A laminar flow element and a multi-channel proportional gas distribution device to which it is applied

Abstract

In the technical field of semiconductor devices of the present invention, a laminar flow element and a multi-channel proportional gas mixing device to which the laminar flow element is applied are proposed. The laminar flow element includes: a first component; and a second component configured to move relative to the first component to change the opening area of the laminar flow element through which a fluid flows; wherein at least one of the first and second components has a first Reynolds number characteristic dimension, and a laminar flow sheet is provided on at least one of the first and second components. The laminar flow sheet has a second Reynolds number characteristic dimension, and the second Reynolds number characteristic dimension is smaller than the first Reynolds number characteristic dimension. The laminar flow element can rectify the flow pattern of the gas flow of the reaction gas from turbulent flow to laminar flow, and can achieve true proportional flow control when applied in a multi-channel proportional gas mixing device, greatly improving the reproducibility and repeatability of the adjustment process. And it is not necessary to control the back pressure upstream of the nozzle, removing the back pressure constraints of multiple MFCs, and the pressure drop ΔP of the pipeline i is formed naturally, avoiding the generation of over-constraints.

Description

Technical Field

[0001] The present invention generally relates to the technical field of semiconductor devices. Specifically, the present invention relates to a laminar flow element and a multi-channel proportional gas distribution device to which it is applied. Background Art

[0002] In semiconductor devices, multi-channel proportional gas distribution is a common requirement, where multi-channel gas distribution means that after a given total mass flow rate, it is distributed at multiple outlets in a specified ratio. Figure 1 、 Figure 2 、 Figure 3 The structural schematic diagram of a multi-channel proportional gas distribution semiconductor device in the prior art is shown.

[0003] As Figure 1 shown, the U.S. Patent "US20060216417A1" discloses a System for control of gas injectors, which includes an injector, an inlet, and a plurality of manual metering valves, where the inlet controlled by a mass flow controller (MFC) gives the total flow rate and is distributed through the manual metering valves. However, this system requires manual adjustment based on experience and cannot perform quantitative automatic adjustment. The parameters determined by investing a large amount of costs (substrate, reaction gas, equipment working hours) on one device cannot be directly implemented on other devices, but require a large amount of time and cost for re-adjustment. In addition, although this system can control the opening degree by means of a motor pushing the manual metering valve, the motor can only record the position of the opening degree (setting an indication range of 0.1 to 4.9 for the manual metering valve in this system), and it is difficult to achieve true mass flow control, and the discovery of process effects is poor.

[0004] As Figure 2 shown, the U.S. Patent "US20180135179A1" discloses a Gas Injector and Vertical Heat Treatment Apparatus, in which mass flow distribution compensation is carried out by arranging a gas distribution pipe with openings and bends, so that multiple horizontally placed substrates can obtain the same flow rate. However, this device has the problem of too small implementation flexibility, and a large number of gas distribution pipes with different shapes and opening sizes need to be prepared in advance for debugging. When the process conditions change, new gas distribution pipes need to be constructed. And due to the excessive combination of the shapes of the gas distribution pipes, the trial-and-error situation is complex.

[0005] In addition, a common technical solution for multi-channel proportional gas distribution in the prior art is to connect multiple MFCs in series and parallel. Among them, the total flow rate is set and controlled by one MFC, or the total flow rate is controlled after mixing multiple gases through multiple MFCs. And multiple parallel MFCs are arranged downstream of one or more MFCs that control the total flow rate located upstream. Each downstream MFC controls the flow rate of a separate gas outlet, thereby realizing multi-channel proportional gas distribution. However, this solution has the following problems:

[0006] First of all, the flow rate outputs of the upstream and downstream MFCs are not strictly equal. When the gas outlet of the downstream MFC is not equal to that of the upstream MFC, the middle section of the system will have a problem of unstable pressure due to the flow rate imbalance. To solve this problem, as Figure 3 shown, the US patent "US20170271184A1" discloses a gas flow ratio control method and component (Methods and assemblies for gas flow ratio cantrol), in which a back pressure valve BPC (backside pressure cantroller) is used to replace one of the multiple downstream MFCs. When the total flow rate of the multiple upstream MFCs 126 is not equal to the flow rate of the multiple downstream MFCs 112, the flow rate is compensated through the back pressure valve 114.

[0007] In addition, existing MFCs are usually mass flow controllers based on pressure control. Under a certain downstream pressure, multiple downstream MFCs need to adjust the pressure control valves inside the MFCs to different pressures. Since the pressure at the downstream outlet of the device is usually limited by the process conditions of the reaction chamber and needs to be controlled by the pressure controller of the reaction chamber and cannot be adjusted by the MFC, only the pressure of the upstream MFC can be adjusted. However, since the upstream MFCs are connected to each other, the upstream pressure adjustment will cause the pressures of the individual upstream MFCs not to conform to the output of the control algorithm. When the flow rates between the MFCs differ greatly, the pressure difference between the large-flow MFC and the small-flow MFC will result in insufficient flow rate at the large-flow MFC. As Figure 3 shown, replacing one of the multiple downstream MFCs with a BPC is still difficult to solve this problem, and using more BFCs will have the problem that the specific flow rates of multiple BFCs are uncontrollable. Summary of the Invention

[0008] Through research, the applicant has found that the reason for the technical problems existing in the prior art's technical solution of multi-channel proportional gas distribution using series and parallel connection of MFCs lies in that each MFC is a single-input single-output system (SISO), while the proportional mass flow control system is a multi-input multi-output system (MIMO). Connecting multiple MFCs (SISOs) in parallel is a harmful simplification of the proportional mass flow control system (MIMO), resulting in an overconstraint problem. As Figure 3 shown, the parallel connection of multiple MFCs (SISOs) generates an overconstraint on the back pressure, and a back pressure valve BFC needs to be used to reduce the constraint conditions.

[0009] To at least partially solve the above problems in the prior art, the present invention proposes a laminar flow element, comprising:

[0010] a first component; and

[0011] a second component configured to move relative to the first component to change the opening area of the laminar flow element through which fluid flows;

[0012] wherein at least one of the first and second components has a first Reynolds number characteristic dimension, and laminar flow sheets are provided on at least one of the first and second components, and the laminar flow sheets have a second Reynolds number characteristic dimension, and the second Reynolds number characteristic dimension is smaller than the first Reynolds number characteristic dimension.

[0013] Here, the term "Reynolds number" refers to the Reynolds number Re = ρVL / μ, where ρ represents the fluid density, V represents the characteristic velocity, L represents the characteristic dimension, and μ represents the dynamic viscosity of the fluid. The term "characteristic dimension" is used to reflect the relative size of the fluid and the surface of the component, and for different flow problems, there can be different characteristic dimensions. For example, in the case of flow in a pipe, the unit characteristic dimension is usually the diameter or hydraulic diameter of the pipe; in the case of flat plate flow, the unit characteristic dimension is the distance between the two flat plates; in the case of an object in a fluid, the unit characteristic dimension is the main dimension of the object (such as the diameter of a sphere or the chord length of a wing).

