Chemical vapor deposition furnace cleaning method and chemical vapor deposition furnace with cleaning function

Abstract

The present invention provides a method for cleaning a chemical vapor deposition furnace and a chemical vapor deposition furnace with a cleaning function. The cleaning method includes sealing a chamber containing a layer to be cleaned, setting environmental conditions within the chamber, and introducing a cleaning gas from the lower part of the chamber to clean the layer to be cleaned within the chamber. Setting environmental conditions within the chamber includes controlling the temperature within the chamber in a gradient from high to constant from the lower part to the upper part. In the cleaning method, increasing the temperature of the lower part of the furnace chamber can accelerate the thermal decomposition rate of the cleaning gas in the lower part of the chamber, which tends to stabilize the cleaning rate throughout the lower part of the chamber. This improves the overall cleaning efficiency of the chamber and shortens the cleaning time, thereby alleviating the problem of damage caused by excessive cleaning of the upper part of the chamber, which requires an extended cleaning time for the lower part of the chamber, and extending the service life of the chamber.

Description

[Technical Field]

[0001] The present invention relates to the technical field of semiconductor manufacturing, and more particularly to a method for cleaning a chemical vapor deposition furnace and a chemical vapor deposition furnace having a cleaning function. [Background technology]

[0002] Equipment maintenance and cleaning are crucial in semiconductor manufacturing processes. In chemical vapor deposition (CVD), silane, a reactive gas source, is introduced into a reaction chamber in gaseous form. Under high temperatures, silane decomposes to produce products such as polysilicon and silicon nitride, which are then deposited on wafers in the reaction chamber. During this process, the products not only deposit on the wafer surface but also in various locations within the chamber, including various regions of the inner chamber of a vertical furnace, the inner sidewalls of the outer chamber, and the gap between the inner and outer chambers. To prevent these products from accumulating over time and affecting the quality of wafer processing, the reaction chamber must be periodically cleaned. Cleaning gases are commonly used as cleaning agents in the industry. The principle is to use strong oxidizing substances produced by high-temperature decomposition of the cleaning gas to react with the products to be removed in the chamber, generating gases that are then pumped out to achieve the cleaning goal.

[0003] However, in actual processes, it has been found that after cleaning the furnace chamber a certain number of times, the upper part of the chamber is damaged, resulting in a decrease in wafer processing yield.To solve this problem, the processing method currently chosen is to replace the furnace chamber after cleaning it a certain number of times, but this method has the problem of high maintenance costs, labor costs, and material costs. Summary of the Invention

[0004] Therefore, an object of the present invention is to provide a chemical vapor deposition furnace cleaning method and a chemical vapor deposition furnace having a cleaning function that can reduce the degree of damage to the upper part of the chamber, extend the service life of the furnace chamber, and save labor costs, maintenance costs, and material costs.

[0005] According to a first aspect, the present invention provides a method for cleaning a chemical vapor deposition furnace, comprising the steps of: The chamber containing the layer to be cleaned is sealed and environmental conditions are established within the chamber. A cleaning gas is introduced from the bottom of the chamber to clean the layer to be cleaned in the chamber. Here, setting the environmental conditions inside the chamber includes controlling the temperature inside the chamber in a gradient from high to low temperatures from the bottom to the top.

[0006] According to a specific implementation of the embodiment of the present application, the cleaning gas is a fluorine-based gas.

[0007] According to a specific implementation of the embodiment of the present invention, setting the environmental conditions in the chamber further includes setting the pressure in the chamber to 0.1 to 1.2 torr.

[0008] According to a specific embodiment of the present invention, when the temperature inside the chamber is controlled in a gradient from high to low from the bottom to the top, the temperature at the bottom of the chamber is 15 to 30°C higher than the temperature at the top of the chamber.

[0009] According to a specific implementation of the embodiment of the present invention, the cleaning method further includes a step of, after the layer to be cleaned in the chamber has been cleaned, continuously introducing a cleaning gas into the layer to be cleaned for a certain period of time to completely clean the layer to be cleaned.

[0010] According to a specific embodiment of the present invention, after the layer to be cleaned in the chamber is cleaned, the cleaning gas is continuously introduced for 3 to 5 minutes.

[0011] According to a specific implementation of the embodiment of the present invention, the cleaning method further includes a step of removing by-products in the chamber by continuously introducing an inert gas or nitrogen gas into the chamber for a certain period of time after the layer to be cleaned in the chamber has been cleaned.

