Method for controlling flow ratio between inner and outer cavities of mocvd apparatus

Abstract

The present invention relates to the technical field of the control of MOCVD exhaust gas. Provided is a method for controlling the flow ratio between inner and outer cavities of an MOCVD apparatus. An inner cavity and an outer cavity are comprised, wherein an inner-cavity exhaust gas filter, a first high-precision closed-loop control instrument, a first sensor, first PID, a first analog pair instrument, an inner-cavity electric control valve and an inner-cavity flowmeter are arranged at the tail of the inner cavity and are connected in sequence; an outer-cavity exhaust gas filter, a second high-precision closed-loop control instrument, a second sensor, second PID, a second analog pair instrument, an outer-cavity electric control valve and an outer-cavity flowmeter are arranged at the tail of the outer cavity and are connected in sequence; and the tail ends of the inner-cavity flowmeter and the outer-cavity flowmeter are in communication with a PUMP. Therefore, the accuracy of a reaction is ensured, the quality of a product is improved, the uniformity and consistency of material growth are promoted, and an appropriate flow ratio can prevent unnecessary gas flow and reduce energy consumption, thereby reducing production costs.

Description

A method for controlling the flow ratio of the inner and outer cavities of an MOCVD device Technical Field

[0001] This invention relates to the field of MOCVD exhaust gas control technology, and more specifically, to a method for controlling the flow ratio of the inner and outer cavities of an MOCVD device. Background Technology

[0002] In the reaction chamber of an MOCVD device, there is an inner chamber and an outer chamber. The main gases, such as the MO source and hydride source, flow in the inner chamber, while the outer chamber contains only some protective gases (such as nitrogen and hydrogen). The inner chamber is generally made of materials such as quartz and graphite. It is impossible to completely seal the inner and outer chambers, and there will always be gas exchange between them.

[0003] When there is exchange between the inner and outer cavities, it is necessary to control the flow rate ratio of the exchange. Otherwise, the product quality will be reduced, affecting the uniformity and consistency of material growth. At the same time, energy will be wasted in a serious manner, and the service life of the equipment will be shortened. Therefore, it is necessary to control the flow rate ratio between the inner and outer cavities of the MOCVD equipment.

[0004] Therefore, in view of this, we will study and improve the existing structure and its shortcomings, and provide a method for controlling the flow ratio of the inner and outer cavities of MOCVD equipment, in order to achieve a more practical purpose. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for controlling the flow rate ratio between the inner and outer cavities of an MOCVD device.

[0006] The present invention provides a method for controlling the flow rate ratio between the inner and outer cavities of an MOCVD device, which is achieved by the following specific technical means:

[0007] A method for controlling the flow ratio of the inner and outer cavities of an MOCVD equipment includes an inner cavity and an outer cavity. The inner cavity is provided with an inner cavity exhaust gas filter, a first high-precision closed-loop control instrument, a first sensor, a first PID controller, a first analog signal transducer, an inner cavity electric regulating valve, and an inner cavity flow meter connected in sequence at its tail end. The outer cavity is provided with an outer cavity exhaust gas filter, a second high-precision closed-loop control instrument, a second sensor, a second PID controller, a second analog signal transducer, an outer cavity electric regulating valve, and an outer cavity flow meter connected in sequence at its tail end. The inner cavity flow meter and the outer cavity flow meter are connected by a pump.

[0008] Furthermore, the specific steps are as follows:

[0009] 8) Check that all components are installed correctly and are working properly.

[0010] 9) Start the MOCVD equipment. The inner and outer chambers begin to work, and the gas flows within them and a reaction occurs.

[0011] 10) The exhaust gas generated in the inner cavity first passes through the inner cavity exhaust gas filter to remove impurities and particulate matter, while the exhaust gas generated in the outer cavity passes through the outer cavity exhaust gas filter.

[0012] 11) The filtered exhaust gas in the inner cavity reaches the first high-precision closed-loop control instrument, which measures the relevant parameters of the exhaust gas. The filtered exhaust gas in the outer cavity reaches the second high-precision closed-loop control instrument for parameter measurement.

