Method for removing Sb2O3 gas in single crystal furnace and single crystal furnace

Abstract

The invention discloses a method for removing Sb2O3 gas in a single crystal furnace and the single crystal furnace. The method for removing the Sb2O3 gas in the single crystal furnace comprises the following steps: S1, switching current inert gas to target inert gas after the furnace is shut down; s2, introducing the target inert gas into a furnace chamber of the single crystal furnace at a target flow rate; and S3, after the temperature in the furnace chamber is reduced to the target temperature, introducing of the target inert gas is stopped. According to the method for removing the Sb2O3 gas in the single crystal furnace, the nitrogen is used for purging the furnace chamber, so that the cost is saved, the furnace cover can be opened after no Sb2O3 gas is left in the furnace, the safety of field personnel is ensured, the cooling speed in the furnace can be increased, the time for blowing out the furnace and disassembling and cleaning the furnace is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of single crystal silicon preparation, and in particular to a method for removing Sb2O3 gas in a single crystal furnace and a single crystal furnace. Background Art

[0002] It is pointed out in the related art that antimony is widely used as a dopant in the pulling of N-type single crystals. Its main function is to control the resistivity of single crystals. Antimony is a silvery white, brittle, fusible crystalline solid with poor electrical and thermal conductivity. It does not undergo oxidation reaction with oxygen at room temperature. At high temperature, antimony easily reacts with oxygen to generate highly toxic Sb2O3. Inert gases such as argon and nitrogen are introduced during the pulling process of N-type single crystals, which mainly play the role of protection, temperature control, maintaining atmosphere conditions, removing impurities and reducing the content on the surface of the crystal.

[0003] After the N-type single crystal pulling operation is completed and the single crystal furnace is shut down, the temperature inside the furnace is still high and the reaction between antimony and oxygen will still proceed. At this time, if the single crystal furnace is opened for dismantling and cleaning, the workers are at risk of being directly exposed to the Sb2O3 atmosphere. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention is to provide a method for removing Sb2O3 gas in a single crystal furnace, which can save costs and effectively remove Sb2O3 gas in the single crystal furnace.

[0005] The present invention also provides a single crystal furnace using the above method for removing Sb2O3 gas in the single crystal furnace.

[0006] The method for removing Sb2O3 gas in a single crystal furnace according to the first aspect of the present invention comprises:

[0007] Step S1, switching the current inert gas to the target inert gas after the furnace is shut down;

[0008] Step S2, allowing the target inert gas to flow into the furnace chamber of the single crystal furnace at a target flow rate;

[0009] Step S3, after the temperature in the furnace chamber drops to the target temperature, the introduction of the target inert gas is stopped.

[0010] According to the method for removing Sb2O3 gas in a single crystal furnace of the present invention, by using nitrogen to purge the furnace chamber, it is not only possible to save costs, but also to ensure that there is no Sb2O3 gas remaining in the furnace before opening the furnace cover, thereby ensuring the safety of on-site personnel, and also to speed up the cooling speed in the furnace, reduce the time for stopping the furnace and cleaning, and improve production efficiency.

[0011] In some embodiments, the step S2 includes: allowing the target inert gas to flow into the furnace chamber of the single crystal furnace at a target flow rate for 10 min-30 min.

[0012] In some embodiments, the target flow rate is no less than 100 L / min.

[0013] In some embodiments, the target temperature is less than 600°C.

[0014] In some embodiments, the target inert gas is introduced into the furnace chamber from top to bottom.

[0015] In some embodiments, the target inert gas is nitrogen.

[0016] In some embodiments, the step S2 further includes: maintaining the negative pressure in the furnace chamber at 10 Torr-11 Torr.

[0017] According to the second aspect of the present invention, the single crystal furnace uses the method for removing Sb2O3 gas in the single crystal furnace according to the first aspect of the present invention, and the single crystal furnace includes: a furnace body, a furnace cavity is defined in the furnace body, an upper portion of the furnace body is formed with an air inlet connected to the furnace cavity, and the furnace body is formed with an air outlet connected to the furnace cavity; a first gas tank, the first gas tank stores the target inert gas, the first gas tank is connected to the air inlet; a first air pump, the first air pump is arranged between the first gas tank and the furnace body to drive the target inert gas from the first gas tank to flow into the furnace cavity; a temperature sensor, the temperature sensor is arranged in the furnace cavity to monitor the temperature in the furnace cavity; a pressure sensor, the pressure sensor is arranged in the furnace cavity to monitor the pressure in the furnace cavity.

[0018] According to the single crystal furnace of the present invention, by using the method of removing Sb2O3 gas in the single crystal furnace according to the first aspect, costs are saved, and the furnace cover is opened only after no Sb2O3 gas remains in the single crystal furnace, thereby ensuring the safety of on-site personnel, and speeding up the cooling speed in the furnace, reducing the time for stopping the furnace and dismantling it, thereby improving production efficiency.

