to adjust the flow rate of the component gas in the delivery pipeline where it is located according to the gas ratio information and the preset gas ratio, this technical solution can effectively avoid the situation that the stability and uniformity of the etching process are affected due to the fluctuation of the ratio of the component gases in the etching chamber, thereby further improving the yield rate of the etching process and the performance of the finally obtained device.

[0016] Optionally, a concentration acquisition component for acquiring the concentration information of the component gas is provided on each delivery pipeline, and the process by which the controller controls the flow rate adjustment component to adjust the flow rate of the component gas in the delivery pipeline where it is located according to the gas ratio information and the preset gas ratio includes: Obtain the ratio adjustment amount of each component gas according to the difference between the gas ratio information and the preset gas ratio; Obtain the flow rate adjustment amount of each component gas according to the ratio adjustment amount and the corresponding component gas concentration information; Control the corresponding flow rate adjustment component to adjust the flow rate of the component gas in the delivery pipeline where it is located according to the flow rate adjustment amount.

[0017] Optionally, a gas distributor is provided in the etching chamber.

[0018] The gas distributor of this technical solution is preferably an existing device, which can optimize the distribution state of the etching gas entering the etching chamber so that the etching gas diffuses evenly in the etching chamber. Therefore, this technical solution can effectively avoid the situation where the etching rates in different regions vary due to the uneven distribution of the etching gas in the etching chamber.

[0019] Second, the present application also provides a variable-pressure plasma etching method, which is applied to the variable-pressure plasma etching system provided in the first aspect above. The variable-pressure plasma etching method includes the following steps: S1. Control the voltage distribution adjustment component to adjust the voltage of each etching area according to the preset etching rate and the actual etching rate, so as to adjust the difference between the preset etching rate and the actual etching rate of each etching area to be within the preset range.

[0020] The variable-pressure plasma etching method provided by the present application can, through the cooperation of the voltage distribution adjustment component and the etching rate acquisition component, adjust the difference between the preset etching rate and the actual etching rate of each etching area to be within the preset range. That is, even if unexpected situations such as uneven gas distribution, uneven temperature distribution, or uneven pressure distribution occur, the present application can still stabilize the actual etching rate of each etching area near the preset etching rate. Therefore, the present application can effectively improve the uniformity of the etching rate distribution, thereby effectively solving the problems that the device obtained by the plasma etching process is inconsistent with the target device, the device performance is affected, and even waste products are produced due to the reduction of the etching rate distribution uniformity.

[0021] Third, the present application provides an etching device, which includes a variable-pressure plasma etching system provided in the first aspect above.

[0022] The etching device provided by the present application can, through the cooperation of the voltage distribution adjustment component and the etching rate acquisition component, adjust the difference between the preset etching rate and the actual etching rate of each etching area to be within the preset range. That is, even if unexpected situations such as uneven gas distribution, uneven temperature distribution, or uneven pressure distribution occur, the present application can still stabilize the actual etching rate of each etching area near the preset etching rate. Therefore, the present application can effectively improve the uniformity of the etching rate distribution, thereby effectively solving the problems that the device obtained by the plasma etching process is inconsistent with the target device, the device performance is affected, and even waste products are produced due to the reduction of the etching rate distribution uniformity.

[0023] As can be seen from the above, a variable-voltage plasma etching system, method and etching equipment provided by the present application can adjust the difference between the preset etching rate and the actual etching rates of each etching area to be within the preset range through the cooperation of the voltage distribution adjustment component and the etching rate acquisition component. That is, even in the event of unexpected situations such as uneven gas distribution, uneven temperature distribution or uneven pressure distribution, the present application can also stabilize the actual etching rates of each etching area near the preset etching rate. Therefore, the present application can effectively improve the distribution uniformity of the etching rate, thereby effectively solving the problems that the devices obtained by the plasma etching process are inconsistent with the target devices, the device performance is affected, and even waste products are generated due to the reduction of the distribution uniformity of the etching rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 FIG. is a schematic structural diagram of a variable-voltage plasma etching system provided by an embodiment of the present application.

