Vaporizer for chemical vapor deposition

Abstract

The present invention relates to the technical field of vaporizers. Provided is a vaporizer for chemical vapor deposition, comprising: an atomizer configured to break a liquid into liquid droplets; a heating container, wherein a container wall of the heating container is configured to form a first heat exchange surface, a filter is provided inside the heating container, atomized liquid droplets enter the heating container, the filter is configured to intercept the liquid droplets or other particles, and the first heat exchange surface heats a gas in the heating container so that the gas exchanges heat with the liquid droplets to vaporize the liquid droplets; and a reaction chamber, wherein vaporized liquid droplets enter the reaction chamber for a chemical vapor deposition reaction. The present invention has the advantages of stability, precise flow control, complete vaporization, low possibility of thermal decomposition, precise control of low flow rates, high vapor content, maintenance-free operation, low carrier gas consumption, fast response speed, small size, high level of integration, etc.

Description

A vaporizer for chemical vapor deposition TECHNICAL FIELD

[0001] The present invention relates generally to the field of vaporizer technology. In particular, the present invention relates to a vaporizer for chemical vapor deposition. BACKGROUND

[0002] Conventional vaporizers include bubbler vaporizers, injection method vaporizers, and flash vaporization vaporizers.

[0003] Figure 1 shows a schematic diagram of a bubbler vaporizer in the prior art. As shown in Figure 1, in a conventional bubbler vaporizer, the bubbler needs to be maintained at a constant temperature, but the change in liquid level in the bubbler will cause a change in pressure, resulting in a change in flow rate at the outlet, and the different bubble sizes in the bubbler will cause the vaporization gas-liquid interface area to change, resulting in a change in evaporation amount, so two-stage bubbler tanks are usually used to compensate for the performance requirements of the vaporizer. Figure 2 shows a schematic diagram of a vaporizer with a MFC (mass flow control) module and a VCC (vapor concentration control) module in the prior art, in which the ratio of gas and liquid in the carrier gas is measured, and the flow rate is controlled to obtain a more accurate evaporation amount. Figure 3 shows a schematic diagram of a bubbler vaporization system. In a bubbler vaporization system, the bubbler has the problems of large volume, large amount of carrier gas used, low vapor content, and slow response, and the bubbler is usually built at the plant end, as shown in Figure 3, so the gas needs to flow through a long pipeline before entering the equipment, which has the risk of condensation decomposition or other parasitic effects.

[0004] Injection method vaporizers include liquid injection method vaporizers and mixed injection method vaporizers. Figure 4A shows a schematic diagram of a liquid injection method vaporizer in the prior art. Figure 4B shows a schematic diagram of a mixed injection method vaporizer in the prior art. As shown in Figures 4A and 4B, in an injection method vaporizer, the liquid raw material is mixed and vaporized in a flow control valve, in which the liquid raw material is provided according to the amount required by the actual process, and the flow rate of the liquid raw material is controlled for vaporization, and the vaporization efficiency of the mixed injection method is higher than that of the liquid injection method. However, the injection method vaporizer has the problem of low complete vaporization rate, and is only suitable for liquids with high vapor pressure in the gas-liquid phase diagram.

[0005] Figure 5 shows a schematic diagram of a flash tank vaporizer in the prior art. As shown in Figure 5, a flash tank vaporizer throttles and vaporizes a heated liquid mixture (or liquid and gas mixture) through a valve to vaporize the liquid mixture and separate the components of the liquid mixture. The flash process can be regarded as a single-stage distillation process, the principle of which is that when the gas phase and condensed phase of the liquid mixture reach equilibrium at a separation temperature and pressure, equilibrium vaporization occurs. However, the flash tank vaporizer has the problems of low vaporization rate, difficulty in being applied to small flow raw materials, and complex structure and control, and is less applied in the semiconductor field.

[0006] SUMMARY

[0007] To at least partially solve the above problems in the prior art, the present application provides a vaporizer for chemical vapor deposition, characterized in that it comprises:

[0008] an atomizer configured to atomize a liquid into liquid droplets;

[0009] a heating container connected to the atomizer, a container wall of the heating container being configured to form a first heat exchange surface, and a filter being arranged inside the heating container, wherein the liquid droplets after atomization enter the heating container, the filter is configured to reduce the pressure of the liquid droplets, and the first heat exchange surface heats the liquid droplets to vaporize the liquid droplets; and

[0010] a reaction cavity connected to the heating container, wherein the vaporized liquid droplets enter the reaction cavity for chemical vapor deposition reaction.

