TW201907052A - Apparatus and Method of Atomic Layer Deposition Having A Recycle Module - Google Patents

Abstract

The present invention provides an apparatus and method of atomic layer deposition having a recycling module. The apparatus mainly comprises a gas delivering module used for providing a least a gas; a reaction chamber, having an outlet line and a number of intake lines, used for receiving the gas from the gas delivering module; a vacuum pump, connected to the reaction chamber with the chamber outlet line, having an outlet line, used for withdrawing an unreacted gas and an by-product from the reaction chamber; and a gas recovery module, connected with the outlet line of the vacuum pump, used for separating effectively the unreacted gas and the by-product from the reaction chamber. By using the recycling module of the present invention, the atomic layer deposition apparatus can effectively recycle the precursor, thus reducing the environmental pollution.

Description

 Atomic layer coating system and method with recycling module  

The present invention relates to a coating apparatus and method, and more particularly to an atomic layer coating system having a recycling module, which can efficiently recover unreacted precursors and reduce environmental pollution of exhaust gas.

Atomic layer deposition technology uses the process gas to chemically adsorb the surface of the material. Since the reaction only reacts on the surface, it has self-limited characteristics, so that each time the growth cycle, only a layer of atomic film is formed on the surface. It can control the film thickness to the atomic level (0.1 nm), which is the coating technology for the highest quality film in all existing coating methods.

Atomic layer deposition technology can be used for ultra-thin high-k material coating, and can also provide hole filling capability for small circuit structures in dynamic random access memory (Dynamic Random Access Memory) with high aspect ratio. DRAM) provides a uniform thickness coating in the capacitor structure and MEMS components; on the component package, the atomic layer deposition technique with high density is gradually introduced into the package of the Organic Light-Emitting Diode (OLED) component. A conventional atomic layer coating system has a precursor transport module for providing a precursor vapor pressure to the process chamber.

The typical atomic layer coating film formation mechanism is roughly divided into four steps:

Step 1: In a time zone T1, the precursor A is injected and adsorbed on the surface of the substrate, and the injected precursor and the surface of the substrate react. This reaction is self-limiting and the excess precursor is no longer adsorbed onto the adsorbed precursor molecules.

Step 2: In the T2 zone, the excess unreacted precursor A and the by-products after the reaction are removed. In this step, unreacted precursors and by-products are pumped away from the reaction chamber by means of an inert gas or a low-reaction gas such as argon or nitrogen.

Step 3: In a time zone T3, the reactant B is injected and adsorbed on the surface of the substrate to form a newly bonded compound.

Step 4: In the T4 zone, the excess unreacted reactant B and the by-products after the reaction are removed. This step is also carried out by pumping unreacted precursors and by-products through the vacuum pump by means of an inert gas or a low-reaction gas such as argon or nitrogen.

Figure 1 is a schematic diagram of a prior art atomic layer coating system. The atomic layer coating system 100 includes a reaction chamber 110, a gas delivery module 120, a vacuum pump 130, and an exhaust gas treatment module 140. The reaction chamber 110 receives gas from the gas delivery module 120; the vacuum pump 130 is used to extract unreacted gases and by-products from the reaction chamber 110; and the exhaust treatment module 140 is used to process the reaction Unreacted gases and by-products of the chamber 110. The gas transfer module 120 mainly includes a cylinder 121a and a cylinder 121b, and an intake line 122a and an intake line 122b. The switching element cylinder 121a transfers the vapor of the precursor A into the reaction chamber 110 through the inlet line 122a; the cylinder 121b transfers the vapor of the reactant B into the reaction chamber 110 by the inlet line 122b. The reactant B switching element 124 can introduce the vapor of the precursor A or the vapor of the reactant B into the intake line 126 into the reaction chamber 110 at an appropriate time. The gas outlet line 112 of the reaction chamber 110 is connected to the reaction chamber 110 and the vacuum pump 130, and has a switching element 124 that can cooperate with the pumping function of the vacuum pump 130. The outlet pipe 132 of the vacuum pump 130 is connected to the vacuum pump 130 and the exhaust gas treatment module 140, and has a switching element 134, which can cooperate with the pumping function of the vacuum pump 130 to allow unreacted gas and by-products to arrive. The exhaust gas treatment module 140 is processed and discharged by the exhaust line 142. The exhaust gas treatment module 140 is typically treated by burning unreacted gases and by-products and discharging them. However, the typical atomic layer coating film formation mechanism in the first step of the precursor injected, the ratio of reaction with the surface of the substrate is usually less than 1%, and the remaining precursors and by-products are pumped away by the vacuum pump 130. After being burned and discharged into the atmosphere, in addition to causing pollution, the precursor is also lost.