[0013] 12) The first sensor detects physical quantities such as the temperature of the exhaust gas in the inner cavity and transmits the data to the first PID. The first PID performs calculations based on the set temperature value and the actual temperature value detected by the first sensor and outputs a control signal. The second sensor detects information such as the temperature of the exhaust gas in the outer cavity and transmits it to the second PID.

[0014] 13) The first analog pair instrument processes and converts the control signal output by the first PID, and the processed signal acts on the inner cavity electric regulating valve. The regulating valve adjusts its opening according to the signal, thereby controlling the flow rate in the inner cavity. The second PID performs calculations and outputs a control signal to the second analog pair instrument. After the second analog pair instrument processes and converts the control signal, it acts on the outer cavity electric regulating valve to control the flow rate in the outer cavity.

[0015] The internal flow meter measures the actual flow rate of the exhaust gas in the internal cavity in real time and feeds the flow data back to the control system. The external flow meter measures the actual flow rate of the exhaust gas in the external cavity. The flow data measured by the internal and external flow meters are transmitted to the PUMP. The PUMP adjusts the pumping power based on the received flow data to control the flow ratio between the actual internal and external cavities.

[0016] Furthermore, when the opening degree of the external cavity electric regulating valve is 8%, the reading of the external cavity flow meter is 0.4, the degree of the internal cavity flow meter is 40, and the flow ratio between the internal cavity and the external cavity is 100:1. When the opening degree of the external cavity electric regulating valve is 10%, the reading of the external cavity flow meter is 0.5, the degree of the internal cavity flow meter is 50, and the flow ratio between the internal cavity and the external cavity is 100:1. When the opening degree of the external cavity electric regulating valve is 16%, the reading of the external cavity flow meter is 0.8, the degree of the internal cavity flow meter is 80, and the flow ratio between the internal cavity and the external cavity is 100:1.

[0017] Furthermore, the inner cavity flow meter, the outer cavity flow meter, and the PUMP are electrically connected.

[0018] Furthermore, the inner cavity electric regulating valve is a large-diameter regulating valve, and the outer cavity electric regulating valve is a small-diameter regulating valve.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The flow rate of the exhaust gas in the inner cavity is controlled by an internal exhaust gas filter, a first high-precision closed-loop control instrument, a first sensor, a first PID controller, a first analog signal transducer, an internal electric regulating valve, and an internal flow meter connected to the inner cavity. Similarly, the flow rate of the exhaust gas in the outer cavity is controlled by an external exhaust gas filter, a second high-precision closed-loop control instrument, a second sensor, a second PID controller, a second analog signal transducer, an external electric regulating valve, and an external flow meter connected to the outer cavity. This optimizes the flow ratio between the inner and outer cavities, ensuring reaction accuracy, improving product quality, and promoting uniform and consistent material growth. An appropriate flow ratio avoids unnecessary gas flow, reduces energy consumption, lowers production costs, and minimizes the impact and erosion of airflow on internal components of the reaction chamber, thus extending the equipment's lifespan.

[0021] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0022] Figure 1 is a flowchart of the present invention.

[0023] In the diagram, the correspondence between component names and drawing numbers is as follows:

[0024] 1. Inner cavity; 2. Inner cavity exhaust gas filter; 3. First high-precision closed-loop control instrument; 4. First sensor; 5. First PID; 6. First analog signal pair instrument; 7. Inner cavity electric regulating valve; 8. Inner cavity flow meter; 9. Outer cavity; 10. Outer cavity exhaust gas filter; 11. Second high-precision closed-loop control instrument; 12. Second sensor; 13. Second PID; 14. Second analog signal pair instrument; 15. Outer cavity electric regulating valve; 16. Outer cavity flow meter; 17. PUMP. Detailed Implementation

[0025] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0026] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" 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. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Example

[0028] As shown in Figure 1:

[0029] This invention provides a method for controlling the flow ratio of the inner and outer cavities of an MOCVD (Multi-Cavity Vacuum-Device) device. The device includes an inner cavity 1 and an outer cavity 9. The inner cavity 1 is equipped with an inner cavity exhaust gas filter 2, a first high-precision closed-loop control instrument 3, a first sensor 4, a first PID controller 5, a first analog signal transducer 6, an inner cavity electric regulating valve 7, and an inner cavity flow meter 8, all connected in sequence. The outer cavity 9 is equipped with an outer cavity exhaust gas filter 10, a second high-precision closed-loop control instrument 11, a second sensor 12, a second PID controller 13, a second analog signal transducer 14, an outer cavity electric regulating valve 15, and an outer cavity flow meter 16, all connected in sequence. A pump 17 connects the inner cavity flow meter 8 and the outer cavity flow meter 16. The inner cavity exhaust gas filter 2 filters impurities and particulate matter from the exhaust gas, preventing them from entering the device and causing damage or affecting measurement accuracy. The first high-precision closed-loop control instrument 3 accurately measures and monitors parameters such as temperature, pressure, and flow rate of the exhaust gas. The first PID controller 5 performs calculations based on proportional, integral, and derivative operations and the actual values ​​detected by the first sensor 4 to precisely adjust parameters such as the temperature of the inner cavity, keeping them near the set value. The first analog signal transducer 6 processes and converts the analog signal, transmitting it to the inner cavity electric regulating valve 7. The inner cavity electric regulating valve 7 adjusts its opening according to the signal, thereby controlling the flow rate of the exhaust gas in the inner cavity. The inner cavity flow meter 8 measures the actual flow rate of the exhaust gas in the inner cavity in real time and feeds the data back to the control system.

[0030] The specific steps are as follows:

[0031] 14) Check that all components are installed correctly and are working properly.

[0032] 15) Start the MOCVD equipment. Inner chamber 1 and outer chamber 9 begin to work, and gas flows and reacts within them.

[0033] 16) The exhaust gas generated in the inner cavity 1 is first filtered by the inner cavity exhaust gas filter 2 to remove impurities and particulate matter, and the exhaust gas generated in the outer cavity 9 is filtered by the outer cavity exhaust gas filter 10.

[0034] 17) The filtered exhaust gas in the inner cavity 1 reaches the first high-precision closed-loop control instrument 3, which measures the relevant parameters of the exhaust gas. The filtered exhaust gas in the outer cavity 9 reaches the second high-precision closed-loop control instrument 11 for parameter measurement.

[0035] 18) The first sensor 4 detects physical quantities such as the temperature of the exhaust gas in the inner cavity 1 and transmits the data to the first PID 5. The first PID 5 performs calculations based on the set temperature value and the actual temperature value detected by the first sensor 4, and outputs a control signal. The second sensor 12 detects information such as the temperature of the exhaust gas in the outer cavity 9 and transmits it to the second PID 13.

[0036] 19) The first analog signal pair instrument 6 processes and converts the control signal output by the first PID 5. The processed signal acts on the inner cavity electric regulating valve 7. The regulating valve adjusts its opening according to the signal, thereby controlling the flow rate of the inner cavity 1. The second PID 13 performs calculations and outputs a control signal to the second analog signal pair instrument 14. After the second analog signal pair instrument 14 processes and converts the control signal, it acts on the outer cavity electric regulating valve 15 to control the flow rate of the outer cavity 9.

[0037] The internal flow meter 8 measures the actual flow rate of the exhaust gas in the internal cavity 1 in real time and feeds the flow data back to the control system. The external flow meter 16 measures the actual flow rate of the exhaust gas in the external cavity 9. The flow data measured by the internal flow meter 8 and the external flow meter 16 are transmitted to the PUMP 17. The PUMP 17 adjusts the pumping power according to the received flow data to control the flow ratio between the actual internal cavity 1 and the external cavity 9.