[0025] Figure 2 FIG. is a schematic control relationship diagram of a variable-voltage plasma etching system provided by an embodiment of the present application.

[0026] Reference numerals: 1, etching chamber; 2, wafer to be etched; 3, conveying pipeline; 4, voltage distribution adjustment component; 5, etching rate acquisition component; 6, controller; 7, flow rate adjustment component; 8, concentration acquisition component; 9, gas distributor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Usually, the components of the embodiments of the present application described and shown in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application claimed, but only represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0028] It should be noted that: similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of the present application, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0029] In the first aspect, as Figure 1 and Figure 2As shown, the present application provides a variable voltage plasma etching system, which includes: An etching reaction chamber, which includes an etching chamber 1 for placing the wafer 2 to be etched, and the wafer 2 to be etched is divided into a plurality of etching regions; An etching gas supply component, which is communicated with the etching chamber 1 and is used for supplying etching gas into the etching chamber 1; A voltage distribution adjustment component 4, which is arranged below the wafer 2 to be etched and is used for adjusting the voltage of different etching regions; An etching rate acquisition component 5, which is arranged in the etching chamber 1 and is used for acquiring the actual etching rate corresponding to each etching region; A controller 6, which is used for controlling the voltage distribution adjustment component 4 to adjust the voltage of each etching region according to the preset etching rate and the actual etching rate, so as to adjust the difference between the preset etching rate and the actual etching rate of each etching region to be within the preset range.

[0030] Among them, the etching reaction chamber of this embodiment can be an existing plasma etching chamber. The etching reaction chamber includes an etching chamber 1 for placing the wafer 2 to be etched. The wafer 2 to be etched is a wafer that needs to be subjected to plasma etching. In this embodiment, the wafer 2 to be etched can be divided into multiple etching regions by pre-dividing the wafer 2 to be etched according to the device layout or process requirements on the wafer 2 to be etched. In this embodiment, the wafer 2 to be etched can also be divided into multiple etching regions by using grid lines to divide the wafer 2 to be etched. In this embodiment, the wafer 2 to be etched can also be divided into multiple etching regions by constructing multiple concentric circles centered on the center of the wafer 2 to be etched. The etching gas supply component of this embodiment can be an existing etching gas supply component. The etching gas supply component is communicated with the etching chamber 1. The etching gas supply component is used to supply etching gas into the etching chamber 1. The etching gas is the gas required for performing the etching process. The voltage distribution adjustment component 4 of this embodiment is arranged below the wafer 2 to be etched. The voltage distribution adjustment component 4 can adjust the voltage of different etching regions. Specifically, the voltage distribution adjustment component 4 of this embodiment includes multiple voltage adjustment units. Each etching region corresponds to at least one voltage adjustment unit. The voltage adjustment unit is preferably a variable voltage electrode. The etching rate acquisition component 5 of this embodiment can measure the actual etching rate corresponding to each etching region by means of optical measurement, electrical measurement, etc. Specifically, the etching rate acquisition component 5 of this embodiment includes multiple etching rate acquisition units. Each etching region corresponds to at least one etching rate acquisition unit. The etching rate acquisition unit can be a depth acquisition component. Since during the etching process, the etching depth of the wafer 2 to be etched is positively correlated with the etching time, in this embodiment, the actual etching rate of the corresponding etching region can be obtained by dividing the etching depth in the etching region by the etching time. The actual etching rate is equivalent to the average etching rate of the etching process. In this embodiment, the actual etching rate corresponding to the etching region can also be obtained by periodically collecting the etching depth in the etching region by using the depth acquisition component and dividing the change amount of the etching depth by the interval time for collecting the etching depth.