[0012] According to a specific embodiment of the present invention, the flow rate of the inert gas or nitrogen gas introduced into the chamber is 1.5 SL to 2 SL, and the continuous introduction time is 3 to 5 minutes.

[0013] According to a second aspect, the present invention provides a chemical vapor deposition furnace having a cleaning function, as follows. at least two temperature control modules for heating the sealed chamber of the furnace; Controlling the temperature control module to adjust the environmental conditions within the chamber; and a control module configured to control a cleaning gas introduced into the chamber from a lower portion of the chamber to clean the layer to be cleaned in the chamber. The environmental conditions are controlled by grading the temperature within the chamber from hot to cold from bottom to top.

[0014] According to a specific implementation of an embodiment of the present application, each temperature control module includes at least one heating unit.

[0015] According to a specific implementation of the embodiment of the present invention, the control module is further configured to control the pressure control module to adjust environmental conditions in the chamber, and the environmental conditions include a pressure in the chamber of 0.1 to 1.2 torr.

[0016] The present invention relates to a chemical vapor deposition furnace and a method for cleaning such a furnace. By increasing the temperature of the lower chamber of the furnace, the thermal decomposition rate of the cleaning gas in the lower chamber can be increased, thereby achieving a more constant cleaning rate throughout the chamber. This improves overall chamber cleaning efficiency, shortens chamber cleaning time, and alleviates the problem of damage to the upper chamber due to excessive cleaning, which occurs when the lower chamber requires a longer cleaning time. The present invention extends the chamber's service life, ensures wafer processing quality, and simultaneously reduces labor, maintenance, and material costs. Other features and advantages of the present invention will be set forth in the following specification, and in part will be apparent from the specification or may be learned by practice of the invention. The objectives and other advantages of the present invention will be achieved and obtained by the configurations particularly illustrated in the specification and accompanying drawings. [Brief explanation of the drawings]

[0017] In order to more clearly describe the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below. It goes without saying that the drawings in the following description are part of the embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative efforts. [Figure 1] FIG. 1 is a schematic diagram showing the cross-sectional structure of the furnace device. [Figure 2] FIG. 2 is a schematic flow diagram of a method for cleaning a chemical vapor deposition furnace according to an embodiment of the present invention. [Figure 3] FIG. 3 is a schematic structural diagram of a chemical vapor deposition furnace having a cleaning function according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described in detail and completely below with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and are not all of the embodiments. All other embodiments that can be obtained by those skilled in the art based on the embodiments of the present invention without requiring creative efforts also fall within the protection scope of the present invention.

[0019] Before describing the method for cleaning a chemical vapor deposition furnace of the present invention, it is necessary to first understand the structure of the furnace apparatus. Please refer to FIG. 1. FIG. 1 is a schematic diagram showing the cross-sectional structure of the furnace apparatus. As shown in FIG. 1, the furnace apparatus comprises a furnace body 100 and a chamber, which comprises an outer chamber 200 and an inner chamber 300. The inner chamber 300 is installed vertically inside the furnace body 100, and the outer chamber 200 is fitted outside the inner chamber 300. The outer chamber 200 is also installed vertically inside the furnace body 100, with a gap formed between the inner chamber 300 and the outer chamber 200, and the top of the outer chamber 200 is sealed. The inner chamber 300 actually has a cylindrical structure, and the inner space of the outer chamber 200 and the inner chamber 300 together form the chamber. A temperature control region is provided on the sidewall of the furnace body 100. Due to the large size of the furnace structure, some areas may be too hot or too cold during heating in the temperature control area, resulting in temperature non-uniformity. However, high temperature accuracy and uniformity are required when performing chemical vapor deposition on wafers. In manufacturing and production processes, uniform temperature control of each area of ​​the chamber is essential to more accurately control the temperature throughout the chamber. Therefore, the temperature control area is typically divided into five heating units: first heating unit 400, second heating unit 500, third heating unit 600, fourth heating unit 700, and fifth heating unit 800. Controlling multiple heating units to simultaneously heat the furnace to the same target temperature during processing further controls the temperature within the furnace chamber and achieves better temperature uniformity. Specifically, each heating unit consists of a heater, a temperature sensor, and a controller. During the heating process, the controller controls the heater to heat the chamber. At the same time, the temperature sensor monitors the temperature within the chamber and transmits the monitored temperature data to the controller in real time. When the temperature inside the chamber reaches a preset target temperature, the controller immediately controls the heater to stop heating.