[0011] In an embodiment of the present application, the heating container is cylindrical.

[0012] In an embodiment of the present application, the vaporizer for chemical vapor deposition further comprises:

[0013] an atomizing nozzle connected to the atomizer, wherein the atomizer breaks the liquid into liquid droplets, and the liquid droplets are injected into the first end of the heating container through the atomizing nozzle.

[0014] In an embodiment of the present application, the first end of the heating container is provided with an air inlet, wherein the carrier gas and / or the doping gas enters the heating container from the air inlet; or

[0015] the carrier gas and / or the doping gas enters the heating container from the atomizing nozzle.

[0016] In an embodiment of the present application, the vaporizer for chemical vapor deposition further comprises:

[0017] A fluid control device is arranged between the heating container and the reaction cavity.

[0018] In one embodiment of the present application, a second heater is arranged in the heating container to form a second heat exchange surface, or the first heater heats the filter to form a second heat exchange surface to increase the heat exchange area.

[0019] In one embodiment of the present application, the second heat exchange surface is coaxial with the first heat exchange surface

[0020] In one embodiment of the present application, the atomizer comprises a single-channel ultrasonic atomizer; or

[0021] The atomizer comprises a double-channel carrier gas breaking atomizer; or

[0022] The atomizer comprises a single-channel ultrasonic atomizer and a double-channel carrier gas breaking atomizer in series or in parallel.

[0023] In one embodiment of the present application, the heating container is configured such that the atomized liquid droplets form a cyclone inside the heating container.

[0024] In one embodiment of the present application, the inner wall of the heating container is configured with a spiral line or a rifling to form the cyclone; and / or

[0025] The inner part of the heating container is arranged with a spiral blade or a spiral plate to form the cyclone; and / or

[0026] The atomized liquid droplets, carrier gas or doping gas are injected tangentially into the heating container to form a cyclone.

[0027] In one embodiment of the present application, the particle size of the atomized liquid droplets is less than VMD 200um or SMD 200um.

[0028] In one embodiment of the present application, the first heat exchange surface and / or the second heat exchange surface is configured such that the liquid droplets are overheated to increase the enthalpy of the liquid droplets. The overheating can be achieved by infrared radiation of the heat exchange surface to the liquid droplets, or heat exchange of the film of liquid intercepted by the heat exchange surface.

[0029] In one embodiment of the present application, the filter comprises a horizontal filter or a vertical filter, and the atomized liquid droplets diffuse from the middle to the outside of the filter or from the outside to the middle of the filter.

[0030] In one embodiment of the present application, the filter is coaxial with the first heat exchange surface

[0031] In one embodiment of the present application, the filter is configured to restrict flow.

[0032] In one embodiment of the present application, the fluid control device comprises a mass flow meter, a pressure control valve, a pressure regulator, a flow restrictor, an opening valve or a shut-off valve.

[0033] In one embodiment of the present application, the vaporizer for chemical vapor deposition further comprises:

[0034] a pre-heater configured to pre-heat the carrier gas, the dopant gas or the mixed gas.

[0035] In one embodiment of the present application, the length of the connecting pipe between the heating container and the reaction cavity is less than 500 mm.

[0036] In one embodiment of the present application, the second end of the heating container is the gas inlet nozzle of the reaction cavity.

[0037] In one embodiment of the present application, the heating container comprises a plurality of segmented structures, wherein the plurality of segmented structures are connected by a head, a body flange, a threaded port, welding or a sleeve.

[0038] In one embodiment of the present application, the vaporizer comprises a single heating container and a plurality of mass flow meters, wherein the single heating container is connected to the reaction cavity through the plurality of mass flow meters; or

[0039] the vaporizer comprises a plurality of heating containers, and the plurality of heating containers are respectively connected to the reaction cavity.

[0040] In one embodiment of the present application, the atomized liquid droplets are intercepted by the first heat exchange surface and / or the second heat exchange surface to form a film heater.

[0041] In one embodiment of the present application, the flow direction of the atomized liquid droplets is coaxial with the first heat exchange surface; and / or

[0042] the flow direction of the atomized liquid droplets is coaxial with the direction of the outlet at the end of the vaporizer.

