Positive and negative pressure conversion system and method for chemical vapor deposition equipment

Abstract

The invention relates to a positive and negative pressure conversion system for chemical vapor deposition equipment. The positive and negative pressure conversion system comprises a nitrogen storage device, a compressed air supply device, a reaction kettle, a feeding tank, a discharging tank, a tail gas filtering device and a vacuum pump, the invention further relates to a working method of the positive and negative pressure conversion system. The system and the method have the beneficial effects that under the support of the system and the method, feeding and discharging can be carried out under the negative pressure, and a powder material is coated by adopting CVD (Chemical Vapor Deposition) equipment; the powder material can also be coated and processed by adopting CVD (Chemical Vapor Deposition) equipment under positive pressure; more use schemes can be provided for customers; the reaction rate of a chemical reaction in chemical vapor deposition can be controlled by adjusting the pressure, so that the growth process of the thin film is optimized; according to the chemical vapor deposition equipment, the pressure of chemical reaction in chemical vapor deposition can be adjusted according to different materials, so that the chemical vapor deposition equipment can meet the deposition requirements of various materials, experimental steps can be simplified, and experimental materials can be completely taken out.

Description

Technical Field

[0001] The present invention belongs to the technical field of positive-negative pressure conversion of chemical vapor deposition equipment, and in particular relates to a positive-negative pressure conversion system and method of chemical vapor deposition equipment. Background Art

[0002] At present, most chemical vapor deposition (CVD) equipment can only use positive pressure experiments and loading and unloading, so there are limitations on the development of powder and fluidized coating processes. In the prior art, when positive pressure is used for powder transfer, the pressure will gradually increase to about 6kg. This pressure level will cause certain damage to the connection seals of the reactor pipes that have been used for a long time. If the impact force of pneumatic conveying during unloading is too large, the powder material will be broken. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a positive-negative pressure conversion system and method for chemical vapor deposition equipment.

[0004] The positive and negative pressure conversion system for chemical vapor deposition equipment includes: a nitrogen storage device, a compressed air supply device, a reactor, a feed tank, a discharge tank, an exhaust gas filter device and a vacuum pump.

[0005] The air outlet of the nitrogen storage device is connected to the air inlet of the compressed air supply device, and the air outlet of the compressed air supply device is divided into three ways to connect the air inlets of the reactor, the loading tank and the unloading tank respectively; the air inlet of the tail gas filter device is connected to the air outlet of the reactor and the unloading tank respectively; the air outlet of the tail gas filter device is connected to a vacuum pump;

[0006] The bottom of the upper material tank and the lower material tank are both provided with air inlets, and the bottom air inlets of the upper material tank and the lower material tank are both connected to the air outlet of the compressed air supply device;

[0007] The discharge port of the reactor is connected to the feed port of the lower feed tank, and the discharge port at the bottom of the upper feed tank is connected to the feed port at the top of the reactor;

[0008] The connection device between the feed tank and the compressed air supply device is provided with a valve; the connection device between the reactor and the feed tank is provided with at least one feed valve; valves are provided on the connection devices between the air outlet of the compressed air supply device and the reactor, the feed tank and the discharge tank; a valve and an exhaust valve are provided on the connection device between the exhaust gas filter device and the reactor, and a valve and an exhaust valve are also provided on the connection device between the exhaust gas filter device and the discharge tank;

[0009] The reactor can be heated.

[0010] As a preferred embodiment, a heating device is also provided for the reaction kettle.

[0011] A working method of a positive-negative pressure conversion system for positive pressure loading and unloading, comprising the following steps:

[0012] First, prepare: heat the reactor and introduce nitrogen into the reactor to replace the gas in the reactor with nitrogen;

[0013] Positive pressure feeding: open the valve between the compressed air supply device and the feeding tank, inject compressed nitrogen into the feeding tank, and then pressurize the inside of the feeding tank; when the internal air pressure of the feeding tank reaches the set value, open the feed valve between the reactor and the feeding tank, keep the connecting airway between the nitrogen storage device, the tail gas filter device and the feeding tank open, and transport the powder material in the feeding tank to the reactor by the pressure of nitrogen. After the feeding is completed, close the feed valve between the reactor and the feeding tank; repeat the above operation two to three times to ensure that all the powder material in the feeding tank is transported to the reactor due to the air pressure;

[0014] Positive pressure feeding: close the exhaust valve between the reactor and the tail gas filter device, inject compressed air into the reactor, and after the pressure in the reactor reaches the set value, open the valve between the feeding tank and the reactor, the reactor is connected with the feeding tank, and the powder material in the reactor is transported to the feeding tank by the pressure in the reactor;

[0015] Carry out positive pressure fluidization, open the exhaust valve between the reactor and the exhaust gas filter device, inject nitrogen with sufficient pressure into the bottom of the reactor, blow up the powder material in the reactor, and make the powder material fully fluidized in the reactor.

