A variable pressure plasma etching system, method and etching apparatus

Abstract

The application relates to the technical field of plasma etching, and particularly provides a variable-pressure plasma etching system, a variable-pressure plasma etching method and an etching device. The system comprises an etching reaction chamber, an etching gas supply assembly, a voltage distribution adjusting assembly arranged below a wafer to be etched and used for adjusting the voltage of different etching areas, an etching rate collecting assembly arranged in the etching chamber and used for collecting the actual etching rate corresponding to each etching area, and a controller used for controlling the voltage distribution adjusting assembly to adjust the voltage of each etching area according to a preset etching rate and the actual etching rate, so that the difference 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 problem that the device obtained by the plasma etching process is inconsistent with a target device, the device performance is affected, and even a waste product is produced due to the reduction of the uniformity of the etching rate distribution.

Description

Technical Field

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

[0002] In the field of semiconductor technology, related technologies require forming the desired devices on wafers through a plasma etching process. During the plasma etching process, the parameters of the plasma etching process cannot be adjusted. If uneven gas distribution, uneven temperature distribution, or uneven pressure distribution occur during the plasma etching process, the uniformity of the etching rate distribution will be affected. Therefore, related technologies have the problem that due to the reduced uniformity of the etching rate distribution, the devices obtained by the plasma etching process are inconsistent with the target devices, the device performance is affected, and even the device is rejected.

[0003] There is no effective technical solution to the above problems. It should be noted that the above information disclosed in this section is only used to understand the background of the present invention, and therefore may contain information that does not constitute prior art. Summary of the Invention

[0004] The purpose of this application is to provide a variable pressure plasma etching system, method and etching equipment, which can effectively solve the problem that the devices obtained by the plasma etching process are inconsistent with the target devices due to the reduced distribution uniformity of the etching rate, the device performance is affected, and even waste is generated.

[0005] In a first aspect, the present application provides a variable pressure plasma etching system, comprising:

[0006] An etching reaction chamber includes an etching cavity for placing a wafer to be etched, and the wafer to be etched is divided into a plurality of etching areas;

[0007] An etching gas supply assembly is communicated with the etching chamber and is used to supply etching gas into the etching chamber;

[0008] A voltage distribution adjustment component is provided below the wafer to be etched and is used to adjust the voltage of different etching areas;

[0009] An etching rate acquisition component is provided in the etching chamber and is used to acquire the actual etching rate corresponding to each etching area;

[0010] 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 the preset range.

[0011] The present application provides a variable-pressure plasma etching system that can adjust the difference between a preset etching rate and the actual etching rate of each etching area to within a preset range through the cooperation of a voltage distribution adjustment component and an etching rate acquisition component. That is, even if unexpected conditions such as uneven gas distribution, uneven temperature distribution, or uneven pressure distribution occur, the present application can 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 problem of devices obtained by the plasma etching process being inconsistent with the target device, device performance being affected, and even waste being generated due to reduced etching rate distribution uniformity.

[0012] Optionally, 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:

[0013] A1. Generate a target voltage adjustment value corresponding to each etching area according to the difference between the preset etching rate and the actual etching rate;

[0014] A2. Control the voltage distribution adjustment component to adjust the voltage of the corresponding etching area according to the target voltage adjustment amount.

[0015] Optionally, step A1 includes:

[0016] A11. generating a preliminary voltage adjustment value corresponding to each etching area according to the difference between the preset etching rate and the actual etching rate;

[0017] A12. Calculate the coupling interference amount corresponding to the target etching area based on 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 target voltage adjustment amount corresponding to the target etching area based on 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 calculation is required.

[0018] 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.

[0019] Since this technical solution first calculates the coupling interference amount of the target etching area, and then calculates the target voltage adjustment amount based on the coupling interference amount corresponding to the target etching area and the preliminary voltage adjustment amount, this technical solution can effectively avoid the situation where the voltage of a certain etching area will be coupled to the voltage of the adjacent etching area when adjusting the voltage, resulting in the voltage adjustment based on the target voltage adjustment amount obtained according to the difference between the preset etching rate and the actual etching rate being unable to adjust the difference between the preset etching rate and the actual etching rate to within the preset range. 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.

