Rectification three-way pipe, pressure control system and pressure control method

Abstract

The invention relates to a rectification three-way pipe, a pressure control system and a pressure control method. The rectification three-way pipe comprises a first branch, a second branch and a third branch, the first branch is used for an airflow inflow end, and the second branch is used for an airflow outflow end; boundary lines are formed among the first branch, the second branch and the third branch, and a plurality of rectifying grooves are formed in each boundary line; the length direction of each rectifying groove is perpendicular to the boundary line where the rectifying groove is located. Therefore, the flow resistance is reduced, the branch airflow stability is improved, and the pressure measurement is accurate and stable. And meanwhile, the airflow which is influenced by the vortex fluctuation effect and flows to the closed section branch is rectified, so that the vortex is attenuated more quickly, and the airflow of the closed section branch is more stable.

Description

Technical Field

[0001] This application relates primarily to the field of semiconductor manufacturing equipment, and more particularly to a rectifier tee, a pressure control system, and a pressure control method. Background Technology

[0002] Chemical vapor deposition (CVD) equipment is a key piece of equipment in the field of materials preparation, and the stability of its gas path system directly determines the process accuracy and product quality. In the complex process flow of CVD equipment, the gas path system is generally in a high vacuum environment, and multiple pressure measurement points need to be set up to achieve process monitoring. The three-way pipe, as the core component of the gas path branch of the CVD equipment, works with various gas valves to achieve the orderly transmission of various special gases in a high vacuum environment.

[0003] However, existing T-junctions have the following drawbacks in practical applications: vortices are easily formed when airflow passes through the branch junctions of the T-junction. On the one hand, vortices consume energy and increase airflow resistance; on the other hand, the periodic fluctuations of the vortices cause uneven airflow distribution. When the distal end of a branch of the T-junction is closed, the closed section of the airflow will experience Helmholtz resonance due to the periodic vortices at the T-junction, further exacerbating airflow instability.

[0004] In the aforementioned gas paths, common problems include uneven gas splitting, high flow resistance, and unstable airflow in the blind-end branches. This leads to unstable airflow in the branches after splitting, making it impossible to obtain accurate pressure values. In particular, the closed-section branches exhibit periodic fluctuations due to the influence of Helmholtz resonance.

[0005] For certain specific equipment, such as high-density plasma (HDP) equipment, the helium (He) gas channel in its electrostatic chuck (ESC) has extremely high requirements for airflow stability. If the gas channel experiences large-amplitude periodic fluctuations due to Helmholtz resonance, it will affect the pressure control accuracy of the mass flow meter (MFM), leading to deviations in process parameters and ultimately affecting the process results. Summary of the Invention

[0006] One objective of this application is to provide a rectifier tee, a pressure control system, and a pressure control method to solve the problems of uneven gas distribution, high flow resistance, and unstable airflow in blind-end branches of the tee used in the prior art.

[0007] According to one aspect of this application, a rectifier tee is provided, the rectifier tee comprising: a first branch, a second branch, and a third branch;

[0008] The first branch is used for the airflow inlet end, and the second branch is used for the airflow outlet end;

[0009] The first branch road forms a boundary line with the second and third branches, and multiple rectifier slots are provided at each boundary line;

[0010] The length of each rectifier slot is perpendicular to the boundary line it is located on.

[0011] Optionally, the rectifier tee adopts a T-shaped structure, with the first branch and the second branch being parallel to each other, and the third branch being perpendicular to both the first branch and the second branch;

[0012] Multiple rectifier slots are provided at the T-shaped junction formed by the first branch, the second branch and the third branch.

[0013] Optionally, the number of rectifier slots is 4 to 20, and the number of rectifier slots at each junction is not less than 2.

[0014] Optionally, the rectifier slots are evenly distributed along the boundary line and the boundary line is equally divided, and the distance between the center points of adjacent rectifier slots ranges from 1.1mm to 3.8mm.

[0015] Optionally, the edges of the rectifier slot are chamfered.