In order to solve the above problems, it is desirable to provide an atomic layer coating system to overcome the disadvantages of the prior art.

The main object of the present invention is to provide an atomic layer coating system with a recycling module and an atomic layer coating method with a recycling module, which can effectively recover unreacted precursors and reduce environmental pollution of waste gas.

In order to achieve the primary object of the present invention, the present invention provides an atomic layer coating system comprising a gas delivery module; a reaction chamber; a vacuum pump; and a gas processing module.

The gas delivery module provides at least one gas; the reaction chamber has a plurality of intake lines and an outlet line for receiving the gases from a gas delivery module; the vacuum pump is connected to the reaction chamber The gas outlet pipe has an gas outlet pipe for extracting unreacted gas and by-products from the reaction chamber; and the gas processing module is connected to the gas outlet pipe of the vacuum pump Unreacted gases and by-products that effectively separate the reaction chamber.

The gas processing module comprises: a switching element; a recovery device and an exhaust gas treatment device. The switching element is connected to a first path line and a second path line; the recovery device is connected to the first path line for unreacted gas and by-products of the received reaction chamber Performing a recycling process; the exhaust gas treatment device is connected to the second path line for discharging the unreacted gas and by-products of the reaction chamber received and decomposing.

According to a feature of the invention, the recovery device has a cooling replenishing element and a collection container for condensing and collecting the unreacted gas received to condense into a liquid or a solid.

According to a feature of the invention, the recovery device has a function of adjusting the temperature, and can control the condensation of the unreacted gas of the reaction chamber received into the liquid or the solid to discharge the by-products received. .

In order to achieve the object of the present invention, the present invention provides a gas recovery method for atomic layer coating, comprising the following steps: Step 1: receiving at least one gas from a gas delivery module in a reaction chamber; Step 2: extracting the unreacted gas and by-products of the reaction chamber using a vacuum pump; and Step 3: treating the unreacted gas and by-products of the reaction chamber using a gas processing module.

In the third step, the following steps are included: at a first time, the unreacted gas and by-products of the reaction chamber received are first introduced into the gas processing module by a switching element. a path line; at a second time, the unreacted gas and by-products of the reaction chamber received are introduced into a second path of the gas processing module by the switching element.

According to a feature of the invention, the first path line is connected to a recovery device having a cooling replenishing element for recycling the unreacted gas and by-products of the reaction chamber received. deal with.

According to a feature of the invention, the second path line is connected to an exhaust gas treatment device for decomposing the unreacted gas and by-products of the reaction chamber received.

The atomic layer coating system with the recycling module of the invention has the following effects:

1. The unreacted precursor is efficiently recovered to improve the efficiency of use of the precursor.

2. Effectively recover unreacted precursors and reduce environmental pollution of waste gas.

In order to make the objects, features and advantages of the present invention more comprehensible, the following detailed description of the preferred embodiments and the accompanying drawings.