[0020] When a furnace chamber needs to be cleaned after the completion of a wafer chemical vapor deposition process, taking into account the structural characteristics of existing furnace chambers, a typical method is as follows: Multiple heating units are controlled to uniformly heat the entire chamber at the same temperature. Cleaning gas is introduced into the inner chamber 300 through a gas inlet 201 at the bottom of the outer chamber 200 of the furnace apparatus. The gas reaches the top of the inner chamber 300, passes through the gap between the inner chamber 300 and the outer chamber 200, and is finally discharged through a gas outlet 202 at the bottom of the outer chamber 200. The cleaning gas is generally selected depending on the layer to be cleaned. However, the present inventors have discovered that wafer processing yields decrease after a certain number of cleanings. Through their analysis, the present inventors have found that cleaning the furnace chamber a certain number of times results in excessive cleaning of the upper part of the furnace, generating particles that affect wafer processing during wafer processing. Currently, to avoid the reduction in wafer yield due to the above reasons, the treatment method of replacing the furnace chamber after cleaning it a certain number of times is selected, but this method results in relatively high maintenance costs, labor costs, and material costs. Therefore, the inventors of the present invention have considered the above situation and proposed a chemical vapor deposition furnace cleaning method that can reduce the degree of damage to the upper part of the furnace chamber, extend the service life of the furnace chamber, and save labor costs, maintenance costs, and material costs.

[0021] Please refer to Fig. 2. Fig. 2 shows a schematic flow diagram of a method for cleaning a chemical vapor deposition furnace according to an embodiment of the present invention. As shown in Fig. 2, the method for cleaning a chemical vapor deposition furnace of the present invention includes the following steps: Step S100: The chamber in which the layer to be cleaned is deposited is sealed, and the environmental conditions within the chamber are set.

[0022] Specifically, as shown in FIG. 1 , when sealed, the outer chamber 200 is fitted onto the outside of the inner chamber 300, creating a sealed environment inside. The layer to be cleaned refers to products deposited on areas other than the wafer surface during the chemical vapor deposition process. In the embodiment of the present invention, the other areas include each area of ​​the inner chamber 300, the inner sidewall of the outer chamber 200, and the gap between the inner chamber 300 and the outer chamber 200. Setting the environmental conditions inside the chamber includes controlling the temperature inside the chamber in a gradient from high to low from the bottom to the top.

[0023] When the cleaning gas enters the lower part of the inner chamber 300, its temperature is too low to reach the reaction temperature. Therefore, cleaning does not begin immediately after the cleaning gas first enters the inner chamber 300. The cleaning gas is continuously heated during the upward circulation process, causing a partial thermal decomposition reaction during the heating process. However, the reaction during the cleaning process is exothermic. Therefore, the temperature of the gas at the upper part of the inner chamber 300 is significantly higher than that at the lower part of the inner chamber 300. During the cleaning process, cleaning gases such as chlorine trifluoride are preferentially and completely decomposed at the upper parts of the inner chamber 300 and the outer chamber 200, generating sufficient fluorine gas to react with the layer to be cleaned within the furnace chamber and then gradually spread toward the lower part of the chamber. This makes it easier for cleaning of the upper part of the chamber to begin, and cleaning of the lower part of the chamber is completed after a certain period of time has passed. As a result, cleaning of the upper part of the chamber is completed, but cleaning of the lower part is not. Therefore, to ensure that the lower portions of the inner chamber 300 and the outer chamber 200 are also cleaned, the cleaning time of the entire cleaning program must be extended. As a result, damage to the upper portions of the chambers due to excessive cleaning is unavoidable. After a certain number of cleanings, the damage to the upper portions of the chambers becomes significant, resulting in a decrease in the yield rate of wafer processing.

[0024] To solve this problem, in an actual cleaning method according to an embodiment of the present invention, different cleaning gases are selected according to the different products generated by different chemical vapor deposition processes. Then, based on the reaction temperatures of the actual cleaning gases, the temperature control region of the furnace body can be divided into regions using multiple heating units, and the heating temperature for each region of the furnace body can be selected and set. This setting can also include dividing the temperature control region of the furnace body into regions and controlling the temperature inside the furnace in a gradient from high to low from the bottom to the top.

