Flow proportion control method and related device

Abstract

The embodiment of the invention provides a flow proportion control method, which comprises the following steps: on one hand, when the flow proportion of each gas branch is adjusted, the flow proportion of each gas branch is gradually close to a target set value through a gradual adjustment mode; output pressure fluctuation possibly caused by direct switching of the current set value of each gas branch to the target set value is avoided; on the other hand, when the number of simulation changes determined through the switching curve corresponding to each gas branch is larger than 1, the switching curve corresponding to each gas branch is corrected through the intermediate flow proportion, so that a target switching curve is obtained; the middle flow proportion corresponding to the first target branch is greater than or equal to the middle flow proportion corresponding to the second target branch, so that the flow proportion of each gas branch passes through the switching process of the branch with the maximum flow proportion at most once in the process of changing the current set value into the target set value; and the problem of frequent fluctuation of output gas pressure caused by frequent switching of the gas branch with the maximum flow ratio is avoided.

Description

Technical Field

[0001] The present specification relates to the field of automation control technology, specifically, to flow ratio control technology in the field of automation control technology, and more specifically, to a flow ratio control method and related devices. Background Art

[0002] In fields such as semiconductor technology, accurate flow control is crucial to the manufacturing process. Taking gas flow control as an example, a flow ratio controller (FRC) can be used to control the flow ratio of various gases to ensure stability and repeatability during the production process. For example, in the production process of semiconductor devices, a flow ratio controller can control the supply of gas to multiple process chambers. Accurately controlling the gas flow ratio to each process chamber is an important factor in ensuring the production yield and performance of the device. However, at present, there is a situation in which the pressure of the output gas may fluctuate frequently during the flow ratio control process, which has a negative impact on the production process. Summary of the invention

[0003] The embodiments of this specification provide a flow ratio control method and related devices to solve the problem of frequent fluctuations in the pressure of the output gas during the flow ratio adjustment process.

[0004] To achieve the above technical objectives, the embodiments of this specification provide the following technical solutions:

[0005] In a first aspect, an embodiment of the present specification provides a flow ratio control method, which is applied to a flow ratio controller, wherein the flow ratio controller includes a plurality of gas branches, and the gas branches include valves. The flow ratio control method includes:

[0006] In response to the current set values ​​of the plurality of gas branches changing to target set values, based on the switching curves corresponding to the gas branches, the number of simulated changes is determined, the number of simulated changes including the number of changes of the branch where the maximum set flow ratio is located when switching is performed according to the switching curves corresponding to the gas branches; the current set value is used to characterize the current set flow ratio of the gas branch, and the target set value is used to characterize the set flow ratio to be switched to by the gas branch; the switching curve is used to describe the manner in which the set flow ratio of the gas branch corresponding to the switching curve gradually changes from the current set value to the target set ratio;

[0007] If the number of simulated changes is greater than 1, the switching curve corresponding to each gas branch is corrected based on the intermediate flow ratio corresponding to each gas branch to obtain a target switching curve, wherein the target switching curve is used to describe the flow change of the set flow ratio of the gas branch corresponding to the target switching curve gradually changing from the current set value to the intermediate flow ratio, and then switching from the intermediate flow ratio to the target set value; the intermediate flow ratio corresponding to the first target branch is greater than or equal to the intermediate flow ratio corresponding to the second target branch, and the intermediate flow ratio corresponding to the second target branch is greater than or equal to the intermediate flow ratios corresponding to the other gas branches except the first target branch; the first target branch includes the gas branch with the largest current set value, and the second target branch includes the gas branch with the largest target set value;

[0008] Based on the target switching curve corresponding to each gas branch, the valve of the gas branch is controlled to gradually change the set flow ratio of the gas branch corresponding to the target switching curve from the current set value to the intermediate flow ratio, and then switch from the intermediate flow ratio to the target set value.

[0009] In a second aspect, an embodiment of the present specification provides a flow ratio controller, comprising: a plurality of gas branches and a control module, wherein the gas branches include valves; wherein:

[0010] The control module is configured to: in response to the current set values ​​of the plurality of gas branches changing to the target set values, determine the number of simulated changes based on the switching curves corresponding to the gas branches, the number of simulated changes including the number of changes of the branch where the maximum set flow ratio is located when switching according to the switching curves corresponding to the gas branches; the current set value is used to characterize the current set flow ratio of the gas branch, and the target set value is used to characterize the set flow ratio to be switched to by the gas branch; the switching curve is used to describe the way in which the set flow ratio of the gas branch corresponding to the switching curve gradually changes from the current set value to the target set ratio;

[0011] If the number of simulated changes is greater than 1, the switching curve corresponding to each gas branch is corrected based on the intermediate flow ratio corresponding to each gas branch to obtain a target switching curve, wherein the target switching curve is used to describe the flow change of the set flow ratio of the gas branch corresponding to the target switching curve gradually changing from the current set value to the intermediate flow ratio, and then switching from the intermediate flow ratio to the target set value; the intermediate flow ratio corresponding to the first target branch is greater than or equal to the intermediate flow ratio corresponding to the second target branch, and the intermediate flow ratio corresponding to the second target branch is greater than or equal to the intermediate flow ratios corresponding to the other gas branches except the first target branch; the first target branch includes the gas branch with the largest current set value, and the second target branch includes the gas branch with the largest target set value;

[0012] Based on the target switching curve corresponding to each gas branch, the valve of the gas branch is controlled to gradually change the set flow ratio of the gas branch corresponding to the target switching curve from the current set value to the intermediate flow ratio, and then switch from the intermediate flow ratio to the target set value.

[0013] In a third aspect, an embodiment of the present specification further provides a semiconductor process equipment, comprising: a flow ratio controller and a plurality of process chambers, wherein the flow ratio controller comprises any of the flow ratio controllers described above;

[0014] The multiple gas branches in the flow ratio controller are respectively used to provide gas to the multiple process chambers.

[0015] In a fourth aspect, an embodiment of the present specification further provides a computing device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the flow ratio control method as described above when executing the computer program.

[0016] In a fifth aspect, an embodiment of the present specification further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the flow ratio control method as described above is implemented.

[0017] In a sixth aspect, an embodiment of the present specification provides a computer program product or a computer program, wherein the computer program product includes a computer program, and the computer program is stored in a computer-readable storage medium; the processor of the computer device reads the computer program from the computer-readable storage medium, and the processor implements the steps of the above-mentioned flow ratio control method when executing the computer program.