[0016] Optionally, the rectifier slot includes a central region rectifier slot and an edge region rectifier slot;

[0017] The central region rectifier tank is located in the central axis region of the third branch, and the edge region rectifier tank is located away from the central axis of the third branch;

[0018] The width of the central region rectifier groove ranges from 0.2mm to 0.6mm, and the width of the edge region rectifier groove ranges from 0.4mm to 1.2mm.

[0019] Optionally, the width of the central region rectifier groove is 0.4 to 0.6 times the width of the vortex at the boundary line, and the width of the edge region rectifier groove is 0.4 to 0.6 times the length of the vortex at the boundary line.

[0020] Optionally, the ratio of the width to the depth of the rectifier groove is less than 2.

[0021] Optionally, the rectifier is applied in a vacuum environment with a vacuum level ranging from 0.5 to 100 torr.

[0022] According to another aspect of this application, a pressure control system for an internal heating and cooling system is also provided, the system comprising:

[0023] As mentioned above, the rectifier tee and mass flow meter;

[0024] The rectifier tee is used to connect the second branch as a blind end to the wafer back-side pipeline of the internal heating and cooling system.

[0025] The mass flow meter is installed upstream of the first branch in the rectifier tee, and the outlet end of the mass flow meter is connected to the inlet of the first branch.

[0026] The mass flow meter is configured to control the pressure at its outlet to a target value, the target value being the pressure on the back side of the wafer;

[0027] The rectifier groove in the rectifier tee improves the consistency between the pressure at the outlet of the mass flow meter and the pressure at the blind end.

[0028] According to another aspect of this application, a pressure control method for an internal heating and cooling system is also provided, the method comprising:

[0029] Using the aforementioned rectifier tee, the second branch is connected as a blind terminal to the wafer back-side piping of the internal heating and cooling system.

[0030] A mass flow meter is installed upstream of the first branch, and the outlet end of the mass flow meter is connected to the inlet of the first branch. The mass flow meter is used to control the pressure at its outlet end to a target value, which is the pressure on the back side of the wafer.

[0031] The blind end is connected to the process chamber to measure the pressure value inside the process chamber and compare it with the target value.

[0032] Compared with existing technologies, this application provides a rectifying tee tube, which includes a first branch, a second branch, and a third branch. The first branch is used for the airflow inlet, and the second branch is used for the airflow outlet. A boundary line is formed between the first branch and the second and third branches, and multiple rectifying slots are provided at each boundary line. The length direction of each rectifying slot is perpendicular to the boundary line. This reduces flow resistance, improves the stability of the branch airflow, and makes pressure measurement accurate and stable. Simultaneously, it rectifyes the airflow that is affected by vortex wave effects flowing towards the closed-section branch, causing vortices to decay more quickly and making the airflow in the closed-section branch more stable. Attached Figure Description

[0033] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings, wherein:

[0034] Figure 1 A schematic diagram of a rectifier tee structure provided according to one aspect of this application is shown;

[0035] Figure 2 This illustration shows a schematic diagram of a vortex in one embodiment of the present application;

[0036] Figure 3 This illustration shows a structural schematic diagram of the rectifier tank in one embodiment of this application;

[0037] Figure 4 This diagram illustrates the distribution of rectifier slots along the same boundary line in one embodiment of this application.

[0038] Figure 5 A schematic diagram of airflow using a standard tee pipe is shown;

[0039] Figure 6 A schematic diagram of airflow using the rectifier tee tube described in this application is shown;

[0040] Figure 7 A schematic diagram of a pressure control system for an internal heating and cooling system is shown according to another aspect of this application.

[0041] Figure 8 This diagram illustrates the pressure changes within the process chamber in one embodiment of this application.

[0042] Figure 9 This diagram illustrates a pressure control method for an internal heating and cooling system according to another aspect of this application.

[0043] The same or similar reference numerals in the accompanying drawings represent the same or similar parts. Detailed Implementation

[0044] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0045] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein, and therefore this application is not limited to the specific embodiments disclosed below.