100‧‧‧Atomic layer coating system

110‧‧‧Reaction chamber

120‧‧‧ gas transmission module

122a‧‧‧Intake line

122b‧‧‧Intake line

124‧‧‧Switching components

124‧‧‧Intake line

130‧‧‧vacuum pump

132‧‧‧Exhaust line

134‧‧‧Switching components

140‧‧‧Exhaust gas treatment module

142‧‧‧Exhaust line

200‧‧‧Atomic Coating System

210‧‧‧Reaction chamber

212‧‧‧Exhaust line

220‧‧‧ gas transmission module

222a‧‧‧Intake line

222b‧‧‧Intake line

224‧‧‧Switching components

230‧‧‧vacuum pump

232‧‧‧Exhaust line

235‧‧‧Switching components

236‧‧‧First path pipeline

238‧‧‧Second path pipeline

240‧‧‧Gas Handling Module

250‧‧‧Recycling device

252‧‧‧Cooling and retrieving components

256‧‧‧ bottom collection end

254‧‧‧Exhaust line

258‧‧‧Collection container

260‧‧‧Exhaust pump

262‧‧‧Exhaust line

270‧‧‧Exhaust gas treatment device

272‧‧‧Exhaust line

The above and other objects, features, and advantages of the present invention will become more apparent and understood. While the invention may be embodied in various forms, the embodiments illustrated in the drawings It is not intended to limit the invention to the particular embodiments illustrated and/or described.

Figure 1: Schematic diagram of a prior art atomic layer coating system.

Fig. 2 is a schematic view showing the implementation of the atomic layer coating system with the recycling module of the present invention.

Fig. 3 is a schematic view showing the implementation of the recovery apparatus to which the present invention is applied.

Fig. 4 is a flow chart showing the implementation of a gas recovery method using the atomic layer coating system of the present invention.

The invention will be more fully understood from the following detailed description of the drawings. Certain illustrative embodiments are now described to provide a comprehensive understanding of the structure, function, One or more embodiments of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will recognize that the devices and methods that are specifically described and illustrated in the drawings are non-limiting exemplary embodiments, and the scope of the invention is defined only by the scope of the claims. Features illustrated or described in connection with an exemplary embodiment may be combined with features of other embodiments. Such modifications and variations are intended to be included within the scope of the invention.

The present invention may be embodied in a different form of embodiment, and the following description of the invention is intended to be a preferred embodiment of the invention. It is not intended to limit the invention to the particular embodiments illustrated and/or described.

Referring now to Figure 2, there is shown a schematic diagram of an atomic layer coating system to which the recycling module of the present invention is applied. An atomic layer coating system 200 according to the present invention includes a reaction chamber 210; a vacuum pump 230; and a gas processing module 240.

The gas delivery module 210 provides at least one gas, particularly a precursor gas. The gas delivery module 120 mainly includes a cylinder 221a and a cylinder 221b, and an intake line 222a and an intake line 222b. The cylinder 221a transfers vapor of a precursor into the reaction chamber 210 through the inlet line 222a; the cylinder 221b transfers vapor of the other precursor into the reaction chamber 210 by the inlet line 222b. A switching element 224 can introduce vapors of different precursors into the reaction chamber 210 at appropriate times.

The reaction chamber 210 has a plurality of intake lines 226 and an outlet line 212 for receiving gas from the gas transfer module 220; and the outer surface of the reaction chamber 210 is grounded. The vapor of the precursor enters the reaction chamber 210 and is adsorbed on the surface of a substrate, and the injected precursor reacts with the surface of the substrate. This reaction is self-limiting and the excess precursor is no longer adsorbed onto the adsorbed precursor molecules. In the figure, a plurality of intake lines are indicated by intake line 226, but in fact, the reaction chamber 210 can be connected to a plurality of intake lines at the same time. In more detail, the intake line 122a represents one of the conduits through which the precursor A enters the reaction chamber 210 via the intake line 226, and the intake line 122b represents the reactant B entering the passage via the intake line 226. One of the conduits of the reaction chamber 210.