[0018] It can be seen from the above technical scheme that the gas flow ratio control method provided in the embodiment of this specification determines the number of simulated changes based on the switching curve corresponding to each gas branch when the current set value of multiple gas branches changes to the target set value. The simulated change number includes the number of changes in the branch where the maximum set flow ratio is located when switching according to the switching curve corresponding to each gas branch; the current set value is used to characterize the current set flow ratio of the gas branch, and the target set value is used to characterize the set flow ratio to be switched to the gas branch; the switching curve is used to describe the way in which the set flow ratio of the gas branch corresponding to the switching curve gradually changes from the current set value to the target set ratio; when the number of simulated changes is greater than 1, the switching curve corresponding to each gas branch is corrected based on the intermediate flow ratio corresponding to each gas branch to obtain the target switching curve, and the target switching curve is used The invention is used to describe the flow change in which the set flow ratio of the gas branch corresponding to the target switching curve gradually changes from the current set value to the intermediate flow ratio, and then switches from the intermediate flow ratio to the target set value; the intermediate flow ratio corresponding to the first target branch is greater than or equal to the intermediate flow ratio corresponding to the second target branch, and the intermediate flow ratio corresponding to the second target branch is greater than or equal to the intermediate flow ratios corresponding to the other gas branches except the first target branch; the first target branch includes the gas branch with the largest current set value, and the second target branch includes the gas branch with the largest target set value; finally, based on the target switching curve corresponding to each gas branch, the valve of the gas branch is controlled to achieve the purpose of gradually changing the set flow ratio of the gas branch corresponding to the target switching curve from the current set value to the intermediate flow ratio, and then switching from the intermediate flow ratio to the target set value. In this way, on the one hand, when adjusting the flow ratio of each gas branch, the flow ratio of each gas branch is gradually adjusted to gradually approach the target setting value, thereby avoiding the output pressure fluctuation that may be caused by the current setting value of each gas branch being directly switched to the target setting value; on the other hand, when the number of simulated changes determined by the switching curve corresponding to each gas branch is greater than 1, the switching curve corresponding to each gas branch is corrected by the intermediate flow ratio to obtain the target switching curve. Since the intermediate flow ratio corresponding to the first target branch is greater than or equal to the intermediate flow ratio corresponding to the second target branch, this makes the flow ratio of each gas branch change from the current setting value to the target setting value. The process of switching the branch with the maximum flow ratio is at most once, thereby avoiding the problem of frequent fluctuations in output gas pressure caused by frequent switching of the gas branch with the maximum flow ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this specification. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0020] Figure 1 A schematic diagram of an application scenario of a flow ratio controller provided in one embodiment of this specification;

[0021] Figure 2 A schematic diagram of a flow rate ratio control method provided for one embodiment of this specification;

[0022] Figure 3 For Figure 2 Schematic diagram of the change of the branch number of the maximum set ratio when the flow ratio is adjusted by the method shown;

[0023] Figure 4 A flow chart of a flow ratio control method provided for one embodiment of this specification;

[0024] Figure 5 A schematic diagram of a target switching curve provided for one embodiment of this specification;

[0025] Figure 6 A schematic diagram of a target switching curve provided for another embodiment of this specification;

[0026] Figure 7 For Figure 5 or Figure 6 The schematic diagram of the change of the branch number of the maximum set ratio when the target switching curve is adjusted for the flow ratio;

[0027] Figure 8 A schematic diagram of a target switching curve provided for yet another embodiment of this specification;

[0028] Fig. 9 A schematic diagram of the control principle of a PID controller provided for one embodiment of this specification;

[0029] Fig.10 A schematic diagram of the structure of a semiconductor process equipment provided for one embodiment of the present specification;

[0030] Fig.11 A schematic diagram of the structure of a computing device provided for one embodiment of the present specification. DETAILED DESCRIPTION

[0031] Unless otherwise defined, the technical terms or scientific terms used in the embodiments of this specification shall have the common meanings understood by persons with ordinary skills in the field to which this specification belongs. The words "first", "second" and similar words used in the embodiments of this specification do not indicate any order, quantity or importance, but are only used to avoid confusion of constituent elements.

[0032] Unless the context requires otherwise, throughout the specification, "plurality" means "at least two", and "including" is interpreted as an open, inclusive meaning, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "examples", "specific examples" or "some examples" are intended to indicate that a particular feature, structure, material or characteristic associated with the embodiment or example is included in at least one embodiment or example of the specification. The schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0033] The technical solutions in the embodiments of this specification will be described below in conjunction with the drawings in the embodiments of this specification. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this specification.

[0034] Overview

[0035] In related technologies, precise control of flow ratio is crucial to the production process, such as Figure 1 As shown, taking the production process of semiconductor devices as an example, the gas supply equipment provides gas to the flow ratio controller. After the gas is input into the common input end of multiple gas branches, each gas branch transmits it to its connected process chamber respectively; in order to control the gas flow ratio passing through each gas branch, the control module in the flow ratio controller can collect the gas flow in each gas branch, and control the valve opening in each gas branch based on the gas flow ratio set for each gas branch, thereby realizing the flow ratio adjustment of the gas branch.

[0036] In some embodiments, in order to reduce the pressure drop caused by the gas passing through the flow ratio controller, at a certain moment, the valve opening in the gas branch with the largest gas flow ratio is usually maintained at a larger value, and needs to be greater than the valve opening in other gas branches. This is because, if it is to be ensured that the gas branch with the largest gas flow ratio can be adjusted to have the largest gas flow ratio, its valve opening is usually larger than the valve opening in other gas branches. If the valve opening in the gas branch with the largest gas flow ratio is smaller than the valve opening in any other gas branch, it is difficult for the gas branch with the largest gas flow ratio to be adjusted to have the largest gas flow ratio, and more gas will flow out through the gas branch with a larger opening. Under the premise that the valve opening in the gas branch with the largest gas flow ratio is larger than the valve opening in other gas branches, if the pressure drop caused by the gas passing through the flow ratio controller is to be reduced as much as possible, the valve opening in the gas branch with the largest gas flow ratio needs to be maintained at a larger value, or even keep the valve opening fully open, so as to reduce the pressure drop when the gas passes through the flow ratio control valve.

