Cooling system and cleaning method for gas spray header in chemical vapor deposition equipment

Abstract

The invention discloses a cooling system and a cleaning method of a gas spray header, the cooling system comprises the gas spray header, a liquid supply device, a liquid storage barrel and a gas source, the gas spray header comprises a cooling channel, and the liquid storage barrel comprises an exhaust pipe; the liquid supply device, the first liquid supply pipe, the liquid storage barrel, the second liquid supply pipe, the cooling channel and the liquid return pipe form a circulating flow path of cooling liquid of the gas spray header; the gas source, the first gas conveying pipe, the cooling channel, the liquid discharging pipe, the liquid storage barrel and the exhaust pipe form a gas flowing path which is output by the gas source and used for emptying cooling liquid in the cooling channel. In the in-situ cleaning process, cooling liquid in a cooling channel of the gas spraying head can be discharged into the liquid storage barrel, and the problem that valves or other parts are damaged due to the fact that the cooling liquid is heated to generate too high vapor pressure is solved; and meanwhile, the cooling liquid discharged into the liquid storage barrel can be recycled in the subsequent deposition process.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor equipment, and particularly to a cooling system and a cleaning method for a gas showerhead in a chemical vapor deposition equipment. Background Art

[0002] A chemical vapor deposition (CVD) equipment is used to grow a thin film on the surface of a substrate. Its chamber generally includes a tray, a heater, a support shaft and a gas showerhead, where the gas showerhead is used to supply process gases for growing the thin film. During the process, the temperature in the equipment chamber is relatively high. To avoid damage to the gas showerhead caused by excessive temperature and prevent the reaction of process gases in the gas showerhead, cooling channels through which a coolant flows are usually included in the gas showerhead.

[0003] After the chemical vapor deposition equipment has been working for a period of time, deposits will inevitably form on the surface of the gas showerhead exposed to the process gas atmosphere. At this time, it is necessary to heat the gas showerhead and introduce a cleaning gas into the chamber to remove the deposits on the surface of the gas showerhead. However, during the in-situ cleaning process, due to the high temperature of the gas showerhead, the coolant in the cooling channels will generate a high-temperature vapor pressure, and the excessive high-temperature vapor pressure will damage components such as valves in the cooling pipes.

[0004] It should be noted that the content of the above background art was discovered by the inventor during the process of implementing the invention, and it is an important part of the inventive concept of the present invention and does not constitute the prior art. Summary of the Invention

[0005] The purpose of the present invention is to provide a chemical vapor deposition equipment and its gas showerhead to solve the problem that the residual coolant in the cooling channels generates an excessive vapor pressure when heated during the in-situ cleaning process.

[0006] To achieve the above purpose, the present invention provides a cooling system for a gas showerhead. The cooling system includes a gas showerhead, a liquid supply device, a liquid storage bucket and a gas source. The gas showerhead includes cooling channels, and the liquid storage bucket includes an exhaust pipe; the liquid supply device is connected to the liquid storage bucket through a first liquid supply pipe, the liquid storage bucket is connected to the cooling channels through a second liquid supply pipe, the cooling channels are connected to the liquid supply device through a return pipe, the gas source is connected to the cooling channels through a first gas transmission pipe, and the cooling channels are connected to the liquid storage bucket through a drain pipe; the liquid supply device, the first liquid supply pipe, the liquid storage bucket, the second liquid supply pipe, the cooling channels and the return pipe constitute the circulating flow path of the coolant of the gas showerhead; the gas source, the first gas transmission pipe, the cooling channels, the drain pipe, the liquid storage bucket and the exhaust pipe constitute the flow path of the gas output by the gas source for evacuating the coolant in the cooling channels.

[0007] Optionally, the first intake pipe communicates with the second liquid supply pipe at a first connection point, and a first intake valve is provided at a position on the first intake pipe between the gas source and the first connection point.

[0008] Optionally, a second liquid supply valve is provided on the second liquid supply pipe, and the second liquid supply valve is provided between the first connection point and the liquid inlet of the second liquid supply pipe located in the liquid storage barrel.

[0009] Optionally, one end of the drain pipe communicates with the return pipe at a second connection point, and the second connection point is located between the liquid inlet and the liquid outlet of the return pipe; the other end of the drain pipe is connected to the liquid storage barrel.

[0010] Optionally, the other end of the drain pipe is located above the liquid level of the coolant in the liquid storage barrel.