[0043] In one embodiment of the present application, the first heater and the first surface of the filter form the second heat exchange surface, the second surface of the filter forms the third heat exchange surface, and the fourth heat exchange surface is formed at a position after the filter in the movement direction of the liquid droplets, wherein the liquid droplets are 100% vaporized by the pressure difference of the vaporizer filter and the enthalpy of overheating of at least one of the first to fourth heat exchange surfaces.

[0044] In one embodiment of the present application, the filter has a filtering particle size of 10 um-10 nm. When the diameter of the filtered particles is very small, the unvaporized liquid droplets are intercepted by the filter, and then pass through the membrane to be heated, vaporized and superheated to achieve complete vaporization. In addition, there is no thermal decomposition in the vaporizer container, so it can be considered that the input liquid is approximately 100% vaporized and enters the reaction chamber completely. This 100% vaporization of the metered liquid and 100% entry into the reaction chamber is of great significance to improve the uniformity and repeatability of the film forming process.

[0045] In the present application, the commonly used term in the industry is atomization. The liquid particles obtained after atomization are commonly referred to as liquid droplets.

[0046] In the present application, the definition of the droplet particle size is the VMD volume particle size distribution or the SMD surface particle size distribution, as well as the industry standard.

[0047] The present application has at least the following beneficial effects: the present application proposes a vaporizer for chemical vapor deposition, which has the advantages of stability, precise flow control, complete vaporization, low possibility of thermal decomposition, precise control of small flow, high steam content, maintenance-free, small amount of carrier gas, fast response speed (very important for ALD processes that require rapid filling of the chamber), small volume, high integration, etc. The process uniformity and repeatability of the downstream reaction chamber can be greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0048] To further clarify the advantages and features of the embodiments of the present application, a more particular description of the embodiments of the present application will be presented with reference to the accompanying drawings. It can be understood that these drawings only depict typical embodiments of the present application, and therefore should not be considered as limiting its scope. In the drawings, the same or similar components will be denoted by the same or similar reference numerals for the sake of clarity.

[0049] FIG. 1 shows a schematic diagram of a bubble method vaporizer in the prior art.

[0050] FIG. 2 shows a schematic diagram of a vaporizer with an MFC module and a VCC module in the prior art.

[0051] FIG. 3 shows a schematic diagram of a bubble method vaporization system.

[0052] FIG. 4A shows a schematic diagram of a liquid injection method vaporizer in the prior art.

[0053] FIG. 4B shows a schematic diagram of a hybrid injection method vaporizer in the prior art.

[0054] FIG. 5 shows a schematic diagram of a flash tank vaporizer in the prior art.

[0055] Figure 6 shows a schematic diagram of a vaporization principle.

[0056] Figure 7 shows a schematic diagram of an ultrasonic atomizer.

[0057] Figure 8 shows a schematic diagram of a frame of a vaporizer using a bubbler in the prior art.

[0058] Figure 9 shows a schematic diagram of a vaporizer system for chemical vapor deposition in an embodiment of the present application.

[0059] Figure 10 shows a schematic diagram of a structure of a porous metal sintered filter in an embodiment of the present application.

[0060] Figure 11 shows a schematic diagram of a pressure drop versus flow rate.

[0061] Figure 12A shows a schematic diagram of a multi-channel control system having multiple injection ports sharing a vaporizer.

[0062] Figure 12B shows a schematic diagram of a multi-channel control system having multiple vaporizers.

[0063] Figure 13 shows a schematic diagram of a vaporizer system for chemical vapor deposition in another embodiment of the present application.

[0064] Figure 14 shows a schematic diagram of an atomizer in an embodiment of the present application. DETAILED DESCRIPTION

[0065] It should be noted that components in the various figures can be exaggerated for the purpose of illustration and are not necessarily to scale. In the various figures, like components are denoted by like reference numerals.

[0066] In the present application, unless specifically indicated otherwise, "arranged on", "arranged above", and "arranged over" do not exclude the presence of an intermediate object between the two. Furthermore, "arranged on or above" merely indicates the relative positional relationship between two components, which can be converted to "arranged below or under" in certain cases, such as after reversing the product direction, and vice versa.

[0067] In the present application, each embodiment is merely intended to illustrate the scheme of the present application, and should not be understood as limiting.

[0068] In the present application, unless specifically indicated otherwise, the quantifier "one", "a" does not exclude the scenario of multiple elements.