[0020] Optionally, step A12 includes:

[0021] A121. Obtain etching parameter information, and obtain a preset coupling weight according to the etching parameter information and a first preset conversion relationship;

[0022] 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;

[0023] A123. Calculate the corresponding target voltage adjustment amount according to the preliminary voltage adjustment amount and coupling interference amount corresponding to the target etching area.

[0024] Since changes in etching parameter information will cause changes in the plasma state and etching reaction characteristics, thereby causing changes in the degree of coupling interference between adjacent etching areas, this technical solution is equivalent to dynamically adjusting the preset coupling weights based on the etching parameter information. Therefore, this technical solution 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.

[0025] Optionally, the process of dividing the etching area includes:

[0026] B1. Divide the wafer to be etched into regions based on preset division rules to obtain multiple preliminary regions while meeting the distribution accuracy of the voltage distribution adjustment component and the etching rate acquisition component;

[0027] B2. Obtain device density corresponding to each preliminary area based on a predetermined wafer design layout;

[0028] B3. Analyze whether the density of all devices is within the preset density range. If so, treat each preliminary area as an etching area. If not, execute step B4.

[0029] B4, analyzing the device density of the preliminary region adjacent to the preliminary region exceeding the preset density range is within the preset density range, and if so, proceed to step B5, if not, proceed to step B8;

[0030] B5. Randomly divide the preliminary area that exceeds the preset density range and the area adjacent to the preliminary area where the device density is within the preset density range, while meeting the distribution accuracy of the voltage distribution adjustment component and the etch rate acquisition component;

[0031] B6. Obtaining the device density of the preliminary area after random area division based on the wafer design layout;

[0032] B7, analyzing whether the device density of the preliminary area obtained after random area division is within the preset density range, if so, using the preliminary area obtained after random area division as the etching area, if not, re-performing random area division and returning to step B5;

[0033] 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.

[0034] Since the plasma density and plasma energy in different areas are the same, the device density in the etching area is related to the etching rate, and this technical solution divides the wafer to be etched into multiple etching areas based on the device density. Therefore, this technical solution can effectively avoid the situation where the etching rate adjustment accuracy of different etching areas is too different and the etching rate uniformity is reduced due to the large difference in device density in different etching areas.

[0035] Optionally, the etching gas includes multiple component gases, and the etching gas supply assembly includes multiple gas pipelines, each gas pipeline is used to transport a component gas, and each gas pipeline is provided with a flow regulating assembly. A gas ratio collection assembly is also provided in the etching chamber, and the gas ratio collection assembly is used to collect gas ratio information. The gas ratio information is the ratio of different component gases. The controller is also used to control the flow regulating assembly 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 the same as the preset gas ratio.

[0036] Since this technical solution can accurately control the proportions of various component gases in the etching chamber by controlling the flow regulating component to adjust the flow of the component gases in the delivery pipeline according to the gas ratio information and the preset gas ratio, this technical solution can effectively avoid the stability and uniformity of the etching process being affected by fluctuations in the proportions of the component gases in the etching chamber, thereby further improving the yield of the etching process and the performance of the final device.

[0037] Optionally, each delivery pipeline is provided with a concentration collection component for collecting component gas concentration information, and 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. The process includes:

[0038] Obtaining the proportional adjustment amount of each component gas according to the difference between the gas proportion information and the preset gas proportion;

[0039] Obtaining the flow rate adjustment amount of each component gas according to the proportional adjustment amount and the corresponding component gas concentration information;

[0040] The corresponding flow regulating component is controlled according to the flow regulating amount to regulate the flow of the component gas in the conveying pipeline where it is located.

[0041] Optionally, a gas distributor is provided in the etching chamber.

[0042] 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 can be evenly diffused in the etching chamber. Therefore, this technical solution can effectively avoid the situation where the etching rate in different areas is different due to the uneven distribution of the etching gas in the etching chamber.

[0043] In a second aspect, the present application further 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 comprises the following steps:

[0044] S1. 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, 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.

