A chlorosilane vaporizer for HCVD

Abstract

The present invention provides a chlorosilane vaporizer for HCVD, comprising: a vaporizer, a heating vest disposed outside the vaporizer, a graphite heating element disposed within the vaporizer, and an atomizing injector disposed on the top of the vaporizer. The sidewalls of the vaporizer are further provided with a mixed gas outlet, a positive flange assembly, and a negative flange assembly. The atomizing injector is used to inject the gas to be vaporized onto the graphite heating element. The positive flange assembly and the negative flange assembly are both electrically connected to the heating vest and the graphite heating element. By using graphite as the heating element and adopting an innovative structural design, the heating area is increased, the surface temperature of the heating element is constant, and the mixed vaporization effect of the incoming gas is improved. Chlorosilane treated by the chlorosilane vaporizer for HCVD can be delivered to the HCVD in an effectively metered, constant-temperature gas phase, ensuring a uniform and stable gas field in the chemical vapor deposition furnace.

Description

Technical Field

[0001] The present invention relates to the technical field of vaporization devices, in particular to a chlorosilane vaporizer for HCVD. Background Art

[0002] In a high-temperature chemical vapor deposition (HCVD) furnace, how to uniformly vaporize methyltrichlorosilane so that the gas phase entering the furnace is free of liquid, improve the uniformity of the gas field in the HCVD furnace, and avoid contamination of the product surface has always been a key research topic. Therefore, it is urgent to design a vaporization device that can improve the vaporization quality. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a chlorosilane vaporizer for HCVD to solve the technical problems of uneven gas field and liquid inclusion in the gas phase of the prior art vaporizer.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] An embodiment of the present invention provides a chlorosilane vaporizer for HCVD, which includes: a vaporizer, a heating vest arranged on the outside of the vaporizer, a graphite heating element arranged inside the vaporizer, and an atomizing injector arranged on the top of the vaporizer, wherein a mixed gas outlet and a positive flange assembly and a negative flange assembly are also provided on the side wall of the vaporizer, the atomizing injector is used to spray the gas to be vaporized to the graphite heating element, and the positive flange assembly and the negative flange assembly are both electrically connected to the heating vest and the graphite heating element.

[0006] The graphite heating element includes: a heating element body, a plurality of heat conducting sheets connected to the outer wall of the heating element body, and a through hole is also provided in the heating element body.

[0007] Wherein, the heating element body is a tubular body, the heat conducting plate extends axially along the side wall of the tubular body, and the tubular body is further provided with an upper connecting hole and a lower connecting hole.

[0008] The top of the vaporizer is also provided with a top flange, the atomizing injector is connected to the top flange, and the atomizing injector is provided with a first air inlet pipe and a second air inlet pipe. The first air inlet pipe is used to transport hydrogen, and the second air inlet pipe is used to transport methyltrichlorosilane.

[0009] Among them, the positive flange assembly includes: a positive flange plate, a positive copper tube passing through the positive flange plate, and a positive graphite electrode passing through the positive copper tube; wherein, an insulating gasket is also sleeved on the positive copper tube, and the insulating gasket is used to insulate between the positive copper tube and the positive flange plate.

[0010] Among them, the vaporizer is also provided with a positive flange, the positive flange is connected to the positive flange, and a sealing gasket is provided between the positive flange and the positive flange. One end of the positive graphite electrode is electrically connected to the positive copper tube, and the other end is electrically connected to the graphite heating element.

[0011] Among them, the negative flange assembly includes: a negative flange plate, a negative copper tube passing through the negative flange plate, and a negative graphite electrode passing through the negative copper tube; wherein, an insulating gasket is also sleeved on the negative copper tube, and the insulating gasket is used to insulate between the negative copper tube and the negative flange plate.

[0012] Among them, the vaporizer is also provided with a negative electrode flange, the negative electrode flange plate is connected to the negative electrode flange, and a sealing gasket is also provided between the negative electrode flange and the negative electrode flange plate. One end of the negative electrode graphite electrode is electrically connected to the graphite heating element, and the other end is electrically connected to the negative electrode copper tube.

[0013] Wherein, a sealing gasket is further provided between the top end of the vaporizer and the top end flange.

[0014] Wherein, a pad is further provided at the bottom end of the graphite heating element, and the pad is connected to the bottom of the vaporizer.

[0015] The chlorosilane vaporizer for HCVD of the present invention adopts graphite material for the heating element and has an innovative structural design to increase the heating area. The surface temperature of the heating element is constant, so that the mixed vaporization effect of the incoming gas is better. The chlorosilane treated by the chlorosilane vaporizer for HCVD can be fed into the HCVD in an effectively measured and constant temperature gas phase state, ensuring that the gas field of the chemical vapor deposition furnace is uniform and stable.

[0016] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following preferred embodiments are specifically cited and described in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the overall structure of a chlorosilane vaporizer for HCVD according to an embodiment of the present invention.

[0018] Figure 2 This is an exploded view of a chlorosilane vaporizer for HCVD according to an embodiment of the present invention.

[0019] Figure 3 2 is a cross-sectional view of a chlorosilane vaporizer for HCVD according to an embodiment of the present invention.