[0069] It should also be noted that, in the embodiments of the present application, only a part of components or assemblies can be shown for the sake of clarity and simplicity, but those skilled in the art can understand that, under the teaching of the present application, the required components or assemblies can be added according to the specific scene. In addition, the features in different embodiments of the present application can be combined with each other unless otherwise stated. For example, a feature in the second embodiment can replace a corresponding or functionally similar feature in the first embodiment, and the resulting embodiment also falls within the disclosure or description range of the present application.

[0070] It should also be noted that, in the scope of the present application, the words "same", "equal", "equal to" and the like do not mean that the numerical values of the two are absolutely equal, but allow a certain reasonable error, that is, the words also cover "substantially the same", "substantially equal", "substantially equal to". By analogy, in the present application, the terms "perpendicular to", "parallel to" and the like also cover the meanings of "substantially perpendicular to", "substantially parallel to".

[0071] In addition, the numbering of the steps of the methods of the present application does not limit the execution order of the method steps. Unless specifically indicated, the method steps can be executed in different orders.

[0072] The present application will be further described below with reference to the specific embodiments and the accompanying drawings.

[0073] In semiconductor processes, liquid precursors used in chemical vapor deposition equipment need to be accurately metered and completely vaporized before entering the reaction chamber through the gas mixing device.

[0074] Most chemical vapor deposition processes require the use of carrier gas, and the use of carrier gas will cause the vapor concentration to decrease and the deposition rate to decrease. The use of carrier gas-free can improve the deposition rate.

[0075] The use of carrier gas-free can make the vaporizer volume smaller and closer to the reaction chamber, thereby reducing condensation, and can integrate the vaporizer with other fluid control equipment to control the injection of multiple partitions inside the chamber.

[0076] In the present application, the atomizer without carrier gas can be referred to as a single-channel atomizer, and the atomizer using carrier gas can be referred to as a double-channel atomizer. Some terminology systems will refer to single-fluid (only liquid) atomization and double-fluid (liquid + gas) atomization.

[0077] Single channel atomizers usually have lower outlet pressure, lower flow rate, and more stable pressure, so longer residential time can be achieved.

[0078] Figure 6 shows a schematic diagram of vaporization. As shown in Figure 6, the vaporization process of liquid can be moving liquid from liquid phase to gas phase by increasing temperature or decreasing pressure.

[0079] In the present invention, a single channel vaporizer is proposed, in which the vaporized precursor can be mixed with dopant directly in the injector and injected into the reaction chamber.

[0080] Traditional atomizers usually achieve atomization by breaking droplets with the fluid kinetic energy of carrier gas. In order to achieve a high breaking rate (that is, VMD or SMD distribution < 200 μm), a high flow rate of carrier gas is required. However, the high flow rate of carrier gas can be collided with the atomized droplets and aggregated into large droplets, and the high flow rate of carrier gas will make the residential time shorter, resulting in that the unvaporized liquid meets the chamber wall of the vaporizer in advance and accumulates, so that the vaporization process changes from large surface area droplet vaporization to small surface area film vaporization.

[0081] Therefore, a low flow rate, long residence time atomizer is required, such as an ultrasonic atomizer. In the present invention, the carrier gas in the atomizer or vaporizer is configured to perform soft vaporization, that is, to vaporize droplets by heat and mass transfer at the gas-liquid interface, rather than to break droplets by the fluid kinetic energy of the carrier gas, and in order to improve the heat transfer efficiency, the carrier gas can be preheated before entering the vaporizer. In addition, preheating the carrier gas can also reduce the volume of the heater. At the same time, the eccentric layout can cause part of the atomized particles to contact the first heating surface before other parts. The coaxial design (the flow direction of the atomized particles is coaxial with the first and second heat transfer surfaces, and even the filter) can make all atomized particles as much as possible to delay the situation of droplet aggregation on the heating surface to form a film heating, so that the vaporization efficiency is improved.

[0082] In the vaporizer of the present invention, droplets can be broken by atomization to expand the volume specific surface area of the gas-liquid heat transfer surface and evaporation surface, in which an ultrasonic atomizer can be used. Figure 7 shows a schematic diagram of an ultrasonic atomizer.

[0083] The gas stick after the vaporizer (usually a gas stick contains MFC, pneumatic valve, hand valve, flow restrictor filter from the vaporizer, these sticks are connected by VCR joints and / or C seal, W seal, etc. standard industrial joints) becomes shorter, almost directly into the cavity, which can improve the response speed, and can be well applied to atomic layer deposition (ALD) or molecular layer deposition (MLD).

