Gas distribution method applied to wafer processing equipment

Abstract

The invention provides a gas distribution method applied to wafer processing equipment. The gas distribution method comprises the following steps: S1, providing a controller, a pressure gauge, a main pipeline and at least one branch pipeline; the controller is respectively connected with the pressure gauge and the valve; and S2, the controller controls the opening value of the valve according to the change of the mean value of the pressure values of the pressure meter in the first plurality of different clock periods. The gas distribution method provided by the invention can provide stable flow change.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer processing equipment for semiconductor equipment, and in particular to the field of a gas distribution device and method for wafer processing equipment. Background Art

[0002] Semiconductor wafer processing equipment is a device for processing wafers. It can perform etching, thin film deposition, cleaning and other processes on the wafer surface. The above-mentioned wafer processing equipment all require the introduction of process gases during the process. However, the control of process gases (such as flow rate and flow velocity) is crucial to the process results. In the prior art, the process gases are controlled by installing a mass flow controller (MFC) in the gas pipeline.

[0003] However, during the process, when adjusting the process gas flow, the sudden flow change will cause the process gas to be unstable. This phenomenon is more serious when there are multiple zones at the inlet end due to the mutual influence between the zones. How to quickly respond to flow changes and reduce the impact of such changes on process quality has become an urgent problem to be solved. Summary of the invention

[0004] The object of the present invention is to provide a gas distribution device and a wafer processing equipment for solving the problem of stable airflow control.

[0005] In order to achieve the above objectives, the present invention is implemented by the following technical solutions:

[0006] The present invention provides a gas distribution method applied to wafer processing equipment, comprising:

[0007] S1. Provide a controller, a pressure gauge, a main pipeline and at least one branch pipeline, one end of each branch pipeline is connected to the main pipeline, and the other end of each branch pipeline is respectively connected to a corresponding area of ​​the air inlet of the chamber of the wafer processing equipment; a valve is arranged on the branch pipeline; the pressure gauge is arranged upstream of the valve to detect the pressure value upstream of the valve; the controller is respectively connected to the pressure gauge and the valve;

[0008] S2. The controller controls the opening value of the valve according to the change of the average value of the pressure values ​​of different previous clock cycles of the pressure gauge.

[0009] 13. Optionally, in step S2, the valve opening value is controlled to be:

[0010] Mean value calculation step, the controller obtains a first average pressure according to the pressure values ​​of the first N clock cycles, and obtains a second average pressure according to the pressure values ​​of the first M clock cycles, wherein N and M are both positive integers, and N>M;

[0011] A determination step, in which the controller determines whether the first average pressure and the second average pressure are both greater than a first threshold;

[0012] Adjustment step: if the judgment result is yes, the action of adjusting the opening value of the valve is executed to enter the adjustment stage.

[0013] Optionally, in step S2, during the adjustment phase, a continuous judgment step is also included, wherein the controller controls whether the valve continues to adjust the opening value according to changes in the average value of the pressure values ​​of different previous clock cycles of the pressure gauge.

[0014] Optionally, the first multiple clock cycles of the adjustment phase are greater than the first multiple clock cycles before the adjustment phase.

[0015] Optionally, to control whether the valve continues to adjust the opening value: during the adjustment stage, the controller obtains a third average pressure based on the pressure values ​​of the previous N1 clock cycles, and obtains a fourth average pressure based on the pressure values ​​of the previous M1 clock cycles. The controller determines whether the third average pressure and the fourth average pressure are simultaneously greater than the second threshold value, and if so, continues to adjust the opening value of the valve; wherein N1 and M1 are both positive integers, N1>M1, N1>N, M1>M.

[0016] Optionally, the second threshold is greater than the first threshold.

[0017] Optionally, in step S2, after the judgment step and / or the continuous judgment step, a delayed rejudgment step is also included.

[0018] Optionally, the delayed re-judgment step is:

[0019] After a delay time Δt, it is determined whether the first average pressure and the second average pressure are both greater than the first threshold value, and if so, the valve opening value adjustment action is performed;

[0020] And / or, after a delay time Δt, it is determined whether the third average pressure and the fourth average pressure are both greater than the second threshold value, and if so, an action of adjusting the opening value of the valve is performed.