[0011] Optionally, a drain valve is provided on the drain pipe.

[0012] Optionally, a return valve is provided on the return pipe between the second connection point and the liquid supply device.

[0013] Optionally, a first liquid supply valve is provided on the first liquid supply pipe.

[0014] Optionally, an exhaust valve is provided on the exhaust pipe, the intake end of the exhaust pipe is located above the liquid level of the coolant in the liquid storage barrel, the outlet end communicates with the atmosphere, and the exhaust valve is provided in the atmospheric environment.

[0015] Optionally, the gas source includes a heating device for heating the gas in the gas source.

[0016] Optionally, the gas output by the gas source is an inert gas or nitrogen.

[0017] Optionally, the pressure of the gas output by the gas source is 0.1 - 0.5 MPa.

[0018] Optionally, the cooling system further includes a second intake pipe and a second intake valve, the second intake valve is provided on the second intake pipe, the second intake pipe connects the gas source and the liquid storage barrel, and the outlet end of the second intake pipe is located in the liquid storage barrel and above the liquid level of the coolant in the liquid storage barrel.

[0019] Optionally, the intake end of the second intake pipe communicates with the first intake pipe at a third connection point, and the third connection point is located between the intake end of the first intake pipe and the first intake valve.

[0020] The present invention also provides a chemical vapor deposition apparatus, which includes a chamber wall and a cooling system of the gas showerhead as described in any one of the above, and the chamber wall and the gas showerhead form a reaction chamber of the chemical vapor deposition apparatus.

[0021] The present invention also provides a cleaning method for the chemical vapor deposition apparatus as described above, and the cleaning method includes the following steps: Step S1, stop supplying coolant to the cooling channels of the gas showerhead; Step S2, supply gas to the cooling channels to drain the coolant in the cooling channels into a liquid storage bucket; Step S3, perform in-situ cleaning on the gas showerhead; Step S4, refill the coolant in the cooling channels.

[0022] Optionally, between Step S3 and Step S4, there is also included Step S31 of supplying normal temperature gas to the cooling channels.

[0023] Optionally, a first liquid supply valve is provided on the first liquid supply pipe of the cooling system, a second liquid supply valve is provided on the second liquid supply pipe, a liquid return valve is provided on the liquid return pipe, a first air inlet valve is provided on the first air inlet pipe, a liquid discharge valve is provided on the liquid discharge pipe, and an exhaust valve is provided on the exhaust pipe; in Step S1, close the first liquid supply valve, the second liquid supply valve, and the liquid return valve.

[0024] Optionally, in Step S2, open the first air inlet valve, the liquid discharge valve, and the exhaust valve.

[0025] Optionally, in Step S2, heat the gas source.

[0026] Optionally, in Step S3, close the first air inlet valve, heat the gas showerhead, and introduce a cleaning gas into the reaction chamber.

[0027] Optionally, in Step S4, close the liquid discharge valve and the exhaust valve, and open the first liquid supply valve, the second liquid supply valve, and the liquid return valve.

[0028] Optionally, in Step S31, open the first air inlet valve.

[0029] The present invention also provides an operation method for the cooling system of the gas showerhead as described above, and the operation method includes that when the gas showerhead is in a working state and the liquid supply device fails, the gas source outputs gas into the liquid storage bucket, so that the coolant in the liquid storage bucket returns to the liquid supply device through the second liquid supply pipe, the cooling channels, and the liquid return pipe.

[0030] Optionally, a first liquid supply valve is provided on the first liquid supply pipe of the cooling system, a second liquid supply valve is provided on the second liquid supply pipe, a liquid return valve is provided on the liquid return pipe, a first air inlet valve is provided on the first air inlet pipe, a liquid discharge valve is provided on the liquid discharge pipe, and an exhaust valve is provided on the exhaust pipe. The operation method includes keeping the second air inlet valve, the second liquid supply valve, and the liquid return valve in an open state, and keeping the first liquid supply valve, the first air inlet valve, the liquid discharge valve, and the exhaust valve in a closed state.

[0031] The beneficial effects of the present invention at least include:

[0032] (1) The cooling system of the gas spray head proposed by the present invention can discharge the coolant in the cooling channel of the gas spray head into the liquid storage bucket during the in-situ cleaning process, solving the problem that the coolant generates too high a vapor pressure when heated, which may damage valves or other components; at the same time, the coolant discharged into the liquid storage bucket can be recycled in the subsequent deposition process.