[0031] The controller 6 of this embodiment is electrically connected to the voltage distribution adjustment component 4 and the etching rate acquisition component 5 respectively. The working principle of the variable-voltage plasma etching system of this embodiment is as follows: After the wafer 2 to be etched is placed in the etching chamber 1, the etching gas supply component supplies etching gas into the etching chamber 1. The etching reaction chamber forms plasma by ionizing the etching gas. The voltage distribution adjustment component 4 forms an electric field by providing a voltage. Under the action of the electric field, the plasma will physically bombard the wafer or chemically react with the wafer, thereby realizing the etching of the wafer. Since the magnitude of the voltage is related to the intensity of the formed electric field, and the change in the electric field intensity will cause changes in the density and energy of the plasma, and both the density and energy of the plasma are positively correlated with the etching rate, this embodiment can adjust the etching rate in the etching area by using the voltage distribution adjustment component 4 to adjust the voltage in the etching area. This embodiment is equivalent to performing voltage zoning adjustment on the wafer 2 to be etched.

[0032] A variable-voltage plasma etching system provided by the present application can adjust the difference between the preset etching rate and the actual etching rate of each etching area to be within the preset range through the cooperation of the voltage distribution adjustment component 4 and the etching rate acquisition component 5, that is, even if unexpected situations such as uneven gas distribution, uneven temperature distribution, or uneven pressure distribution occur, the present application can also keep the actual etching rate of each etching area stable near the preset etching rate. Therefore, the present application can effectively improve the distribution uniformity of the etching rate, thereby effectively solving the problems that the devices obtained by the plasma etching process are inconsistent with the target devices, the device performance is affected, and even defective products are generated due to the reduction of the distribution uniformity of the etching rate, that is, the present application can effectively improve the yield rate of the etching process.

[0033] In some preferred embodiments, the process of the controller 6 controlling the voltage distribution adjustment component 4 to adjust the voltage of each etching area according to the preset etching rate and the actual etching rate includes: A1. Generate a target voltage adjustment amount corresponding to each etching area according to the difference between the preset etching rate and the actual etching rate; A2. Control the voltage distribution adjustment component 4 to adjust the voltage of the corresponding etching area according to the target voltage adjustment amount.

[0034] The target voltage adjustment amount in step A1 is the change amount of the voltage corresponding to the etching area before and after adjusting the difference between the preset etching rate and the actual etching rate to the preset range. Step A1 can generate the corresponding target voltage adjustment amount by substituting the difference between the preset etching rate and the actual etching rate into the pre-set voltage adjustment amount calculation formula. Step A1 can also obtain the target voltage adjustment amount of each etching area according to the difference between the preset etching rate and the actual etching rate and the second preset conversion relationship. The second preset conversion relationship is a mapping relationship between the etching rate deviation value and the voltage adjustment amount. In this embodiment, the corresponding target voltage adjustment amount can be obtained from the second preset conversion relationship according to the difference between the preset etching rate and the actual etching rate by means of data extraction.

[0035] In some preferred embodiments, step A1 includes: A11. Generate the preliminary voltage adjustment amount corresponding to each etching area according to the difference between the preset etching rate and the actual etching rate; A12. Calculate the coupling interference amount corresponding to the target etching area according to the preliminary voltage adjustment amount or the target voltage adjustment amount of the etching area adjacent to the target etching area and the preset coupling weight, and then calculate the corresponding target voltage adjustment amount according to the preliminary voltage adjustment amount and the coupling interference amount corresponding to the target etching area. The target etching area is the etching area for which the target voltage adjustment amount needs to be calculated; A13. Analyze whether there is an etching area for which the target voltage adjustment amount has not been calculated. If so, use any etching area for which the target voltage adjustment amount has not been calculated as the new target etching area, and return to step A12. If not, execute step A2.