[0046] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0047] Furthermore, the terms “up,” “down,” “left,” “right,” “top,” “bottom,” “horizontal,” and “vertical” used in the following description should be understood as the orientations shown in the paragraph and related figures. This relative terminology is for illustrative purposes only and does not imply that the described device must be manufactured or operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0048] It is understood that although terms such as “first,” “second,” “third,” etc., may be used here to describe various pipes, channels, components, areas, layers, and / or parts, these components, areas, layers, and / or parts should not be limited by these terms, and these terms are only used to distinguish different pipes, channels, components, areas, layers, and / or parts.

[0049] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show components relevant to the present invention and are not drawn according to the actual number, shape, and size of the components in the actual implementation. In the actual implementation, the form, quantity, and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex. To keep the illustrations as concise as possible, not all structures are shown in the figures.

[0050] Figure 1 The diagram shows a rectifier tee structure according to one aspect of this application. The rectifier tee includes a first branch 10, a second branch 20, and a third branch 30. The first branch 10 is used for the airflow inlet, and the second branch 20 is used for the airflow outlet. A boundary line 40 is formed between the first branch 10, the second branch 20, and the third branch 30. A plurality of rectifier slots 50 are provided at each boundary line 40. The length direction of each rectifier slot 50 is perpendicular to the boundary line 40.

[0051] Design a rectifier tee where airflow enters through one parallel branch and exits through the other two branches. The parallel exit branches are suitable for applications with closed ends. Airflow passes through the junction of the tee, such as... Figure 2 As shown, the formed vortex is elongated in the central region and flattened on both sides; E1 is a flat vortex, and E2 is an elongated vortex. A flow straightener 50 can be installed at the junction of the three branches, with multiple flow straighteners 50 at each junction to guide the airflow.

[0052] The length direction of each rectifier slot 50 is perpendicular to the boundary line 40, such as Figure 3 As shown, aligning or perpendicular the tank to the fluid flow direction helps smooth the flow path, optimizes fluid dynamics, reduces turbulence and pressure oscillations, and helps improve the accuracy of pressure or flow measurements.

[0053] It should be noted that the rectifier channel can be cast, welded or stamped, and machined.

[0054] In one embodiment of this application, the rectifier is applied in a vacuum environment with a vacuum level ranging from 0.5 to 100 torr.

[0055] Based on the commonly used 5mm diameter gas pipeline in semiconductor deposition equipment, with a vacuum level of 0.5~100 torr, the gas flow passing through the junction of the T-junction forms a vortex, as... Figure 2 As shown, the vortex length l´ is 1~2mm and the width w´ is 0.5~1mm. Taking into account the diameter of the tee pipe, the size and location of the vortex, multiple evenly distributed rectifier slots are set at the junction of the tee pipe branches.

[0056] In one embodiment of this application, the rectifier tee adopts a T-shaped structure, the first branch 10 and the second branch 20 are parallel to each other, and the third branch 30 is perpendicular to the first branch 10 and the second branch 20; multiple rectifier slots are provided at the T-shaped junction line formed by the first branch, the second branch and the third branch.

[0057] The first branch 10 serves as the fluid inlet, the second branch 20 serves as the fluid outlet, and the third branch 30 branches vertically. The third branch 30 connects to the center position between the first branch 10 and the second branch 20. That is, the first branch 10 and the second branch 20 are symmetrically distributed in parallel with respect to the third branch 30. The third branch 30 is used to assist in the flow distribution.

[0058] The three branches converge at a T-shaped junction, where multiple flow straighteners are installed. The length of these flow straighteners is perpendicular to the T-junction edge, ensuring that vortex-breaking action is focused on the vortex-forming region. Using this T-shaped tee promotes uniform fluid distribution, effectively smoothing the fluid transition and preventing turbulence and vortex generation. The T-shaped structure allows for a compact design and reduces upstream piping, improving the overall system's reliability and maintainability.

[0059] In one embodiment of this application, the number of rectifier slots is 4 to 20, and the number of rectifier slots at each boundary edge is not less than 2.

[0060] Flow rectifiers can be used to reduce pressure loss and fluctuations in fluid flow, thereby improving measurement accuracy. The number and distribution of flow rectifiers affect the uniformity and stability of the fluid. Therefore, at the junction of T-junction branches, 4 to 20 evenly distributed flow rectifiers can be installed to ensure that the fluid in all directions can be effectively rectified.