[0084] In addition, water as a gas phase precursor is usually difficult to vaporize in the prior art. In the prior art, steam is usually generated in-situ by H2+O2 flame in the in-situ steam generation chamber (ISSG) in the process of generating SiO x using H2+O2. Using the present application, complete vaporization of water can be achieved, and the performance of the rapid thermal oxidation (RTO) process can be improved.

[0085] The atomized particles and droplets can be intercepted by the heater and the filter, and at this time the heater and the filter are film heaters.

[0086] Figure 8 shows a schematic diagram of a frame of a vaporizer using a bubbler in the prior art. As shown in Figure 8, the bubbler is arranged upstream of the gas panel.

[0087] Figure 9 shows a schematic diagram of a vaporizer system for chemical vapor deposition in an embodiment of the present application. The vaporizer system comprises a gas distribution cabinet 901, a vaporizer 902, a reaction cavity 903, a filter 904, and a heater 906.

[0088] In this system, one design strategy is that the non-filter part can complete 95% of the vaporization process, and the remaining 5% of the vaporization process is completed at the filter 904. This system uses an ultrasonic atomizer for atomization, which is a single-channel (single-fluid), carrier gas-free atomizer, which can make the system respond quickly and control more accurately. The single-channel (single-fluid) ultrasonic atomizer has a high breakage rate, which can increase the specific surface area of the particle volume, is beneficial to vaporization (VMD or SMD 20-200 μm or lower), and atomizes the carrier gas to make the particles smaller.

[0089] The filter 904 can have the functions of a heater, a mixer and a filter integrated simultaneously. The function of the mixer can be realized by setting a helical line or a rifling line with internal threads on the filter 904 shell, or by tangential entry of the gas through a cyclone structure, or simply by a sufficient residential time. By increasing the residential time and enhancing the mixing effect, the gas mixing and heating efficiency can be improved. The filter 904 can have second and third heat exchange surfaces, so that the heat exchange efficiency and the vaporization effect are better. The second and third gases can realize gas mixing at the atomizing nozzle 905 and help to realize cyclone. The filter 904 can also function as a flow limiter.

[0090] In the system, the vaporizer 902 can be separated from the gas distribution cabinet 901 and placed upstream of the reaction cavity 903, that is, the system can be connected in the order of the gas distribution cabinet 901, the vaporizer 902 and the reaction cavity 903, so that the response is faster.

[0091] In another embodiment of the present application, the gas can pass through the filter 904 from the inside to the outside.

[0092] The filter 904 can be a porous metal sintered filter, and the filtering capacity and cleanliness requirements of the porous sintered filter can meet the semiconductor-level gas delivery requirements. FIG. 10 shows a structural schematic diagram of a porous metal sintered filter in an embodiment of the present application. Since the metal has good heat transfer properties, after being heated by the heater 906 (first heat exchange surface), it can further heat the fluid as a second heater. Since the front and back surfaces of the filter can exchange heat with the gas, the second heater introduces second and third heat exchange surfaces, so that the heat exchange effect is better and the vaporization effect is better.

[0093] The filter 904 can increase the pneumatic resistance, and after the opening size, opening rate and area of the filter 904 are determined, a pressure drop can be obtained. FIG. 11 shows a schematic diagram of the relationship between pressure drop and flow rate. Generally, the smaller the pressure drop of the filter, the better. In the present application, the pressure drop generated by the filter 904 can help the working medium move from the liquid phase side (high pressure) to the gas phase side (low pressure) of the phase diagram, so a relatively large pressure drop is beneficial to the occurrence of vaporization. The heater 906 can be a superheater, that is, the fluid is superheated (by sensible heat) to increase the enthalpy of the fluid. The filter 904 can have a capillary structure, and when the superheated fluid passes through the filter 904, a pressure drop occurs. The enthalpy of the sensible heat can help the unvaporized liquid to further realize vaporization.

[0094] When the vaporizer 902 achieves full vaporization, the pressure drop across the subsequent tubing is small and the temperature will remain steady without a large temperature drop. Normally, the fluid control element or joint will create an additional pressure drop, in the present invention, the filter 904 functions as a flow restrictor and is integrated inside the vaporizer 902, which helps to reduce the condensation of the gas after it leaves the vaporizer 902. In addition, the heating control of the filter 902 also helps to vaporize and reduce the occurrence of condensation.