[0036] The process of step A11 generating the preliminary voltage adjustment amount corresponding to each etching region according to the difference between the preset etching rate and the actual etching rate is preferably the same as the process of step A1 in the above embodiment of generating the target voltage adjustment amount corresponding to each etching region according to the difference between the preset etching rate and the actual etching rate. The preset coupling weight in step A12 can reflect the influence degree of the voltage adjustment of adjacent etching regions on the target etching region. Since the etching regions adjacent to the target etching region can be the etching regions for which the target voltage adjustment amount has not been calculated or the etching regions for which the target voltage adjustment amount has been calculated, step A12 needs to calculate the coupling interference amount corresponding to the target etching region according to the preliminary voltage adjustment amount or the target voltage adjustment amount of the etching regions adjacent to the target etching region and the preset coupling weight. Specifically, the process of step A12 calculating the coupling interference amount can be: summing up the preliminary voltage adjustment amount or the target voltage adjustment amount of the etching regions adjacent to the target etching region; taking the result of multiplying the summation result by the preset coupling weight as the coupling interference amount corresponding to the target etching region. Step A12 can obtain the target adjustment amount by subtracting the corresponding coupling interference amount from the preliminary voltage adjustment amount corresponding to the target etching region. It should be understood that when step A12 is executed for the first time (that is, the target voltage adjustment amount has not been calculated for all etching regions), this embodiment can randomly select an etching region as the target etching region. Since this embodiment first calculates the coupling interference amount of the target etching region, and then calculates the target voltage adjustment amount according to the coupling interference amount and the preliminary voltage adjustment amount corresponding to the target etching region, this embodiment can effectively avoid the situation that when adjusting the voltage of a certain etching region, it will cause coupling interference to the voltage of the adjacent etching regions, resulting in that adjusting the voltage based on the target voltage adjustment amount obtained according to the difference between the preset etching rate and the actual etching rate cannot adjust the difference between the preset etching rate and the actual etching rate to within the preset range. That is, this embodiment can effectively improve the accuracy of the target voltage adjustment amount and the etching rate adjustment, thereby further improving the uniformity of the etching rate and the yield of the etching process.

[0037] In some preferred embodiments, step A12 includes: A121. Obtain etching parameter information, and obtain a preset coupling weight according to the etching parameter information and a first preset conversion relationship; A122. Calculate the coupling interference amount corresponding to the target etching region according to the preliminary voltage adjustment amount or the target voltage adjustment amount of the etching regions adjacent to the target etching region and the preset coupling weight; A123. Calculate the target voltage adjustment amount corresponding to it according to the preliminary voltage adjustment amount and the coupling interference amount of the target etching region.

[0038] The etching parameter information of step A121 is the parameter that affects the etching quality or etching rate in the etching process. This etching parameter information can be obtained by real-time collection of sensors disposed in the etching chamber 1. The etching parameter information of step A121 can also be the data output by the etching reaction chamber. This etching parameter information can include any one or more of the etching gas pressure, etching gas flow rate, plasma density, etching temperature, etc. that can affect the etching process. The first preset conversion relationship of this embodiment is preferably a pre-constructed mapping relationship between the etching parameters and the coupling weights. Step A121 can obtain the corresponding preset coupling weight from the first preset conversion relationship according to the etching parameter information by means of data extraction. The principles of steps A122 and A123 are the same as those of step A12 in the above embodiment, and will not be elaborated here in detail. Since the change of the etching parameter information will cause the change of the state of the plasma and the etching reaction characteristics, resulting in the change of the coupling interference degree between adjacent etching regions, and this embodiment is equivalent to dynamically adjusting the preset coupling weight according to the etching parameter information, so this embodiment can effectively improve the accuracy of the coupling interference amount, thereby further improving the accuracy of the target voltage adjustment amount and the etching rate adjustment.