[0014] In an embodiment of the present invention, it is stipulated that the first component has a first Reynolds number characteristic dimension, and the first component is tubular or hole-shaped; and

[0015] the second component has laminar flow sheets, wherein the outer contour of the second component moves relative to the inner contour of the first component to change the opening area of the laminar flow element.

[0016] In an embodiment of the present invention, it is stipulated that the laminar flow element comprises:

[0017] An internal component having a base on which a plurality of first laminar flow plates are arranged, the spacing between the first laminar flow plates constituting a second Reynolds number characteristic dimension, and the internal component being nested inside an outer cylinder component; and

[0018] An outer cylinder component, the inner diameter of the cylinder wall thereof constituting a first Reynolds number characteristic dimension, the first laminar flow plates being in contact with the inner wall of the outer cylinder component, and the internal component being configured to move relatively in the axial direction of the outer cylinder component to adjust the opening area of the laminar flow element, wherein the opening area includes the size of the gap between the base and the upper edge of the outer cylinder component, and the second Reynolds number characteristic dimension is smaller than the first Reynolds number characteristic dimension.

[0019] In an embodiment of the present invention, it is stipulated that the first laminar flow plates are configured to reduce the Reynolds number of the fluid to 1 / (first Reynolds number characteristic dimension / second Reynolds number characteristic dimension) so as to rectify the flow state of the fluid from turbulent flow to laminar flow.

[0020] In an embodiment of the present invention, it is stipulated that when the internal component moves in the axial direction of the outer cylinder component until the first laminar flow plates are completely fitted with the outer cylinder component, the opening area of the laminar flow element is zero.

[0021] In an embodiment of the present invention, it is stipulated that the internal component forms an inner cone at the axis, and the inner cone is configured to reduce the potential fluid retention caused by the narrow space of the first laminar flow plates at the axis.

[0022] In an embodiment of the present invention, it is stipulated that a second laminar flow plate is arranged on the inner side of the outer cylinder component, the gap between the second laminar flow plates constituting a third Reynolds number characteristic dimension, and the gap between the first laminar flow plates and the second laminar flow plates constituting a fourth Reynolds number characteristic dimension, wherein the fluid flows from the first side of the laminar flow element through the gap between the first laminar flow plates and the second laminar flow plates and flows to the second side of the laminar flow element from the through hole.

[0023] In an embodiment of the present invention, it is stipulated that any one of the second, third, and fourth Reynolds number characteristic dimensions is smaller than the first Reynolds number characteristic dimension.

[0024] In an embodiment of the present invention, differential pressure gauges are arranged on the first side and the second side of the laminar flow element, and an absolute pressure gauge is arranged to provide a reference for the differential pressure gauges to measure the pressure difference ΔP = P UP -P DOWN where P UP represents the pressure on the first side of the laminar flow element, and P DOWN represents the pressure on the second side of the laminar flow element; or

[0025] The first side and the second side of the laminar flow element are arranged with absolute pressure gauges to measure the pressure difference ΔP = P UP -P DOWN .

[0026] In an embodiment of the present invention, it is stipulated that the inner cone is configured such that when adjusting the opening area, the cross-sectional areas inside the laminar flow element do not change drastically.

[0027] In an embodiment of the present invention, it is stipulated that the second laminar flow sheet is configured such that laminar flow sheets are provided in each flow channel inside the laminar flow element to form a fully laminar flow.

[0028] The present invention also provides a multi-channel proportional gas distribution device, which is characterized by including:

[0029] An air inlet device configured to transport reaction gas to the throttle orifice;

[0030] A plurality of laminar flow elements, the first side of which is connected to the air inlet device and the second side is connected to the reaction cavity, wherein the laminar flow element is the laminar flow element in the above embodiment; and

[0031] A reaction cavity, wherein the reaction gas enters the reaction cavity through the throttle orifice to carry out a reaction.

[0032] The present invention has at least the following beneficial effects: The present invention provides a laminar flow element and a multi-channel proportional gas distribution device to which it is applied. The laminar flow element can rectify the flow state of the gas flow of the reaction gas from turbulent flow to laminar flow, and can adjust the opening area of the laminar flow element by adjusting the gap size between the laminar flow sheets. When applied to a multi-channel proportional gas distribution device, compared with a device that uses a manual metering valve for gas distribution, it can achieve true proportional flow control, greatly improving the reproducibility and repeatability of the adjustment process. Compared with a device that uses multiple MFCs for gas distribution, this device does not require controlling the back pressure upstream of the nozzle, removing the back pressure constraints of multiple MFCs, and the pressure drop ΔP i of the pipeline is naturally formed, avoiding the generation of over-constraint. At the same time, this device integrates a large number of components corresponding to traditional MFCs in the air inlet device, which can greatly reduce the number of sensors to be arranged, make the system more compact, and greatly reduce the cost of the device. In addition, compared with a device that uses multiple MFCs for gas distribution, this device greatly reduces the length of the pipeline for transporting the reaction gas, can reduce the influence of the residual gas remaining in the pipeline, improves the response speed and accuracy, and is beneficial to improving the growth rate and control accuracy of the ALD process. Description of the Drawings

[0033] To further clarify the advantages and features of the embodiments of the present invention and others, a more specific description of the embodiments of the present invention will be presented with reference to the accompanying drawings. It can be understood that these drawings only depict typical embodiments of the present invention and will not be considered as a limitation of its scope. In the drawings, for clarity, the same or corresponding components will be denoted by the same or similar reference numerals.

[0034] Figures 1 - 3 The structural schematic diagram of a semiconductor device with multi-channel proportional gas distribution in the prior art is shown.

[0035] Figure 4 The structural schematic diagram of a multi-channel proportional gas distribution device with a single-channel intake in an embodiment of the present invention is shown.

[0036] Figure 5 The schematic diagram of a throttle hole in an embodiment of the present invention is shown.

[0037] Figure 6 The structural schematic diagram of a multi-channel proportional gas distribution device with multi-channel intake in an embodiment of the present invention is shown.

[0038] Figure 7 The structural schematic diagram of a multi-channel proportional gas distribution device with independent control in an embodiment of the present invention is shown.

[0039] Figure 8A -B shows the structural schematic diagram of a vertical furnace tube in an embodiment of the present invention.

[0040] Figure 9 The schematic diagram of the gas flow path in a vertical furnace tube is shown.

[0041] Figure 10 The schematic diagram of a vertical furnace tube based on a multi-channel proportional gas distribution device with independent control in an embodiment of the present invention is shown.