[0037] For example, assuming that there are three gas branches, namely branch A, branch B and branch C, and assuming that the gas flow ratios set for branch A, branch B and branch C at a certain moment are 10%, 40% and 50% respectively, then the valve opening of branch C can be made the maximum opening of the valves in the three branches, for example, 100%; on this basis, the valve opening of branch B can be adjusted to 80%, and the valve opening of branch A can be adjusted to 20%. When the cross-sectional area of ​​the branches is the same, the actual gas flow ratio can be adjusted to 10%, 40% and 50%. In this case, the obstruction of the flow ratio controller to the input gas can be minimized to the greatest extent, and the pressure drop caused by the gas passing through the flow ratio controller can be reduced.

[0038] Still taking the above example, assuming that the valve opening in branch C is adjusted to 50%, then in order to achieve the set gas flow ratio, the valve opening of branch B and branch A cannot be greater than 50%. Assuming that the valve opening of branch B is adjusted to 40%, and the valve opening of branch A is adjusted to 10%, although the purpose of adjusting the actual flow ratio to the set flow ratio can be achieved, the overall opening of the valves of each branch in the flow ratio controller becomes smaller, the gas resistance increases, and the pressure drop caused by the gas passing through the flow ratio controller is larger.

[0039] In some embodiments, in order to improve the service life of the valve and avoid possible damage to the valve when the valve opening is 100%, the valve opening of the branch with the largest flow ratio can be set to a larger value (for example, 80%, 90%, 95%), and this manual does not limit this.

[0040] The inventor has found that under the above-mentioned flow ratio control strategy, if the valve opening is directly adjusted according to the current set value and the target set value, it may cause the gas in the branch to fluctuate significantly. For example, assuming that the valve opening in branch A needs to be adjusted from 10% to 80%, if the valve opening is directly adjusted from 10% to 80% instantly, the cross-sectional area through which the gas in branch A can pass suddenly becomes larger, resulting in a large fluctuation in gas pressure. This gas fluctuation may affect the normal operation of subsequent process chambers and other gas receiving equipment. In order to avoid this problem, a gradual approach switching strategy can be set, that is, when the flow ratio of branch A needs to be switched from 10% to 80%, the flow ratio of branch A can be gradually converged from the current set value (e.g., 10%) to the target set value (e.g., 80%) by controlling the gradual change of the valve opening, thereby avoiding drastic changes in the gas in branch A.

[0041] However, the inventors discovered through further research that when the set values ​​of multiple branches change, if each branch gradually adjusts the flow ratio from the current set value to the target set value in a certain manner, the branch with the maximum set flow ratio at the current moment may change multiple times at different moments in the adjustment process. When the maximum set flow ratio changes, it is necessary to set the valve opening of the branch with the maximum set flow ratio to a larger value (for example, the valve is fully open, the reason is described above). Such multiple switching of the branch with the maximum set flow ratio will also cause the valve opening in some branches to change significantly at certain moments, thereby causing the gas pressure of the branch to fluctuate.

[0042] like Figure 2 and Figure 3 As shown, still taking the three branches 1, 2, and 3 as an example, assuming that the current set values ​​are 60%, 40%, and 0%, and the target set values ​​are 10%, 40%, and 50%, respectively, if the gas flow ratios of the three branches 1, 2, and 3 start from the current set values ​​and gradually approach the target set values ​​in a linear manner. Figure 2 ( Figure 2 In the example, the horizontal axis is time, the vertical axis is flow rate ratio, the unit is %) and Figure 3 As shown in the figure, during the change of gas flow ratio, the branch with the maximum set flow ratio (or Figure 31, the branch number of the maximum setting ratio shown in the figure changes twice, from branch 1 to branch 2 at time t1, and finally to branch 3 at time t2. Thus, before time t1, the branch number of the maximum setting ratio is 1 (i.e., MaxSet=1), and the valve opening of branch 1 remains at its maximum. At time t1, the branch number of the maximum setting ratio changes to 2 (i.e., MaxSet=2), and the valve of branch 1 switches from its maximum opening to the valve opening corresponding to the flow ratio set at time t1, and the valve of branch 2 switches from the valve opening corresponding to the flow ratio of 40% to the maximum opening; from time t1 to time t2, the valve opening of branch 2 remains at its maximum; after time t3, the branch number of the maximum setting ratio changes to 3 (i.e., MaxSet=3), and the valve opening of branch 3 remains at its maximum, i.e., at time t3, the valve of branch 2 switches from its maximum opening to the valve opening corresponding to the flow ratio of 40%, and the valve of branch 3 switches from the valve opening corresponding to the flow ratio set at time t3 to the maximum opening. During the above adjustment process, the valve opening of each branch has experienced at least one jump (from the opening corresponding to the set flow ratio at a certain moment to the maximum opening, or from the maximum opening to the opening corresponding to the set flow ratio at a certain moment). This jump will cause the gas pressure in the branch to fluctuate greatly.

[0043] In order to avoid frequent changes in the branch with the maximum flow ratio set during the flow ratio adjustment process, the inventors found through research that still referring to Figure 2 , before adjustment, based on the switching curve corresponding to each gas branch (the switching curve may be, for example, Figure 2Y1, Y2 and Y3 in the figure, Y1, Y2 and Y3 are the switching curves corresponding to branches 1, 2 and 3 respectively, which describe the way in which the set flow ratio of branches 1, 2 and 3 gradually changes from the current set value to the target set ratio), determine the number of simulated changes, the number of simulated changes includes the number of changes of the branch where the maximum set flow ratio is located when switching according to the switching curve corresponding to each gas branch; when the number of simulated changes is greater than 1, the switching curve corresponding to each gas branch can be corrected based on the intermediate flow ratio corresponding to each gas branch to obtain a target switching curve, the target switching curve is used to describe the flow change in which the set flow ratio of the gas branch corresponding to the target switching curve gradually changes from the current set value to the intermediate flow ratio, and then switches from the intermediate flow ratio to the target set value; the intermediate flow ratio corresponding to the first target branch is greater than or equal to the intermediate flow ratio corresponding to the second target branch, and the intermediate flow ratio corresponding to the second target branch is greater than or equal to the intermediate flow ratio corresponding to the other gas branches except the first target branch; the first target branch includes the gas branch with the largest current set value, and the second target branch includes the target branch. The target switching curve corresponding to each gas branch is used to control the valve of the gas branch so that the set flow ratio of the gas branch corresponding to the target switching curve is gradually changed from the current set value to the intermediate flow ratio, and then switched from the intermediate flow ratio to the target set value. In this way, on the one hand, when adjusting the flow ratio of each gas branch, the flow ratio of each gas branch is gradually adjusted to approach the target set value, thereby avoiding the output pressure fluctuation caused by the current set value of each gas branch directly switching to the target set value. On the other hand, when the number of simulated changes determined by the switching curve corresponding to each gas branch is greater than 1, the switching curve corresponding to each gas branch is corrected by the intermediate flow ratio to obtain the target switching curve. Since the intermediate flow ratio corresponding to the first target branch is greater than or equal to the intermediate flow ratio corresponding to the second target branch, the flow ratio of each gas branch changes from the current set value to the target set value. The switching process of the branch with the maximum flow ratio is at most once, thereby avoiding the problem of frequent fluctuations in the output gas pressure caused by frequent switching of the gas branch with the maximum flow ratio.