[0039] In some preferred embodiments, the process of dividing the etching regions includes: B1. Divide the wafer 2 to be etched based on a preset division rule to obtain a plurality of preliminary regions on the premise of meeting the distribution accuracy of the voltage distribution adjustment component 4 and the etching rate acquisition component 5; B2. Obtain the device density corresponding to each preliminary region according to the pre-determined wafer design layout; B3. Analyze whether all the device densities are within the preset density range. If so, each preliminary region is used as an etching region. If not, execute step B4; B4. Analyze whether the device density of the preliminary region adjacent to the preliminary region exceeding the preset density range is within the preset density range. If so, execute step B5. If not, execute step B8; B5. Perform random region division on the region where the preliminary region exceeding the preset density range and the preliminary region adjacent to it with the device density within the preset density range are located on the premise of meeting the distribution accuracy of the voltage distribution adjustment component 4 and the etching rate acquisition component 5; B6. Obtain the device density of the preliminary region obtained after the random region division according to the wafer design layout; B7. Analyze whether the device densities of the preliminary regions obtained after the random region division are all within the preset density range. If so, the preliminary regions obtained after the random region division are used as etching regions. If not, re-perform random region division and return to step B5; B8. On the premise of meeting the distribution accuracy of the voltage distribution adjustment component 4 and the etching rate acquisition component 5, randomly divide the wafer to be etched 2, and return to step B2.

[0040] The preset division rule in step B1 can be grid division, polar coordinate division or any other suitable area division method. Step B1 is equivalent to initially dividing the wafer into multiple regions where the voltage can be independently controlled. Meeting the distribution accuracy of the voltage distribution adjustment component 4 and the etching rate acquisition component 5 in step B1 is equivalent to making each initial region correspond to at least one voltage adjustment unit and at least one etching rate acquisition unit. Since before etching the wafer to be etched 2, relevant personnel will design the devices to be formed on the wafer to be etched 2, the wafer design layout in this embodiment is the layout obtained after the design is completed, and this wafer design layout can reflect the distribution of the devices on the wafer to be etched 2. Therefore, in step B2, the device density corresponding to each initial region can be obtained according to the wafer design layout. The device density is preferably the value obtained by dividing the number of devices included in the initial region by the area of the initial region. Since when the plasma density and plasma energy are the same in different regions, the device density in the etching region is related to the etching rate, and this embodiment divides the wafer to be etched 2 into multiple etching regions based on the device density, so this embodiment can effectively avoid the situation that the etching rate adjustment accuracy difference between different etching regions is too large and the etching rate uniformity decreases due to the too large difference in the device density of different etching regions. It should be understood that when the execution times of step B8 reach the preset times, this embodiment stops dividing the etching regions and generates an alarm message to remind relevant personnel to divide the wafer to be etched manually.

[0041] In some preferred embodiments, the etching gas includes multiple component gases, and the etching gas supply assembly includes multiple gas delivery pipelines. Each gas delivery pipeline is used to transport a component gas, and a flow rate adjustment assembly 7 is provided on each gas delivery pipeline. A gas ratio acquisition assembly is further provided in the etching chamber 1. The gas ratio acquisition assembly is used to acquire gas ratio information, where the gas ratio information is the ratio of different component gases. The controller 6 is further used to control the flow rate adjustment assembly 7 to adjust the flow rate of the component gas in the delivery pipeline 3 where it is located according to the gas ratio information and a preset gas ratio, so as to adjust the gas ratio information to be the same as the preset gas ratio. The gas ratio acquisition assembly of this embodiment is arranged in the etching chamber 1. The gas ratio acquisition assembly can be an existing gas analyzer, and is used to acquire in real time the ratio of different component gases (gas ratio information) inside the etching chamber 1. The controller 6 of this embodiment can control the flow rate adjustment assembly 7 to adjust the flow rate of the component gas in the delivery pipeline 3 where it is located according to the gas ratio information and the preset gas ratio, so as to adjust the gas ratio information to be the same as the preset gas ratio, thereby realizing precise control of the gas ratio in the etching chamber 1. Preferably, the controller 6 of this embodiment can control the flow rate adjustment assembly 7 to adjust the flow rate of the component gas in the delivery pipeline 3 where it is located according to the gas ratio information and the preset gas ratio based on the PID control algorithm. Since this embodiment can precisely control the ratio of various component gases in the etching chamber 1 by controlling the flow rate adjustment assembly 7 to adjust the flow rate of the component gas in the delivery pipeline 3 where it is located according to the gas ratio information and the preset gas ratio, this embodiment can effectively avoid the stability and uniformity of the etching process being affected due to fluctuations in the ratio of the component gases in the etching chamber 1, thereby further improving the yield rate of the etching process and the performance of the finally obtained device.