[0038] Specifically, when the opening degree of the external cavity electric regulating valve 15 is 8%, the reading of the external cavity flow meter 16 is 0.4, the degree of the internal cavity flow meter 8 is 40, and the flow ratio between the internal cavity 1 and the external cavity 9 is 100:1. When the opening degree of the external cavity electric regulating valve 15 is 10%, the reading of the external cavity flow meter 16 is 0.5, the degree of the internal cavity flow meter 8 is 50, and the flow ratio between the internal cavity 1 and the external cavity 9 is 100:1. When the opening degree of the external cavity electric regulating valve 15 is 16%, the reading of the external cavity flow meter 16 is 0.8, the degree of the internal cavity flow meter 8 is 80, and the flow ratio between the internal cavity 1 and the external cavity 9 is 100:1. The experimental data can be used to verify the specific operation of the equipment and the feasibility of the experiment.

[0039] The internal flow meter 8, the external flow meter 16, and the PUMP 17 are electrically connected. The PUMP is a vacuum pump. The connection between the internal flow meter 8, the external flow meter 16, and the PUMP 17 allows the PUMP 17 to transmit the actual flow data of the internal cavity 1 and the external cavity 9 in real time, enabling the PUMP 17 to understand the current flow situation. The internal flow meter 8 and the external flow meter 16 provide the PUMP 17 with accurate flow information, allowing it to precisely adjust the pumping power and speed according to the flow requirements of the internal cavity 1 and the external cavity 9, thereby achieving precise control of the flow ratio between the internal and external cavities. The three components work together in harmony.

[0040] The internal cavity electric regulating valve 7 is a large-diameter regulating valve, while the external cavity electric regulating valve 15 is a small-diameter regulating valve. The internal cavity has a larger airflow rate, requiring a large-diameter regulating valve to meet a wider flow rate regulation range. The external cavity mainly contains protective gas, with a relatively smaller flow rate requirement. This allows for more precise control of the flow rate ratio between the external cavity 9 and the internal cavity 1, thereby reducing equipment costs and achieving energy savings.

[0041] When in use, the MOCVD equipment is started, and the inner cavity 1 and outer cavity 9 begin to work. Gas flows and reacts within them. The exhaust gas generated in the inner cavity first passes through the inner cavity exhaust gas filter 2, which filters out impurities and particulate matter. The filtered exhaust gas then reaches the first high-precision closed-loop control instrument 3, which measures relevant parameters of the exhaust gas. The first sensor 4 detects physical quantities such as the temperature of the exhaust gas and transmits the data to the first PID controller 5. The first PID controller 5 performs calculations based on the set temperature value and the actual temperature value detected by the first sensor 4, and outputs a control signal. The first analog signal transducer 6 processes and converts the control signal output by the first PID controller 5. The processed signal acts on the inner cavity electric regulating valve 7, which adjusts its opening according to the signal, thereby controlling the flow rate in the inner cavity. The inner cavity flow meter 8 measures the actual flow rate of the exhaust gas in the inner cavity in real time and transmits the data. The flow data is fed back to the control system. The exhaust gas generated in the outer cavity is filtered by the outer cavity exhaust gas filter 10. The filtered exhaust gas reaches the second high-precision closed-loop control instrument 11 for parameter measurement. The second sensor 12 detects information such as the temperature of the exhaust gas in the outer cavity and transmits it to the second PID 13. The second PID 13 performs calculations and outputs a control signal to the second analog quantity pair instrument 14. After the second analog quantity pair instrument 14 processes and converts the control signal, it acts on the outer cavity electric regulating valve 15 to control the flow in the outer cavity. The outer cavity flow meter 16 measures the actual flow of the exhaust gas in the outer cavity. The flow data measured by the inner cavity flow meter 8 and the outer cavity flow meter 16 are transmitted to the PUMP pump 17. The pump 17 adjusts the pumping power according to the received flow data to achieve flow ratio control between the inner and outer cavities.