In the present invention, the reaction chambers 210 are all formed by processing carbon steel, stainless steel, titanium, titanium alloy, aluminum or aluminum alloy. The inner and outer layers of the reaction chamber 210 may also be plated with a low activity metal such as gold or coated with a coating of nano material to prevent the precursor from corroding the cavity or the external environment compound from damaging the reaction chamber 210.

The vacuum pump 230 is connected to the gas outlet pipe 212 of the reaction chamber 210 and has an gas outlet pipe 232 for extracting unreacted gas and by-products from the reaction chamber 210. The vacuum pump 230 can be implemented using a conventional vacuum pump. The vacuum pump 230 is used to extract the gas in the reaction chamber 210 by the control of the control element 214 during the process, so that the pressure inside the reaction chamber 210 is between 0.5-760 Torr. .

The gas processing module 240 is connected to the gas outlet pipe 232 of the vacuum pump 230 for treating unreacted gases and by-products of the reaction chamber 210. The gas processing module 300 includes: a switching element 235; a recovery device 250 and an exhaust gas treatment device 260. The switching element 235 is connected to a first path line 236 and a second path line 238. The recovery device 250 is connected to the first path line 236 and has a cooling replenishing member 252 for recycling the unreacted gas and by-products of the reaction chamber 210 received; The device 240 is connected to the second path line 236 for decomposing the unreacted gas and by-products of the reaction chamber 210 received and discharging.

In the present invention, the recovery device 250 is formed by processing carbon steel, stainless steel or titanium, or aluminum alloy. The inner and outer layers of the recovery device 250 may also be plated with a low-activity metal such as gold, or may be galvanized on the outer layer or may have a nano-coating on the inner and outer layers to prevent the precursor from corroding the cavity or the external environmental compound from damaging the recovery device 250. The cooling replenishing element 252 is formed by processing carbon steel, stainless steel, titanium, titanium alloy, aluminum or aluminum alloy. The inner and outer layers of the cooling and retrieving element 252 may also be plated with a low activity metal such as gold or coated with a coating of nano material to prevent the precursor from corroding the cavity or the external environment compound from damaging the cooling replenishing element 252.

Referring now to Figure 3, a schematic diagram of a recovery apparatus to which the present invention is applied is further illustrated. The recycling module 250 mainly includes a cooling and replenishing component 252 and a collection container 258. The cooling replenishing element 252 condenses the unreacted gas of the reaction chamber 210 received into a liquid or a solid. The collection vessel 258 is used to collect the condensation into the liquid or solid. The recovery unit 250 has a function of adjusting the temperature, and can control the unreacted gas of the received reaction chamber 210 to be condensed into the liquid or solid to discharge the by-products received. The recovery device 250 further includes an outlet line 254 connected to an evacuation pump 270 for receiving by-products of the reaction chamber 210 and being discharged by an exhaust line 272.

The cooling replenishing element 252 is a condensing element and is a device that can condense a gaseous substance into a liquid state, such as a heat exchanger. The cooling replenishing element 252 condenses the substance by means of cooling, and the substance releases latent heat during the coagulation process, so that the temperature of the refrigerant of the condensing element rises. The structure of the cooling replenishing element 252 can be a mesh such that the condensed liquid or solid can enter the bottom collection end 256 of the recovery unit 250 and be removed after entering the collection container 258. Preferably, the collection container 258 is of a circular configuration, that is, the bottom collection end 256 is preferably in the shape of a circle. The collection container 258 is separable from the recovery module 250. When the collection container 258 collects the liquid or solid condensed by the unreacted gas to a certain amount, the collection container 258 can be removed, and the continuously condensed liquid or solid can enter the bottom of the recovery device 250 to collect. End 256.

It should be noted that the recovery device 250 of the present invention has a function of adjusting the temperature. The set temperature of the recovery unit 250 is primarily designed to allow the received unreacted gas to be condensed into a liquid or solid by the cooling replenishing element 252 of the recovery unit 250, leaving the byproducts non-condensing. The liquid or solid continues to be exhausted by the pumping pump 270 through the outlet line 272. Therefore, it can also be said that the function of the recovery device 250 to adjust the temperature is mainly to control the temperature of the cooling and replenishing member 252.