[0042] In some preferred embodiments, a concentration acquisition assembly 8 for acquiring the concentration information of the component gas is provided on each delivery pipeline 3. The process by which the controller 6 controls the flow rate adjustment assembly 7 to adjust the flow rate of the component gas in the delivery pipeline 3 where it is located according to the gas ratio information and the preset gas ratio includes: Obtaining the ratio adjustment amount of each component gas according to the difference between the gas ratio information and the preset gas ratio; Obtaining the flow rate adjustment amount of each component gas according to the ratio adjustment amount and the corresponding component gas concentration information; Controlling the corresponding flow rate adjustment assembly 7 to adjust the flow rate of the component gas in the delivery pipeline 3 where it is located according to the flow rate adjustment amount.

[0043] Since, under the condition that the proportional adjustment amount remains unchanged, the greater the concentration of the component gas, the smaller the change amount of the flow rate of the component gas, that is, under the condition of the same proportional adjustment amount, the component gas concentration information is negatively correlated with the flow rate adjustment amount, and the product of the component gas concentration information and the flow rate adjustment amount is equal to the product of the proportional adjustment amount and the volume of the etching gas introduced into the etching chamber 1. Therefore, in this embodiment, the flow rate adjustment amounts of various component gases can be obtained according to the proportional adjustment amount and the corresponding component gas concentration information. Since this embodiment calculates the flow rate adjustment amount by combining the proportional adjustment amount and the component gas concentration information, this embodiment effectively avoids the situation that the flow rate adjustment amount calculated only based on the proportional adjustment amount is different from the actually required flow rate adjustment amount due to the fluctuation of the concentration of the component gas, and the gas ratio information after the flow rate adjustment is still different from the preset gas ratio.

[0044] In some preferred embodiments, a gas distributor 9 is provided in the etching chamber 1. The gas distributor 9 in this embodiment is preferably an existing device, and the gas distributor 9 can optimize the distribution state of the etching gas entering the etching chamber 1, so that the etching gas diffuses uniformly in the etching chamber 1. Therefore, this embodiment can effectively avoid the situation that the etching rates in different regions are different due to the uneven distribution of the etching gas in the etching chamber 1.

[0045] As can be seen from the above, a variable-pressure plasma etching system provided by the present application can adjust the difference between the preset etching rate and the actual etching rates of each etching region to be within the preset range through the cooperation of the voltage distribution adjustment component 4 and the etching rate acquisition component 5, that is, even if unexpected situations such as uneven gas distribution, uneven temperature distribution, or uneven pressure distribution occur, the present application can also make the actual etching rates of each etching region stable near the preset etching rate. Therefore, the present application can effectively improve the distribution uniformity of the etching rate, thereby effectively solving the problems that the devices obtained by the plasma etching process are inconsistent with the target devices, the device performance is affected, and even waste products are generated due to the reduction of the distribution uniformity of the etching rate.

[0046] In a second aspect, the present application also provides a variable-pressure plasma etching method. The variable-pressure plasma etching method is applied to the variable-pressure plasma etching system provided in the first aspect above. The variable-pressure plasma etching method includes the following steps: S1. Control the voltage distribution adjustment component 4 to adjust the voltage of each etching region according to the preset etching rate and the actual etching rate, so as to adjust the difference between the preset etching rate and the actual etching rates of each etching region to be within the preset range.