[0021] Optionally, in step S2, in the judgment step and / or the continuous judgment step, if the judgment result is no, the flow ratio control mode is entered.

[0022] Optionally, in step S2, after the judgment step and / or the continuous judgment step, if the judgment result is yes, the delayed re-judgment step is performed; if the judgment result is no, the flow ratio control mode is entered.

[0023] Optionally, the first threshold and the second threshold both correspond to different total flows of the main pipeline and different flow ratios of each branch pipeline.

[0024] Optionally, the chamber has three zones.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] The pressure gauge of the present invention can monitor the pressure upstream of the valve in real time. When the flow is switched, the pressure gauge can monitor the change in pressure. The controller adjusts the opening value of the valve according to the change in pressure, thereby reducing the pressure change at the pressure gauge, thereby quickly stabilizing the flow of the branch pipeline. In addition, the present invention controls the opening value of the valve by changing the mean value of the pressure values ​​of different previous multiple clock cycles, so that the change in pressure can be judged more accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for the description. Obviously, the drawings described below are an embodiment of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work:

[0028] Figure 1 A schematic diagram of the structure of the wafer processing equipment provided by the present invention;

[0029] Figure 2 Another structural schematic diagram of the wafer processing equipment provided by the present invention;

[0030] Figure 3 A corresponding list of the first threshold, the second threshold, the total flow rate and the flow rate ratio provided by the present invention;

[0031] Figure 4 Another structural schematic diagram of the wafer processing equipment provided by the present invention;

[0032] Figure 5 Another structural schematic diagram of the wafer processing equipment provided by the present invention;

[0033] Figure 6 A schematic diagram of the gas distribution method provided by the present invention;

[0034] Figure 7 A schematic flow chart of the gas distribution method provided by the present invention;

[0035] Figure 8 Another schematic flow chart of the gas distribution method provided by the present invention. DETAILED DESCRIPTION

[0036] The scheme proposed by the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the implementation method of the present invention. In order to make the purposes, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the accompanying drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no technical substantive significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope of the technical content disclosed by the present invention.

[0037] Figure 1 FIG. 2 shows a wafer processing device of the present invention. Figure 1 As shown, the wafer processing equipment includes: a chamber 200, a source 300 and a gas distribution device 100. The chamber 200 is used to perform semiconductor process on the wafer; the source 300 is connected to the chamber 200 through the gas distribution device 100; the source is used to store process gas. Optionally, the chamber 200 is at least one of an epitaxial chamber, a rapid thermal processing chamber, a CVD chamber, and an etching chamber. Different chambers correspond to different process treatments. For example, the epitaxial chamber is used for epitaxial process treatment, the rapid thermal processing chamber is used for rapid annealing process treatment, and the etching chamber is used for etching process treatment, including but not limited to silicon etching, dielectric etching or metal etching. The present invention takes the epitaxial chamber as an example.

[0038] The chamber 200 shown includes a cavity, an air inlet 201, and an exhaust 203. The cavity is used to accommodate wafers and perform semiconductor process on the wafers. The air inlet 201 is arranged at one end of the cavity, and the exhaust 203 is arranged at the other end of the cavity. The positions of the air inlet 201 and the exhaust 203 are opposite to each other in the horizontal plane. Optionally, the air inlet 201 includes at least two zones separated from each other, and the gas control between each zone is independent; preferably, the air inlet is divided into three zones, namely zone A, zone B and zone C, so that the process gas is divided into three paths on the surface of the wafer W, and the flow rates of the three process gases can be independently controlled, thereby controlling the film deposition quality of the epitaxial layer in the three zones on the surface of the wafer W.

[0039] The wafer processing equipment further includes a pump 205, which is connected to the chamber 200 and is used to control the process pressure of the wafer process in the chamber and to discharge the process gas after the process. Specifically, the pump 205 is connected to the exhaust member 203 through a pipeline.