[0044] Based on the above concept, the embodiment of the present specification provides a flow ratio control method. The flow ratio control method provided in the embodiment of the present specification will be exemplarily described below in conjunction with the accompanying drawings.

[0045] Exemplary Methods

[0046] Taking the control module applied to the flow ratio controller as an example, some embodiments of this specification exemplify the flow ratio control method, wherein the flow ratio controller includes a plurality of gas branches, and the gas branches include valves, such as Figure 4 As shown, the flow ratio control method includes:

[0047] S401: In response to the current set values ​​of the plurality of gas branches changing to target set values, based on the switching curves corresponding to the respective gas branches, determining the number of simulated changes, the number of simulated changes including the number of changes of the branch where the maximum set flow ratio is located when switching according to the switching curves corresponding to the respective gas branches; the current set value is used to characterize the current set flow ratio of the gas branch, and the target set value is used to characterize the set flow ratio to be switched to by the gas branch; the switching curve is used to describe the manner in which the set flow ratio of the gas branch corresponding to the switching curve gradually changes from the current set value to the target set ratio;

[0048] The set flow ratio may refer to the flow ratio that the gas branch hopes to achieve at a certain moment. In this embodiment, a switching curve is used to describe how the set flow ratio of the gas branch changes over time, with the starting point of the change being the current set value and the end point of the change being the target set ratio; at a certain moment, after the set flow ratio of the gas branch is determined, the valve opening can be controlled according to the set flow ratio at that moment, so that the gas flow in the gas branch can be adjusted to the set flow ratio at that moment, so that the gas flow in the gas branch reaches the set flow ratio. Reference Figure 2 , Figure 2 Y1, Y2 and Y3 in are the switching curves corresponding to branches 1, 2 and 3. The set flow ratio at each moment can be found in the switching curve. The branch with the maximum set flow ratio can refer to the gas branch with the largest set flow ratio at a certain moment.

[0049] In some embodiments, based on the switching curves corresponding to the gas branches, the intersection (X 1,2 and X 1,3 ) The number of simulated changes is determined by comparing these intersection points. In some embodiments below, the feasible implementation methods of this method will be specifically introduced.

[0050] S402: If the number of simulated changes is greater than 1, then based on the intermediate flow ratio corresponding to each gas branch, the switching curve corresponding to each gas branch is corrected to obtain a target switching curve, wherein the target switching curve is used to describe the flow change of the set flow ratio of the gas branch corresponding to the target switching curve gradually changing from the current set value to the intermediate flow ratio, and then switching from the intermediate flow ratio to the target set value; the intermediate flow ratio corresponding to the first target branch is greater than or equal to the intermediate flow ratio corresponding to the second target branch, and the intermediate flow ratio corresponding to the second target branch is greater than or equal to the intermediate flow ratios corresponding to the other gas branches except the first target branch; the first target branch includes the gas branch with the largest current set value, and the second target branch includes the gas branch with the largest target set value;

[0051] exist Figure 2 and Figure 3 In the example shown, the number of simulated changes is 2, which is greater than 1. Then, the corresponding intermediate flow ratio can be determined for each gas branch, and the switching curve corresponding to each gas branch can be corrected based on the intermediate flow ratio corresponding to each gas branch to obtain the target switching curve. Figure 5 to Figure 7 , Figure 5 and Figure 6 Two intermediate flow ratio settings are shown in Figure 5 In the figure, the intermediate flow ratios corresponding to each gas branch are different. The intermediate flow ratios corresponding to branches 1 to 3 are S m，temp , S o，temp and S i，temp(i =2), and satisfies S m，temp ≥S o，temp ≥S i，temp(i＝2) The target switching curves corresponding to branches 1 to 3 are as follows: Figure 5 As shown, by gradually adjusting the set flow ratio based on the target switching curve, it is found that only after the intersection of the target switching curves corresponding to branch 1 and branch 2, the branch number of the maximum set ratio changes once (that is, from MaxSet=1 to MaxSet=3). That is, during the entire adjustment process, only one branch with the maximum set flow ratio changes. This helps to reduce the number of gas fluctuations in each gas branch during the flow ratio adjustment process, and avoids the problem of frequent fluctuations in output gas pressure caused by frequent switching of the gas branch with the maximum flow ratio. Figure 5In the method of setting the intermediate flow ratio, the intermediate flow ratio corresponding to the first target branch is greater than or equal to the intermediate flow ratio corresponding to the second target branch, and the intermediate flow ratio corresponding to the second target branch is greater than or equal to the intermediate flow ratio corresponding to the other gas branches except the first target branch, wherein branch 1 is the first target branch, and branch 3 is the second target branch. Figure 6 In the figure, a special case is shown, that is, the intermediate flow ratio corresponding to the first target branch is equal to the intermediate flow ratio corresponding to the second target branch, and the intermediate flow ratio corresponding to the second target branch is equal to the intermediate flow ratio corresponding to the other gas branches except the first target branch, that is, the intermediate flow ratios corresponding to the gas branches are equal. For example, the intermediate flow ratios of each gas branch can be 33.3%. Both of these settings can achieve the purpose of changing the branch where the maximum set flow ratio is located only once.

[0052] S403: Based on the target switching curve corresponding to each gas branch, control the valve of the gas branch to gradually change the set flow ratio of the gas branch corresponding to the target switching curve from the current set value to the intermediate flow ratio, and then switch from the intermediate flow ratio to the target set value.