[0047] A variable-pressure plasma etching method provided by the present application is applied to a variable-pressure plasma etching system provided in the first aspect above. The principle of the variable-pressure plasma etching method provided in this embodiment is the same as that of the variable-pressure plasma etching system provided in the first aspect, and will not be elaborated here in detail.

[0048] In a third aspect, the present application provides an etching apparatus, which includes a variable-pressure plasma etching system provided in the first aspect above.

[0049] An etching apparatus provided by the present application includes a variable-pressure plasma etching system provided in the first aspect above. The principle of the etching apparatus provided in this embodiment is the same as that of the variable-pressure plasma etching system provided in the first aspect, and will not be elaborated here in detail.

[0050] As can be seen from the above, a variable-pressure plasma etching system, method, and etching apparatus provided by the present application can adjust the difference between the preset etching rate and the actual etching rate of each etching area to be within the preset range through the cooperation of the voltage distribution adjustment component 4 and the etching rate acquisition component 5. That is, even in the event of unexpected situations such as uneven gas distribution, uneven temperature distribution, or uneven pressure distribution, the present application can also stabilize the actual etching rate of each etching area near the preset etching rate. Therefore, the present application can effectively improve the distribution uniformity of the etching rate, thereby effectively solving the problems that the devices obtained by the plasma etching process are inconsistent with the target devices, the device performance is affected, and even waste products are generated due to the reduction of the distribution uniformity of the etching rate.

[0051] In the embodiments provided by the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the above-mentioned unit division is only a logical function division, and there may be other division methods in actual implementation. For another example, multiple units or components can be combined or integrated into another robot, or some features can be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection can be through some communication interfaces. The indirect coupling or communication connection of the device or unit can be in electrical, mechanical or other forms.

[0052] In addition, the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be raised to one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0053] Furthermore, in each embodiment of the present application, each functional module may be integrated together to form an independent part, or each module may exist alone, or two or more modules may be integrated to form an independent part.

[0054] In this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0055] The above description is only for the embodiments of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A variable pressure plasma etching system, characterized in that: The variable pressure plasma etching system comprises: An etching reaction chamber, comprising an etching cavity for placing a wafer to be etched, wherein the wafer to be etched is divided into a plurality of etching areas; An etching gas supply assembly, communicated with the etching chamber, and used for supplying etching gas into the etching chamber; A voltage distribution adjustment component, disposed below the wafer to be etched, for adjusting the voltage of different etching areas; An etching rate collection component, disposed in the etching chamber, for collecting actual etching rates corresponding to each etching area; The controller is used to control the voltage distribution adjustment component to adjust the voltage of each etching area according to the preset etching rate and the actual etching rate, so as to adjust the difference between the preset etching rate and the actual etching rate of each etching area to be within a preset range.

2. The variable pressure plasma etching system according to claim 1, characterized in that: The process of the controller controlling the voltage distribution adjustment component to adjust the voltage of each etching area according to the preset etching rate and the actual etching rate includes: A1. generating a target voltage adjustment amount corresponding to each etching area according to a difference between a preset etching rate and the actual etching rate; A2. Control the voltage distribution adjustment component to adjust the voltage of the corresponding etching area according to the target voltage adjustment amount.

3. The variable pressure plasma etching system according to claim 2, characterized in that: Step A1 includes: A11, generating a preliminary voltage adjustment amount corresponding to each etching area according to the difference between the preset etching rate and the actual etching rate; A12, calculating the coupling interference amount corresponding to the target etching area according to the preliminary voltage adjustment amount or the target voltage adjustment amount of the etching area adjacent to the target etching area and the preset coupling weight, and then calculating the corresponding target voltage adjustment amount according to the preliminary voltage adjustment amount and the coupling interference amount corresponding to the target etching area, wherein the target etching area is the etching area for which the target voltage adjustment amount calculation is required; A13. Analyze whether there is an etching area for which the target voltage adjustment amount has not been calculated. If so, take any etching area for which the target voltage adjustment amount has not been calculated as a new target etching area and return to step A12. If not, execute step A2.