[0045] The present application provides a variable-pressure plasma etching method that can adjust the difference between a preset etching rate and the actual etching rate of each etching area to within a preset range through the cooperation of a voltage distribution adjustment component and an etching rate acquisition component. That is, even if unexpected conditions such as uneven gas distribution, uneven temperature distribution, or uneven pressure distribution occur, the present application can 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 problem of devices obtained by the plasma etching process being inconsistent with the target device, device performance being affected, and even waste being generated due to reduced etching rate distribution uniformity.

[0046] In a third aspect, the present application provides an etching device, which includes a variable pressure plasma etching system provided in the first aspect.

[0047] The present application provides an etching device that can adjust the difference between a preset etching rate and the actual etching rate of each etching area to within a preset range through the cooperation of a voltage distribution adjustment component and an etching rate acquisition component. That is, even if unexpected situations such as uneven gas distribution, uneven temperature distribution, or uneven pressure distribution occur, the present application can 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 problem that the device obtained by the plasma etching process is inconsistent with the target device, the device performance is affected, and even waste is generated due to the reduction in the distribution uniformity of the etching rate.

[0048] From the above, it can be seen that the variable pressure 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 rate of each etching area to within a preset range through the cooperation of the voltage distribution adjustment component and the etching rate acquisition component. That is, even if unexpected situations such as uneven gas distribution, uneven temperature distribution or uneven pressure distribution occur, the present application can 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 problem that the device obtained by the plasma etching process is inconsistent with the target device, the device performance is affected, and even waste is generated due to the reduction in the distribution uniformity of the etching rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A schematic structural diagram of a variable pressure plasma etching system provided in an embodiment of the present application.

[0050] Figure 2 A schematic diagram of the control relationship of a variable pressure plasma etching system provided in an embodiment of the present application.

[0051] Figure numerals: 1. Etching chamber; 2. Wafer to be etched; 3. Delivery pipeline; 4. Voltage distribution adjustment component; 5. Etching rate acquisition component; 6. Controller; 7. Flow adjustment component; 8. Concentration acquisition component; 9. Gas distributor. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the 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 of the embodiments. The components of the embodiments of the present application generally described and shown in the 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 drawings is not intended to limit the scope of the application for protection, but merely 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 making creative work fall within the scope of protection of the present application.

[0053] 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 or explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and should not be understood as indicating or implying relative importance.

[0054] First, as Figure 1 and Figure 2 As shown, the present application provides a variable pressure plasma etching system, which includes:

[0055] An etching reaction chamber includes an etching chamber 1 for placing a wafer 2 to be etched, and the wafer 2 to be etched is divided into a plurality of etching areas;

[0056] An etching gas supply assembly, communicated with the etching chamber 1, and configured to supply etching gas into the etching chamber 1;

[0057] A voltage distribution adjustment component 4 is provided below the wafer 2 to be etched and is used to adjust the voltage of different etching areas;

[0058] The etching rate collection component 5 is provided in the etching chamber 1 and is used to collect the actual etching rate corresponding to each etching area;

[0059] The controller 6 is used to control 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, 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.

[0060] Among them, the etching reaction chamber of this embodiment can be an existing plasma etching chamber, and the etching reaction chamber includes an etching chamber 1 for placing the wafer 2 to be etched, and the wafer 2 to be etched is a wafer that needs to be plasma etched. This embodiment can divide the wafer 2 to be etched into multiple etching areas by pre-dividing the wafer 2 to be etched according to the device layout or process requirements on the wafer 2 to be etched. This embodiment can also divide the wafer 2 to be etched into multiple etching areas by dividing the wafer 2 to be etched using grid lines. This embodiment can also divide the wafer 2 to be etched into multiple etching areas by constructing multiple rings with the center of the wafer 2 to be etched as the center. The etching gas supply component of this embodiment can be an existing etching gas supply component, and the etching gas supply component is connected to the etching chamber 1. The etching gas supply component is used to supply etching gas into the etching chamber 1, and the etching gas is the gas required to perform 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 areas. Specifically, the voltage distribution adjustment component 4 of this embodiment includes multiple voltage adjustment units, each etching area corresponds to at least one voltage adjustment unit, and the voltage adjustment unit is preferably a variable voltage electrode. The etching rate collection component 5 of this embodiment can measure the actual etching rate corresponding to each etching area by optical measurement or electrical measurement. Specifically, the etching rate collection component 5 of this embodiment includes multiple etching rate collection units, and each etching area corresponds to at least one etching rate collection unit. The etching rate collection unit can be a depth collection component. Since the etching depth of the wafer 2 to be etched is positively correlated with the etching time during the etching process, this embodiment can obtain the actual etching rate of the corresponding etching area by dividing the etching depth in the etching area by the etching time. The actual etching rate is equivalent to the average etching rate of the etching process. This embodiment can also use the depth collection component to periodically collect the etching depth in the etching area, and obtain the actual etching rate corresponding to the etching area by dividing the etching depth change by the interval time of collecting the etching depth.