[0040] During the epitaxial process, the process gas is distributed from the source 300 into different zones of the gas inlet 201 through the gas distribution device 100. The gas distribution device 100 can independently control the gas flow between different zones in the gas inlet 201. The process gas between different zones is independently controlled by the gas distribution device 100, thereby forming a stable flow field in multiple zones on the surface of the wafer W. Under the action of thermal radiation, the process gas decomposes and a uniform epitaxial layer thin film grows on the surface of the wafer. Finally, under the control of the pump 205, the post-process process gas is extracted from the cavity through the exhaust member 203.

[0041] Of course, the gas distribution device 100 is also applicable to other wafer processing equipment, especially wafer processing equipment with multiple zone gas inlet, such as etching, CVD, RTP, etc.

[0042] Figure 1 The gas distribution device of the present invention is shown as Figure 1 As shown in the dashed box, the gas distribution device 100 includes: a main pipeline 101, a branch pipeline 103, a pressure gauge 104 and a controller 105.

[0043] The main pipeline 101 is connected to a source 300 of process gas;

[0044] There are at least two branch pipelines 103, one end of each of the branch pipelines is connected to the main pipeline 101, and the other end of each of the branch pipelines is respectively connected to a corresponding zone of the air inlet 201 of the chamber of the wafer processing equipment; the branch pipeline includes a valve 102, and the valve is arranged on the branch pipeline; optionally, there are three branch pipelines 103, and correspondingly, there are also three zones of the air inlet, and the three branch pipelines 103 are connected in parallel, respectively connected to zone A, zone B and zone C of the air inlet 201.

[0045] The pressure gauge 104 is disposed upstream of the valve 102 and is used to detect the pressure value upstream of the valve. The gas distribution device further includes a distribution pipeline 109, and the main pipeline is connected to the branch pipelines through the distribution pipeline 109. The main pipeline 101 includes a mass flow controller 116, which is disposed in the main pipeline and is used to control the flow of each process gas in the main pipeline 101.

[0046] The controller 105 is connected to the pressure gauge 104 and the valve 102 respectively, and is used to control the opening value of the valve according to the change of the pressure value of the pressure gauge. Figure 2 The schematic diagram of the controller is shown in FIG. Figure 2As shown, the controller 105 includes a connected calculation module, a judgment module, an execution module and a storage module. Optionally, the controller 105 is used to control the opening value of the valve according to the change of the mean value of the pressure values ​​of the pressure gauge 104 in different previous clock cycles. There may be two mean values ​​of different pressure values. By judging the increase of the pressure value and adjusting the opening value, the problem of process gas instability caused by flow switching can be well suppressed.

[0047] In some embodiments, specifically, the control of the valve opening value is: the controller 105 obtains the first average pressure according to the pressure values ​​of the first N clock cycles, and obtains the second average pressure according to the pressure values ​​of the first M clock cycles. The controller determines whether the first average pressure and the second average pressure are greater than the first threshold at the same time. If so, the valve opening value adjustment action is performed; wherein N and M are both positive integers, N>M; the clock cycle is the sampling cycle of the pressure gauge 104, the first M clock cycles are the first M clock cycles of the current sampling cycle, and taking M=3 as an example, the second average pressure obtained by the pressure value of the first M clock cycles = (the pressure value of the first 1 clock cycle of the current clock cycle + the pressure value of the first 2 clock cycles of the current clock cycle + the pressure value of the first 3 clock cycles of the current clock cycle) / 3. Similarly, the first average pressure can be obtained. Optionally, 10≤N≤35, 5≤M≤20. By determining the two average values, the situation where the pressure value increases and then falls back due to accidental factors can be avoided, misjudgment can be avoided, and the accuracy of judgment is improved.

[0048] The first threshold is an empirical value obtained from experiments, and the first threshold corresponds to different total flows of the main pipeline 101 and different flow ratios of the branch pipelines 103, that is, different total flows and flow ratios correspond to different first thresholds. Figure 3 As shown, it is only an example, not a specific limitation. It can be seen that: as the total flow rate and the flow rate ratio change, the first threshold value also changes. In the above steps, the controller first determines the first threshold value based on the total flow rate and the flow rate ratio, and then determines the relationship between the first average pressure and the second average pressure and the first threshold value. The advantage of this is that it can better suppress the problem of process gas instability under different conditions, and the judgment is more accurate.