[0016] A working method of a positive-negative pressure conversion system for negative pressure loading and unloading, comprising the following steps:

[0017] First, prepare: heat the reactor and introduce nitrogen into the reactor to replace the gas in the reactor with nitrogen;

[0018] Carry out negative pressure feeding: first open the vacuum pump at the rear of the system, and open the exhaust valve between the reactor and the exhaust gas filter device, evacuate the reactor until its vacuum degree reaches the set value; open the feed valve between the reactor and the feeding tank, and feed the powder into the reactor under the action of the negative pressure generated inside and outside the reactor; repeat the above operation two to three times to ensure that all the powder materials in the feeding tank are transported to the reactor due to the air pressure;

[0019] Carry out negative pressure feeding: open the exhaust valve between the feeding tank and the tail gas filter device, and evacuate the feeding tank until its vacuum degree reaches the set value; open the valve between the feeding tank and the reactor, connect the feeding tank with the reactor, and transfer the powder in the reactor to the feeding tank under the pressure difference between the feeding tank and the reactor;

[0020] Perform negative pressure fluidization: open the exhaust valve between the reactor and the exhaust gas filter device, and turn on the vacuum pump at the end of the system to evacuate the inside of the reactor until the vacuum degree reaches the set value. The powder is fully fluidized under the drive of the gas entering from the bottom of the reactor.

[0021] The beneficial effects of the present invention are:

[0022] In order to keep the integrity of the powder material during powder transfer and not damage the connection seals of the reactor pipeline when using positive pressure for powder transfer, the present invention has made technical improvements on the basis of the existing technology, and added a positive and negative pressure conversion system and a positive and negative pressure conversion method for chemical vapor deposition equipment. With the support of the system and method of the present invention, it is possible to load and unload materials under negative pressure, and use CVD equipment to coat powder materials; it is also possible to use CVD equipment to coat powder materials under positive pressure; it can provide customers with more usage solutions.

[0023] The positive-negative pressure conversion system of the present invention can meet the requirements of various deposition processes for positive and negative pressures, thereby improving the process adaptability of the equipment. In some deposition processes, positive pressure can help improve the fluidity and uniformity of the gas, while negative pressure can help improve the deposition rate of the deposition process and the density of the resulting film. In short, the positive-negative pressure conversion system of the present invention can optimize the deposition process and improve the quality of the film.

[0024] The positive-negative pressure conversion method of the present invention can control the reaction rate of the chemical reaction in chemical vapor deposition by adjusting the pressure, thereby optimizing the thin film growth process. The positive-negative pressure conversion method can adjust the pressure of the chemical reaction in chemical vapor deposition according to different materials, so that the chemical vapor deposition equipment can meet the deposition requirements of various materials, and can also simplify the experimental steps and completely remove the experimental materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the positive-negative pressure conversion system for chemical vapor deposition equipment of the present invention.

[0026] Explanation of the reference numerals: reactor 1, feeding tank 2, valve 3, exhaust valve 4, unloading tank 5, vacuum pump 6, feed valve 7, nitrogen storage device 8, compressed air supply device 9, exhaust gas filtering device 10. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for ordinary persons in the art, without departing from the principle of the present invention, the present invention can also be modified in some ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0028] Example 1

[0029] like Figure 1 As shown, a positive and negative pressure conversion system for chemical vapor deposition equipment comprises: a nitrogen storage device 8, a compressed air supply device 9, a reactor 1, a feeding tank 2, a discharging tank 5, an exhaust gas filter device 10 and a vacuum pump 6; the air outlet of the nitrogen storage device 8 is connected to the air inlet of the compressed air supply device 9, and the air outlet of the compressed air supply device 9 is divided into three paths and connected to the air inlets of the reactor 1, the feeding tank 2 and the discharging tank 5 respectively; the air inlet of the exhaust gas filter device 10 is connected to the air outlet of the reactor 1 and the discharging tank 5 respectively; the air outlet of the exhaust gas filter device 10 is connected to the vacuum pump 6; the bottom of the feeding tank 2 and the discharging tank 5 are both provided with air inlets, and the bottom air inlets of the feeding tank 2 and the discharging tank 5 are both connected to the compressed The air outlet of the air supply device 9; the discharge port of the reactor 1 is connected to the feed port of the lower material tank 5, and the discharge port at the bottom of the upper material tank 2 is connected to the feed port at the top of the reactor 1; the connecting device between the upper material tank 2 and the compressed air supply device 9 is provided with a valve 3; at least one feed valve 7 is provided on the connecting device between the reactor 1 and the upper material tank 2; valves 3 are provided on the air outlet of the compressed air supply device 9 and the connecting devices between the reactor 1, the upper material tank 2 and the lower material tank 5; valves 3 and exhaust valves 4 are provided on the connecting device between the exhaust gas filter device 10 and the reactor 1, and valves 3 and exhaust valves 4 are also provided on the connecting device between the exhaust gas filter device 10 and the lower material tank 5; a heating device matching the reactor 1 is also provided.