In one embodiment, the temperature of the recovery device 250 is set between 10 and 50 degrees Celsius. In the most common alumina (Al ₂ O ₃ ) process, the reaction chamber 210 has a process temperature of between 140 and 350 degrees, and the trimethylaluminum (Al(CH ₃ ) ₃ , TMA) to be condensed and recovered. The boiling point at normal temperature and pressure is 125 degrees. Therefore, when the temperature of the recovery device 250 is set between 10 and 50 degrees Celsius, the trimethyl aluminum can be condensed into a liquid state, but its by-product methyl group ( CH ₄ ) is still in a gaseous state.

In the present invention, the exhaust gas treatment device 260 can have many embodiments. A typical commercial method is a device that uses a liquid to clean a gas stream, or a wet collector or a wet scrubber, including : cyclone scrubber, fume scrubber, ionizing scrubber, mechanical scrubber, orifice scrubber, packed tower A packed tower, a plate scrubber, a spray chamber, a venturi scrubber, a wet filter, and the like. The scrubber is suitable for handling high temperature, flammable and explosive gases. The exhaust gas treatment device 260 brings the gas stream into close contact with the liquid, and the contaminants such as particles, vapors or gases in the gas stream are thus separated from the exhaust gas. The scrubber wets the contaminant particles in a variety of ways and then impacts the wetted or unwetted particles onto the collection surface, followed by rinsing the liquid to remove the collected particles. In addition to physical effects, chemical reactions (such as absorption, dissolution, reaction with additives, etc.) may occur during scouring removal.

The plurality of intake and exhaust lines of the present invention include a plurality of intake lines 122a, 122b of the gas transfer module 210, an intake line 226 of the reaction chamber 210, and a reaction chamber 210. An outlet line 212, the outlet line 232 of the vacuum pump 230, the first path line 238 of the gas processing module 300, and the second path line 236, etc., due to the use of the pipelines The vapor of the material, especially affected by the cooling of the surrounding environment, is likely to form gas residuals and accumulation in the pipeline at a low temperature point of the pipeline. As the accumulation increases, problems such as condensation of the precursor into a liquid or formation of solid particles of the precursor are generated. Therefore, the heating package or the heating protective sleeve is wound on the outside of the above-mentioned pipeline, and each pipeline is heated to maintain the state of the precursor gas in the pipeline to prevent the precursor gas from condensing into a liquid in the intake pipeline and the outlet pipeline. Or forming solid particles of the precursor, on the one hand, avoiding further entry of the particles into the reaction chamber 210, causing film defects, on the one hand, prolonging the service life of the pipeline, and allowing the gas to smoothly recover the higher purity precursor gas in the pipeline.

In addition, there are usually some switching elements on the pipeline. For example, switching element 124, switching element 214, switching element 235, and the like. The basic functions of the switching elements are a valve or a mass flow controller (MFC). The valve can be actuated manually or automatically, by controlling the pressure, temperature, electromagnetic field and flow changes of the fluid medium to activate the valve. The valve can perform continuous or repeated operations on these changes. Preferably, in the present embodiment, an automatic control valve, particularly a valve that can be quickly switched, is used to enable the valve to accurately control the requirements of the fluid medium.

Referring now to Figure 4, there is shown a gas recovery method for the atomic layer coating system of the present invention. The method is an implementation flow chart of an atomic layer coating system with a recycling module of the present invention. That is, the method uses the systems of FIGS. 2 and 3, and therefore all components will not be described herein. The gas recovery method for atomic layer coating of the present invention comprises the following steps: Step 1: receiving at least one gas from a gas transfer module 220 in a reaction chamber 210; Step 2: using a vacuum pump 230 The unreacted gas and by-products of the reaction chamber 210 are withdrawn; and the third step: treating the unreacted gas and by-products of the reaction chamber 210 with a gas treatment module 240; wherein the following steps are included in the third step: In a first time, through the switching element 235, the unreacted gas and by-products of the reaction chamber 210 are introduced into the first path line 236 of the gas processing module 240; In a second time, the unreacted gas and by-products of the reaction chamber 210 received are introduced into the second path line 238 of the gas processing module 240 by the switching element 235.