[0042] Figure 11 The structural schematic diagram of a multi-channel proportional gas distribution device integrated with an intake device in an embodiment of the present invention is shown.

[0043] Figure 12 The schematic diagram of a reaction chamber arranged with a multi-channel proportional gas distribution device integrated with an intake device in an embodiment of the present invention is shown.

[0044] Figure 13 The schematic diagram at a throttle hole in an embodiment of the present invention is shown.

[0045] Figure 14 The schematic diagram of the change of pressure and flow rate of a choked flow in an embodiment of the present invention is shown.

[0046] Figure 15A -B shows a schematic diagram of a laminar flow element arranged in a pipeline in an embodiment of the present invention.

[0047] Figure 16A Shows a schematic structural diagram of a laminar flow element in an embodiment of the present invention.

[0048] Figure 16B Shows a schematic structural diagram of an outer cylinder component in an embodiment of the present invention.

[0049] Figure 16C Shows a top view of an outer cylinder component in an embodiment of the present invention.

[0050] Figure 16D Shows a schematic structural diagram of an inner cone component in an embodiment of the present invention.

[0051] Figure 17 Shows a schematic diagram of an air flow passing through a laminar flow element in an embodiment of the present invention. Detailed implementation manners

[0052] It should be noted that the components in each drawing may be exaggerated for illustration purposes and are not necessarily drawn to the correct scale. In each drawing, the same or functionally identical components are provided with the same reference numerals.

[0053] In the present invention, unless otherwise specified, "arranged on", "arranged above", and "arranged over" do not exclude the existence of intermediate objects between the two. In addition, "arranged on or above" only represents the relative positional relationship between two components, and in certain cases, such as after reversing the product direction, it can also be converted to "arranged under or below", and vice versa.

[0054] In the present invention, each embodiment is only intended to illustrate the solution of the present invention and should not be construed as restrictive.

[0055] In the present invention, unless otherwise specified, the quantifiers "a" and "one" do not exclude the scenario of multiple elements.

[0056] It should also be noted here that in the embodiments of the present invention, for the sake of clarity and simplicity, only a part of the components or assemblies may be shown. However, those of ordinary skill in the art can understand that under the teaching of the present invention, the required components or assemblies can be added according to the specific scenario requirements. In addition, unless otherwise stated, the features in different embodiments of the present invention can be combined with each other. For example, a certain feature in the second embodiment can be used to replace the corresponding or functionally identical or similar feature in the first embodiment, and the resulting embodiment also falls within the scope of disclosure or the scope of record of this application.

[0057] It should also be noted here that within the scope of the present invention, terms such as "identical", "equal", "equivalent" do not mean that the two values are absolutely equal, but allow for a certain reasonable error. That is to say, these terms also cover "substantially identical", "substantially equal", "substantially equivalent". By analogy, in the present invention, terms indicating direction such as "perpendicular to", "parallel to", etc. also cover the meanings of "substantially perpendicular to", "substantially parallel to".

[0058] In addition, the numbering of the steps of each method of the present invention does not limit the execution order of the method steps. Unless otherwise specified, the method steps can be executed in different orders.

[0059] The present invention will be further described below in conjunction with specific embodiments with reference to the accompanying drawings.

[0060] Figure 4 The structural schematic diagram of a multi-channel proportional gas distribution device with single-channel intake in an embodiment of the present invention is shown. As Figure 4 shown, the device may include a pressure distribution container 401, a plurality of throttle holes (4021, 4022... 402i... 402n), a reaction cavity 403, a control unit (Controller Unit) 404, a mass flow meter (MFC, Mass Flow Meter) 405, and a vacuum pump (Vaccum Pump) 406. Figure 6 The structural schematic diagram of a multi-channel proportional gas distribution device with multi-channel intake in an embodiment of the present invention is shown. Compared with Figure 4 the single-channel intake device, multiple MFCs can be provided upstream of this device to mix reaction gases with different masses and flows to form a total gas that needs to be proportionally distributed, and is distributed and output at multiple ports according to the specified mass ratio downstream. The total gas enters the pressure distribution container 401 through the mass flow meter 405, where the mass flow meter 405 is not essential in the multi-channel intake device.

[0061] The pressure distribution container 401 may be a preset channel in a pipe tube or an injector, which is configured such that the pressures at each throttle hole 402i downstream or at the outlet of the pressure distribution container 40 are close. For example, the bending of the pressure distribution container 401 can be reduced, the inlet of the pressure distribution container 401 can be set at the center relative to the multiple outlets, and the largest possible inner diameter of the container can be used when possible. A pressure regulating valve is provided at the outlet of the pressure distribution container 401, and the pressure at the inlet of the pressure distribution container 401 can be adjusted to P through the pressure regulating valve PDVInside the pressure distribution container 401, a container pressure gauge and a container thermometer can be provided to measure the temperature inside the pressure distribution container 401, or the container pressure gauge may not be provided, and the pressure P at the upstream of the throttle orifice 402i closest to the inlet UPi is used as P PDV .

[0062] A plurality of throttle orifices 402i are provided at the outlet of the pressure distribution container 401. Figure 5 The schematic diagram of a throttle orifice in an embodiment of the present invention is shown. As Figure 5 shown, the opening area A of the throttle orifice 402i i is adjustable. In addition, in other embodiments of the present invention, the throttle orifice can also be replaced by a laminar flow element (LFE).

[0063] When a large pressure drop is generated due to the pressure distribution container 401 being too long or too thin, or when a large pressure drop is generated due to a large difference in the opening areas between the respective throttle orifices 402i downstream of the pressure distribution container 401, resulting in poor pressure equalization effect of the pressure distribution container 401, upstream pressure gauges (PT, Pressure Transducer) (PT UP1 ...PP UPi ...PT UPn ) need to be provided at the upstream of each throttle orifice 402i to measure the accurate pressure P at the upstream of each throttle orifice 402i UP1 ...P UPi ...P UPn . Downstream pressure gauges PT can be provided at the downstream of each throttle orifice 402i DOWN1 ...PT DOWNi ...PT DOWNn to measure the accurate pressure P at the downstream of each throttle orifice 402i DOWN1 ...P DOWNi ...P DOWNn , where when the air flow through each throttle orifice 402i is choked flow, that is, the flow rate is not sensitive to the downstream pressure (P UPi > 2 × P DOWNi ), or when the volume of the downstream reaction chamber 403 is large, the pressure gradient at the downstream of each throttle orifice 402i is small, and the respective Ps DOWNi are relatively close to each other, the downstream pressure gauges can be combined into PT DOWN , or the measured value P of the chamber pressure gauge PT of the reaction chamber 403 chamber is used as the pressure at the downstream of the throttle orifice 402i chamber .