[0030] Example 2

[0031] A working method of a positive-negative pressure conversion system for chemical vapor deposition equipment for positive pressure loading and unloading is as follows:

[0032] Perform preparation work: heat the reactor 1, and introduce nitrogen into the reactor 1 to replace the gas in the reactor 1 with nitrogen;

[0033] When feeding under positive pressure: open valve 19#, inject compressed nitrogen into the upper feeding tank 2, and then pressurize the inside of the feeding tank 2; when the internal air pressure of the feeding tank 2 reaches the set value, open the feed valve 23# and the feed valve 24#, and open the valve 19#, keep the connecting airway between the nitrogen storage device 8, the tail gas filter device 9 and the feeding tank 2 open, and transport the powder material in the feeding tank 2 to the reactor 1 by the pressure of nitrogen. After the feeding is completed, close the feed valve 23# and the feed valve 24#; repeat the above operation two to three times to ensure that all the powder material in the feeding tank 2 is transported to the reactor 1 due to the air pressure;

[0034] When feeding under positive pressure: close the 17# exhaust valve and the 18# exhaust valve, inject compressed air into the reactor 1, and after the pressure in the reactor 1 reaches the set value, open the 25# valve of the feeding tank 5 and the 26# valve of the reactor 1, the reactor 1 is connected with the feeding tank 5, and the powder material in the reactor 1 is transported to the feeding tank 5 by the pressure in the reactor 1;

[0035] During positive pressure fluidization, open the 17# exhaust valve and the 18# exhaust valve, and inject nitrogen with sufficient pressure into the bottom of the reactor 1 to blow up the powder material in the reactor 1, so that the powder material is fully fluidized in the reactor.

[0036] Example 3

[0037] A working method of a positive-negative pressure conversion system for chemical vapor deposition equipment for negative pressure loading and unloading is as follows:

[0038] Performing preparation work: heating the reactor 1, and introducing nitrogen into the reactor 1, so as to replace the gas in the reactor 1 with the nitrogen;

[0039] When feeding under negative pressure: first open the vacuum pump 6 at the rear of the system, and open the 17# exhaust valve and 18# exhaust valve at the top of the reactor 1, and draw the vacuum degree of the reactor 1 to 100 Pa; open the 23# feed valve and 24# feed valve, and under the action of the negative pressure generated inside and outside the reactor 1, the powder is fed into the reactor 1;

[0040] When feeding under negative pressure: open the 21# exhaust valve of the feeding tank 5, and draw the vacuum degree of the feeding tank 5 to 100 Pa; open the 25# valve on the feeding tank 5 and the 26# valve on the reactor 1, and the feeding tank 5 is connected with the reactor 1. Under the pressure difference between the feeding tank 5 and the reactor 1, the powder in the reactor 1 is transferred to the feeding tank;

[0041] During negative pressure fluidization: open the 17# exhaust valve and 18# exhaust valve at the upper end of the reactor 1, and turn on the vacuum pump 6 at the end of the system to evacuate the inside of the reactor 1 to 100 Pa. The powder is fully fluidized under the drive of the gas entering from the bottom of the reactor 1.

[0042] Table 1 below shows the chemical vapor deposition control test under positive pressure / negative pressure for different precursor gases acetylene-2 ​​and silane-5 conducted by the positive and negative pressure conversion system for chemical vapor deposition equipment in Examples 2 and 3 on three dates in June 2024. In Table 1 below, C is the experimental group code. It can be seen from the table that the system and method of the present invention are helpful to improve the coating rate, thereby improving the deposition rate and film density.

[0043] Table 1 Comparative experimental results of positive and negative pressure conversion system for chemical vapor deposition equipment

[0044]