[0019] In some embodiments, the single crystal furnace also includes: a second gas tank, which stores the current inert gas and is connected to the air inlet; an air inlet valve, wherein the air inlet end of the air inlet valve is respectively connected to the first gas tank and the second gas tank, and the air outlet end of the air inlet valve is connected to the air inlet.

[0020] In some embodiments, the single crystal furnace also includes: a second air pump, which is connected to the air outlet to drive the gas in the furnace chamber to flow from the furnace chamber to the outside of the furnace chamber; and a control module, which is electrically connected to at least the first air pump, the temperature sensor, the pressure sensor and the second air pump.

[0021] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 4 is a flow chart of a method for removing Sb2O3 gas in a single crystal furnace according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0024] Reference below Figure 1 A method for removing Sb2O3 gas in a single crystal furnace according to an embodiment of the first aspect of the present invention is described.

[0025] like Figure 1 As shown, the method for removing Sb2O3 gas in a single crystal furnace according to the first embodiment of the present invention comprises:

[0026] Step S1, switching the current inert gas to the target inert gas after the furnace is shut down;

[0027] Step S2, passing the target inert gas into the furnace chamber of the single crystal furnace at a target flow rate;

[0028] Step S3: After the temperature in the furnace chamber drops to the target temperature, the introduction of the target inert gas is stopped.

[0029] It can be understood that after the furnace is shut down, the current inert gas is switched to the target inert gas (preferably nitrogen). If the current inert gas is nitrogen, no switching is required. Then, the nitrogen is introduced into the furnace chamber of the single crystal furnace at a target flow rate. In this way, choosing the appropriate flow rate can ensure effective replacement. After the temperature in the furnace chamber drops to the target temperature, the introduction of nitrogen is stopped. This avoids too fast or too slow cooling to protect the integrity of the single crystal structure and the safety of the equipment.

[0030] According to the method for removing Sb2O3 gas in a single crystal furnace according to an embodiment of the present invention, by purging the furnace chamber with nitrogen, it is possible to save costs and ensure that there is no Sb2O3 gas remaining in the furnace before opening the furnace cover, thereby ensuring the safety of on-site personnel, speeding up the cooling speed in the furnace, reducing the time required for stopping the furnace and cleaning it, and improving production efficiency.

[0031] In some embodiments of the present invention, step S2 includes: allowing the target inert gas to pass into the furnace chamber of the single crystal furnace at a target flow rate for 10 minutes to 30 minutes. It is understandable that the ventilation time of 10 minutes to 30 minutes can be adjusted according to actual conditions. The specific length of time depends on the volume of the furnace chamber, the initial oxygen content, and the flow rate of the selected inert gas. For a furnace chamber with a larger volume or a higher initial oxygen content, it may take longer to ensure complete replacement. Thus, it can be ensured that the Sb2O3 gas in the furnace chamber is completely discharged, providing a safe working environment for operators.

[0032] Optionally, the target flow rate is not less than 100 L / min. Thus, the Sb2O3 gas in the furnace chamber can be quickly and completely purged out of the furnace chamber. For example, the target flow rate can be 100 L / min, 105 L / min, 110 L / min, 115 L / min, 120 L / min, 125 L / min, 130 L / min, 135 L / min, 140 L / min, 145 L / min, 150 L / min, etc.

[0033] Further, the target temperature is less than 600° C. For example, the target temperature may be 600° C., 595° C., 590° C., 585° C., 580° C., 575° C., 570° C., 565° C., 560° C., and so on.

[0034] Preferably, in order to ensure that the Sb2O3 gas in the furnace chamber can be completely discharged from the single crystal furnace, the target inert gas is introduced into the furnace chamber from top to bottom, which helps to form a stable inert gas layer and gradually pushes the Sb2O3 gas downward.

[0035] Since nitrogen has stable chemical properties and relatively low cost, the target inert gas is nitrogen.

[0036] In order to ensure safety during the process of removing Sb2O3 gas from the single crystal furnace, step S2 further includes: maintaining the negative pressure in the furnace chamber at 10 Torr-11 Torr. For example, the negative pressure in the furnace chamber can be maintained at 10 Torr, 10.1 Torr, 10.2 Torr, 10.3 Torr, 10.4 Torr, 10.5 Torr, 10.6 Torr, 10.7 Torr, 10.8 Torr, 10.9 Torr, 11 Torr, etc.

[0037] According to the single crystal furnace of the second embodiment of the present invention, the single crystal furnace uses the method for removing Sb2O3 gas in the single crystal furnace according to the first embodiment of the present invention.

[0038] Specifically, the single crystal furnace includes: a furnace body, a furnace cavity is defined in the furnace body, an air inlet connected to the furnace cavity is formed at the upper part of the furnace body, and an air outlet connected to the furnace cavity is formed in the furnace body; a first gas tank, the first gas tank stores the target inert gas, and the first gas tank is connected to the air inlet; a first air pump, the first air pump is arranged between the first gas tank and the furnace body to drive the target inert gas to flow from the first gas tank to the furnace cavity; a temperature sensor, the temperature sensor is arranged in the furnace cavity to monitor the temperature in the furnace cavity; a pressure sensor, the pressure sensor is arranged in the furnace cavity to monitor the pressure in the furnace cavity.