[0061] To ensure the vortex-breaking effect, there should be no fewer than two straightening channels at each junction. For example, at a T-shaped junction, there should be at least two straightening channels on each confluence side to balance the flow splitting and merging processes.

[0062] In one embodiment of this application, the rectifier slots are evenly distributed along the boundary line and equally divide the boundary line, and the distance between the center points of adjacent rectifier slots ranges from 1.1mm to 3.8mm.

[0063] like Figure 4 As shown, the rectifier slots are evenly distributed on the same boundary, bisecting the boundary line equally. The center points of two rectifier slots are d apart, where d ranges from 1.1mm to 3.8mm. The structure of each rectifier slot is enlarged, as shown below. Figure 3 As shown, the depth of the rectifier slot is h, the width is w, and the length is l. The length direction of each rectifier slot is perpendicular to the boundary edge to make its width-to-depth ratio more regular and its size distribution more uniform.

[0064] In one embodiment of this application, the edge of the rectifier tank is chamfered, and the radius of the chamfer can be 0.05 mm to prevent particle deposition.

[0065] In one embodiment of this application, the rectifier slot includes a central region rectifier slot and an edge region rectifier slot. The central region rectifier slot is located in the central axis region of the third branch, and the edge region rectifier slot is located away from the central axis of the third branch. The width of the central region rectifier slot ranges from 0.2mm to 0.6mm, and the width of the edge region rectifier slot ranges from 0.4mm to 1.2mm.

[0066] The width of the rectifier slot is set in segments. The slot width is 0.2mm~0.6mm in the area near the center of the third branch and 0.4mm~1.2mm in the area near the edge of the parallel branch.

[0067] The central region can be the area near the central axis of the third branch, such as within a fan-shaped area of ​​±15° on both sides of the central axis. It is directly impacted by the vertically flowing airflow, forming a high-velocity core area with a small vortex width w´, which is 0.5mm~1mm. The edge region is the area beyond the ±15° range of the central region of the boundary line, such as ±15°~90°. It is in the airflow separation zone, where the vortex is stretched into a long strip shape with a larger vortex length l´, which is 1mm~2mm.

[0068] In one embodiment of this application, the width of the central region rectifier groove is 0.4 to 0.6 times the width of the vortex at the boundary line, and the width of the edge region rectifier groove is 0.4 to 0.6 times the length of the vortex at the boundary line.

[0069] The ratio of the width to the depth of the rectifier channel is less than 2.

[0070] The central region groove width w satisfies: w = (0.4~0.6)w´, where w´ is the vortex width, and the edge region groove width w satisfies: w = (0.4~0.6)l´, where l´ is the vortex length.

[0071] For example, the length of the rectifier slot l is 0.5~0.8mm, and the width w of the rectifier slot in the central region is set to 0.4~0.6 times the vortex size w´, which is 0.2mm~0.6mm; the width w of the rectifier slot in the edge region is set to 0.4~0.6 times the vortex size l´, which is 0.4mm~1.2mm.

[0072] For gas paths in a vacuum environment, in order to ensure the vortex breaking effect, the width-to-depth ratio of the rectifier groove should be less than 2, and the depth h should be 0.1mm~0.6mm.

[0073] like Figure 5 As shown, when using a common T-shaped tee, 'a' represents the airflow direction, and region A represents the flow separation zone. A large vortex is formed in region A, with a vortex length d1 reaching 5 mm. At point B, the flow splits along the wall, and at point C near the closed section D, a large vortex is formed with a length d2 of approximately 10 mm.

[0074] Using the rectifier tee described in this application, such as Figure 6 As shown, delaying the separation of airflow at the interface causes the airflow to adhere more closely to the wall after turning, significantly reducing vortices. At point A, the vortex length d1 decreases from 5mm to 2mm, reducing flow resistance and improving the stability of the branch airflow, thus making pressure measurement accurate and stable. Simultaneously, the airflow flowing towards the closed branch D, affected by vortex fluctuations, is rectified, breaking large vortices into smaller ones. Specifically, the vortex length d2 at point C decreases from 10mm to 3mm, attenuating more rapidly and making the airflow in the closed branch more stable.