The first path line 236 is connected to a recovery device 250 having a cooling replenishing element 252 for recycling the unreacted gas and by-products of the reaction chamber received. The second path line 238 is connected to an exhaust gas treatment device 260 for decomposing the unreacted gas and by-products of the reaction chamber 210 received.

As described in the prior art, a typical atomic layer coating film formation mechanism is roughly divided into four steps:

Step 1: In a time zone T1, the precursor A is injected and adsorbed on the surface of the substrate, and the injected precursor and the surface of the substrate react. This reaction is self-limiting and the excess precursor is no longer adsorbed onto the adsorbed precursor molecules.

Step 2: In the T2 zone, the excess unreacted precursor A and the by-products after the reaction are removed. In this step, unreacted precursors and by-products are pumped away from the reaction chamber by means of an inert gas or a low-reaction gas such as argon or nitrogen.

Step 3: In a time zone T3, the reactant B is injected and adsorbed on the surface of the substrate to form a newly bonded compound.

Step 4: In the T4 zone, the excess unreacted reactant B and the by-products after the reaction are removed. This step is also carried out by pumping unreacted precursors and by-products through the vacuum pump by means of an inert gas or a low-reaction gas such as argon or nitrogen.

Usually, the four steps are completed in one cycle, and each cycle completes film formation with a thickness close to one atomic level. To increase the thickness of the film, it is necessary to continue the cycle of the above four steps.

In the gas recovery method for atomic layer coating of the present invention, the first time is between the reference time zone T1 and less than or equal to the sum of the time zone T1 and the time zone T2. That is, the setting of the first time includes at least the time T1 of the first step, but at most the sum of the time T1 of the first step and the time T2 of the second step. That is, during the first time, the unreacted gas and by-products of the reaction chamber 210 received are introduced into the first path tube of the gas processing module 240 by a switching element 235. Road 236 is sent to the recovery unit 250 for further recovery. For example, if the time T1 zone is 1 second and the time T2 zone is 2 seconds, the first time setting is less than 1 second (T1 time), but less than 3 seconds (the sum of T1 and T2).

The second time period includes at least the sum of the time T3 zone and the time T4 zone of the typical atomic layer coating film formation mechanism, but less than the sum of the time T2 to the time T4 zone. During the second time, the unreacted gas and by-products of the reaction chamber 210 received are introduced into the second path line 238 of the gas processing module 240 by the switching element 235. It is sent to the exhaust gas treatment device 260 for further processing. For example, if the T1 area is 1 second, the time T2 area is 2 seconds, the time T3 area is 4 seconds, and the time T2 is 2 seconds, the second time setting is greater than 6 seconds (the sum of T3 and T4), but less In 8 seconds (T2, T3 and T4 total).

In one embodiment, the reaction chamber 210 is preferably a cavity for a plasma process having a plasma impedance. And the frequency of the plasma is between 10 and 150 MHz. Preferably, the frequency of the plasma is 40.68 MHz. Due to the chemical nature of atomic layer coating growth, not all materials are suitable for growth with atomic layer coating. Since the plasma excites to form many free radicals, its free radicals can help bond the film and form a reaction surface that is favorable for the next reaction, so it can grow at a lower process temperature. Therefore, the reaction is not limited by insufficient heat. Therefore, the plasma can provide free radicals to increase its reactivity, and the growth reaction is more complete at low temperatures. Therefore, by means of the plasma-assisted method, it is possible to grow a thin film material which cannot be grown by a conventional heated atomic layer coating.