[0039] It can be understood that an air inlet connected to the furnace chamber is formed on the upper part of the furnace body to enable the target inert gas to pass into the furnace chamber from top to bottom; the first gas tank stores the target inert gas, and the first air pump is arranged between the first gas tank and the furnace body to drive the target inert gas to flow from the first gas tank to the furnace chamber, so as to enable the target inert gas to be passed into the furnace chamber of the single crystal furnace at a target flow rate of not less than 100L / min for 10min-30min; a pressure sensor is provided to maintain the negative pressure in the furnace chamber at 10Torr-11Torr; a temperature sensor is provided to stop the introduction of the target inert gas after the temperature in the furnace chamber drops to the target temperature.

[0040] The single crystal furnace according to the embodiment of the present invention saves costs by using the method for removing Sb2O3 gas in the single crystal furnace according to the first embodiment, ensures that there is no Sb2O3 gas remaining in the single crystal furnace before opening the furnace cover, ensures the safety of on-site personnel, and can also speed up the cooling speed in the furnace, reduce the time for stopping the furnace and cleaning, and improve production efficiency.

[0041] Furthermore, the single crystal furnace further includes: a second gas tank, the second gas tank stores the current inert gas, the second gas tank is connected to the gas inlet; an inlet valve, the inlet end of the inlet valve is connected to the first gas tank and the second gas tank respectively, and the outlet end of the inlet valve is connected to the gas inlet. It is understandable that another inert gas (such as argon Ar) or other working gas that may be used in the pulling process is switched to the first gas tank to pass nitrogen when removing the Sb2O3 gas in the single crystal furnace.

[0042] Furthermore, the single crystal furnace also includes: a second air pump, which is connected to the air outlet to drive the gas in the furnace chamber to flow from the furnace chamber to the outside of the furnace chamber, thereby maintaining the negative pressure in the furnace chamber; a control module, which is electrically connected to at least the first air pump, the temperature sensor, the pressure sensor and the second air pump, thereby realizing automatic coordinated control and improving the safety and efficiency of operation.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0044] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0045] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0047] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for removing Sb2O3 gas in a single crystal furnace, characterized in that: include: Step S1, switching the current inert gas to the target inert gas after the furnace is shut down; Step S2, allowing the target inert gas to flow into the furnace chamber of the single crystal furnace at a target flow rate; Step S3, after the temperature in the furnace chamber drops to the target temperature, the introduction of the target inert gas is stopped.

2. The method for removing Sb2O3 gas in a single crystal furnace according to claim 1, characterized in that: The step S2 includes: allowing the target inert gas to flow into the furnace chamber of the single crystal furnace at a target flow rate for 10 minutes to 30 minutes.

3. The method for removing Sb2O3 gas in a single crystal furnace according to claim 1, characterized in that: The target flow rate is not less than 100 L / min.

4. The method for removing Sb2O3 gas in a single crystal furnace according to claim 1, characterized in that: The target temperature is less than 600°C.

5. The method for removing Sb2O3 gas in a single crystal furnace according to claim 1, characterized in that: The target inert gas is introduced into the furnace chamber from top to bottom.

6. The method for removing Sb2O3 gas in a single crystal furnace according to claim 1, characterized in that: The target inert gas is nitrogen.

7. The method for removing Sb2O3 gas in a single crystal furnace according to claim 2, characterized in that: The step S2 further includes: maintaining the negative pressure in the furnace chamber at 10 Torr-11 Torr.

8. A single crystal furnace, characterized in that: The single crystal furnace uses the method for removing Sb2O3 gas in the single crystal furnace according to any one of claims 1 to 7, and the single crystal furnace comprises: A furnace body, wherein a furnace cavity is defined in the furnace body, an air inlet communicating with the furnace cavity is formed at the upper portion of the furnace body, and an air outlet communicating with the furnace cavity is formed on the furnace body; a first gas tank, wherein the first gas tank stores the target inert gas, and the first gas tank is connected to the gas inlet; a first air pump, the first air pump being disposed between the first gas tank and the furnace body to drive the target inert gas to flow from the first gas tank into the furnace chamber; A temperature sensor is disposed in the furnace cavity to monitor the temperature in the furnace cavity; A pressure sensor is disposed in the furnace cavity to monitor the pressure in the furnace cavity.

9. The single crystal furnace according to claim 8, characterized in that: Also includes: A second gas tank, wherein the second gas tank stores the current inert gas, and the second gas tank is connected to the gas inlet; An air intake valve, wherein the air intake end of the air intake valve is connected to the first gas tank and the second gas tank respectively, and the air outlet end of the air intake valve is communicated with the air inlet.

10. The single crystal furnace according to claim 8 or 9, characterized in that: Also includes: a second air pump, the second air pump being connected to the air outlet to drive the gas in the furnace cavity to flow from the furnace cavity to the outside of the furnace cavity; A control module is electrically connected to at least the first air pump, the temperature sensor, the pressure sensor and the second air pump.

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