[0033] (2) A liquid storage bucket is added between the gas spray head and the liquid supply device. Using the gas source to press the coolant in the cooling channel into the liquid storage bucket only needs to overcome one atmospheric pressure, and the air pressure requirement for the gas source is relatively low. By setting the second air inlet pipe, when the liquid supply device fails, the coolant in the liquid storage bucket can briefly provide coolant for the gas spray head to prevent the chemical vapor deposition equipment from malfunctioning.

[0034] (3) During the process of discharging the coolant in the cooling channel by the gas source, high-temperature gas can be provided, which is beneficial to quickly and thoroughly removing the residual coolant in the cooling channel; after the in-situ cleaning is completed, normal-temperature gas can be provided to avoid sudden increase in air pressure and sudden cooling and heating in the gas spray head. Description of the Drawings

[0035] Figure 1 It is a schematic diagram of a chemical vapor deposition equipment in the prior art;

[0036] Figure 2 It is a schematic diagram of the cooling system of the gas spray head provided in Embodiment 1;

[0037] Figure 3 It is a schematic diagram of the cooling system of the gas spray head provided in Embodiment 2;

[0038] Figure 4 It is a flow chart of the in-situ cleaning of the chemical vapor deposition equipment.

[0039] 10 - Deposition device; 100 - Gas spray head; 101 - Cooling channel; 102 - Liquid inlet; 103 - Liquid outlet; 104 - Chamber wall; 110 - Process gas supply device; 111 - Process gas supply pipeline; 120 - Liquid supply device; 121 - Liquid supply pipe; 122 - Return liquid pipe; 130 - Tray; 140 - Heater; 150 - Support shaft; 160 - Vacuum device; 20 - Cooling system; 200 - Gas spray head; 210 - Liquid supply device; 211 - First liquid supply pipe; 212 - First liquid supply valve; 213 - Liquid storage bucket; 214 - Second liquid supply pipe; 215 - Second liquid supply valve; 216 - Return liquid pipe; 217 - Return liquid valve; 220 - Gas source; 221 - First intake pipe; 222 - First intake valve; 223 - Drain pipe; 224 - Drain valve; 225 - Exhaust pipe; 226 - Exhaust valve; 227 - Second intake pipe; 228 - Second intake valve. Detailed implementation manners

[0040] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0041] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0042] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", "connected" 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; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0043] As Figure 1As shown, the chemical vapor deposition apparatus 10 includes a gas showerhead 100 and a chamber wall 104, and the gas showerhead 100 and the chamber wall 104 form a reaction chamber. The gas showerhead 100 is connected to a process gas supply device 110 through a process gas supply pipeline 111 for supplying reaction gas into the reaction chamber during the process. The reaction chamber further includes a tray 130 for placing a wafer and a heater 140 for heating the wafer. The heater 140 can be located below the tray 130 or inside the tray 130. The tray 130 is supported by at least a support shaft 150. Preferably, the support shaft 150 is connected to a rotation driving device (not shown), and the rotation driving device can drive the support shaft 150 to rotate, thereby driving the tray 130 to rotate. The chemical vapor deposition apparatus 10 further includes a vacuum device 160 for maintaining the vacuum degree in the reaction chamber.

[0044] In one example, the chemical vapor deposition apparatus 10 is used to grow tungsten metal on a substrate. The process gases are B2H6, WF6, H2, Ar, etc., and the reaction temperature is 450°C. Under these process conditions, too high a temperature will damage the gas showerhead 100. Therefore, a cooling channel 101 is provided in the gas showerhead 100. The cooling channel 101 includes a liquid inlet 102 and a liquid outlet 103. The coolant output by the liquid supply device 120 is supplied to the liquid inlet 102 through a liquid supply pipe 121, then flows in the cooling channel 101 to take away the heat of the gas showerhead 100, and then returns to the liquid supply device 120 through the liquid outlet 103 and a return pipe 122. The liquid supply device 120 provides circulating coolant for the gas showerhead 100, thereby maintaining the gas showerhead 100 at a lower temperature. The coolant can be any flowable substance capable of absorbing heat. Preferably, the coolant uses circulating cooling water, which has the advantages of low cost and high cooling efficiency.