[0064] Inside the reaction chamber 403, a chamber pressure gauge PT is provided chamber to measure the chamber pressure P chamber , and a vacuum pump 406 or other exhaust device (Exhaust) is provided in the reaction chamber 403 for evacuation. A pressure control valve (PCV, Pressure Control Valve) can be provided between the reaction chamber 403 and the vacuum pump 406 so that the reaction chamber 403 can obtain a specified pressure. Components such as PT, MFC, and MFM can be controlled by the control unit 404.

[0065] The present invention proposes a multi-channel proportional gas distribution device. In this device, the upstream of multiple throttle holes (4021, 4022... 402i... 402n) is connected to a pressure distribution vessel 401 (PDV, Pressure Distribution Vessel). A valve is provided at the inlet of the pressure distribution vessel 401, and this valve can adjust the pressure at the inlet of the pressure distribution vessel 401 to P PDV , and the gas flows from the inlet of the pressure distribution vessel 401 to the i-th throttle hole 402i, generating a pressure drop ΔP i = P UPi - P PDV , where P UPi represents the pressure at the upstream of the i-th throttle hole 402i. Among them, the flow rate Q i at the i-th throttle hole 402i is UPi determined by the pressure P PDV at the upstream of the i-th throttle hole 402i, the pressure P chamber at the inlet of the pressure distribution vessel 401, the pressure P i in the reaction chamber 403, and the opening area A i of the i-th throttle hole 402i. Based on the relationship between flow rate and pressure difference in fluid mechanics, and according to the multi-channel proportional gas distribution requirements, the required opening area A i at each throttle hole 402i can be calculated to obtain a specified flow rate Q

[0066] Different from the traditional technical solution of controlling the pressure gradient of the MFC by a pressure regulating valve to control the flow rate, the present invention controls the flow rate by adjusting the opening area A i of the throttle hole (Variable Opening Orifice). Since in the present invention, it is not necessary to control the pressure P UPi at the upstream of each throttle hole 402i, and the pressure P UPi at the upstream of each throttle hole 402i is not adjusted DOWNiThe flow rate is controlled by the pressure difference therebetween, so there is no impact on the pressure drop ΔP i which avoids the over-constraint problem in the prior art.

[0067] In this device, the multi-channel proportional gas distribution part (i.e., the pressure distribution container 401 and multiple throttle holes (4021, 4022... 402i... 402n)) can be arranged in a manner similar to multiple MFCs. Multiple independently controlled throttle holes 402i are connected to the reaction chamber through pipelines; it can also be integrated with the intake device. That is to say, the intake device can be provided with n nozzles, and each nozzle is internally provided with a throttle hole and an upstream pressure gauge. The pressure distribution container 401 is connected to the throttle hole and the upstream pressure gauge inside the intake device through pipelines or VCR connectors, etc. Further, the pressure distribution container 401 can also be a pipeline preset inside the intake device, and the pressure gauge of the pressure distribution container 401 can be located inside the intake device.

[0068] Figure 7 FIG. shows a schematic structural diagram of an independently controlled multi-channel proportional gas distribution device in an embodiment of the present invention. Taking three outlet pipelines as an example, that is, after the total gas intake with a given mass flow rate is proportionally distributed to the three outlet pipelines according to process requirements. A pressure regulating valve is provided at the pressure distribution container 401 to make the pressure at the inlet of the pressure distribution container 401 stable at P PDV .

[0069] The volume arrangement of the independently controlled device can be very compact. The pitch of the 1.125-inch surface mount devices of the Semi specification can be 28 mm, the diameter of the 3 / 8-inch pipeline can be only 9.525 mm, and the diameter of the 1 / 4-inch pipeline can be 6.35 mm. The compression pipelines of the throttle holes 4021 - 4023 should be arranged as parallel as possible, and the distance between the compression pipelines can be 1x mm (3 / 8 pipe diameter) or 8 - 10 mm (1 / 4 pipe diameter) to reduce the pressure drop ΔP i , so that P UPi = P PDV .

[0070] Throttle holes 4021 - 4023 are provided downstream of the pressure distribution container 401. The throttle hole (Viable Opening Orifice) can also be replaced with a variable opening laminar flow element (Variable Opening LFE). In this device, due to the P of the pipeline downstream of the throttle holes 4021 - 4023 DOWNiThey may vary, so independent pressure sensors can be arranged separately downstream of each throttle orifice. Adjust the opening area of throttle orifices 4021 - 4023 according to the data in the database to distribute the flow rate of each gas outlet pipe in a preset ratio. If a very small flow rate needs to be distributed to one of the gas outlet pipes, or if the flow rates distributed between different gas outlet pipes vary greatly (e.g., by an order of magnitude), P can be measured separately upstream of each throttle orifice 4021 - 4023 UPi , to compensate for the error caused by the pressure drop.

[0071] In an embodiment of the present invention, as Figure 6 shown, the reaction chamber 403 in the multi-channel proportional gas distribution device with multi-channel intake air can be a vertical furnace tube. Figure 8A -B shows a schematic structural diagram of a vertical furnace tube in an embodiment of the present invention. Compared with Figure 6 , Figure 8A -B, multiple horizontally placed substrates 801 are provided in the vertical furnace tube from top to bottom. The substrates 801 can be placed on a substrate carrier (which can also be a cassette or a wafer boat). A quartz, graphite, or ceramic high-temperature lining can be provided in a quartz tube or a metal chamber (bell jar) to construct the reaction chamber 403 of the vertical furnace tube. The vertical furnace tube is heated by an induction infrared lamp or a resistance heater. The substrate carrier can be rotatable, and a pedestal can be arranged on the substrate carrier. The pedestal can be a coated graphite disk, and multiple substrates can be arranged on each layer of the substrate carrier. The number of gas outlet ports of the pressure distribution container 401 is close to the number of layers of the substrates 801. Each throttle orifice 402i can correspond to multiple gas outlet ports, that is, one throttle orifice can control multiple gas outlet ports to control costs. A plasma source or a plasma generator can be provided in the vertical furnace tube, and the vertical furnace tube can perform a thermal catalyst acceleration reaction. The vertical furnace tube can be used for atomic layer deposition (ALD) or chemical vapor deposition (CVD). The device can be provided with multiple pressure distribution containers 401 to achieve rapid switching of multiple gas types. There are different vertical heights between different substrates, corresponding to multiple openings, corresponding to the fluids in different height layers in the laminar flow. Multiple throttle orifices can correspond one-to-one with the exhaust ports in the horizontal direction.