Claims

1. A positive and negative pressure conversion system for chemical vapor deposition equipment, characterized in that: include: A nitrogen storage device (8), a compressed air supply device (9), a reaction kettle (1), a feed tank (2), a discharge tank (5), an exhaust gas filter device (10) and a vacuum pump (6); The air outlet of the nitrogen storage device (8) is connected to the air inlet of the compressed air supply device (9), and the air outlet of the compressed air supply device (9) is connected in three ways to the air inlets of the reaction kettle (1), the upper material tank (2) and the lower material tank (5), respectively; the air inlet of the tail gas filter device (10) is connected to the air outlet of the reaction kettle (1) and the lower material tank (5), respectively; the air outlet of the tail gas filter device (10) is connected to a vacuum pump (6); The upper material tank (2) and the lower material tank (5) are both provided with air inlets at the bottom, and the air inlets at the bottom of the upper material tank (2) and the lower material tank (5) are both connected to the air outlet of the compressed air supply device (9); The discharge port of the reaction kettle (1) is connected to the feed port of the lower material tank (5), and the discharge port at the bottom of the upper material tank (2) is connected to the feed port at the top of the reaction kettle (1); A valve (3) is provided on the connection device between the upper material tank (2) and the compressed air supply device (9); at least one feed valve (7) is provided on the connection device between the reactor (1) and the upper material tank (2); valves (3) are provided on the connection devices between the air outlet of the compressed air supply device (9) and the reactor (1), the upper material tank (2) and the lower material tank (5); a valve (3) and an exhaust valve (4) are provided on the connection device between the exhaust gas filter device (10) and the reactor (1), and a valve (3) and an exhaust valve (4) are also provided on the connection device between the exhaust gas filter device (10) and the lower material tank (5); The reaction vessel (1) can be heated.

2. The positive and negative pressure conversion system for chemical vapor deposition equipment according to claim 1, characterized in that: A heating device is also provided for the reaction kettle (1).

3. A working method of the positive and negative pressure conversion system according to claim 1 for loading and unloading materials under positive pressure, characterized in that: The following steps are involved: First, preparatory work is performed: the reaction kettle (1) is heated, and nitrogen is introduced into the reaction kettle (1), and the gas in the reaction kettle (1) is replaced with nitrogen; Positive pressure feeding is adopted: the valve (3) between the compressed air supply device (9) and the feeding tank (2) is opened, and compressed nitrogen is injected into the feeding tank (2), thereby pressurizing the inside of the feeding tank (2); when the internal air pressure of the feeding tank (2) reaches the set value, the feed valve (7) between the reactor (1) and the feeding tank (2) is opened, and the connecting air passages between the nitrogen storage device (8), the tail gas filter device (10) and the feeding tank (2) are kept open, and the powder material in the feeding tank (2) is transported to the reactor (1) by the pressure of the nitrogen. After the feeding is completed, the feed valve (7) between the reactor (1) and the feeding tank (2) is closed; the above operation is repeated two to three times to ensure that all the powder material in the feeding tank (2) is transported to the reactor (1) due to the air pressure; Positive pressure feeding is adopted: the exhaust valve (4) between the reactor (1) and the exhaust gas filter device (10) is closed, and compressed air is injected into the reactor (1). After the pressure in the reactor (1) reaches a set value, the valve (3) between the feeding tank (5) and the reactor (1) is opened, and the reactor (1) is connected with the feeding tank (5). The powder material in the reactor (1) is transported to the feeding tank (5) by the pressure in the reactor (1); Positive pressure fluidization is performed by opening the exhaust valve (4) between the reactor (1) and the exhaust gas filter device (10), injecting nitrogen gas of sufficient pressure into the bottom of the reactor (1), blowing up the powder material in the reactor (1), and making the powder material fully fluidized in the reactor.

4. A working method of the positive and negative pressure conversion system according to claim 1 for negative pressure loading and unloading, characterized in that: The following steps are involved: First, preparatory work is performed: the reaction kettle (1) is heated, and nitrogen is introduced into the reaction kettle (1), so that the gas in the reaction kettle (1) is replaced by the nitrogen; Carry out negative pressure loading: first, open the vacuum pump (6) at the rear of the system, and open the exhaust valve (4) between the reactor (1) and the exhaust gas filter device (10), and evacuate the reactor (1) until its vacuum degree reaches a set value; open the feed valve (7) between the reactor (1) and the loading tank (2), and load the powder into the reactor (1) under the action of the negative pressure generated inside and outside the reactor (1); repeat the above operation two to three times to ensure that all the powder materials in the loading tank (2) are transported to the reactor (1) due to the air pressure; Carrying out negative pressure feeding: opening the exhaust valve (4) between the feeding tank (5) and the tail gas filter device (10), evacuating the feeding tank (5) until its vacuum degree reaches a set value; opening the valve (3) between the feeding tank (5) and the reactor (1), connecting the feeding tank (5) with the reactor (1), and transferring the powder in the reactor (1) to the feeding tank (5) under the action of the pressure difference between the feeding tank (5) and the reactor (1); Conduct negative pressure fluidization: open the exhaust valve (4) between the reactor (1) and the exhaust gas filter device (10), and turn on the vacuum pump (6) at the end of the system to evacuate the interior of the reactor (1) until the vacuum degree reaches a set value. The powder is fully fluidized under the influence of the gas entering from the bottom of the reactor (1).

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