Rapid pressurizing method for single crystal furnace

Abstract

The invention provides a quick pressurizing method for a single crystal furnace, which is mainly used for pressurizing an auxiliary chamber of the single crystal furnace, and is characterized in that external gas is introduced into the auxiliary chamber before the auxiliary chamber of the single crystal furnace is separated from a main chamber, so that the auxiliary chamber is recovered from a negative pressure state to a normal pressure state. According to the rapid pressurizing method for the single crystal furnace, the compressed gas is introduced into the auxiliary chamber to replace the existing inert gas, and the flow of the compressed gas is automatically controlled, so that the negative pressure state of the auxiliary chamber can be rapidly changed into the normal pressure state, no gas harmful to growth of a crystal bar is left in the auxiliary chamber, and no residual waste gas is generated on the inner wall of the auxiliary chamber; meanwhile, the use cost of inert gas for single crystal drawing can be reduced, and the utilization rate of matching of the auxiliary chamber and the main chamber is improved; according to the method, the cooling time of the auxiliary chamber can be shortened to be within 60 s from existing 4 min, the production efficiency of the whole crystal pulling process is improved, high operability and stability are achieved, safety is achieved, the automation degree is high, and personnel interference is not needed.

Description

Technical Field

[0001] The present application belongs to the technical field of Czochralski single crystal production, and in particular, relates to a method for rapidly pressurizing a single crystal furnace. Background Art

[0002] The characteristics of the single crystal silicon growth furnace currently require the main chamber and the auxiliary chamber to be separated in the isolation steps such as taking the shoulder, taking the single crystal, and taking the re-throwing tube, and the auxiliary chamber must be filled from negative pressure to normal pressure before the next operation can be carried out. The current industry single crystal auxiliary chamber isolation uses argon gas with the maximum flow rate to fill the auxiliary chamber to normal pressure. It takes 4 minutes to fill the auxiliary chamber to normal pressure, and the equipment wastes work time and consumes argon gas during the waiting process. Summary of the invention

[0003] The present application provides a method for rapid pressurization of a single crystal furnace, which solves the technical problems of long cooling time and large energy loss in the existing auxiliary chamber.

[0004] In order to solve at least one of the above technical problems, the technical solution adopted in this application is:

[0005] A single crystal furnace rapid pressurization method is mainly used for pressurizing a single crystal furnace auxiliary chamber. Before the auxiliary chamber of the single crystal furnace is separated from a main chamber, external gas is introduced into the auxiliary chamber to restore the auxiliary chamber from a negative pressure state to a normal pressure state.

[0006] Furthermore, before the external gas is introduced into the sub-chamber, the connecting window between the sub-chamber and the main chamber is closed, and the introduction of the inert gas into the sub-chamber is stopped; and the gas pressure in the sub-chamber is monitored.

[0007] Furthermore, the process of introducing the external gas into the secondary chamber also includes continuing to introduce the inert gas into the main chamber while keeping the gas flow rate unchanged.

[0008] Furthermore, the external gas introduced into the secondary chamber is filtered air, including:

[0009] Start the external compressor;

[0010] Filter the air output from the compressor;

[0011] The filtered air is then input into the secondary chamber through a pipeline.

[0012] Furthermore, the pipeline for transmitting the filtered gas is directly connected to the valve on the wall of the isolation chamber below the secondary chamber.

[0013] Furthermore, a solenoid valve and a flow meter for controlling the gas flow are provided on the pipeline.

[0014] Furthermore, a pressure regulator is provided on the pipeline.

[0015] Furthermore, the air input into the auxiliary chamber is at room temperature.

[0016] Furthermore, the flow rate of the air input into the auxiliary chamber is adjusted in stages, and the input flow rate is from fast to slow.

[0017] Furthermore, the ventilation time does not exceed 60 seconds.

[0018] A single crystal furnace rapid pressurization method designed by the present application can quickly change the sub-chamber from a negative pressure state to a normal pressure state by introducing compressed gas into the sub-chamber instead of the existing inert gas and automatically controlling the flow rate of the compressed gas, without leaving any gas harmful to the growth of the crystal rod in the sub-chamber and without generating residual waste gas on the inner wall of the sub-chamber; at the same time, it can also reduce the use cost of the inert gas for single crystal pulling and improve the utilization rate of the coordination between the sub-chamber and the main chamber; this method can reduce the cooling time of the sub-chamber from the existing 4 minutes to less than 60 seconds, thereby improving the production efficiency of the entire crystal pulling process, and has high operability and stability, is safe and highly automated, and does not require human intervention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of a single crystal furnace rapid pressurization method according to an embodiment of the present application.