[0025] For example, in combination with the structure of the furnace device, if the temperature control region of the furnace body is divided into multiple regions and the temperature control region is divided into a lower, central, and upper region, the lower region would be the fourth heating unit 700 and fifth heating unit 800, the central region would be the second heating unit 500 and third heating unit 600, and the upper region would be the first heating unit 400. A specific setting method is to set the temperature of the lower chamber 10 to 20°C higher than the temperature of the central region, and the temperature of the central region would be set 5 to 10°C higher than the temperature of the upper region. The temperature is maintained constant in the lower region, and the temperatures in the central and upper regions are also maintained constant.

[0026] In another embodiment, the temperature control region of the furnace body is divided into regions depending on the structure of the furnace apparatus. When the temperature control region is divided into a lower and upper region, the lower region is the fourth heating unit 700 and the fifth heating unit 800, and the upper region is the first heating unit 400, the second heating unit 500, and the third heating unit 600. Specifically, the temperature of the lower region of the chamber is set 15 to 30°C higher than the temperature of the upper region of the chamber. The temperatures of the lower region and the upper region are kept constant.

[0027] Furthermore, setting the environmental conditions in the chamber further includes setting the pressure in the chamber to 0.1 to 1.2 torr.

[0028] Step S200: A cleaning gas is introduced from the bottom of the chamber, and a product (for example, fluorine gas) produced by the decomposition reaction of the cleaning gas is used to clean the layer to be cleaned in the chamber.

[0029] Furthermore, the flow rate of the cleaning gas introduced into the chamber is 1.5SL-2SL.

[0030] Preferably, the cleaning process further includes step S300. Step S300: After the layer to be cleaned in the chamber is cleaned, cleaning gas is continuously introduced into the chamber for a certain period of time to further ensure that the layer to be cleaned is completely cleaned. For example, in an embodiment of the present invention, cleaning gas can be continuously introduced for 3 to 5 minutes, with the flow rate maintained constant. Since the time required for cleaning the layer to be cleaned in the chamber can be determined empirically, the time until cleaning is complete can also be directly determined as the reference time for cleaning completion. Furthermore, a temperature sensor installed in the heating unit can monitor temperature changes in the chamber in real time and can be used for this determination. When cleaning gas is continuously introduced and the temperature monitored by the temperature sensor matches the temperature controlled in the temperature control zone, i.e., when the detected temperature matches the temperature heated by the heating unit in the temperature control zone, cleaning can be determined to be complete. This determination is possible because the reaction that occurs when the cleaning gas cleans the layer to be cleaned is an exothermic reaction; the specific reaction that occurs will be described later. As long as the layer to be cleaned is not cleaned, the cleaning gas continues to react with the layer to be cleaned. The temperature in the chamber detected by the temperature sensor remains higher than the temperature heated by the heating unit in the temperature control area, and when the temperature in the chamber detected by the temperature sensor becomes equal to the temperature heated by the heating unit in the temperature control area, it indicates that the cleaning reaction is not occurring again, meaning that the layer to be cleaned has been completely cleaned.

[0031] Preferably, the cleaning process further includes step S400. Step S400: After the cleaning gas is continuously introduced for a certain period of time, an inert gas or nitrogen gas is continuously introduced into the chamber for a certain period of time to remove by-products in the chamber and complete the cleaning process. For example, in this embodiment of the present invention, nitrogen gas is selected. Furthermore, in this embodiment of the present invention, the flow rate of the nitrogen gas introduced into the chamber is 1.5 SL to 2 SL, and the continuous introduction time is 3 to 5 minutes.

[0032] In the semiconductor manufacturing technology field, fluorine-based gases are commonly used as cleaning gases for chemical vapor deposition products, with chlorine trifluoride being particularly popular. Chlorine trifluoride is relatively stable at room temperature, and its activity is similar to that of chlorine gas. However, upon heating, its activity increases rapidly, and decomposition begins at 250°C, producing chlorine fluoride and fluorine gas as decomposition products. This reaction generates a large amount of heat, which further accelerates the decomposition of chlorine trifluoride and generates more fluorine gas. When the temperature reaches 600°C, chlorine trifluoride is completely decomposed. The fluorine gas generated by this reaction reacts with chemical vapor deposition products such as polysilicon, silicon nitride, and silicon carbide / nitride in the chamber to generate silicon tetrafluoride gas, which is then pumped out, achieving the cleaning purpose.