[0049] Once the controller determines that the first average pressure and the second average pressure are simultaneously greater than the first threshold, it starts to execute the action of adjusting the opening value of the valve, that is, entering the adjustment stage. During the period of adjusting the opening value of the valve (that is, the adjustment stage), the controller 105 is also used for continuous judgment, that is, controlling whether the valve continues to adjust the opening value according to the change of the average value of the pressure value of the previous multiple clock cycles of the pressure gauge; wherein the previous multiple clock cycles are based on the current clock cycle as the starting point; the average values ​​of different pressure values ​​can be two.

[0050] Preferably, in the adjustment stage, the first multiple clock cycles are greater than the first multiple clock cycles before adjusting the opening value of the valve, that is: in the adjustment stage, the two clock cycles are N1 and M1 respectively, N1 and M1 are both positive integers, N1>M1, N1>N, M1>M.

[0051] Specifically, to control whether the valve continues to adjust the opening value: during the period of adjusting the opening value of the valve, the controller obtains the third average pressure according to the pressure values ​​of the previous N1 clock cycles, and obtains the fourth average pressure according to the pressure values ​​of the previous M1 clock cycles. The controller determines whether the third average pressure and the fourth average pressure are greater than the second threshold at the same time. If so, the action of continuing to adjust the opening value of the valve is executed; wherein the second threshold is greater than the first threshold. Like the first threshold, the second threshold is also an empirical value obtained experimentally. The second threshold corresponds one-to-one to different total flow rates of the main pipeline 101 and different flow ratios of each branch pipeline 103, that is, different total flow rates and flow ratios correspond to different first thresholds. Figure 3 The above is shown as an example only and is not intended to be limiting.

[0052] In some preferred embodiments, a delayed re-judgment step is also included. After the controller determines whether the two average pressures (the first average pressure and the second average pressure, or the third average pressure and the fourth average pressure) are simultaneously greater than the threshold value (the first threshold value or the second threshold value), the action of adjusting the opening value of the valve is temporarily not performed. After a delay time Δt, the two average pressures (the first average pressure and the second average pressure, or the third average pressure and the fourth average pressure) are simultaneously greater than the threshold value (the first threshold value or the second threshold value). Only when both judgments are established, the action of adjusting the opening value of the valve is performed. Among them, the delay time Δt is 1-5 clock cycles. This step can further determine that the increase in pressure value is not accidental, which increases the accuracy of judgment.

[0053] Optionally, the calculation module is used to calculate the average pressure, that is, to calculate the first average pressure, the second average pressure, the third average pressure, and the fourth average pressure. The judgment module is used to judge whether the average pressure is greater than a threshold value, that is, to judge whether the first average pressure and the second average pressure are greater than a first threshold value, and whether the third average pressure and the fourth average pressure are greater than a second threshold value. The controller also includes an execution module, which is used to execute the action of adjusting the opening value of the valve. The controller also includes a storage module, which is used to store threshold values, that is, to store the first threshold value and the second threshold value.

[0054] Figure 4 Another embodiment is shown, Figure 4As shown, the pressure gauge 104 is arranged on at least one of the branch pipelines. Preferably, each branch pipeline is provided with a pressure gauge 104, and the pressure value for calculating the average value is the value of the pressure gauge 104 on the branch pipeline closest to the main pipeline 101, so that the fluctuation can be minimized. At the same time, when one pressure gauge 104 is damaged, the pressure value of other pressure gauges 104 can also be used.

[0055] Figure 5 Another embodiment is shown, Figure 5 As shown, the branch pipeline further includes a flow meter 106, which is disposed upstream of the valve 102, and the pressure gauge 104 is disposed upstream of the flow meter, and the flow meter is used to monitor the flow of the corresponding branch pipeline 103 in real time. Of course, the pressure gauge 104 can also be disposed in the main pipeline 101.

[0056] Optionally, there is at least one main line 101, preferably, there are four main lines 101; and each main line 101 is respectively connected to a corresponding source 300 of process gas, and the process gas includes a silicon source, a germanium source, a carrier gas, and a doping gas; the silicon source, the germanium source, the carrier gas, and the doping gas are respectively placed in the corresponding sources 300, and then collected and mixed through the four main lines 101.