[0075] Figure 7 This illustration shows a schematic diagram of a pressure control system for an internal heating and cooling system according to another aspect of this application. The system includes:

[0076] As described above, the rectifier tee 100 and the mass flow meter 200;

[0077] The rectifier tee 100 is used to connect the second branch as a blind end to the wafer back-side pipeline of the internal heating and cooling system.

[0078] The mass flow meter 200 is installed upstream of the first branch in the rectifier tee 100, and the outlet end of the mass flow meter 200 is connected to the inlet of the first branch. The mass flow meter 200 is configured to control the pressure at its outlet end to a target value, the target value being the pressure on the back side of the wafer.

[0079] The rectifier slots provided in the rectifier tee 100 improve the consistency between the pressure at the outlet end of the mass flow meter and the pressure at the blind end.

[0080] For the IHC (Internal Heating and Cooling) system of an HDP (High-Density Plasma) machine, the MFM (Mass Flow Meter) controls the pressure upstream of the T-junction, with the control pressure being the MFM outlet pressure. This pressure is the required pressure on the back side of the wafer in the IHC system, and the IHC piping on the back side of the wafer is the blind end of the T-junction. Therefore, adding a rectifier slot can improve the consistency between the MFM outlet pressure and the pressure on the back side of the wafer in the IHC piping.

[0081] The IHC system also includes a supply valve 300, a needle valve 400, a roughing pump 500, a helium cooling valve 600, an exhaust valve 700, and a process chamber 800.

[0082] The supply valve 300 is located at the front end of the MFM to control the opening or closing of the gas supply, ensuring that gas flows into the system as needed.

[0083] The needle valve 400 is connected to the third branch of the three-way pipe and is installed on the discharge line L1. It is used to finely regulate the flow rate of the discharged fluid, thereby accurately controlling the system pressure release rate and optimizing pressure consistency.

[0084] The roughing pump 500 is connected to the discharge line L1 and is used for initial vacuuming and discharge of unwanted gases to reduce system pressure and maintain a low-pressure environment in the process chamber.

[0085] The helium cooling valve 600 is located on the second branch of the rectifier tee and is used to control the flow of helium to achieve a cooling effect.

[0086] The fore-stage pipeline L2 is connected to the outlet of the helium cooling valve 600. An exhaust valve 700 is installed on the fore-stage pipeline L2 to control the fore-stage pipeline L2 to discharge fluid to the downstream vacuum pump or processing section; the process chamber 800 is connected to the second branch.

[0087] The IHC system was operated with MFM pressure control at 8 torr, and the pressure inside the process chamber 800 was tested using a vacuum gauge. During the test, the IHC pipeline was connected to the process chamber, and the process chamber was then closed to form a blind end of a tee.

[0088] like Figure 8 As shown in the figure, the results indicate that when the MFM outlet is connected to a regular tee pipe, the pressure fluctuation in the process chamber is relatively large; when connected to a rectifier tee pipe, the pressure fluctuation is relatively stable.

[0089] Figure 9 This diagram illustrates a pressure control method for an internal heating and cooling system according to another aspect of this application, the method comprising:

[0090] Step S11: Using the aforementioned rectifier tee, the second branch is connected as a blind terminal to the wafer back-side pipeline of the internal heating and cooling system.

[0091] The second branch of the rectifier tee is used as a blind end, i.e. a closed end, and connected to the back-side pipeline of the wafer. The first branch is used as the inlet, and the third branch is used as an auxiliary outlet. The rectifier slot is set at the junction of the three branches to help the fluid be evenly distributed.

[0092] Step S12: Install a mass flow meter upstream of the first branch and connect the outlet of the mass flow meter to the inlet of the first branch. The mass flow meter is used to control the pressure at its outlet to a target value, where the target value is the pressure on the back side of the wafer.