[0072] Compared with the conventional device for multi-channel proportional gas distribution through multiple MFCs, the throttle orifices or laminar flow elements in the furnace tube are closer to the reaction chamber than the conventional MFCs. Therefore, when switching gases, there is less residual gas between the throttle orifices and the reaction chamber. Figure 9 shows a schematic diagram of the gas flow path in a vertical furnace tube, where path 901 represents the path of the gas flowing from the throttle orifice to the exhaust port according to the present invention, and path 902 represents the path of the gas flowing through in the conventional device. AsFigure 9 As shown, compared with traditional equipment, the path through which the reaction gas flows in the present invention is much shorter. For a large furnace tube with more than 100 substrates arranged, the additional path that the reaction gas flows through when reaching the substrate at the farthest end can be more than 1 m. Assuming that the additional path will bring an additional 1 s of residence time for the reaction gas, in one ALD cycle, the first precursor, the second precursor, and the two purge gases will add a total of 4 s. In traditional equipment, one ALD cycle requires, for example, 12 s. Using the present invention, the cycle time can be shortened to 8 s, improving the production capacity by 1 / 3.

[0073] Moreover, in traditional equipment, when the valve is closed, there may be residual gas in the gas distribution pipeline up to 1 m long. The residual gas will affect the gas intake distribution of the next gas intake and may decompose. Especially in the furnace tube, when the ambient temperature is too high, the decomposition probability of the residual gas will increase significantly. By reducing the flow path of the reaction gas, the present invention can greatly reduce the residual gas remaining. In addition, when the purge in the furnace tube is insufficient, the adsorption is insufficient, or the precursor is insufficient, it will affect the film thickness. The present invention can achieve precise gas distribution for each substrate, so it can solve the problem of gas flow control on the substrate in a large multi-substrate ALD furnace tube.

[0074] In an embodiment of the present invention, as Figure 7 shown, the reaction chamber in the independently controlled multi-channel proportional gas distribution equipment can be a vertical furnace tube. Figure 10 FIG. shows a schematic diagram of a vertical furnace tube of an independently controlled multi-channel proportional gas distribution equipment in an embodiment of the present invention. Compared with Figure 7 , the throttle holes 4021-4023 are connected to the injector, and each throttle hole controls two substrates.

[0075] Figure 11 FIG. shows a schematic diagram of the structure of a multi-channel proportional gas distribution equipment integrated with an injector in an embodiment of the present invention. As Figure 11 shown, a plurality of MFCs are provided on the right side of the injector. After mixing multiple different gases and sending them into the injector, the pressure at the inlet of the injector can be stabilized at P PDV through a pressure regulating valve or other means. The pressure distribution vessel PDV can be a pipeline machined inside the injector, and the pressure distribution vessel PDV connects a plurality of nozzles together. A pressure sensor is provided upstream of each nozzle to measure the pressure P UPi upstream of each nozzle. There is a pressure drop ΔP i = P PDV - P UPi, a plurality of throttle holes are provided downstream of the nozzle, and the reaction gas enters the reaction chamber through the throttle holes. In this device, the pressure difference between the downstream of each nozzle can be ignored, and the pressure P of the reaction chamber is measured DOWNi instead of measuring the pressure difference between P chamber DOWNi . According to the calibration data in the database, the opening area of the throttle hole can be adjusted so that each nozzle distributes the flow rate according to a preset ratio.

[0076] Compared with the device for gas distribution by a manual metering valve, this device can achieve true proportional flow control, greatly improving the reproducibility and repeatability of the adjustment process. Compared with the device for gas distribution by multiple MFCs, this device does not need to control the back pressure upstream of the nozzle, removing the back pressure constraints of multiple MFCs. The pressure drop ΔP of the pipeline i is formed naturally, avoiding overconstraint. At the same time, this device integrates a large number of components corresponding to traditional MFCs in the intake device, which can greatly reduce the number of sensors to be arranged, make the system more compact, and greatly reduce the cost of the device. In addition, compared with the device for gas distribution by multiple MFCs, this device greatly reduces the length of the pipeline for transporting the reaction gas, can reduce the influence of the residual gas remaining in the pipeline, improve the response speed and accuracy, and is beneficial to improving the growth rate and control accuracy of the ALD process.

[0077] Figure 12 shows a schematic diagram of a reaction chamber with a multi-channel proportional gas distribution device integrated with an intake device in an embodiment of the present invention. As Figure 12 shown, the reaction chamber in this device can be a quartz chamber or a metal chamber (such as a bell jar), and a quartz, graphite or ceramic high-temperature lining is provided inside the quartz chamber or metal chamber. A susceptor 1201 or an electrostatic chuck (E-Chuck) can be arranged in the reaction chamber. The susceptor 1201 can be rotatable, and a layer of substrate can be horizontally arranged on the susceptor 1201, and this layer of substrate can include one or more pieces. A side intake device 1202 (V00 Side Injector) can be arranged on the side of the susceptor 1201 to make the reaction gas flow through the substrate in the horizontal direction. The reaction chamber can be heated by induction, infrared lamp or resistance heater.

[0078] The horizontal intake device can be provided with a plurality of horizontal air outlets so that the reaction gas flows through the substrate surface in zones. The side intake device 1202 can be Figure 11 ​The air intake device shown in the figure can control the mass flow ratio by means of a throttle hole and a pressure distribution container. Two or more reaction gases can be mixed upstream of the side air intake device 1202 by means of multiple MFCs. A plasma source or a plasma generator is provided in the reaction chamber, and a thermal catalyst can be used to accelerate the reaction in the reaction chamber. The reaction chamber can be used for atomic layer deposition (ALD) or chemical vapor deposition (CVD). A vacuum pump or an exhaust device can be provided in the reaction chamber, and a pressure control device can be provided. It is easy to understand that the side air intake device 1202 can also be Figure 7 The independently controlled multi-way proportional gas distribution equipment shown.

[0079] An upper air inlet device 1203 (V00 Top Injector) may also be arranged above the base 1201. The upper air inlet device 1203 may be provided with a plurality of air outlets for flow rate proportional control through independent throttle holes, wherein a plurality of air outlets may be provided downstream of each independent throttle hole. The upper air inlet device 1203 may purge the top of the reaction chamber to control the boundary layer height of the reaction gas entering horizontally, wherein the upper air inlet device 1203 may be provided with air intake through diffusion control.

[0080] In traditional gas distribution equipment, problems such as gas dead spots, hysteresis, swirl, and uneven gas discharge are easily generated in the long gas distribution pipe, which affect the process. In order to suppress these gas flow phenomena, the existing technology usually solves the above problems by changing the shape, flow direction, topology, pipe diameter, and opening of the pipe. However, these technical solutions often bring new problems while solving one problem. For example Figure 2 The prior art shown in the figure achieves mass flow distribution compensation by adding a 180-degree airflow return, but also prolongs the path length of the airflow, increases the volume and molar amount of the residual gas retained in the air intake device, and creates new problems. The present invention can achieve consistency of gas distribution in principle and meet the requirements of no airflow hysteresis, dead angle, etc.