[0053] In summary, the flow ratio regulation method provided in the implementation mode of the present specification, on the one hand, when adjusting the flow ratio of each gas branch, gradually adjusts the flow ratio of each gas branch to gradually approach the target setting value, thereby avoiding the output pressure fluctuation that may be caused by the current setting value of each gas branch being directly switched to the target setting value; on the other hand, when the number of simulated changes determined by the switching curve corresponding to each gas branch is greater than 1, the switching curve corresponding to each gas branch is corrected by the intermediate flow ratio to obtain the target switching curve. Since the intermediate flow ratio corresponding to the first target branch is greater than or equal to the intermediate flow ratio corresponding to the second target branch, this makes the flow ratio of each gas branch change from the current setting value to the target setting value, and at most goes through the switching process of the branch with the maximum flow ratio once, thereby avoiding the problem of frequent fluctuations in output gas pressure caused by frequent switching of the gas branch with the maximum flow ratio.

[0054] The switching curve may be a curve drawn based on a linear equation or a curve drawn based on a nonlinear equation such as an exponential equation. This specification does not limit this. In a feasible implementation manner, the switching curve corresponding to each gas branch includes: a linear curve with a set difference as a slope and the current set value as an intercept, and the set difference includes the target set value of the gas branch minus the current set value of the gas branch; for example, assuming that the switching curve of the i-th gas branch is Yi (i=1, 2, ..., n), the expansion of Yi is shown as follows:

[0055] Yi=(S i,new -S i,old )x+S i,old ; Among them, S i,old Indicates the current setting value of the gas branch, S i,new represents the target setting value of the gas branch. Based on the above formula, the setting difference (S i,new -S i,old ) is the slope of the switching curve, S i,old This is the intercept of the switching curve.

[0056] The determining of the number of simulated changes based on the switching curves corresponding to the gas branches includes:

[0057] Based on the switching curves corresponding to the gas branches, a first target intersection point and a second target intersection point are determined, wherein the first target intersection point includes an intersection point of the switching curve corresponding to the first target branch and a switching curve corresponding to the second target branch, and the second target intersection point includes an intersection point of the switching curve corresponding to the first target branch and a switching curve corresponding to a third target branch; the third target branch includes gas branches other than the second target branch and the first target branch;

[0058] If the first distance is greater than any second distance, it is determined that the number of simulated changes is greater than 1, the first distance includes the distance from the current set value to the first target intersection in the switching curve corresponding to the first target branch, and the second distance includes the distance from the current set value to the second target intersection in the switching curve corresponding to the first target branch;

[0059] If the first distance is less than or equal to any of the second distances, it is determined that the number of simulation changes is less than or equal to 1.

[0060] Still reference Figure 2 , still taking the three branches 1, 2, and 3 as an example, assuming that the current set values ​​are 60%, 40%, and 0%, respectively, and the target set values ​​are 10%, 40%, and 50%, respectively, the switching curve Yi of each gas branch can be expressed as:

[0061] Yi=(S i,new -S i,old )x+S i,old i = 1, 2, ..., n;

[0062] S i,new represents the target setting value corresponding to the i-th gas branch, S i,oldRepresents the current set value corresponding to the i-th gas branch, assuming that m represents the gas branch number with the largest current set value (in this example, m=1), o is the gas branch number with the largest target set value (in this example, o=3), and i is the number of other gas branches (in this example, i=2, in other examples, if the number of gas branches is greater than 3, then the number of i can be multiple).

[0063] The intersection point of Ym and Yo (i.e. the first target intersection point) can be expressed as:

[0064]

[0065] The intersection point of Ym and Yi (i.e., the second target intersection point) can be expressed as:

[0066]

[0067] According to the number of gas branches, we can get N-2 x m,i , calculate the distance (first distance) from the current set value of the first target branch to the first target intersection, and respectively calculate the distance (second distance) from the current set value of the first target branch to each of the second target intersections. If the first distance is greater than any second distance (then it indicates that when the set gas flow of the first target branch changes from the current set value to the first target intersection, the set gas flow of other gas branches except the second target branch has been greater than the set gas flow of the first target branch at a certain moment, and it is necessary to open the valve opening of the other gas branch to the maximum at this moment, and the target set value of the second target branch is the largest, and it is necessary to adjust the branch where the maximum set flow ratio is located at least once afterwards, that is, it is impossible to adjust the gas flow of each gas branch to the target set value when the number of changes in the branch where the maximum set flow ratio is located is 1), then it is determined that the number of simulated changes is greater than 1. This method can simply and quickly determine the number of simulated changes, which is conducive to improving the execution efficiency of the method.

[0068] In an optional embodiment, the sum of the intermediate flow ratios corresponding to each of the multiple gas branches is 1; the intermediate flow ratios corresponding to each of the gas branches are equal, and the intermediate flow ratios are equal to 100% / N, where N includes the number of gas branches in the flow ratio controller, thereby ensuring that the total valve opening of the flow ratio controller can be larger, thereby reducing the pressure drop of the gas when passing through the flow ratio controller.

[0069] In an optional embodiment, the controlling the valve of the gas branch based on the target switching curve corresponding to each gas branch includes:

[0070] Based on the target switching curves corresponding to the gas branches, first set values ​​corresponding to the gas branches at multiple target moments are obtained; the first set values ​​represent the flow rate ratio that the gas branches corresponding to the first set values ​​need to achieve at the current moment;

[0071] The valve opening of the maximum gas branch at the current moment is set to a preset opening; the maximum gas branch is the gas branch with the largest first set value corresponding to the current moment;

[0072] Determine the flow rate ratio error corresponding to the gas branch to be adjusted according to the actual flow rate ratio of the gas branch to be adjusted at the current moment and the first set value corresponding to the gas branch to be adjusted; the actual flow rate ratio of the gas branch to be adjusted at the current moment includes the ratio of the actual flow rate of the gas branch to be adjusted at the current moment to the total gas flow rate, and the total gas flow rate includes the sum of the actual flow rates of the multiple gas branches at the current moment;

[0073] Based on the flow rate ratio error corresponding to the gas branch to be regulated, a control signal corresponding to the gas branch to be regulated is generated, and the control signal is used to adjust the valve opening of the gas branch to be regulated.

[0074] refer to Figure 8 In this embodiment, still taking the above example as an example, taking the target switching curve corresponding to branch 1 as an example, in the two adjustment stages (gradually changing from the current set value to the intermediate flow ratio, and switching from the intermediate flow ratio to the target set value), the first set values ​​(first set values ​​1 to 4) corresponding to each other are determined at different target moments (target moments 1 to 4). At target moment 1 and target moment 2, since branch 1 is the maximum gas branch, the valve opening of branch 1 can be set to the preset opening. At target moment 3 and target moment 4, since branch 1 is no longer the maximum gas branch, the flow ratio error corresponding to branch 1 can be determined at target moment 3 and target moment 4 according to the actual flow ratio of branch 1 and the first set value corresponding to the branch (first set value 3 and first set value 4), and the control signal corresponding to branch 1 is generated based on the flow ratio error to achieve valve opening adjustment of branch 1. The adjustment logic of other branches is similar and will not be repeated in this article.