[0093] An MFM (mass flow meter) is installed upstream of the first branch. The outlet of the MFM is connected to the inlet of the first branch. The control pressure value of the MFM is the pressure at its own outlet. This control pressure value is set as the target pressure on the back side of the wafer. The rectifier slot design ensures that the pressure signal is efficiently transmitted to the blind end. By precisely controlling the inlet pressure value through the MFM, the rectifier slot reduces turbulence losses and improves pressure control consistency.

[0094] Step S13: Connect the blind end to the process chamber to measure the pressure value inside the process chamber and compare it with the target value.

[0095] The second branch (i.e., the blind end) is connected to the process chamber, which is the chamber where the wafer is located. The actual pressure value in the chamber is measured in real time. This actual pressure value is compared and analyzed with the pressure control value of MFM, realizing one-click verification and greatly improving the test accuracy, efficiency and reliability.

[0096] The basic concepts have been described above. Obviously, for those skilled in the art, the above disclosure is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0097] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0098] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of scope in some embodiments of this application are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

Claims

1. A rectifier tee, characterized in that, The rectifier tee includes: a first branch, a second branch, and a third branch; The first branch is used for the airflow inlet end, and the second branch is used for the airflow outlet end; The first branch road forms a boundary line with the second and third branches, and multiple rectifier slots are provided at each boundary line; The length of each rectifier slot is perpendicular to the boundary line it is located on.

2. The rectifier tee according to claim 1, characterized in that, The rectifier tee adopts a T-shaped structure, with the first branch and the second branch being parallel to each other, and the third branch being perpendicular to both the first branch and the second branch; Multiple rectifier slots are provided at the T-shaped junction formed by the first branch, the second branch and the third branch.

3. The rectifier tee according to claim 1, characterized in that, The number of rectifier slots is 4 to 20, and the number of rectifier slots at each junction is no less than 2.

4. The rectifier tee according to claim 1, characterized in that, The rectifier slots are evenly distributed along the boundary line and equally divide the boundary line. The distance between the center points of adjacent rectifier slots ranges from 1.1mm to 3.8mm.

5. The rectifier tee according to claim 1, characterized in that, The edges of the rectifier slot are chamfered.

6. The rectifier tee according to claim 1, characterized in that, The rectifier slot includes a central region rectifier slot and an edge region rectifier slot. The central region rectifier slot is located in the central axis region of the third branch, and the edge region rectifier slot is located away from the central axis of the third branch. The width of the central region rectifier groove ranges from 0.2mm to 0.6mm, and the width of the edge region rectifier groove ranges from 0.4mm to 1.2mm.

7. The rectifier tee according to claim 6, characterized in that, The width of the central region rectifier groove is 0.4 to 0.6 times the width of the vortex at the boundary line, and the width of the edge region rectifier groove is 0.4 to 0.6 times the length of the vortex at the boundary line.

8. The rectifier tee according to claim 6, characterized in that, The ratio of the width to the depth of the rectifier channel is less than 2.

9. The rectifier tee according to claim 1, characterized in that, The rectifier tank is used in a vacuum environment with a vacuum level ranging from 0.5 to 100 torr.

10. A pressure control system for an internal heating and cooling system, characterized in that, The system includes: a rectifier tee and a mass flow meter as described in any one of claims 1 to 9; The rectifier tee is used to connect the second branch as a blind end to the wafer back-side pipeline of the internal heating and cooling system. The mass flow meter is installed upstream of the first branch in the rectifier tee, and the outlet end of the mass flow meter is connected to the inlet of the first branch. The mass flow meter is configured to control the pressure at its outlet end to a target value, the target value being the pressure on the back side of the wafer. The rectifier groove in the rectifier tee improves the consistency between the pressure at the outlet of the mass flow meter and the pressure at the blind end.

11. A pressure control method for an internal heating and cooling system, characterized in that, The method includes: Using any one of the rectifier tee tubes of claims 1 to 9, the second branch is connected as a blind end to the wafer back-side pipeline of the internal heating and cooling system; A mass flow meter is installed upstream of the first branch, and the outlet end of the mass flow meter is connected to the inlet of the first branch. The mass flow meter is used to control the pressure at its outlet end to a target value, which is the pressure on the back side of the wafer. The blind end is connected to the process chamber to measure the pressure value inside the process chamber and compare it with the target value.

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