[0045] Although not shown in Figure 1 it should be understood that the gas showerhead 100 further includes a channel for supplying the process gas from the inside of the gas showerhead 100 to the reaction chamber. In one embodiment, the gas showerhead 100 further includes a gas distribution cavity. The process gas output by the process gas supply device 110 is input into the gas distribution cavity through the process gas supply pipeline 111, and then enters the reaction chamber through a channel connecting the reaction chamber and the gas distribution cavity. The cooling channel 101 is not connected to the gas distribution cavity and the channel.

[0046] After the chemical vapor deposition equipment 10 has been operating for a period of time, deposits will inevitably form on the surface of the gas showerhead 100 exposed to the process gas atmosphere and the inner wall of the chamber. The deposits may fall on the wafer during subsequent processes, affecting the yield of the wafer. Therefore, it is necessary to regularly clean the deposits on the surface of the gas showerhead 100 and the inner wall of the chamber. In the prior art, the deposits are mainly cleaned by two methods: opening the chamber for cleaning and in-situ cleaning. Among them, in-situ cleaning means not opening the chamber and exposing the chamber to the atmospheric environment, but removing the deposits by means of high temperature and introducing a cleaning gas into the reaction chamber.

[0047] In one example, the temperature in the reaction chamber is heated to above 250°C, and a cleaning gas, such as NF3, Cl2, etc., is introduced into the reaction chamber. The cleaning gas reacts with the deposits to remove the deposits. During the cleaning process, the liquid supply device 120 stops supplying the coolant. However, the high temperature above 250°C will cause the coolant remaining in the cooling channel 101 to generate a high-temperature vapor pressure, and the excessive high-temperature vapor pressure will damage components such as valves in the cooling pipeline.

[0048] Embodiment 1

[0049] Figure 2 It is a schematic diagram of the cooling system 20 of the gas showerhead 200 proposed by the present invention. The coolant output by the liquid supply device 210 flows into the liquid storage barrel 213 through the first liquid supply pipe 211. The liquid outlet of the first liquid supply pipe 211 can be above or below the liquid level of the coolant in the liquid storage barrel 213. When the amount of coolant in the liquid storage barrel 213 reaches a certain amount, the coolant flows into the cooling channel through the second liquid supply pipe 214. Then, the coolant returns to the liquid supply device 210 through the liquid return pipe 216, so as to realize cooling the gas showerhead 200 with circulating coolant during the deposition process.

[0050] In one embodiment, a first liquid supply valve 212 is provided on the first liquid supply pipe 211 to control whether to supply coolant to the cooling channel. In other embodiments, it is also possible to control whether to supply coolant by controlling the start and stop of the liquid supply device 210 and other means.

[0051] The cooling system 20 proposed in this embodiment further includes a gas source 220 and a first intake pipe 221 connected thereto. The first intake pipe 221 communicates with the second liquid supply pipe 214 at a first connection point. A first intake valve 222 is provided at a position on the first intake pipe 221 between the gas source 220 and the first connection point. In one embodiment, the gas source 220 itself is equipped with a valve for controlling whether the gas source 220 supplies gas. A second liquid supply valve 215 is provided on the second liquid supply pipe 214, and the second liquid supply valve 215 is provided between the first connection point and the liquid inlet of the second liquid supply pipe located in the liquid storage barrel 213. The gas output by the gas source 220 can be an inert gas or nitrogen. In one embodiment, the gas source 220 includes a heating device for heating the gas in the gas source 220 to a certain temperature or above, such as 80 °C.

[0052] The cooling system 20 further includes a drain pipe 223 and an exhaust pipe 225. A drain valve 224 is provided on the drain pipe 223, and an exhaust valve 226 is provided on the exhaust pipe 225. One end of the drain pipe 223 communicates with the return pipe 216 at a second connection point, and the second connection point is located between the liquid inlet and the liquid outlet of the return pipe 216; the other end of the drain pipe 223 is connected to the liquid storage barrel 213. Preferably, the other end of the drain pipe 223 is located above the liquid level of the coolant in the liquid storage barrel 213, which is beneficial for drainage; the intake end of the exhaust pipe 225 is located above the liquid level of the coolant in the liquid storage barrel 213, and the outlet end communicates with the atmosphere, and the exhaust valve 226 is provided in the atmospheric environment. A return valve 217 is provided on the return pipe 216 between the second connection point and the liquid supply device 210.