[0081] The multi-way proportional gas distribution method of the present invention is described in detail below.

[0082] In the present invention, different calculation methods are used for choked flow and non-choked flow. Choked flow and non-choked flow are introduced below.

[0083] The calculation formula of sound speed can be expressed as follows:

[0084]

[0085] Where c represents the speed of sound, K sLet \(k\) represent the stiffness coefficient and \(\rho\) represent the density. The stiffness coefficient indicates the ease of compression of the material. The higher the stiffness coefficient, the more difficult it is to compress the material. From this formula, it can be seen that the speed of sound is proportional to the square root of the stiffness coefficient and inversely proportional to the square root of the density. The smaller the density, the faster the speed of sound.

[0086] For gases, since the propagation of sound waves in gases can be regarded as adiabatic compression, the stiffness coefficient \(K\) of the gas can be obtained by differentiating the formula \(PV\) γ \(= C\) (\(C\) represents a constant and \(\gamma\) represents the adiabatic index), because sound waves can be regarded as having small amplitudes and the gas can be approximately regarded as a linear medium. Differentiating gives \(K = \gamma P\). Therefore, the stiffness coefficient of the gas depends only on the adiabatic index and the pressure.

[0087] Substituting \(K = \gamma P\) into the calculation formula for the speed of sound, the following formula can be obtained:

[0088]

[0089] When the temperature is constant, the pressure and density of the gas are proportional, so the two exactly cancel each other out. Therefore, the speed of sound is independent of the pressure. In addition to pressure, the only factors that can affect density are temperature and the mass of gas molecules. Since the higher the temperature, the smaller the density, the higher the temperature, the greater the speed of sound. Since the smaller the mass of gas molecules, the smaller the density, the lighter the gas (such as hydrogen), the greater the speed of sound.

[0090] Since the speed of sound is independent of the pressure, the calculation formula for the speed of sound can be expressed as the following formula:

[0091]

[0092] where \(k\) represents the Boltzmann coefficient, \(T\) represents the temperature, and \(m\) represents the mass of gas molecules. The higher the temperature, the smaller the mass of gas molecules, and the faster the speed of sound.

[0093] The choking phenomenon refers to the situation where when the flow velocity at a certain cross-section in the pipeline reaches the speed of sound, no matter how much the pressure outside the pipeline outlet decreases, the flow velocity and pressure of the air flow before the sonic cross-section no longer change, and the flow rate also remains unchanged as a result. There are many situations where choking flow is likely to occur, and common ones include the starting choking of a supersonic wind tunnel (see wind tunnel), the choking of an aircraft inlet, the choking of a friction pipe, and the choking of a heating pipe.

[0094] Taking the choking in an aircraft inlet as an example, when the Mach number \(Ma\) of the air flow far ahead of the inlet 00 \(< 1\), the air flow velocity ahead of the inlet increases, the flow velocity at the inner throat of the inlet increases, and the flow rate increases; when the Mach number \(Ma\) at the throat 00 \(= 1\), no matter how much the air flow velocity ahead of the inlet increases, the flow rate no longer increases, and only supersonic flow and shock waves appear behind the throat; when the Mach number \(Ma\) of the air flow far ahead 00When \(M>1\), the supersonic airflow is not disturbed before entering the inlet and directly flows into the intake duct. When the throat area is large enough for all the entering gas to pass through, the intake duct is unblocked; when the throat area is too small and the flow rate that can pass through is less than the directly entering flow rate, the throat is blocked, the gas accumulates in front of the throat, the pressure rises, and an off-body shock wave forms in front of the inlet. Part of the excess airflow overflows outside the outlet, and a supersonic region and a shock wave appear behind the throat. The blockage in the aircraft intake duct will greatly increase the resistance on the aircraft and significantly reduce the thrust of the engine.

[0095] Figure 13 Shows a schematic diagram at an orifice in an embodiment of the present invention. As Figure 13 shown, for a compressible fluid, if the pressure \(P_1\) at the inlet of the orifice remains constant and the pressure \(P_2\) at the outlet gradually decreases, the mass flow rate through the orifice will gradually increase to a maximum value. At this time, further reducing \(P_2\) will not increase the flow rate anymore, and this situation is called choked flow. Choked flow usually requires \(P_1\geq2P_2\) (the specific ratio is related to the specific heat capacity of the gas). At this time, the flow rate through the orifice is only related to \(P_1\) and is proportional to the absolute value of \(P_1\).

[0096] Figure 14 Shows a schematic diagram of the change in pressure and flow rate of a choked flow in an embodiment of the present invention. The choking point of the fluid is determined by the pressure recovery factor \(F\) of the liquid L and the critical pressure difference ratio coefficient \(X\) of the gas without an attached pipe T and the gas reaches the speed of sound at the constriction neck. The critical choking pressure value of the pressure can be calculated by the following formula:

[0097]

[0098] \(F\) F \(= 0.96 - 0.28(P\) V / \(P\) C ) 1 / 2

[0099] where \(F\) F represents the liquid critical pressure ratio factor, \(P\) V represents the vapor pressure of the fluid, and \(P\) C represents the thermodynamic critical pressure.

[0100] The ratio between the critical choking pressure \(P\) choked at the orifice and \(P_1\) can be expressed by the following formula:

[0101]

[0102] where \(n\) represents the exponent of isentropic expansion / compression. For an ideal gas in a thermal system, \(n\) is the ratio of specific heats: \(n = C_p / C\)v , where Cp represents the specific heat at constant pressure and Cv represents the specific heat at constant volume. For most process steam working in the wet region, n = 1.135, for superheated steam, n = 1.30, for air, n = 1.4, for methane, n = 1.31, and for helium, n = 1.667.

[0103] For air, the calculation of the critical pressure ratio can be expressed as:

[0104]

[0105] The corresponding relationships between n and the critical pressure ratio for other gases can be 1.1135, 0.577; 1.300, 0.546; 1.400, 0.528; 1.667, 0.487.

[0106] The choked flow through the orifice, that is, the mass flow rate of the sonic flow where the minimum pressure equals the critical pressure flowing through the orifice can be expressed by the following formula:

[0107]

[0108] Where, m c represents the mass flow rate of the sonic flow (kg / s), A c represents the nozzle area (m 2 ), and ρ1 represents the density at the inlet of the orifice (kg / m 3 ).

[0109] For the case of non-choked flow, the pressure function of the upstream and downstream of the orifice, the secondary flow rate can be determined according to the following formula Q = k × Function(P UP , P DOWN ).

[0110] At the orifice of non-choked flow, the flow rate Specifically, it can be expressed by the following formula:

[0111]

[0112] According to the above formula, it can be known that when P UP , P DOWN remain unchanged, the flow rate Q i at the orifice of non-choked flow is proportional to the opening area A of non-choked flow. In the present invention, the opening area A can be adjusted by an electrical control circuit and is controlled by a control unit.