[0075] It can be understood that the number of target moments set above is only for illustrative purposes. In the actual adjustment process, the number of target moments in the two adjustment stages can be more than two. The greater the number of target moments, the smoother the adjustment of the flow ratio in each adjustment stage.

[0076] In an optional embodiment, the target time can be determined based on a preset adjustment step, that is, a feasible adjustment step can be set for each adjustment stage, and the target time and the corresponding first set value are determined based on this. Specifically, the target switching curve corresponding to each gas branch is used to obtain the first set value corresponding to each gas branch at multiple target times, including:

[0077] Based on the target switching curve, the first switching step and the second switching step corresponding to each of the gas branches, the first set value corresponding to each of the gas branches at multiple target moments is obtained, the first switching step represents the flow ratio adjustment step when the set flow ratio of the gas branch gradually changes from the current set value to the intermediate flow ratio, and the second switching step represents the flow ratio adjustment step when the gas branch gradually changes from the intermediate flow ratio to the target set value.

[0078] This method can be used to customize the flow ratio adjustment step size in each adjustment stage to meet the adjustment requirements in different scenarios and improve the adaptability of the method.

[0079] In an alternative embodiment, referring to Fig. 9 , the flow ratio controller also includes: a PID controller;

[0080] The generating a control signal corresponding to the gas branch to be regulated based on the flow rate ratio error corresponding to the gas branch to be regulated includes:

[0081] The PID controller takes the flow rate proportional error corresponding to the gas branch to be regulated as input to obtain a control signal corresponding to the gas branch to be regulated.

[0082] exist Fig. 9 In FIG. 1 , a feasible process of the PID controller outputting a control signal based on the flow rate proportional error corresponding to the gas branch to be regulated is shown. Fig. 9In the formula, Ri represents the ratio of the gas mass flow rate of the ith gas branch to be regulated to the gas mass flow rate of all gas branches, Qi(t) represents the actual gas mass flow rate (or actual flow rate) of the ith gas branch to be regulated at time t. ei(t) represents the flow rate proportional error corresponding to the ith gas branch to be regulated, and Si(t) represents the first set value of the ith branch to be regulated at time t. ui(t) represents the control signal corresponding to the ith branch to be regulated at time t, and the control signal can be, for example, a valve-controlled current to adjust the opening of the ith branch to be regulated. Qsum(t) represents the sum of the actual gas mass flow rates of all gas branches at time t. The proportional module i, integral module i and differential module i of the PID controller are used to output the proportional coefficient, integral coefficient and differential coefficient based on the input ei(t), and obtain the final output ui(t) based on the proportional coefficient, integral coefficient and differential coefficient.

[0083] The calculation formula of Ri can be expressed as:

[0084] Ri=Qi / (Q1+Q2+…+Qn)×100% i=1, 2,…, n;

[0085] The calculation formula of ei(t) can be expressed as:

[0086] ei(t)=Si(t)–Ri(t)i=1, 2,…,n;

[0087] The control law expression of output ui(t) and input ei(t) is as follows:

[0088]

[0089] Among them, K P is the proportionality coefficient; K I is the integral coefficient; K D is the differential coefficient.

[0090] It can be understood that the foregoing text focuses on describing the control method when the number of simulated changes is greater than 1. In some embodiments, if the number of simulated changes is less than or equal to 1, the valves of the gas branches can be directly controlled based on the switching curves corresponding to the gas branches to achieve the purpose of gradually adjusting the flow ratio of each gas branch from the current set value to the target set value.

[0091] The following is a specific example to illustrate the feasible execution process of the flow ratio control method:

[0092] Assume that there are gas branches 1 to 3, and the current setting values ​​of gas branches 1 to 3 are 60%, 40%, and 0%, respectively, and the target setting values ​​of gas branches 1 to 3 are 10%, 40%, and 50%, respectively.

[0093] Then Y1~Y3 can be expressed as:

[0094] Y1=(10%-60%)x+60%=-50%x+60%;

[0095] Y2=(40%-40%)x+40%=40%;

[0096] Y3=(50%-0%)x+0%=50%x;

[0097] Assume that m is the number of the first target branch, and o is the number of the second target branch. Since m≠o, it is necessary to determine the number of simulated changes based on the switching curves corresponding to each of the gas branches;

[0098] Specifically, we need to judge x 1,3 With x 1,2 The size of x 1,3 It can be calculated by the following formula:

[0099]

[0100] x 1,2 It can be calculated by the following formula:

[0101]

[0102] Due to x 1,3 >x 1,2 , then the number of simulated changes is greater than 1, and the switching curve needs to be corrected. Assume that the intermediate flow ratio corresponding to each gas branch is 33.33%;

[0103] Taking the linear approach as an example, the process of gradually changing the set flow ratio of the gas branch from the current set value to the intermediate flow ratio (hereinafter referred to as the first step) can be expressed as:

[0104] S 1,t =60%+(33.33%-60%)t / N, (t∈[0,1,2,…,N])

[0105] S 2,t =40%+(33.33%-40%)t / N, (t∈[0,1,2,…,N])

[0106] S 3,t =0%+(33.33%-0%)t / N, (t∈[0,1,2,…,N])

[0107] Wherein, N represents the total number of adjustments in the first step adjustment process (ie, the number of target moments in the first step adjustment process), and this value can be set according to demand.

[0108] When t=N, the first adjustment step is completed.

[0109] The process of switching the set flow rate ratio of the gas branch from the intermediate flow rate ratio to the target set value (hereinafter referred to as the second step) can be expressed as:

[0110] S 1,t =33.33%+(10%-33.33%)t / M, (t∈[0,1,2,…,M])

[0111] S 2,t =33.33%+(40%-33.33%)t / M, (t∈[0,1,2,…,M])

[0112] S 3,t =33.33%+(50%-33.33%)t / M, (t∈[0,1,2,…,M])

[0113] Wherein, M represents the total number of adjustments in the second step adjustment process (ie, the number of target moments in the second step adjustment process), and this value can be set according to demand.

[0114] When t=M, the second step of adjustment ends.