[0061] 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 pressure 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 to the etching chamber 1, and the etching reaction chamber forms plasma by ionizing the etching gas. The voltage distribution adjustment component 4 forms an electric field by providing voltage. Under the action of the electric field, the plasma will physically bombard the wafer or react chemically with the wafer, thereby achieving 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 the density and energy of the plasma to change. The density and energy of the plasma are both positively correlated with the etching rate. Therefore, this embodiment can adjust the etching rate in the etching area by adjusting the voltage of the etching area using the voltage distribution adjustment component 4. This embodiment is equivalent to voltage zoning adjustment of the wafer 2 to be etched.

[0062] The present application provides a variable-pressure plasma etching system, which can adjust the difference between the preset etching rate and the actual etching rate of each etching area to within a 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 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 problem that the device obtained by the plasma etching process is inconsistent with the target device, the device performance is affected, and even waste is generated due to the reduced distribution uniformity of the etching rate. That is, the present application can effectively improve the yield rate of the etching process.

[0063] In some preferred embodiments, the process in which the controller 6 controls 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:

[0064] A1. Generate a target voltage adjustment value corresponding to each etching area according to the difference between the preset etching rate and the actual etching rate;

[0065] A2. Control the voltage distribution adjustment component 4 to adjust the voltage of the corresponding etching area according to the target voltage adjustment amount.

[0066] The target voltage adjustment amount of step A1 is the change in the voltage corresponding to the etching area before and after the difference between the preset etching rate and the actual etching rate is adjusted 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 a preset voltage adjustment amount calculation formula. Step A1 can also obtain the target voltage adjustment amount of each etching area based on 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. This embodiment can obtain the corresponding target voltage adjustment amount from the second preset conversion relationship based on the difference between the preset etching rate and the actual etching rate through data extraction.

[0067] In some preferred embodiments, step A1 includes:

[0068] A11. generating a preliminary voltage adjustment value corresponding to each etching area according to the difference between the preset etching rate and the actual etching rate;

[0069] A12. Calculate the coupling interference amount corresponding to the target etching area based on 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 target voltage adjustment amount corresponding to the target etching area based on 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 calculation is required.

[0070] 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.

[0071] Step A11 generates the preliminary voltage adjustment amount corresponding to each etching area according to the difference between the preset etching rate and the actual etching rate. The process of step A11 is preferably the same as the process of step A1 of the above embodiment of generating the target voltage adjustment amount corresponding to each etching area according to the difference between the preset etching rate and the actual etching rate. The preset coupling weight of step A12 can reflect the influence degree of the voltage adjustment of the adjacent etching area on the target etching area. Since the etching area adjacent to the target etching area can be an etching area that has not performed the target voltage adjustment amount calculation or an etching area that has completed the target voltage adjustment amount calculation, step A12 needs to 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. Specifically, the process of step A12 for calculating the coupling interference amount can be: summing the preliminary voltage adjustment amount or the target voltage adjustment amount of the etching area adjacent to the target etching area; and multiplying the summing result by the preset coupling weight to obtain the coupling interference amount corresponding to the target etching area. Step A12 can obtain the target adjustment amount by subtracting the coupling interference amount corresponding to the target etching area from the preliminary voltage adjustment amount corresponding to the target etching area. It should be understood that, when step A12 is performed for the first time (i.e., all etching areas have not performed the target voltage adjustment amount calculation), this embodiment can randomly select an etching area as the target etching area. Since this embodiment calculates the coupling interference amount of the target etching area first, 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 area, this embodiment can effectively avoid the situation that the target voltage adjustment amount based on 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 be within the preset range due to the coupling interference on the voltage of the etching area adjacent to the etching area whose voltage is adjusted, i.e., 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.