[0057] Figure 6 The present invention also provides a gas distribution method for wafer processing equipment, such as Figure 6 As shown, the method includes:

[0058] S1. Provide a controller, a pressure gauge, a main pipeline and at least one branch pipeline, one end of each branch pipeline is connected to the main pipeline, and the other end of each branch pipeline is respectively connected to a corresponding area of ​​the air inlet of the chamber of the wafer processing equipment; a valve is arranged on the branch pipeline; the pressure gauge is arranged upstream of the valve to detect the pressure value upstream of the valve; the controller is respectively connected to the pressure gauge and the valve; optionally, the controller, the pressure gauge, the main pipeline and at least one branch pipeline are the above-mentioned gas distribution device 100.

[0059] S2. The controller controls the opening value of the valve according to the change of the average value of the pressure values ​​of different previous clock cycles of the pressure gauge.

[0060] Among them, Figure 7 As shown, in step S2, the step of controlling the opening value of the valve includes:

[0061] Mean value calculation step: the controller obtains a first average pressure according to pressure values ​​of the first N clock cycles, and obtains a second average pressure according to pressure values ​​of the first M clock cycles, wherein N and M are both positive integers, and N>M;

[0062] Determination step: the controller determines whether the first average pressure and the second average pressure are both greater than a first threshold;

[0063] Adjustment step: If the judgment result is yes, the action of adjusting the opening value of the valve is executed to enter the adjustment stage.

[0064] Optionally, in step S2, during the adjustment phase, a continuous judgment step is also included, wherein the controller controls whether the valve continues to adjust the opening value according to changes in the average value of the pressure values ​​of different previous clock cycles of the pressure gauge.

[0065] The control of whether the valve continues to adjust the opening value is: in the adjustment stage, the controller obtains the third average pressure according to the pressure values ​​of the previous N1 clock cycles, and obtains the fourth average pressure according to the pressure values ​​of the previous M1 clock cycles. The controller determines whether the third average pressure and the fourth average pressure are greater than the second threshold at the same time. If so, the action of continuing to adjust the opening value of the valve is executed; wherein N1 and M1 are both positive integers, N1>M1. Optionally, the first multiple clock cycles of the adjustment stage are greater than the first multiple clock cycles before the adjustment stage, that is: N1>N, M1>M. Preferably, the second threshold is greater than the first threshold. In the adjustment stage, since the adjustment of the opening itself will affect the fluctuation of the pressure value, N1>N, M1>M, and the second threshold is larger, which is conducive to maintaining the stability of the flow rate in the adjustment stage.

[0066] Optional, such as Figure 8 As shown, in step S2, after the judging step and / or the continuous judging step, a delayed re-judgment step is also included. That is, the delayed re-judgment step can be only after the judging step or after the continuous judging step, or after both the judging step and the continuous judging step.

[0067] Specifically, the delayed re-judgment step is:

[0068] After the judging step, after a delay time Δt, it is judged whether the first average pressure and the second average pressure are both greater than the first threshold value, and if so, the valve opening value adjustment action is performed;

[0069] And / or, after the continuous determination step, after a delay time Δt, determine whether the third average pressure and the fourth average pressure are both greater than the second threshold value, and if so, continue to adjust the valve opening value.

[0070] Optionally, in step S2, in the judging step and / or the continuous judging step, if the judging result is no, the flow ratio control mode is entered. If the judging result is yes, the delayed re-judgment step is entered.

[0071] Optionally, in step S2, after the judging step and / or the continuous judging step, if the judging result is yes, the delay re-judgment step is performed; if the judging result of the delay re-judgment step is no, the flow ratio control mode is entered. If the judging result of the delay re-judgment step is yes, the adjustment step is entered.

[0072] The above flow ratio control, namely, the step of adjusting the opening degree is completed, and the distribution of the process gas is controlled by the flow ratio of each branch pipeline 103 .

[0073] The pressure gauge 104 of the present invention can monitor the pressure upstream of the valve in real time. When the flow is switched, the pressure gauge 104 can monitor the change in pressure. The controller adjusts the opening value of the valve according to the change in pressure, thereby reducing the pressure change at the pressure gauge, thereby quickly stabilizing the flow of the branch pipeline.