[0033] An embodiment of the present invention provides a chemical vapor deposition furnace with a cleaning function suitable for implementing the above-described chemical vapor deposition furnace cleaning method. Please refer to FIG. 3. FIG. 3 is a schematic structural diagram of a chemical vapor deposition furnace with a cleaning function according to an embodiment of the present invention. As shown in FIG. 3, the chemical vapor deposition furnace with a cleaning function 301 is configured as follows: It includes at least two temperature control modules 3012 for heating a sealed chamber 3011 of the furnace; and a control module 3014 configured to control the temperature control modules 3012 to adjust the environmental conditions in the chamber 3011 and control the cleaning gas introduced into the chamber 3011 from the bottom so as to clean the layer to be cleaned in the chamber 3011. Here, the environmental conditions include controlling the temperature in the chamber 3011 in a gradient from high to low from the bottom to the top.

[0034] Additionally, each temperature control module 3012 includes at least one heating unit 30121 .

[0035] Furthermore, the control module 3014 is configured to control the pressure control module 3013 to adjust the environmental conditions within the chamber 3011. The environmental conditions here specifically include maintaining the pressure within the chamber 3011 at 0.1 to 1.2 torr.

[0036] Next, a method for cleaning a chemical vapor deposition reactor according to an embodiment of the present invention will be described by way of example, in which a chamber having a polysilicon thin film is cleaned using chlorine trifluoride gas as a cleaning gas.

[0037] See FIG. 1. In this embodiment of the present invention, a chamber having a polysilicon thin film therein is provided, and the entire chamber is sealed. In this embodiment, the furnace body is provided with five heating units, which are divided from top to bottom into a first heating unit 400, a second heating unit 500, a third heating unit 600, a fourth heating unit 700, and a fifth heating unit 800. Dividing the five heating units into regions enables both precise heating and temperature control in each region, allowing different temperature control to be achieved in each region of the chamber. Temperature and pressure conditions can be set as environmental conditions within the chamber. The temperature within the chamber is controlled in a gradient from high to low from the bottom to the top. In this embodiment of the present invention, the temperature control region of the furnace body is divided into multiple regions, including a lower region, a central region, and an upper region. Specifically, the lower region is divided into the fourth heating unit 700 and the fifth heating unit 800, the central region is divided into the second heating unit 500 and the third heating unit 600, and the upper region is divided into the first heating unit 400. The temperature conditions are specifically set as follows: The temperature of the lower part of the chamber, i.e., the temperature of the fourth heating unit 700 and the fifth heating unit 800, is set to 400°C. The temperature of the lower part of the chamber is 15°C higher than the temperature of the center part of the chamber, i.e., the temperatures of the second heating unit 500 and the third heating unit 600 are set to 385°C. The temperature of the center part of the chamber is 15°C higher than the temperature of the upper part of the chamber, i.e., the temperature of the first heating unit 400 is set to 370°C. In this embodiment of the present invention, the pressure condition in the chamber is set to 1.0 torr.

[0038] Chlorine trifluoride is introduced into the inner chamber 300 through a gas inlet 201 provided at the bottom of the outer chamber 200, and the flow rate is set to 1.75 SL. The fluorine gas produced by the decomposition reaction of chlorine trifluoride can be used to clean the polysilicon inside the chamber. The introduced chlorine trifluoride gas undergoes a decomposition reaction under heated, high-temperature conditions to produce chlorine fluoride and fluorine gas, and the polysilicon layer inside the chamber is cleaned with the fluorine gas produced. In this embodiment of the present invention, cleaning refers to removing the polysilicon layer inside the chamber by utilizing the reaction between fluorine gas and silicon. The decomposition reaction formula of chlorine trifluoride to produce fluorine gas and chlorine fluoride to remove polysilicon is as follows: The reaction proceeds as follows: ClF3 → ClF + F2; Si + F2 → SiF4, and the product SiF4 exists in a gaseous state in the chamber. In the present invention, a fluorine-based gas is introduced into the chamber, and the polysilicon layer in the chamber is cleaned with the fluorine-based gas until the polysilicon layer in the chamber is completely cleaned.