[0095] Fig. 12A and Fig. 12B show two different systems for multi-path control of the vaporizer, where Fig. 12A shows a schematic diagram of a multi-path control system with multiple injection ports sharing a vaporizer, and Fig. 12B shows a schematic diagram of a multi-path control system with multiple vaporizers. In Fig. 12A and Fig. 12B, the dashed line represents the boundary of the process, the portion to the left of the dashed line is the gas panel, MFC represents the gas mass flow meter, LFC represents the liquid flow meter, and the portion to the right of the dashed line is the non-gas panel gas component, which can be arranged in the physical location closest to the reaction chamber. In the multi-path control system with multiple vaporizers shown in Fig. 12B, the back end of the vaporizer is short in distance and few in components from the reaction chamber, which can achieve the fastest response. And in the case of short distance and few components, the possibility of pressure drop and low temperature leading to gas condensation will be small, which can improve the film formation quality in the reaction chamber.

[0096] Fig. 13 shows a schematic diagram of a vaporizer system for chemical vapor deposition in another embodiment of the present invention. For processes where the gas is prone to condensation or the response speed is required to be high, the system shown in Fig. 13 can be used, where the vaporizer is directly inserted at the nozzle or injector, that is, the end of the vaporizer is directly inserted into the nozzle, or the flow restrictor at the end of the vaporizer, the connection flange or the VCR joint is directly connected with the injector. The installation position of the filter can be provided in the injector channel, the shell of the vaporizer is connected with the injector through threads or other connection methods, and the end of the vaporizer is connected with the injector together. In Fig. 13, the vaporizer 2 is exaggeratedly shown, indicating that the injector becomes part of the vaporizer.

[0097] Fig. 14 shows a schematic diagram of an atomizer in an embodiment of the present invention. In the present invention, the atomizer can be a single-channel, carrier gas-free atomizer, where the atomization is achieved by ultrasonic breaking, and the LFC and the ultrasonic generator or controller are arranged in the atomizer; the atomizer can also be a double-channel atomizer, where the atomization is achieved by flow rate breaking, and the LFC and the carrier gas MFC are arranged in the atomizer; the atomizer can also be a hybrid double-channel atomizer, where the atomization is achieved by ultrasonic breaking and flow rate breaking, and the LFC, the carrier gas MFC and the ultrasonic generator or controller are arranged in the atomizer.

[0098] In the cartridge of the vaporizer, the input of carrier gas and dopant gas can be controlled by MFCs; the carrier gas can be preheated by a carrier gas heater; the flow rate and volume loss after the gas filtration can be compensated by a tangential nozzle and by a inner spiral to reduce the pitch of the spiral to form a cyclone. The flow controllers can include back pressure valves, pressure controllers, flow restrictors, MFCs, pressure control valves, etc. The multi-channel vaporizer system can improve uniformity, speed up the purge time of the reaction chamber, and speed up the deposition rate by multiple vaporizers. The reaction chamber can include a polysilicon CVD reactor, a hydrogenation furnace (STC convertor), a hydrochlorination fluidized bed (Hydrochlorination convertor), SACVD, PECVD, HDPCVD, RTO, CVD Epi, ALD, MLD chamber.

[0099] The comparison of the vaporizer of the present application with the prior art vaporizers can be shown in Table 1.

[0100] Table 1

[0101] While the foregoing describes embodiments of the present application, it is understood that they are presented by way of example only and not in limitation. As will be apparent to those of ordinary skill in the art, various modifications, combinations, sub-combinations, and changes can be made to the embodiments without departing from the spirit and scope of the application. Accordingly, the breadth and scope of the present application should not be limited by the above disclosed exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

1. A vaporizer for chemical vapor deposition, characterized by, comprising: an atomizer configured to break liquid into liquid droplets; a heating vessel connected with the atomizer, a vessel wall of the heating vessel is configured to form a first heat exchange surface, an inside of the heating vessel is arranged with a filter, wherein the atomized liquid droplets enter the heating vessel, the filter is configured to intercept the liquid droplets or other particles, and the first heat exchange surface heats a gas in the heating vessel to exchange heat with the liquid droplets to vaporize the liquid droplets; and a reaction chamber connected with the heating vessel, wherein the vaporized liquid droplets enter the reaction chamber for chemical vapor deposition reaction.

2. The vaporizer for chemical vapor deposition according to claim 1, characterized by, The heating vessel is cylindrical.