The atomic layer coating system with the recycling module of the invention has the following effects:

1. The unreacted precursor is efficiently recovered to improve the efficiency of use of the precursor.

2. Effectively recover unreacted precursors and reduce environmental pollution of waste gas.

While the present invention has been described in its preferred embodiments, it is not intended to limit the scope of the invention, and various modifications and changes can be made without departing from the spirit and scope of the invention. As explained above, various modifications and variations can be made without departing from the spirit of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

Claims (14)

 An atomic layer coating system comprising: a gas delivery module providing at least one gas; a reaction chamber having a plurality of intake lines and an outlet line for receiving the gases from a gas delivery module; a vacuum pump, the gas outlet pipe connected to the reaction chamber, having an gas outlet pipe for extracting unreacted gas and by-products from the reaction chamber; and a gas processing module connected to the gas The outlet pipe of the vacuum pump is configured to effectively separate unreacted gases and by-products of the reaction chamber; wherein the gas processing module comprises: a switching component, connecting a first path conduit and a second path a recovery unit connected to the first path line for recycling the unreacted gas and by-products of the reaction chamber received; an exhaust gas treatment device connecting the second path tube The road is used for decomposing the unreacted gas and by-products of the reaction chamber received and then discharging.    The atomic layer coating system of claim 1, wherein the recovery device has a cooling replenishing element that condenses the unreacted gas of the reaction chamber received into a liquid or a solid.    The atomic layer coating system of claim 1, wherein the recovery device further comprises a collection container for collecting the liquid or the solid to be condensed.    The atomic layer coating system according to claim 1, wherein the recovery device has a function of adjusting temperature, and can control the unreacted gas of the received reaction chamber to be condensed into the liquid or the solid, and The by-products received are maintained in a gaseous state for discharge.    The atomic layer coating system according to claim 1, wherein the recovery device is further connected to an evacuation pump for discharging the by-products received by the recovery device.    The atomic layer coating system of claim 1, wherein the switching element switches the unreacted gas and by-products of the reaction chamber received to the first path line at a first time.    The atomic layer coating system of claim 1, wherein the switching element switches the unreacted gas and by-products of the reaction chamber received to the second path line at a second time.    A gas recovery method for atomic layer coating, comprising the following steps: Step 1: receiving at least one gas from a gas delivery module in a reaction chamber; Step 2: using a vacuum pump to the reaction chamber The reaction gas and by-product are withdrawn; and step 3: treating the unreacted gas and by-products of the reaction chamber using a gas treatment module; wherein in step three, the following steps are included: at a first time, by a Switching element, introducing unreacted gas and by-products of the reaction chamber into the first path pipeline of the gas processing module; at a second time, by using the switching component The unreacted gas and by-products of the reaction chamber are introduced into a second path of the gas processing module.    The method for recovering atomic layer coating gas according to claim 8, wherein the first path is connected to a recovery device for recycling the unreacted gas and by-products of the reaction chamber received. .    The method for recovering atomic layer coating gas according to claim 8, wherein the second path line is connected to an exhaust gas treatment device for decomposing the unreacted gas and by-products of the reaction chamber received. Discharge after treatment.    The method for recovering atomic layer coating gas according to claim 8, wherein the recovery device has a cooling replenishing member that condenses the unreacted gas of the reaction chamber received into a liquid or a solid.    The method for recovering atomic layer coating gas according to claim 8, wherein the recovery device further comprises a collection container for collecting and condensing into the liquid or the solid.    The method for recovering atomic layer coating gas according to claim 8, wherein the recovery device has a function of adjusting temperature, and can control condensation of the unreacted gas of the reaction chamber received into the liquid or the solid. The by-products received are kept in a gaseous state for discharge.    The method for recovering atomic layer coating gas according to claim 8, wherein the recovery device further comprises an outlet conduit connected to an evacuation pump for discharging by-products of the reaction chamber received.