[0020] In the figure:

[0021] 10, secondary chamber 20, main chamber 30, isolation chamber

[0022] 40, compressor 50, filter device 60, solenoid valve

[0023] 70. Flow meter 80. Pressure regulator DETAILED DESCRIPTION

[0024] The present application is described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] This embodiment provides a method for rapidly charging a single crystal furnace. Figure 1As shown, it is mainly used for pressurizing the auxiliary chamber 10 of the single crystal furnace, wherein the single crystal furnace includes an auxiliary chamber 10 and a main chamber 20 connected and arranged in a connected manner. Before taking the shoulder, taking the single crystal or taking the re-throwing cylinder, it is necessary to perform an isolation step first, that is, to separate the auxiliary chamber 10 from the main chamber 20 in the single crystal furnace. However, before the auxiliary chamber is separated from the main chamber 20, due to the particularity of crystal growth, the auxiliary chamber 10 and the main chamber 20 that are interconnected must be in a negative pressure state. At the same time, since the position of the main chamber 20 is fixed, the auxiliary chamber 10 can be vertically lifted and moved by the hydraulic column, and then, the separation of the auxiliary chamber 10 from the main chamber 20 is to lift the auxiliary chamber 10 upward to separate it from the main chamber 20 through the control of the hydraulic column. However, if it is necessary to separate the auxiliary chamber 10 from the main chamber 20, the auxiliary chamber 10 in a negative pressure state must be inflated to a normal pressure state first, otherwise, if the auxiliary chamber 10 is directly separated from the main chamber 20, an explosion will occur. Therefore, before the sub-chamber 10 is separated from the main chamber 20 , external gas is introduced into the sub-chamber 10 to restore the sub-chamber 10 from a negative pressure state to a normal pressure state.

[0026] Specifically, before the external gas is introduced into the sub-chamber 10, that is, before the negative pressure in the sub-chamber 10 is adjusted, it is necessary to first close the connection window between the sub-chamber 10 and the main chamber 20, and stop introducing the inert gas into the sub-chamber 10. Because in the actual crystal pulling process, the gas introduced into the sub-chamber 10 and the main chamber 20 is always an inert gas, and since the inert gas is interconnected with the main chamber 20, it takes a long time for the negative pressure to change to normal pressure, and the amount of inert gas consumed is more. Therefore, after adopting this method, it is necessary to first isolate the sub-chamber 10 from the main chamber 20, and then stop introducing the inert gas into the sub-chamber 10, and then automatically monitor the air pressure in the sub-chamber 10 through the barometer to calculate how much air is needed to turn the sub-chamber 10 in the negative pressure state into the sub-chamber 10 in the normal pressure state. These technologies are all calculated by the controller without the need for human operation.

[0027] At the same time, inert gas is continuously introduced into the main chamber 20 and the gas flow rate remains unchanged during the process of introducing external gas into the sub-chamber 10. That is, during the process of changing the negative pressure state in the sub-chamber 10 to the normal pressure state, the negative pressure state in the main chamber 20 is also continuously maintained to avoid affecting the performance of silicon material melting or crystal growth.

[0028] An air compressor 40 is provided outside the single crystal furnace, and a filter device 50 is provided between the air compressor 40 and the single crystal furnace. The filter device 50 is used to filter the air output by the compressor 40 to filter harmful impurities in the airflow to prevent them from radiating to the inner wall of the auxiliary chamber 10, and to prevent them from remaining on the inner wall of the auxiliary chamber 10 or indirectly entering the main chamber 20 to affect the crystal growth. Since it is only necessary to convert the negative pressure in the auxiliary chamber 10 into normal pressure, only air flow at normal temperature is required, that is, the air input into the auxiliary chamber 10 is airflow at normal temperature, and no special treatment is required. It is not only simple to manufacture, but also cheap to obtain the air source.

[0029] In order to monitor the flow rate of air flowing into the auxiliary chamber 10, a solenoid valve 60 and a flow meter 70 are provided on the pipeline; at the same time, a pressure regulator 80 for monitoring the air pressure fluctuation on the pipeline is also provided.

[0030] After knowing the air pressure in the auxiliary chamber 10, the controller calculates how much air flow is required to enter the auxiliary chamber 10 within a preset time through a pre-made program, so that the negative pressure state in the auxiliary chamber 10 becomes a normal pressure state. The compressor 40 and the filter device 50 are started synchronously, and the solenoid valve 60, the flow meter 70 and the pressure regulator 80 are opened synchronously, and the valve body on the isolation chamber 30 is opened at the same time, so that the compressor 40 is connected to the isolation chamber 30.

[0031] After the compressor 40 is started, the compressed air will be circulated to the filter device 50 to filter the air output by the compressor 40; the filtered air is input into the secondary chamber through the pipeline. Among them, the filter device 50 is directly connected to the valve in the isolation chamber 30 through the pipeline. In order to ensure the cleanliness and airflow conditions of the airflow entering the secondary chamber 10, a cleanliness detector is also provided in the filter device 50 to transmit the filtered particle content to the controller in real time. If it is detected that the particle content does not meet the standard requirements, the system will stop it from continuing to output air to the secondary chamber 10; the system will return the air that does not meet the standards and filter it again to ensure that the particle content in the air output from the filter device 50 meets the requirements. If the particle content meets the requirements, the controller will notify the solenoid valve 60 placed on the pipeline to open and input qualified air into the isolation chamber 30.