[0115] After obtaining the first set value at each target moment, valve control can be performed based on the control method of the maximum gas branch described above, and valve control of each gas branch to be adjusted can be performed based on the PID control method described above.

[0116] Exemplary Devices

[0117] In an exemplary embodiment of the present specification, a flow ratio controller is also provided, such as Figure 1 As shown, it includes: a plurality of gas branches and a control module, wherein the gas branches include valves; wherein,

[0118] The control module is configured to: in response to the current set values ​​of the plurality of gas branches changing to the target set values, determine the number of simulated changes based on the switching curves corresponding to the gas branches, the number of simulated changes including the number of changes of the branch where the maximum set flow ratio is located when switching according to the switching curves corresponding to the gas branches; the current set value is used to characterize the current set flow ratio of the gas branch, and the target set value is used to characterize the set flow ratio to be switched to by the gas branch; the switching curve is used to describe the way in which the set flow ratio of the gas branch corresponding to the switching curve gradually changes from the current set value to the target set ratio;

[0119] If the number of simulated changes is greater than 1, the switching curve corresponding to each gas branch is corrected based on the intermediate flow ratio corresponding to each gas branch to obtain a target switching curve, wherein the target switching curve is used to describe the flow change of the set flow ratio of the gas branch corresponding to the target switching curve gradually changing from the current set value to the intermediate flow ratio, and then switching from the intermediate flow ratio to the target set value; the intermediate flow ratio corresponding to the first target branch is greater than or equal to the intermediate flow ratio corresponding to the second target branch, and the intermediate flow ratio corresponding to the second target branch is greater than or equal to the intermediate flow ratios corresponding to the other gas branches except the first target branch; the first target branch includes the gas branch with the largest current set value, and the second target branch includes the gas branch with the largest target set value;

[0120] Based on the target switching curve corresponding to each gas branch, the valve of the gas branch is controlled to gradually change the set flow ratio of the gas branch corresponding to the target switching curve from the current set value to the intermediate flow ratio, and then switch from the intermediate flow ratio to the target set value.

[0121] For the relevant limitations of the flow ratio controller, please refer to the relevant description above, and this manual will not elaborate on it here.

[0122] Optionally, the control module may include a PID controller.

[0123] In an alternative embodiment, Fig.10 As shown, the embodiment of this specification also provides a semiconductor process equipment, including: a flow ratio controller and a plurality of process chambers, the flow ratio controller including the flow ratio controller as described in the above embodiment;

[0124] The multiple gas branches in the flow ratio controller are respectively used to provide gas to the multiple process chambers.

[0125] Optionally, the semiconductor process equipment further comprises: a gas supply device, the gas supply device comprising a first gas output end;

[0126] The input ends of the plurality of gas branches are all connected to the first gas output end, and the second gas output ends of the plurality of gas branches are respectively connected to the plurality of process chambers;

[0127] The gas supply device is configured to provide gas to the plurality of gas branches through the first gas output end.

[0128] Another embodiment of this specification also provides a computing device, see Fig.11As shown, an exemplary embodiment of the present specification also provides a computing device, including: a memory and a processor, the memory storing a computer program, and the processor executing the computer program when executing the computer program performs the steps of the flow ratio control method according to various embodiments of the present specification described in the above embodiments of the present specification.

[0129] The internal structure of the computing device can be as follows Fig.11 As shown, the computing device includes a processor, a memory, a network interface and an input device connected through a system bus. Among them, the processor of the computing device is used to provide computing and control capabilities. The memory of the computing device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computing device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, the steps of the flow ratio control method according to various embodiments of the present specification described in the above embodiments of the present specification are performed.

[0130] The processor may include a main processor and may also include a baseband chip, a modem, etc.

[0131] The memory stores a program for executing the technical solution of the present invention, and may also store an operating system and other key services. Specifically, the program may include a program code, and the program code includes computer operation instructions. More specifically, the memory may include a read-only memory (ROM), other types of static storage devices that can store static information and instructions, a random access memory (RAM), other types of dynamic storage devices that can store information and instructions, a disk storage, a flash, and the like.

[0132] The processor may be a general-purpose processor, such as a general-purpose central processing unit (CPU), a microprocessor, etc., or an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the scheme of the present invention. It may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component.

[0133] The input device may include a device for receiving data and information input by a user, such as a keyboard, a mouse, a camera, a scanner, a light pen, a voice input device, a touch screen, a pedometer, or a gravity sensor.

[0134] Output devices may include means that allow information to be output to a user, such as display screens, printers, speakers, etc.

[0135] The communication interface may include using any transceiver or the like to communicate with other devices or communication networks, such as Ethernet, Radio Access Network (RAN), Wireless Local Area Network (WLAN), etc.

[0136] The processor executes the program stored in the memory and calls other devices, which can be used to implement each step of any flow ratio control method provided in the above embodiments of this specification.

[0137] The computing device may also include a display component and a voice component. The display component may be a liquid crystal display or an electronic ink display. The input device of the computing device may be a touch layer covered on the display component, or a button, trackball or touchpad provided on the housing of the computing device, or an external keyboard, touchpad or mouse.

[0138] Those skilled in the art will understand that Fig.11 The structure shown in the figure is only a block diagram of a part of the structure related to the scheme of this specification, and does not constitute a limitation on the computing device to which the scheme of this specification is applied. The specific computing device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0139] Exemplary computer program products and storage media

[0140] In addition to the above-mentioned methods and devices, the flow ratio control method provided in the embodiments of this specification may also be a computer program product, which includes computer program instructions, which, when executed by a processor, enable the processor to execute the steps of the flow ratio control method according to various embodiments of this specification described in the above-mentioned "Exemplary Method" section of this specification.

[0141] The computer program product may be implemented in hardware, software or a combination thereof. In one optional embodiment, the computer program product is implemented as a computer storage medium. In another optional embodiment, the computer program product is implemented as a software product, such as a software development kit (SDK).

[0142] The computer program product may be written in any combination of one or more programming languages ​​to write program code for performing the operations of the embodiments of the present specification, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0143] In addition, an embodiment of the present specification also provides a computer-readable storage medium on which a computer program is stored, and the computer program is executed by a processor to execute the steps of the flow ratio control method according to various embodiments of the present specification described in the above "Exemplary Method" section of the present specification.

[0144] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this specification can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0145] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0146] The above-mentioned embodiments only express several implementation methods of this specification, and the descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the solutions provided by the embodiments of this specification. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of this specification, which all belong to the protection scope of this specification. Therefore, the protection scope of the patent of this specification shall be based on the attached claims.