[0042] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A method for controlling the flow rate ratio between the inner and outer cavities of an MOCVD device, comprising an inner cavity (1) and an outer cavity (9), characterized in that: The inner cavity (1) is provided with an inner cavity exhaust gas filter (2), a first high-precision closed-loop control instrument (3), a first sensor (4), a first PID (5), a first analog quantity pair instrument (6), an inner cavity electric regulating valve (7), and an inner cavity flow meter (8) connected in sequence at the tail end. The outer cavity (9) is provided with an outer cavity exhaust gas filter (10), a second high-precision closed-loop control instrument (11), a second sensor (12), a second PID (13), a second analog quantity pair instrument (14), an outer cavity electric regulating valve (15), and an outer cavity flow meter (16) connected in sequence at the tail end. The inner cavity flow meter (8) and the outer cavity flow meter (16) are connected by a PUMP (17).

2. The method for controlling the flow rate ratio of the inner and outer cavities of an MOCVD device as described in claim 1, characterized in that... The specific steps are as follows: 1) Check that all components are properly installed and functioning correctly; 2) Start the MOCVD equipment. The inner cavity (1) and outer cavity (9) begin to work, and the gas flows and reacts within them; 3) The exhaust gas generated in the inner cavity (1) first passes through the inner cavity exhaust gas filter (2) to filter out the impurities and particulate matter, and the exhaust gas generated in the outer cavity (9) passes through the outer cavity exhaust gas filter (10) for filtration. 4) The filtered exhaust gas in the inner cavity (1) reaches the first high-precision closed-loop control instrument (3), which measures the relevant parameters of the exhaust gas. The filtered exhaust gas in the outer cavity (9) reaches the second high-precision closed-loop control instrument (11) for parameter measurement. 5) The first sensor (4) detects physical quantities such as the temperature of the exhaust gas in the inner cavity (1) and transmits the data to the first PID (5). The first PID (5) performs calculations based on the set temperature value and the actual temperature value detected by the first sensor (4) and outputs a control signal. The second sensor (12) detects information such as the temperature of the exhaust gas in the outer cavity (9) and transmits it to the second PID (13). 6) The first analog pair instrument (6) processes and converts the control signal output by the first PID (5). The processed signal acts on the inner cavity electric regulating valve (7). The regulating valve adjusts the opening according to the signal, thereby controlling the flow rate of the inner cavity (1). The second PID (13) performs calculations and outputs a control signal to the second analog pair instrument (14). After the second analog pair instrument (14) processes and converts the control signal, it acts on the outer cavity electric regulating valve (15) to control the flow rate of the outer cavity (9). 7) The internal flow meter (8) measures the actual flow rate of the exhaust gas in the internal cavity (1) in real time and feeds the flow data back to the control system. The external flow meter (16) measures the actual flow rate of the exhaust gas in the external cavity (9). The flow data obtained by the internal flow meter (8) and the external flow meter (16) are transmitted to the PUMP (17). The PUMP (17) adjusts the pumping power according to the received flow data to control the flow ratio between the actual internal cavity (1) and the external cavity (9).

3. The method for controlling the flow rate ratio of the inner and outer cavities of an MOCVD device as described in claim 2, characterized in that: When the opening degree of the external cavity electric regulating valve (15) is 8%, the reading of the external cavity flow meter (16) is 0.4, the degree of the internal cavity flow meter (8) is 40, and the flow ratio between the internal cavity (1) and the external cavity (9) is 100:

1. When the opening degree of the external cavity electric regulating valve (15) is 10%, the reading of the external cavity flow meter (16) is 0.5, the degree of the internal cavity flow meter (8) is 50, and the flow ratio between the internal cavity (1) and the external cavity (9) is 100:

1. When the opening degree of the external cavity electric regulating valve (15) is 16%, the reading of the external cavity flow meter (16) is 0.8, the degree of the internal cavity flow meter (8) is 80, and the flow ratio between the internal cavity (1) and the external cavity (9) is 100:

1.

4. The method for controlling the flow rate ratio of the inner and outer cavities of an MOCVD device as described in claim 2, characterized in that: The internal flow meter (8), the external flow meter (16), and the PUMP (17) are electrically connected.

5. The method for controlling the flow rate ratio of the inner and outer cavities of an MOCVD device as described in claim 2, characterized in that: The inner cavity electric regulating valve (7) is a large-diameter regulating valve, and the outer cavity electric regulating valve (15) is a small-diameter regulating valve.

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