[0113] In non-choked flow, the flow rate is limited by the sonic speed at the outlet of the orifice. When the upstream pressure P UP is determined, the flow rate Q iIt is proportional to the opening area A of the non-blocking flow. By configuring multiple throttle holes 402i, the upstream pressure P of the throttle holes 402i can be UPi kept basically unchanged, minimizing the influence of the back pressure. The upstream sides of the multiple throttle holes 402i are connected to each other. When the flow rate (flow velocity) is large and the pipe diameter is small, a pressure difference Δ(P UPi , P UPi+1 ) = v 2 fLρ / 2D will be generated between the throttle holes. By adjusting the throttle holes according to the present invention, P UPi can be maintained basically unchanged, and the pressure difference between the upstream sides of the multiple throttle holes 402i can be received, and the opening area A i can be finely adjusted to achieve precise proportional control without the need to set a pressure control valve for control. In a pressure-flow control device, the opening area at the MFC is fixed. When the downstream pressure is fixed, it is necessary to push up P UPi to control the flow rate. When the flow rate ratio changes, the corresponding Q UPi will also increase as P i increases.

[0114] For choked flow, when Q i doubles, P UPi will also double. Usually, at this time, the flow rate Q j at other throttle holes will decrease, and P UPj will also decrease. Since P UPi and P UPj are interconnected, the back pressures will interfere with each other or even conflict, resulting in an overconstrained situation. When the flow rate difference is too large, it is difficult to achieve precise control. The situation of non-choked flow is similar.

[0115] When the airflow passing through the throttle hole 402i is choked flow, the flow rate Q i at the throttle hole 402i = C × P UPi , where C represents the first correlation coefficient, which is positively correlated with the opening area A i of the i-th throttle hole; when the airflow passing through the throttle hole 402i is non-choked flow (Non Choked Flow), the flow rate total flow rate Q total = ∑Q i (P UPi , A i , P DOWNi ). The pressure drop ΔP i at the throttle hole 402i = P UPi - P PDV , and ΔP i satisfies the following formula:

[0116]

[0117] Among them, ΔP represents the pressure drop (Pa), V represents the flow velocity (m / s), f represents the friction coefficient, L represents the pipeline length (m), and ρ represents the fluid density (kg / m 3 ), and D represents the pipeline diameter (m).

[0118] When the multi-channel proportional gas distribution equipment is operating, the total mass flow (TotalMass Flow) Q is set through an MFM or multiple MFCs total , and the pressure P at the inlet of the pressure distribution container 401 is set through the pressure regulating valve at the outlet of the pressure distribution container 401 PDV .

[0119] Close other orifices except the orifice 402i, and conduct an opening test on the orifice 402i. Among them, according to the measurement value of the upstream MFC or MFM, determine the relationship between the orifice 402i at a given P DOWNi and the P at each flow rate UPi and the opening area A of the orifice 402i i . Repeat the above operations for the orifices 4021 - 402n to determine the Q i Mapping of all orifices 402i, and determine the relationship between each orifice 402i at each flow rate and P PDV and ΔP i . In addition, the opening test can be performed on multiple orifices simultaneously. For example, while keeping the total flow rate unchanged, the opening of one orifice can be increased and the opening of another orifice can be decreased for testing. Based on the above steps, an adaptive algorithm can be established and a database can be constructed.

[0120] Input the given total flow rate Q total and the flow rate Q allocated to each orifice 402i i , where Q total = ∑Q i . Through the database, match the initial opening area A of the orifice 402i i and the corresponding P UPi , P DOWNi , where P UPi should include the reasonable estimated pressure difference between each orifice.

[0121] Operate the equipment according to the initially matched set {P UPi , A i , P DOWNi}, and obtain the actually feedback set {P UPi , A i , P DOWNi}. Generally speaking, PDOWNi It is controlled by the downstream reaction chamber 403 and is relatively stable. The deviation mainly occurs at P UPi and a given P cannot be established at the throttle orifice 402i UPi . A more reasonable {P UPi , A i} can be matched through a neural network algorithm or other adaptive algorithms so that P UPi -P DOWNi approaches zero.

[0122] In the present invention, the throttle orifice (Orifice) can be replaced by a laminar flow element (LFE, Laminar Flow Element). The fluid flows through the laminar flow element. The laminar flow element may include a first component and a second component. The second component can move relative to the first component to change the opening area of the laminar flow element. At least one of the first and second components has a first Reynolds number characteristic dimension. At least one of the first and second components is provided with laminar flow sheets, and the laminar flow sheets have a second Reynolds number characteristic dimension, and the second Reynolds number characteristic dimension is smaller than the first Reynolds number characteristic dimension. For example, the first component has a first Reynolds number characteristic dimension, and the first component is tubular or orifice-shaped, and the second component has laminar flow sheets, and the relative movement between the outer contour of the second component and the inner contour of the first component changes the opening area of the laminar flow element.

[0123] Figure 15A -B shows a schematic diagram of a laminar flow element arranged in a pipeline in an embodiment of the present invention. As Figure 15A shown in -B, the laminar flow element may be a concentric ring arranged in a pipeline, laminar flow sheets arranged at equal intervals, or a honeycomb flow channel, etc. The diameter of the pipeline is the first Reynolds number characteristic dimension D pipe , and the spacing between the laminar flow sheets is the second Reynolds characteristic dimension D LFE , D LFE is significantly smaller than D pipe , so the flow state of the fluid can be rectified from turbulent flow to laminar flow.

[0124] The flow rate Q in the laminar flow element can be calculated by the following formula:

[0125]

[0126] where ΔP represents the pressure drop across the pipeline, D represents the diameter of the pipeline, μ represents the viscosity of the fluid, L represents the length of the pipeline, and k represents a calculation coefficient.

[0127] The structure of the laminar flow element may be a diaphragm valve or a bellows valve. Figure 16A shows a schematic diagram of the structure of a laminar flow element in an embodiment of the present invention. AsFigure 16A As shown, the laminar flow element may include an inner cone member 1601 and an outer cylinder member 1602. Figure 16B The structural schematic diagram of an outer cylinder member in an embodiment of the present invention is shown. Figure 16C The top view of an outer cylinder member in an embodiment of the present invention is shown. Figure 16D The structural schematic diagram of an inner cone member in an embodiment of the present invention is shown. As Figure 16A shown in -D, the inner diameter of the outer cylinder member 1602 may be the same as the outer diameter of the inner cone member 1601. A plurality of first laminar flow sheets may be provided on the inner cone member 1601, and a plurality of second laminar flow sheets may be arranged in a surrounding manner on the inner side of the cylinder wall of the outer cylinder member 1602. The inner cone member 1601 may be embedded in the outer cylinder member 1602, and the first laminar flow sheets may be fitted with the second laminar flow sheets. An opening is provided on the outer cylinder member 1602. The outer diameter of the inner cone member 1601 / the inner diameter of the outer cylinder member 1602 is the characteristic dimension D of the first Reynolds number pipe , the spacing between the first laminar flow sheets / the second laminar flow sheets is the characteristic dimension D of the second Reynolds number LFE , D LFE is significantly smaller than D pipe , so the flow state of the fluid can be rectified from turbulent flow to laminar flow.