[0053] In this embodiment, the first intake pipe 221 communicates with the second liquid supply pipe 214 at a first connection point, and one end of the drain pipe 223 communicates with the return pipe 216 at a second connection point. When draining the residual coolant in the cooling channel, the coolant in the second liquid supply pipe 214 and the return pipe 216 adjacent to the gas spray head 200 can be emptied, preventing the coolant in the adjacent pipes from being heated to form a high-temperature vapor pressure. However, it should be understood that in other embodiments, an intake pipe that does not communicate with the second liquid supply pipe and / or a drain pipe that does not communicate with the return pipe can also be used.

[0054] When the chemical vapor deposition equipment runs the film deposition process, the first liquid supply valve 212, the second liquid supply valve 215, and the return valve 217 are in the open state, and the first intake valve 222, the drain valve 224, and the exhaust valve 226 are in the closed state. The coolant provided by the liquid supply device 210 circulates through the first liquid supply pipe 211, the liquid storage barrel 213, the second liquid supply pipe 214, the cooling channel, and the return pipe 216 to cool the gas spray head 200.

[0055] Before in-situ cleaning, the first intake valve 222, the liquid discharge valve 224, and the exhaust valve 226 are in the open state, the first liquid supply valve 212, the second liquid supply valve 215, and the liquid return valve 217 are in the closed state, the supply of coolant to the cooling channel is stopped, and the gas output by the gas source 220 forces the residual coolant in the cooling channel to enter the liquid storage barrel 213 through the liquid return pipe 216 and the liquid discharge pipe 223 in sequence. The residual coolant entering the liquid storage barrel 213 can be recycled in the subsequent deposition process. Therefore, during the in-situ cleaning process, there is no residual coolant in the cooling channel, and there will be no problem of excessive vapor pressure generated by the heating of the coolant.

[0056] During the in-situ cleaning process, the liquid discharge valve 224 and the exhaust valve 226 can be in the open state, the first intake valve 222, the first liquid supply valve 212, the second liquid supply valve 215, and the liquid return valve 217 are in the closed state, and the gas heated and expanded in the cooling channel can be discharged through the liquid return pipe 216, the liquid discharge pipe 223, the liquid storage barrel 213, and the exhaust pipe 225, which can prevent the gas heated and expanded from damaging the gas spray head 200 or other components.

[0057] In one embodiment, the gas output by the gas source 220 is a high-temperature gas, which is beneficial to removing the residual coolant in the cooling channel faster and more thoroughly, and can preheat the gas spray head 200 at the same time, so that it can reach the temperature required for the cleaning process faster.

[0058] The pressure at the liquid supply device 210 is 0.3 - 0.6 MPa. If the coolant in the cooling channel is directly pressed into the liquid supply device by the gas source 220, the pressure at the liquid supply device 210 needs to be overcome, so the air pressure requirement for the gas source 220 is relatively high. In the present invention, a liquid storage barrel 213 is added between the gas spray head 200 and the liquid supply device 210, and when the gas output by the gas source 220 is used to discharge the coolant in the cooling channel, the exhaust valve 226 is in the open state, that is, the area above the liquid level of the coolant in the liquid storage barrel 213 is communicated with the atmosphere, and the pressure in this area is one atmospheric pressure. Therefore, using the gas source 220 to press the coolant in the cooling channel into the liquid storage barrel 213 basically only needs to overcome one atmospheric pressure, and the air pressure requirement for the gas source 220 is relatively low. When the air pressure of the gas output by the gas source 220 is too high, it may damage the electronic components (such as flow meters) in the pipeline. Optionally, the pressure of the gas output by the gas source 220 is 0.1 - 0.5 MPa.

[0059] The cooling system 20 of the gas spray head 200 provided in the first embodiment can be applied to the Figure 1 chemical vapor deposition equipment 10 as shown. The components of the chemical vapor deposition equipment and their connection methods will not be elaborated here.

[0060] Embodiment Two

[0061] Figure 3 FIG. Figure 3 is a schematic diagram of another cooling system 30 for the gas showerhead 200 proposed by the present invention. The difference from the first embodiment is that in this embodiment, the cooling system 30 further includes a second intake pipe 227 and a second intake valve 228, and the second intake valve is disposed on the second intake pipe 227. The intake end of the second intake pipe 227 communicates with the first intake pipe 221 at a third connection point, and the third connection point is located between the intake end of the first intake pipe 221 and the first intake valve 222; the outlet end of the second intake pipe 227 is connected to the liquid storage barrel 213 and is located above the liquid level of the coolant in the liquid storage barrel 213.