[0032] For the air input into the isolation chamber 30, the air flow rate is adjusted in stages and the input flow rate is from fast to slow. This is because the negative pressure in the auxiliary chamber 10 is relatively large at the beginning, and a lot of air needs to be changed quickly to change the negative pressure, so a large amount of air needs to enter the auxiliary chamber 10. When the negative pressure in the auxiliary chamber 10 gradually decreases and is about to reach normal pressure, only a small amount of air is needed to change the air pressure in the auxiliary chamber 10 to normal pressure. The size of the flow rate needs to be determined based on the diameter of the pipeline, and is not specifically limited here.

[0033] By adopting the method proposed in the present application, the negative pressure state in the secondary chamber 10 can be changed to a normal pressure state within a ventilation time of no more than 60 seconds.

[0034] A single crystal furnace rapid pressurization method designed by the present application can quickly change the sub-chamber from a negative pressure state to a normal pressure state by introducing compressed gas into the sub-chamber instead of the existing inert gas and automatically controlling the flow rate of the compressed gas, without leaving any gas harmful to the growth of the crystal rod in the sub-chamber and without generating residual waste gas on the inner wall of the sub-chamber; at the same time, it can also reduce the use cost of the inert gas for single crystal pulling and improve the utilization rate of the coordination between the sub-chamber and the main chamber; this method can reduce the cooling time of the sub-chamber from the existing 4 minutes to less than 60 seconds, thereby improving the production efficiency of the entire crystal pulling process, and has high operability and stability, is safe and highly automated, and does not require human intervention.

[0035] The above is a detailed introduction to a single crystal furnace rapid pressurization method provided by the embodiment of the present application. The description of the above embodiment is only used to help understand the structure and core idea of ​​the present application; at the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

[0036] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that different manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. "Including" mentioned throughout the specification and claims is an open term, so it should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect. The subsequent description of the specification is a preferred embodiment of the present application, but the description is still for the purpose of illustrating the general principles of the present application, and is not used to limit the scope of the present application. The scope of protection of the present application shall be determined by the attached claims.

[0037] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a product or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such a product or system. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the product or system including the elements.

[0038] The above detailed description of the embodiments of the present application is only a preferred embodiment of the present application and cannot be considered to limit the scope of implementation of the present application. All equivalent changes and improvements made within the scope of the present application should still fall within the scope of the patent coverage of the present application.

Claims

1. A method for rapid pressurization of a single crystal furnace, mainly used for pressurizing a sub-chamber of a single crystal furnace, characterized in that: Before the single crystal furnace sub-chamber is separated from the main chamber, external gas is introduced into the sub-chamber to restore the sub-chamber from a negative pressure state to a normal pressure state.

2. A single crystal furnace rapid pressurization method according to claim 1, characterized in that: Before the external gas is introduced into the auxiliary chamber, the connecting window between the auxiliary chamber and the main chamber is closed, and the introduction of the inert gas into the auxiliary chamber is stopped; and the gas pressure in the auxiliary chamber is monitored.

3. A single crystal furnace rapid pressurization method according to claim 2, characterized in that: The process of introducing the external gas into the secondary chamber also includes continuing to introduce the inert gas into the main chamber while keeping the gas flow rate unchanged.

4. A single crystal furnace rapid pressurization method according to any one of claims 1 to 3, characterized in that: The external gas introduced into the auxiliary chamber is filtered air, including: Start the external compressor; Filter the air output from the compressor; The filtered air is then input into the secondary chamber through a pipeline.

5. A single crystal furnace rapid pressurization method according to claim 4, characterized in that: The pipeline for transmitting the filtered gas is directly connected to the valve on the wall of the isolation chamber below the secondary chamber.

6. A single crystal furnace rapid pressurization method according to claim 5, characterized in that: A solenoid valve and a flow meter for controlling the gas flow are arranged on the pipeline.

7. A single crystal furnace rapid pressurization method according to claim 6, characterized in that: A pressure regulator is also provided on the pipeline.

8. A single crystal furnace rapid pressurization method according to any one of claims 5 to 7, characterized in that: The air input into the auxiliary chamber is at room temperature.

9. A single crystal furnace rapid pressurization method according to claim 8, characterized in that: The flow rate of air input into the auxiliary chamber is adjusted in stages, and the input flow rate size is from fast to slow.

10. A method for rapid pressurization of a single crystal furnace according to any one of claims 1-3, 5-7, and 9, characterized in that: The ventilation time should not exceed 60s.

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