[0074] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements. In addition, the term "connection" herein means that A and B are directly connected, or that A and B are indirectly connected, such as A and B are connected through C, or even through more components such as C and D, and A and B can be connected in one piece, or in separate pieces, or removable, or fixed. The term "optional" herein means that the technical feature can be combined or not combined with any feature in the text.

[0075] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A gas distribution method applied to wafer processing equipment, characterized in that: include: S1. Provide a controller, a pressure gauge, a main pipeline and at least one branch pipeline, one end of each branch pipeline is connected to the main pipeline, and the other end of each branch pipeline is respectively connected to a corresponding area of ​​the air inlet of the chamber of the wafer processing equipment; a valve is arranged on the branch pipeline; the pressure gauge is arranged upstream of the valve to detect the pressure value upstream of the valve; the controller is respectively connected to the pressure gauge and the valve; S2. The controller controls the opening value of the valve according to the change of the average value of the pressure values ​​of different previous clock cycles of the pressure gauge.

2. The gas distribution method for wafer processing equipment according to claim 1, characterized in that: In step S2, the valve opening value is controlled to be: Mean value calculation step, the controller obtains a first average pressure according to the pressure values ​​of the first N clock cycles, and obtains a second average pressure according to the pressure values ​​of the first M clock cycles, wherein N and M are both positive integers, and N>M; A determination step, in which the controller determines whether the first average pressure and the second average pressure are both greater than a first threshold; Adjustment step: if the judgment result is yes, the action of adjusting the opening value of the valve is executed to enter the adjustment stage.

3. The gas distribution method for wafer processing equipment according to claim 2, characterized in that: In the step S2, during the adjustment phase, a continuous judgment step is also included, wherein the controller controls whether the valve continues to adjust the opening value according to the change of the average value of the pressure values ​​of different previous clock cycles of the pressure gauge.

4. The gas distribution method for wafer processing equipment according to claim 3, characterized in that: The first plurality of clock cycles of the adjustment phase is greater than the first plurality of clock cycles before the adjustment phase.

5. The gas distribution method for wafer processing equipment according to claim 3, characterized in that: Controlling whether the valve continues to adjust the opening value is: in the adjustment stage, the controller obtains the third average pressure according to the pressure values ​​of the previous N1 clock cycles, and obtains the fourth average pressure according to the pressure values ​​of the previous M1 clock cycles. The controller determines whether the third average pressure and the fourth average pressure are simultaneously greater than the second threshold value. If so, the action of continuing to adjust the opening value of the valve is executed; wherein N1 and M1 are both positive integers, N1>M1, N1>N, M1>M.

6. The gas distribution method for wafer processing equipment according to claim 5, characterized in that: The second threshold is greater than the first threshold.

7. The gas distribution method for wafer processing equipment according to claim 3, characterized in that: In the step S2, after the judging step and / or the continuous judging step, a delayed re-judgment step is also included.

8. The gas distribution method for wafer processing equipment according to claim 7, characterized in that: The delayed re-judgment step is: After a delay time Δt, it is determined whether the first average pressure and the second average pressure are both greater than the first threshold value, and if so, the valve opening value adjustment action is performed; And / or, after a delay time Δt, it is determined whether the third average pressure and the fourth average pressure are both greater than the second threshold value, and if so, an action of adjusting the opening value of the valve is performed.

9. The gas distribution method for wafer processing equipment according to claim 8, characterized in that: In the step S2, in the judging step and / or the continuous judging step, if the judging result is no, the flow ratio control mode is entered.

10. The gas distribution method for wafer processing equipment according to claim 8, characterized in that: In step S2, after the judging step and / or the continuous judging step, if the judging result is yes, the delayed re-judgment step is performed; if the judging result is no, the flow ratio control mode is entered.

11. The gas distribution method for wafer processing equipment according to claim 6, characterized in that: The first threshold and the second threshold both correspond to different total flows of the main pipeline and different flow ratios of each branch pipeline.

12. The gas distribution method for wafer processing equipment according to claim 1, characterized in that: The chamber has three zones.

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