4. The variable pressure plasma etching system according to claim 3, characterized in that: Step A12 includes: A121. Obtain etching parameter information, and obtain a preset coupling weight according to the etching parameter information and a first preset conversion relationship; A122, calculating a coupling interference amount corresponding to the target etching area according to a preliminary voltage adjustment amount or a target voltage adjustment amount of an etching area adjacent to the target etching area and a preset coupling weight; A123. Calculate the corresponding target voltage adjustment amount according to the preliminary voltage adjustment amount and the coupling interference amount corresponding to the target etching area.

5. The variable pressure plasma etching system according to claim 1, characterized in that: The process of dividing the etching area includes: B1. Dividing the wafer to be etched into regions based on a preset division rule to obtain a plurality of preliminary regions under the premise of satisfying the distribution accuracy of the voltage distribution adjustment component and the etching rate acquisition component; B2. Obtaining device densities corresponding to each of the preliminary regions according to a predetermined wafer design layout; B3, analyzing whether the density of all the devices is within the preset density range, if so, taking each of the preliminary regions as an etching region, if not, executing step B4; B4, analyzing whether the device density of the preliminary region adjacent to the preliminary region beyond the preset density range is within the preset density range, and if so, executing step B5, if not, executing step B8; B5. Randomly divide the preliminary area beyond the preset density range and the area adjacent to the preliminary area where the device density is within the preset density range under the premise of satisfying the distribution accuracy of the voltage distribution adjustment component and the etching rate acquisition component; B6. Obtaining device density of a preliminary area after random area division according to the wafer design layout; B7, analyzing whether the device density of the preliminary area obtained after random area division is within the preset density range, if so, the preliminary area obtained after random area division is used as the etching area, if not, re-random area division and return to step B5; B8. Randomly divide the wafer to be etched into regions under the premise of satisfying the distribution accuracy of the voltage distribution adjustment component and the etching rate acquisition component, and return to step B2.

6. The variable pressure plasma etching system according to claim 1, characterized in that: The etching gas includes multiple component gases, and the etching gas supply component includes multiple gas pipelines, each of which is used to transport one of the component gases. Each of the gas pipelines is provided with a flow regulating component. A gas ratio collection component is also provided in the etching chamber, and the gas ratio collection component is used to collect gas ratio information, wherein the gas ratio information is the ratio of different component gases. The controller is also used to control the flow regulating component to adjust the flow of the component gas in the delivery pipeline according to the gas ratio information and the preset gas ratio, so as to adjust the gas ratio information to be the same as the preset gas ratio.

7. The variable pressure plasma etching system according to claim 6, characterized in that: Each of the delivery pipelines is provided with a concentration collection component for collecting component gas concentration information, and the process in which the controller controls the flow regulating component to regulate the flow of the component gas in the delivery pipeline according to the gas ratio information and the preset gas ratio includes: Obtaining a ratio adjustment amount of each of the component gases according to a difference between the gas ratio information and a preset gas ratio; Obtaining flow rate adjustment amounts of various component gases according to the proportional adjustment amounts and corresponding component gas concentration information; The corresponding flow regulating component is controlled according to the flow regulating amount to regulate the flow of the component gas in the delivery pipeline where it is located.

8. The variable pressure plasma etching system according to claim 1, characterized in that: A gas distributor is arranged in the etching chamber.

9. A variable pressure plasma etching method, characterized in that: The variable pressure plasma etching method is applied in the variable pressure plasma etching system according to any one of claims 1 to 8, and the variable pressure plasma etching method comprises the following steps: S1. Control the voltage distribution adjustment component to adjust the voltage of each etching area according to the preset etching rate and the actual etching rate, so as to adjust the difference between the preset etching rate and the actual etching rate of each etching area to be within a preset range.

10. An etching device, characterized in that: The etching equipment comprises the variable pressure plasma etching system as described in any one of claims 1-8.

Images