[0128] By adjusting the depth of the inner cone member 1601 embedded in the outer cylinder member 1602, the size of the gap between the first laminar flow sheets and the second laminar flow sheets can be adjusted, and thus the opening area of the laminar flow element can be adjusted. When the inner cone member 1601 and the outer cylinder member 1602 are completely fitted, the opening area of the laminar flow element drops to 0, that is, it is completely closed. When no laminar flow sheets are provided on the outer cylinder member 1602 and the inner cone member 1601, it is easy to understand that this device is an embodiment of the throttle orifice (V00) with an adjustable opening area proposed by the present invention. In the simplified design of this embodiment, the inner cone can be cancelled, and the second laminar flow sheets of the outer cylinder 1602 can also be cancelled. The role of the inner cone is to ensure that when the opening area is different, the cross-sectional areas inside the laminar flow element do not change drastically. The role of the second laminar flow sheets is to ensure that there are laminar flow sheets in each flow channel inside the laminar flow element, achieving complete laminar flow.

[0129] Figure 17 The schematic diagram of the air flow passing through the laminar flow element in an embodiment of the present invention is shown. As Figure 17 shown, the air flow can flow from the upstream to the downstream of the laminar flow element along path 1701. The pressure difference ΔP = P UP -P DOWN, and at least one absolute pressure gauge is set to provide a reference for the differential pressure gauge. Usually, this absolute pressure gauge is the pressure gauge of the reaction cavity or the pressure gauge of the PDV. When the flow rate of a single laminar element is very small or very large, the differential pressure gauge can improve the control accuracy of the laminar element with a small flow rate.

[0130] Although the embodiments of the present invention have been described above, it should be understood that they are presented only as examples and not as limitations. It will be apparent to those skilled in the relevant art that various combinations, modifications, and changes can be made thereto without departing from the spirit and scope of the present invention. Therefore, the width and scope of the present invention disclosed herein should not be limited by the above-described exemplary embodiments, but should be defined only by the appended claims and their equivalents.

Claims

1. A laminar flow element, characterized in that, Comprising: A first component; And A second component configured to move relative to the first component to change the opening area of the laminar flow element through which fluid flows; Wherein at least one of the first and second components has a first Reynolds number characteristic dimension, and a plurality of laminar flow sheets are provided on at least one of the first and second components, and the spacing between the plurality of laminar flow sheets constitutes a second Reynolds number characteristic dimension, and the second Reynolds number characteristic dimension is less than the first Reynolds number characteristic dimension, Wherein when the second component moves axially relative to the first component to cause the plurality of laminar flow sheets to be fully engaged with the first component, the opening area of the laminar flow element is zero.

2. The laminar flow element according to claim 1, characterized in that, The first component has a first Reynolds number characteristic dimension, and the first component is tubular or orifice-shaped; and The second component has a plurality of laminar flow sheets, and relative movement between the outer contour of the second component and the inner contour of the first component changes the opening area of the laminar flow element.

3. A laminar flow element, characterized in that, Comprising: An internal component having a base on which a plurality of first laminar flow sheets are arranged, and the spacing between the first laminar flow sheets constitutes a second Reynolds number characteristic dimension, and the internal component is nested inside an outer cylinder component; and An outer cylinder component, the inner diameter of whose cylinder wall constitutes a first Reynolds number characteristic dimension, the first laminar flow sheets are in contact with the inner wall of the outer cylinder component, and the internal component is configured to move relative to the outer cylinder component in the axial direction to adjust the opening area of the laminar flow element, wherein the opening area includes the size of the gap between the base and the upper edge of the outer cylinder component, and the second Reynolds number characteristic dimension is less than the first Reynolds number characteristic dimension, Wherein when the internal component moves axially relative to the outer cylinder component to cause the first laminar flow sheets to be fully engaged with the outer cylinder component, the opening area of the laminar flow element is zero.

4. The laminar flow element according to claim 3, wherein The first laminar flow sheets are configured to reduce the Reynolds number of the fluid to 1 / (first Reynolds number characteristic dimension / second Reynolds number characteristic dimension) to rectify the flow state of the fluid from turbulent flow to laminar flow.

5. The laminar flow element according to claim 3, characterized in that, The internal component forms an inner cone at the axis, and the inner cone is configured to reduce potential fluid retention caused by the narrow space at the axis of the first laminar flow sheets.

6. The laminar flow element according to claim 5, wherein, Second laminar flow sheets are arranged on the inner side of the outer cylinder component, and the gap between the second laminar flow sheets constitutes a third Reynolds number characteristic dimension, and the gap between the first laminar flow sheets and the second laminar flow sheets constitutes a fourth Reynolds number characteristic dimension, and fluid flows from the first side of the laminar flow element through the gap between the first laminar flow sheets and the second laminar flow sheets and flows from the through hole to the second side of the laminar flow element.

7. The laminar flow element according to claim 6, wherein Any one of the second, third, and fourth Reynolds number characteristic dimensions is less than the first Reynolds number characteristic dimension.

8. The laminar flow element according to claim 6, characterized in that, A differential pressure gauge is arranged on the first side and the second side of the laminar flow element, and an absolute pressure gauge is arranged to provide a reference for the differential pressure gauge to measure the pressure difference ΔP = P UP ―P DOWN , where P UP represents the pressure on the first side of the laminar flow element, and P DOWN represents the pressure on the second side of the laminar flow element; or The first side and the second side of the laminar flow element are provided with absolute pressure gauges to measure the pressure difference ΔP = P UP ―P DOWN .

9. The laminar flow element according to claim 5, characterized in that, The inner cone is configured such that when adjusting the opening area, the cross-sectional areas inside the laminar flow element do not change drastically.

10. The laminar flow element according to claim 6, wherein, The second laminar flow sheets are configured such that laminar flow sheets are provided in each flow channel inside the laminar flow element to form fully laminar flow.

11. A multi-channel proportional gas mixing device, characterized in that, Comprising: An intake device configured to transport reaction gas to a throttle orifice; A plurality of laminar flow elements, the first side of which is connected to the intake device and the second side of which is connected to the reaction chamber, wherein the laminar flow element is one of the laminar flow elements described in claims 1-10; and A reaction chamber, wherein reaction gas enters the reaction chamber through the throttle orifice to carry out a reaction.

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