[0072] In some preferred embodiments, step A12 comprises:

[0073] A121, obtaining etching parameter information, and obtaining a preset coupling weight according to the etching parameter information and a first preset conversion relationship;

[0074] A122, calculating a 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;

[0075] A123, calculating the 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.

[0076] The etching parameter information of step A121 is a parameter that affects the etching quality or etching rate in the etching process. The etching parameter information can be collected in real time by a sensor set in the etching chamber 1. The etching parameter information of step A121 can also be data output by the etching reaction chamber. The etching parameter information can include any one or more parameters that can affect the etching process, such as etching gas pressure, etching gas flow rate, plasma density, etching temperature, etc. The first preset conversion relationship of this embodiment is preferably a pre-constructed mapping relationship between etching parameters and coupling weights. Step A121 can obtain the corresponding preset coupling weight from the first preset conversion relationship according to the etching parameter information by data extraction. The principles of steps A122 and A123 are the same as those of step A12 of the above embodiment and will not be discussed in detail here. Since changes in etching parameter information will cause changes in the plasma state and etching reaction characteristics, thereby causing changes in the degree of coupling interference between adjacent etching areas, this embodiment is equivalent to dynamically adjusting the preset coupling weight according to the etching parameter information. Therefore, 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.

[0077] In some preferred embodiments, the process of dividing the etching area includes:

[0078] B1. Divide the wafer 2 to be etched into regions based on a preset division rule, so as to obtain a plurality of preliminary regions while satisfying the distribution accuracy of the voltage distribution adjustment component 4 and the etching rate acquisition component 5;

[0079] B2. Obtain device density corresponding to each preliminary area based on a predetermined wafer design layout;

[0080] B3. Analyze whether the density of all devices is within the preset density range. If so, treat each preliminary area as an etching area. If not, execute step B4.

[0081] B4, analyzing the device density of the preliminary region adjacent to the preliminary region exceeding the preset density range is within the preset density range, and if so, proceed to step B5, if not, proceed to step B8;

[0082] B5. Randomly divide the preliminary area that exceeds the preset density range and the area adjacent to the preliminary area where the device density is within the preset density range, while satisfying the distribution accuracy of the voltage distribution adjustment component 4 and the etching rate acquisition component 5;

[0083] B6. Obtaining the device density of the preliminary area after random area division based on the wafer design layout;

[0084] B7, analyzing whether the device density of the preliminary area obtained after random area division is within the preset density range, if so, using the preliminary area obtained after random area division as the etching area, if not, re-performing random area division and returning to step B5;

[0085] B8. Divide the wafer 2 to be etched into random areas under the premise of satisfying the distribution accuracy of the voltage distribution adjustment component 4 and the etching rate acquisition component 5, and return to step B2.

[0086] The preset division rule of step B1 can be grid division, polar coordinate division, or any other suitable area division method. Step B1 is equivalent to preliminarily dividing the wafer into multiple areas where voltage can be independently controlled. 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 preliminary area correspond to at least one voltage adjustment unit and at least one etching rate acquisition unit. Because before etching the wafer 2 to be etched, relevant personnel will design the devices to be formed on the wafer 2 to be etched, the wafer design layout of this embodiment is the layout obtained after the design is completed. The wafer design layout can reflect the distribution of devices on the wafer 2 to be etched. Therefore, step B2 can obtain the device density corresponding to each preliminary area based on the wafer design layout. The device density is preferably a value obtained by dividing the number of devices contained in the preliminary area by the area of ​​the preliminary area. Since the device density within the etching region is related to the etching rate when the plasma density and plasma energy in different regions are the same, and this embodiment divides the wafer 2 to be etched into multiple etching regions based on the device density, this embodiment can effectively avoid the situation where the etching rate adjustment accuracy of different etching regions is too different due to the large difference in device density between different etching regions, resulting in a decrease in etching rate uniformity. It should be understood that when the number of executions of step B8 reaches the preset number, this embodiment stops dividing the etching regions and generates an alarm message to remind relevant personnel to manually divide the wafer to be etched into regions.