[0039] After cleaning, nitrogen gas is continuously supplied for a certain period of time to remove by-products from the chamber and complete the cleaning process. In an embodiment of the present invention, a gas exhaust device (not shown) is provided at the gas outlet 202, allowing by-products from the chamber to be exhausted through the gap between the inner chamber 300 and the outer chamber 200 through the gas outlet 202. Chlorine trifluoride gas introduced from the bottom of the chamber decomposes to produce fluorine gas and chlorine fluoride. The fluorine gas then reacts with silicon to produce silicon tetrafluoride gas, resulting in the main by-products of silicon tetrafluoride and chlorine fluoride. The reaction is allowed to proceed sufficiently to clean the polysilicon layer inside the furnace. After cleaning, chlorine trifluoride gas is continuously supplied for 3 to 5 minutes to completely clean the polysilicon thin film layer and ensure the cleaning effect. Nitrogen gas is then supplied for 3 to 5 minutes to facilitate the exhaustion of by-products.

[0040] By implementing heating in different furnace zones, the present invention allows precise control of different temperatures in each zone, resulting in more uniform cleaning efficiency throughout the chamber. This also alleviates the problem of the need to extend the chamber cleaning time due to an initial temperature that is not up to standard, resulting in over-cleaning and damage to the upper part of the chamber. This extends the chamber's service life, ensures wafer processing quality, and simultaneously reduces costs.

[0041] Furthermore, by setting the temperature of the lower part of the furnace higher, the cleaning gas in the lower part of the furnace can be promoted to reach the reaction temperature quickly, and the decomposition rate of the cleaning gas can be increased, thereby improving the cleaning efficiency of the lower part of the furnace. For example, when the thickness of the thin polysilicon layer in the chamber is 10 microns, the cleaning time required by the conventional cleaning method is about 130 minutes, while the cleaning time required by the cleaning method of the present invention is about 115 minutes.

[0042] Although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the technical solutions described in the above embodiments can still be modified or some technical features can be replaced with equivalents, but these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of each embodiment of the present invention.

Claims

1. sealing the chamber containing the layer to be cleaned and setting environmental conditions within the chamber; a step of introducing a cleaning gas from a lower portion of the chamber to clean the layer to be cleaned in the chamber, The method for cleaning a chemical vapor deposition furnace, wherein setting the environmental conditions in the chamber includes controlling the temperature in the chamber in a gradient from high to low from the bottom to the top.

2. 2. The method for cleaning a chemical vapor deposition furnace according to claim 1, wherein the cleaning gas is a fluorine-based gas.

3. The setting of the environmental conditions in the chamber includes:

2. The method for cleaning a chemical vapor deposition furnace according to claim 1, further comprising setting the pressure in the chamber to 0.1 to 1.2 torr.

4. 2. The method for cleaning a chemical vapor deposition furnace according to claim 1, wherein when the temperature inside the chamber is controlled in a gradient from high to low from the bottom to the top, the temperature of the lower part of the chamber is 15 to 30° C. higher than the temperature of the upper part of the chamber.

5. 2. The method for cleaning a chemical vapor deposition furnace according to claim 1, further comprising the step of: continuously introducing a cleaning gas for a predetermined period of time after the layer to be cleaned in the chamber has been cleaned, thereby completely cleaning the layer to be cleaned.

6. 6. The method for cleaning a chemical vapor deposition furnace according to claim 5, wherein the cleaning gas is continuously introduced for 3 to 5 minutes after the layer to be cleaned in the chamber has been cleaned.

7. 10. The method for cleaning a chemical vapor deposition furnace according to claim 1, further comprising the step of removing by-products from the chamber by continuously introducing an inert gas or nitrogen gas into the chamber for a certain period of time after the layer to be cleaned in the chamber has been cleaned.

8. 8. The method for cleaning a chemical vapor deposition furnace according to claim 7, wherein the flow rate of the inert gas or nitrogen gas introduced into the chamber is 1.5 SL to 2 SL, and the continuous introduction time is 3 to 5 minutes.

9. at least two temperature control modules for heating the enclosed chamber of the furnace; controlling the temperature control module to regulate environmental conditions within the chamber; a control module configured to control a cleaning gas introduced into the chamber from a lower portion of the chamber to clean the layer to be cleaned in the chamber; The environmental conditions are controlled by grading the temperature in the chamber from high to low from the bottom to the top.

10. 10. The chemical vapor deposition furnace with cleaning function of claim 9, wherein each temperature control module includes at least one heating unit.

11. the control module is further configured to control the pressure control module to regulate environmental conditions within the chamber; 10. The chemical vapor deposition furnace with cleaning function according to claim 9, wherein the environmental conditions include a pressure in the chamber of 0.1 to 1.2 torr.

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