Claims

1. A flow rate ratio control method, characterized in that: Applied to a flow ratio controller, the flow ratio controller includes a plurality of gas branches, the gas branches include valves, and the flow ratio control method includes: In response to the current set values ​​of the plurality of gas branches changing to target set values, based on the switching curves corresponding to the gas branches, the number of simulated changes is determined, the number of simulated changes including the number of changes of the branch where the maximum set flow ratio is located when switching is performed according to the switching curves corresponding to the gas branches; the current set value is used to characterize the current set flow ratio of the gas branch, and the target set value is used to characterize the set flow ratio to be switched to by the gas branch; the switching curve is used to describe the manner in which the set flow ratio of the gas branch corresponding to the switching curve gradually changes from the current set value to the target set ratio; If the number of simulated changes is greater than 1, the switching curve corresponding to each gas branch is corrected based on the intermediate flow ratio corresponding to each gas branch to obtain a target switching curve, wherein the target switching curve is used to describe the flow change of the set flow ratio of the gas branch corresponding to the target switching curve gradually changing from the current set value to the intermediate flow ratio, and then switching from the intermediate flow ratio to the target set value; the intermediate flow ratio corresponding to the first target branch is greater than or equal to the intermediate flow ratio corresponding to the second target branch, and the intermediate flow ratio corresponding to the second target branch is greater than or equal to the intermediate flow ratios corresponding to the other gas branches except the first target branch; the first target branch includes the gas branch with the largest current set value, and the second target branch includes the gas branch with the largest target set value; Based on the target switching curve corresponding to each gas branch, the valve of the gas branch is controlled to gradually change the set flow ratio of the gas branch corresponding to the target switching curve from the current set value to the intermediate flow ratio, and then switch from the intermediate flow ratio to the target set value.

2. The method according to claim 1, characterized in that The switching curve corresponding to each of the gas branches comprises: a linear curve with a set difference as a slope and the current set value as an intercept, wherein the set difference comprises a target set value of the gas branch minus the current set value of the gas branch; The determining of the number of simulated changes based on the switching curves corresponding to the gas branches includes: Based on the switching curves corresponding to the gas branches, a first target intersection point and a second target intersection point are determined, wherein the first target intersection point includes an intersection point of the switching curve corresponding to the first target branch and a switching curve corresponding to the second target branch, and the second target intersection point includes an intersection point of the switching curve corresponding to the first target branch and a switching curve corresponding to a third target branch; the third target branch includes gas branches other than the second target branch and the first target branch; If the first distance is greater than any second distance, it is determined that the number of simulated changes is greater than 1, the first distance includes the distance from the current set value to the first target intersection in the switching curve corresponding to the first target branch, and the second distance includes the distance from the current set value to the second target intersection in the switching curve corresponding to the first target branch; If the first distance is less than or equal to any of the second distances, it is determined that the number of simulation changes is less than or equal to 1.

3. The method according to claim 1, characterized in that The sum of the intermediate flow ratios corresponding to the multiple gas branches is 1; The intermediate flow ratios corresponding to the gas branches are equal, and the intermediate flow ratio is equal to 100% / N, where N includes the number of gas branches in the flow ratio controller.

4. The method according to any one of claims 1 to 3, characterized in that: The controlling of the valves of the gas branches based on the target switching curves corresponding to the gas branches includes: Based on the target switching curves corresponding to the gas branches, first set values ​​corresponding to the gas branches at multiple target moments are obtained; the first set values ​​represent the flow rate ratio that the gas branches corresponding to the first set values ​​need to achieve at the current moment; The valve opening of the maximum gas branch at the current moment is set to a preset opening; the maximum gas branch is the gas branch with the largest first set value corresponding to the current moment; Determine the flow rate ratio error corresponding to the gas branch to be adjusted according to the actual flow rate ratio of the gas branch to be adjusted at the current moment and the first set value corresponding to the gas branch to be adjusted; the actual flow rate ratio of the gas branch to be adjusted at the current moment includes the ratio of the actual flow rate of the gas branch to be adjusted at the current moment to the total gas flow rate, and the total gas flow rate includes the sum of the actual flow rates of the multiple gas branches at the current moment; Based on the flow rate ratio error corresponding to the gas branch to be regulated, a control signal corresponding to the gas branch to be regulated is generated, and the control signal is used to adjust the valve opening of the gas branch to be regulated.

5. The method according to claim 4, characterized in that The obtaining, based on the target switching curves corresponding to the gas branches, of the first set values ​​corresponding to the gas branches at multiple target times comprises: Based on the target switching curve, the first switching step and the second switching step corresponding to each of the gas branches, the first set value corresponding to each of the gas branches at multiple target moments is obtained, the first switching step represents the flow ratio adjustment step when the set flow ratio of the gas branch gradually changes from the current set value to the intermediate flow ratio, and the second switching step represents the flow ratio adjustment step when the gas branch gradually changes from the intermediate flow ratio to the target set value.

6. The method according to claim 4, characterized in that The flow ratio controller also includes: a PID controller; The generating a control signal corresponding to the gas branch to be regulated based on the flow rate ratio error corresponding to the gas branch to be regulated includes: The PID controller takes the flow rate proportional error corresponding to the gas branch to be regulated as input to obtain a control signal corresponding to the gas branch to be regulated.

7. A flow ratio controller, characterized in that: include: A plurality of gas branches and a control module, wherein the gas branches include valves; wherein, The control module includes: a processor, and a memory connected to the processor; the memory is used to store a computer program; the processor is used to call and execute the computer program in the memory to execute the flow ratio control method as described in any one of claims 1-6.

8. A semiconductor process equipment, characterized in that: include: A flow ratio controller and a plurality of process chambers, wherein the flow ratio controller comprises the flow ratio controller according to claim 7; The multiple gas branches in the flow ratio controller are respectively used to provide gas to the multiple process chambers.

9. The device according to claim 8, characterized in that Also includes: A gas supply device, the gas supply device comprising a first gas output end; The input ends of the plurality of gas branches are all connected to the first gas output end, and the second gas output ends of the plurality of gas branches are respectively connected to the plurality of process chambers; The gas supply device is configured to provide gas to the plurality of gas branches through the first gas output end.

10. A computing device, characterized in that: The invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the flow rate ratio control method according to any one of claims 1 to 6 is implemented when the processor executes the computer program.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the flow ratio control method according to any one of claims 1 to 6 is implemented.

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