[0062] In the thin film deposition process, the liquid supply device 210 may malfunction and cannot provide circulating coolant for the gas showerhead 200, resulting in an excessively high temperature of the gas showerhead 200. At this time, the states of the valves are adjusted such that the second intake valve 228, the second liquid supply valve 215, and the liquid return valve 217 are in an open state, and the first liquid supply valve 212, the first intake valve 222, the liquid discharge valve 224, and the exhaust valve 226 are in a closed state. The gas source 220 outputs gas into the liquid storage barrel 213 to increase the air pressure above the liquid level of the coolant, thereby forcing the coolant in the liquid storage barrel 213 to return to the liquid supply device 210 through the second liquid supply pipe 214, the cooling channel, and the liquid return pipe 216, briefly providing coolant for the gas showerhead 200. When the liquid supply device 210 malfunctions, the pressure at the liquid supply device 210 is close to one atmosphere. Therefore, the air pressure requirement for the gas source 220 is relatively low.

[0063] The cooling system 20 for the gas showerhead 200 provided in the second embodiment can be applied to, for example, Figure 1 the chemical vapor deposition apparatus 10 shown in FIG. The components and connection manners of the chemical vapor deposition apparatus are not described herein again.

[0064] As shown in Figure 4 FIG., the present invention also provides a cleaning method for a chemical vapor deposition apparatus having the cooling system 20 for the gas showerhead 200 provided in the first or second embodiment.

[0065] Step S1: Stop supplying coolant to the cooling channel. Specifically, close the first liquid supply valve 212, the second liquid supply valve 215, and the liquid return valve 217. In one embodiment, the liquid supply device 210 may be closed simultaneously.

[0066] Step S2: Supply gas to the cooling channel to drain the coolant in the cooling channel into the liquid storage barrel 213. Specifically, open the first intake valve 222, the liquid discharge valve 224, and the exhaust valve 226, and the gas output by the gas source 220 forces the remaining coolant in the cooling channel to enter the liquid storage barrel 213 through the liquid return pipe 216 and the liquid discharge pipe 223 in sequence.

[0067] Optionally, step S2 further includes heating the gas source 220 so that the gas output from the gas source 220 is high-temperature gas, which is beneficial to more quickly and thoroughly remove the residual coolant in the cooling channel, and at the same time can pre-heat the gas spray head 200 so that it can reach the temperature required for the cleaning step more quickly.

[0068] Step S3, perform in-situ cleaning on the gas spray head 200. Specifically, close the first intake valve 222, heat the temperature of the gas spray head 200 to above 250 °C, and introduce a cleaning gas, such as NF3, Cl2, etc., into the reaction chamber through the process gas supply device 110. The cleaning gas reacts with the deposits to remove the deposits on the gas spray head 200. The drain valve 224 and the exhaust valve 226 are maintained in the open state, and the gas expanded by heat in the cooling channel can be discharged to prevent the gas spray head 200 or other components from being damaged by the heat-expanded gas.

[0069] Step S4, refill the coolant in the cooling channel. Specifically, after the in-situ cleaning step is completed, close the drain valve 224 and the exhaust valve 226, open the first liquid supply valve 212, the second liquid supply valve 215 and the return liquid valve 217, and the coolant provided by the liquid supply device 210 circulates through the first liquid supply pipe 211, the liquid storage barrel 213, the second liquid supply pipe 214, the cooling channel and the return liquid pipe 216 to refill the coolant in the cooling channel.

[0070] Optionally, between steps S3 and S4, there is also step S31 of supplying normal-temperature gas to the cooling channel to cool down the gas spray head 200. Specifically, open the first intake valve 222 and supply normal-temperature gas to the cooling channel to cool down the gas spray head 200. When the gas spray head 200 is in a high-temperature state, sudden filling of coolant will produce high-temperature vapor, resulting in a sudden increase in the air pressure in the cooling channel, damaging the gas spray head 200 or other components; in addition, filling coolant into the high-temperature gas spray head 200 will cause too large an instantaneous temperature difference in the gas spray head 200, causing damage to the gas spray head 200 or other components.