[0087] In some preferred embodiments, the etching gas includes multiple component gases, and the etching gas supply assembly includes multiple gas pipelines, each of which is used to transport a component gas. Each gas pipeline is equipped with a flow regulating assembly 7. A gas ratio acquisition assembly is also provided within the etching chamber 1. The gas ratio acquisition assembly is used to collect gas ratio information, which is the ratio of different component gases. The controller 6 is further used to control the flow regulating assembly 7 to adjust the flow of the component gases in the delivery pipeline 3, where it is located, based on the gas ratio information and a preset gas ratio, to adjust the gas ratio information to the same as the preset gas ratio. The gas ratio acquisition assembly of this embodiment is disposed within the etching chamber 1. The gas ratio acquisition assembly can be an existing gas analyzer and is used to collect the ratio of different component gases (gas ratio information) within the etching chamber 1 in real time. The controller 6 of this embodiment is capable of controlling the flow regulating assembly 7 to adjust the flow of the component gases in the delivery pipeline 3, where it is located, based on the gas ratio information and the preset gas ratio, to adjust the gas ratio information to the same as the preset gas ratio, thereby achieving precise control of the gas ratio within the etching chamber 1. Preferably, the controller 6 of this embodiment can control the flow rate regulating component 7 to adjust the flow rate of the component gases in the delivery pipeline 3 according to the gas ratio information and the preset gas ratio based on the PID control algorithm. Because this embodiment can accurately control the ratio of the various component gases in the etching chamber 1 by controlling the flow rate regulating component 7 to adjust the flow rate of the component gases in the delivery pipeline 3 according to the gas ratio information and the preset gas ratio, this embodiment can effectively avoid the situation where the stability and uniformity of the etching process are affected by fluctuations in the ratio of the component gases in the etching chamber 1, thereby further improving the yield of the etching process and the performance of the resulting device.

[0088] In some preferred embodiments, each delivery pipeline 3 is provided with a concentration collection component 8 for collecting component gas concentration information. The controller 6 controls the flow rate adjustment component 7 to adjust the flow rate of the component gas in the delivery pipeline 3 according to the gas ratio information and the preset gas ratio. The process includes:

[0089] Obtaining the proportional adjustment amount of each component gas according to the difference between the gas proportion information and the preset gas proportion;

[0090] Obtaining the flow rate adjustment amount of each component gas according to the proportional adjustment amount and the corresponding component gas concentration information;

[0091] The corresponding flow regulating component 7 is controlled according to the flow regulating amount to regulate the flow of the component gas in the delivery pipeline 3 where it is located.

[0092] Since, when the proportional adjustment amount remains unchanged, the greater the concentration of the component gas, the smaller the change in the flow rate of the component gas, that is, when the proportional adjustment amount remains unchanged, the component gas concentration information is negatively correlated with the flow adjustment amount, and the product of the component gas concentration information and the flow 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, this embodiment can obtain the flow adjustment amount of various component gases based on the proportional adjustment amount and the corresponding component gas concentration information. Because this embodiment calculates the flow adjustment amount based on the proportional adjustment amount and the component gas concentration information, it effectively avoids the situation where the flow adjustment amount calculated based solely on the proportional adjustment amount differs from the actual required flow adjustment amount due to fluctuations in the concentration of the component gas, and the gas ratio information after the flow adjustment is completed still differs from the preset gas ratio.

[0093] In some preferred embodiments, a gas distributor 9 is provided in the etching chamber 1. The gas distributor 9 of 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 is evenly diffused in the etching chamber 1. Therefore, this embodiment can effectively avoid the situation where the etching rate in different areas is different due to the uneven distribution of the etching gas in the etching chamber 1.