3. The vaporizer for chemical vapor deposition according to claim 1, characterized by, further comprising: an atomizing nozzle connected with the atomizer, wherein the atomizer breaks liquid into liquid droplets, and the liquid droplets are injected into a first end of the heating vessel through the atomizing nozzle, wherein carrier gas and / or dopant gas enters the heating vessel from the atomizing nozzle; or a first end of the heating vessel is provided with a gas inlet, wherein carrier gas and / or dopant gas enters the heating vessel from the gas inlet.

4. The vaporizer for chemical vapor deposition according to claim 1, characterized by, further comprising: a fluid control device arranged between the heating vessel and the reaction chamber, the fluid control device comprising a mass flow meter, a pressure control valve, a pressure regulator, a flow restrictor, an opening valve, or a shut-off valve.

5. The vaporizer for chemical vapor deposition according to claim 1, characterized by, a second heater is arranged in the heating vessel to form a second heat exchange surface, or the first heater heats the filter to form a second heat exchange surface to increase the heat exchange area; and / or the atomized liquid droplets are intercepted by the first heat exchange surface and / or the second heat exchange surface to form a film heater; and / or the first heater and a first surface of the filter form a second heat exchange surface, a second surface of the filter forms a third heat exchange surface, and a position after the filter in the direction of movement of the liquid droplets forms a fourth heat exchange surface; wherein at least one of the first to fourth heat exchange surfaces is configured to superheat the liquid droplets to increase the enthalpy of the liquid droplets, the vaporizer approximately 100% vaporizes the liquid droplets through the pressure difference of the vaporizer filter and the enthalpy of the superheated liquid droplets, and the liquid droplets enter the reaction chamber.

6. The vaporizer for chemical vapor deposition according to claim 1, wherein the atomizer comprises a single-channel ultrasonic atomizer; or the atomizer comprises a double-channel carrier gas breaking atomizer; or the atomizer comprises a single-channel ultrasonic atomizer and a double-channel carrier gas breaking atomizer in series or in parallel.

7. The vaporizer for chemical vapor deposition according to claim 3, characterized by The heating vessel is configured such that the atomized liquid droplets form a cyclone in the inside of the heating vessel; wherein the inner wall of the heating vessel is structured with a spiral line or a rifle line to form the cyclone; and / or the inside of the heating vessel is arranged with spiral vanes or spiral plates to form the cyclone; and / or the atomized liquid droplets, carrier gas, or dopant gas are injected tangentially into the heating vessel to form a cyclone.

8. The vaporizer for chemical vapor deposition according to claim 1, characterized by, The particle size of the atomized liquid droplets is less than VMD 200um or SMD 200um.

9. The vaporizer for chemical vapor deposition according to claim 1, characterized by, The filter includes a horizontal filter or a vertical filter, and the liquid droplets after atomization spread from the middle to the outside of the filter or from the outside to the middle of the filter and / or spread from the front to the back.

10. The vaporizer for chemical vapor deposition according to claim 1, characterized by, The filter is configured to limit flow.

11. The vaporizer for chemical vapor deposition according to claim 3, characterized by, Further comprising: A pre-heater configured to pre-heat the carrier gas, the doping gas or the mixed gas.

12. The vaporizer for chemical vapor deposition according to claim 1, characterized by, The length of the connecting pipeline between the heating container and the reaction cavity is less than 500 mm.

13. The vaporizer for chemical vapor deposition according to claim 1, characterized by, The second end of the heating container is the gas inlet nozzle of the reaction cavity.

14. The vaporizer for chemical vapor deposition according to claim 1, characterized by, The heating container includes a plurality of segmented structures, and the plurality of segmented structures are connected by a head, a body flange, a threaded port, welding or a sleeve.

15. The vaporizer for chemical vapor deposition according to claim 4, characterized by, The single heating container is connected with the reaction cavity through the plurality of mass flow meters; or The vaporizer includes a plurality of heating containers, and each of the plurality of heating containers is connected with the reaction cavity.

16. The vaporizer for chemical vapor deposition according to claim 5, characterized by The second heat exchange surface is coaxial with the first heat exchange surface; And / or The filter is coaxial with the first heat exchange surface; And / or The flow direction of the liquid droplets after atomization is coaxial with the first heat exchange surface; And / or The flow direction of the liquid droplets after atomization is coaxial with the direction of the outlet at the end of the vaporizer.

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