[0071] When the gas spray head 200 is in the working state (i.e., in the thin film deposition process) and the liquid supply device 210 fails, at this time the first liquid supply valve 212, the second liquid supply valve 215 and the return liquid valve 217 are in the open state, and the operation method of the cooling system further includes opening the second intake valve 228 and closing the first liquid supply valve 212. The gas source 220 outputs gas into the liquid storage barrel 213, forcing the coolant in the liquid storage barrel 213 to return to the liquid supply device 210 through the second liquid supply pipe 214, the cooling channel and the return liquid pipe 216. This step can be used to deal with emergencies and provide coolant for the gas spray head 200 in a short time to prevent the chemical vapor deposition equipment from malfunctioning.

[0072] In summary, for the cooling system of the gas showerhead proposed by the present invention, during the in-situ cleaning process, the coolant in the cooling channels of the gas showerhead can be discharged into the liquid storage bucket, solving the problem that the coolant generates too high a vapor pressure when heated, which may damage valves or other components; at the same time, the coolant discharged into the liquid storage bucket can be recycled in the subsequent deposition process. A liquid storage bucket is added between the gas showerhead and the liquid supply device. Using the gas source to press the coolant in the cooling channels into the liquid storage bucket only needs to overcome one atmospheric pressure basically, and the air pressure requirement for the gas source is relatively low. By setting the second intake pipe, when the liquid supply device fails, the coolant in the liquid storage bucket can temporarily provide coolant for the gas showerhead, preventing the chemical vapor deposition equipment from malfunctioning. During the process of discharging the coolant in the cooling channels, the gas source can provide high-temperature gas, which is beneficial to quickly and thoroughly remove the residual coolant in the cooling channels; after the in-situ cleaning is completed, normal-temperature gas can be provided to avoid sudden increase in air pressure and sudden cooling and heating in the gas showerhead.

[0073] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be construed as a limitation of the present invention. After those skilled in the art have read the above content, various modifications and substitutions of the present invention will be obvious. Therefore, the protection scope of the present invention should be defined by the appended claims.

Claims

1. A cooling system for a gas spray head, characterized in that, The cooling system includes a gas spray head, a liquid supply device, a liquid storage barrel, and a gas source. The gas spray head includes a cooling channel, and the liquid storage barrel includes an exhaust pipe; The liquid supply device is connected to the liquid storage barrel via a first liquid supply pipe. The liquid storage barrel is connected to the cooling channel via a second liquid supply pipe. The cooling channel is connected to the liquid supply device via a return pipe. The gas source is connected to the cooling channel via a first gas transmission pipe. The cooling channel is connected to the liquid storage barrel via a drain pipe; The liquid supply device, the first liquid supply pipe, the liquid storage barrel, the second liquid supply pipe, the cooling channel, and the return pipe form a circulating flow path for the coolant of the gas spray head; the gas source, the first gas transmission pipe, the cooling channel, the drain pipe, the liquid storage barrel, and the exhaust pipe form a flow path for the gas output by the gas source to empty the coolant in the cooling channel.

2. The cooling system of the gas shower head according to claim 1, characterized in that, The first intake pipe communicates with the second liquid supply pipe at a first connection point. A first intake valve is provided at a position on the first intake pipe between the gas source and the first connection point.

3. The cooling system of the gas shower head according to claim 2, characterized in that, A second liquid supply valve is provided on the second liquid supply pipe. The second liquid supply valve is provided between the first connection point and the liquid inlet of the second liquid supply pipe located in the liquid storage barrel.

4. The cooling system of the gas showerhead according to claim 3, characterized in that, One end of the drain pipe communicates with the return pipe at a second connection point. The second connection point is located between the liquid inlet and the liquid outlet of the return pipe; the other end of the drain pipe is connected to the liquid storage barrel.

5. The cooling system of the gas showerhead according to claim 4, characterized in that, The other end of the drain pipe is located above the liquid level of the coolant in the liquid storage barrel.

6. The cooling system of the gas shower head according to claim 4, characterized in that, A drain valve is provided on the drain pipe.

7. The cooling system of the gas showerhead according to claim 6, characterized in that, A return valve is provided on the return pipe between the second connection point and the liquid supply device.

8. The cooling system of the gas shower head according to claim 1, characterized in that, A first liquid supply valve is provided on the first liquid supply pipe.

9. The cooling system of the gas showerhead according to claim 1, characterized in that, An exhaust valve is provided on the exhaust pipe. The intake end of the exhaust pipe is located above the liquid level of the coolant in the liquid storage barrel, and the outlet end communicates with the atmosphere. The exhaust valve is provided in the atmospheric environment.