[0094] From the above, it can be seen that the 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 area to be within a 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 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 problem that the device obtained by the plasma etching process is inconsistent with the target device, the device performance is affected, and even waste is generated due to the reduction in the distribution uniformity of the etching rate.

[0095] In a second aspect, the present application further 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 comprises the following steps:

[0096] S1. Control 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, 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.

[0097] A variable pressure plasma etching method provided in 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 the principle of the variable pressure plasma etching system provided in the first aspect above, and will not be discussed in detail here.

[0098] In a third aspect, the present application provides an etching device, which includes a variable pressure plasma etching system provided in the first aspect.

[0099] The etching equipment provided in the present application includes the variable pressure plasma etching system provided in the first aspect above. The etching equipment provided in this embodiment has the same principle as the variable pressure plasma etching system provided in the first aspect above, and will not be discussed in detail here.

[0100] From the above, it can be seen that the variable pressure 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 rate of each etching area to within a 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 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 problem that the device obtained by the plasma etching process is inconsistent with the target device, the device performance is affected, and even waste is generated due to the reduction in the distribution uniformity of the etching rate.

[0101] In the embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the above-mentioned units is only a logical function division. There may be other division methods in actual implementation. For 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 mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interface, the indirect coupling or communication connection of the device or unit can be electrical, mechanical or other forms.

[0102] In addition, the units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0103] Furthermore, the functional modules in each embodiment of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0104] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any actual relationship or order between these entities or operations.

[0105] The above description is merely an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, various modifications and variations of the present application are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection 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 configured to supply etching gas into the etching chamber; A voltage distribution adjustment component is provided below the wafer to be etched and is used to adjust the voltage of different etching areas; An etching rate collection component is provided in the etching chamber and is used to collect the actual etching rate corresponding to each etching area; a controller, configured to control the voltage distribution adjustment component to adjust the voltage of each of the etching regions 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 of the etching regions to be within a preset range; 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. controlling the voltage distribution adjustment component to adjust the voltage of the corresponding etching area according to the target voltage adjustment amount; Step A1 includes: A11. generating a preliminary voltage adjustment amount corresponding to each etching area according to a difference between a preset etching rate and the actual etching rate; A12. Calculating a coupling interference amount corresponding to the target etching area based on 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, and then calculating a target voltage adjustment amount corresponding to the target etching area based on the preliminary voltage adjustment amount and the coupling interference amount corresponding to the target etching area, where 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.

2. The variable pressure plasma etching system according to claim 1, 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 of the target etching area according to the preliminary voltage adjustment amount and the coupling interference amount corresponding to the target etching area.

3. 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 while 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 a preset density range. If so, each of the preliminary regions is used as an etching region. If not, executing step B4; B4, analyzing 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, proceed to step B5, if not, proceed to step B8; B5. Randomly divide the preliminary area outside the preset density range and the area adjacent to the preliminary area where the device density is within the preset density range, while satisfying the distribution accuracy of the voltage distribution adjustment component and the etch rate acquisition component; B6. Obtaining device density in a preliminary area obtained by 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, using the preliminary area obtained after random area division as the etching area, if not, re-performing random area division and returning to step B5; B8. Divide the wafer to be etched into random areas 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.

4. 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 assembly includes multiple gas pipelines, each of which is used to transport one of the component gases. Each gas pipeline is provided with a flow regulating assembly, and a gas ratio collection assembly is also provided in the etching chamber. The gas ratio collection assembly is used to collect gas ratio information, and the gas ratio information is the ratio of different component gases. The controller is also used to control the flow regulating assembly 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.

5. The variable pressure plasma etching system according to claim 4, characterized in that: Each of the delivery pipelines is provided with a concentration collection component for collecting component gas concentration information. 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. The process 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 each of the component gases according to the proportional adjustment amount 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.

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

7. 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 6, 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.

8. An etching device, characterized in that: The etching equipment includes the variable pressure plasma etching system according to any one of claims 1 to 6.

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