10. The cooling system of the gas shower head according to claim 1, characterized in that, The gas source includes a heating device for heating the gas in the gas source.

11. The cooling system of the gas shower head according to claim 1, characterized in that, The gas output by the gas source is an inert gas or nitrogen.

12. The cooling system of the gas showerhead according to claim 1, characterized in that, The pressure of the gas output by the gas source is 0.1 - 0.5 MPa.

13. The cooling system of the gas showerhead according to any one of claims 2-12, characterized in that, The cooling system further includes a second intake pipe and a second intake valve. The second intake valve is provided on the second intake pipe. The second intake pipe connects the gas source and the liquid storage barrel. The outlet end of the second intake pipe is located in the liquid storage barrel and above the liquid level of the coolant in the liquid storage barrel.

14. The cooling system of the gas showerhead according to claim 13, characterized in that, The intake end of the second intake pipe communicates with the first intake pipe at a third connection point. The third connection point is located between the intake end of the first intake pipe and the first intake valve.

15. A chemical vapor deposition device, characterized in that, The chemical vapor deposition device includes a chamber wall and a cooling system of the gas spray head as described in any one of claims 1 - 14. The chamber wall and the gas spray head form a reaction chamber of the chemical vapor deposition device.

16. A cleaning method for a chemical vapor deposition device as described in claim 15, characterized in that, The cleaning method includes the following steps: Step S1: Stop supplying coolant to the cooling channel of the gas spray head; Step S2: Supply gas to the cooling channel to drain the coolant in the cooling channel into the liquid storage barrel; Step S3: Perform in-situ cleaning on the gas spray head; Step S4: Refill the cooling channel with coolant.

17. The cleaning method of the chemical vapor deposition equipment according to claim 16, characterized in that, Between steps S3 and S4, there is also step S31 of supplying normal temperature gas to the cooling channel.

18. The cleaning method of the chemical vapor deposition equipment according to claim 16 or 17, characterized in that, A first liquid supply valve is provided on the first liquid supply pipe of the cooling system, a second liquid supply valve is provided on the second liquid supply pipe, a liquid return valve is provided on the liquid return pipe, a first air inlet valve is provided on the first air inlet pipe, a liquid discharge valve is provided on the liquid discharge pipe, and an exhaust valve is provided on the exhaust pipe; in step S1, the first liquid supply valve, the second liquid supply valve and the liquid return valve are closed.

19. The cleaning method of the chemical vapor deposition equipment according to claim 18, characterized in that, In step S2, the first air inlet valve, the liquid discharge valve and the exhaust valve are opened.

20. The cleaning method of the chemical vapor deposition equipment according to claim 19, characterized in that, In step S2, the gas source is heated.

21. The cleaning method of the chemical vapor deposition equipment according to claim 19 or 20, characterized in that, In step S3, the first air inlet valve is closed, the gas spray head is heated, and a cleaning gas is introduced into the reaction chamber.

22. The cleaning method of the chemical vapor deposition equipment according to claim 21, wherein, In step S4, the liquid discharge valve and the exhaust valve are closed, and the first liquid supply valve, the second liquid supply valve and the liquid return valve are opened.

23. The cleaning method of the chemical vapor deposition equipment according to claim 18, characterized in that, In step S31, the first air inlet valve is opened.

24. A method for operating a cooling system of a gas shower head according to any one of claims 13-14, characterized in that, The operation method includes that when the gas spray head is in a working state and the liquid supply device fails, the gas source outputs gas to the liquid storage bucket, so that the coolant in the liquid storage bucket returns to the liquid supply device through the second liquid supply pipe, the cooling channel and the liquid return pipe.

25. The operating method according to claim 24, wherein A first liquid supply valve is provided on the first liquid supply pipe of the cooling system, a second liquid supply valve is provided on the second liquid supply pipe, a liquid return valve is provided on the liquid return pipe, a first air inlet valve is provided on the first air inlet pipe, a liquid discharge valve is provided on the liquid discharge pipe, and an exhaust valve is provided on the exhaust pipe. The operation method includes keeping the second air inlet valve, the second liquid supply valve and the liquid return valve in an open state, and keeping the first liquid supply valve, the first air inlet valve, the liquid discharge valve and the exhaust valve in a closed state.

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