[0020] Figure 4This is a partial exploded view of the negative electrode flange assembly of a chlorosilane vaporizer for HCVD according to an embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of the structure of the graphite heating element of the chlorosilane vaporizer for HCVD according to an embodiment of the present invention.

[0022] Figure 6 The diagram is a schematic diagram of the system structure of the HCVD chlorosilane vaporizer applied to a specific vaporization system. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work shall fall within the scope of protection of the present invention.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships described in the accompanying drawings, and are 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 understood as limiting the present invention.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0027] In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0028] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0029] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. Throughout this specification, the schematic representations of these terms should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0030] The HCVD chlorosilane vaporizer of this embodiment combines the characteristics of the methyltrichlorosilane vaporization process, and innovatively designs the vaporizer from the perspective of large surface area and low heat load heating vaporization. A graphite heating element, which is a material that is homologous and compatible with the material inside the HCVD furnace, is used, and its structural shape is formed and designed to multiply its surface area. At the same time, through process control, the methyltrichlorosilane liquid is effectively splashed onto the surface of the graphite heater to achieve full-power vaporization.

[0031] The HCVD chlorosilane vaporizer first calculates the heat load required by the process:

[0032] The feeding amount of methyltrichlorosilane vaporized in the process at one time (calculated in 5 hours) is m: 60 kg / 5h.

[0033] Refer to the material properties table, for example: the specific enthalpy of methyltrichlorosilane at 0℃ and 0.3Mpa is: -4055.9kj / kg; the specific enthalpy at 66℃ and 0.3Mpa is: -3991.3kj / kg;

[0034] Calculate the required heat load:

[0035] Q=ξ*m*△H / t=1.5*60*(-3991.3-(-4055.9)) / 5=1162.8kj / h=323w.

[0036] The power of the graphite heating element is designed according to this heat load.

[0037] Using 220V single-phase heating, the power supply is easy to obtain and controllable. The required resistance is calculated as:

[0038] R=P / U2=323 / 2202*1000=6.7mΩ

[0039] According to the above design ideas, it is planned to use a cross-sectional area of ​​50mm 2 , with a height of 240mm and a resistivity of 13.5μΩ·m. Based on the process conditions and supporting space conditions, the relevant dimensions are optimized and finalized, and assembled with the shell to form a vaporizer assembly with the following structure:

[0040] See also Figures 1 to 5 The chlorosilane vaporizer for HCVD of this embodiment comprises: a vaporizer 1, a heating vest 2 provided on the outside of the vaporizer 1, a graphite heating element 5 provided inside the vaporizer 1, and an atomizing injector 8 provided on the top of the vaporizer 1. A mixed gas outlet 13, a positive electrode flange assembly 4, and a negative electrode flange assembly 3 are further provided on the side wall of the vaporizer 1. The atomizing injector 8 is used to inject the mixed gas to be vaporized to the graphite heating element 5. The graphite heating element 5 is used to heat and vaporize the gas. The positive electrode flange assembly 4 and the negative electrode flange assembly 3 are both electrically connected to the heating vest 2 and the graphite heating element 5, and are used to connect to an external AC power supply to power the heating vest 2 and the graphite heating element 5.

[0041] Please refer again Figure 5The graphite heating element 5 includes: a heating element body 51, a plurality of heat-conducting sheets 52 connected to the outer wall of the heating element body 51, and a through-hole 511 extending therethrough is further provided in the heating element body 51. In this embodiment, the heating element body 51 is a tubular body, and the heat-conducting sheets 52 extend axially along the side wall of the tubular body. An upper connecting hole 53 and a lower connecting hole 54 are further provided on the tubular body. The upper connecting hole 53 is used to connect the positive graphite electrode 101, and the lower connecting hole 54 is used to connect the negative graphite electrode 102. The surfaces of the heat-conducting sheets 52 extend radially through the axis of the tubular body to form a plurality of divergent heat-conducting sheets. The through-holes 511 and the divergent heat-conducting sheets 52 increase the surface area of ​​the heating element, so that the incoming gas is more fully heated and vaporized, thereby improving the vaporization quality.

[0042] Please refer again Figure 2 The vaporizer 1 also has a top flange 7 at its top end, to which the atomizing injector 8 is connected. A first air inlet pipe 81 and a second air inlet pipe 82 are provided on the atomizing injector 8. The first air inlet pipe 81 is used to transport hydrogen, and the second air inlet pipe 82 is used to transport methyltrichlorosilane. Specifically, the vaporizer 1 also has a flange 11 at its top end, to which the top flange 8 is screwed. A sealing gasket 9 is provided between the flange 11 and the top flange 8 to improve the sealing performance of the connection between the two.

[0043] Please refer again Figure 4 The negative electrode flange assembly 4 includes: a negative electrode flange 41, a negative electrode copper tube 42 passing through the negative electrode flange 41, and a negative electrode graphite electrode 102 passing through the negative electrode copper tube 42; wherein, an insulating gasket 43 is also sleeved on the negative electrode copper tube 42, and the insulating gasket 43 is used to insulate between the negative electrode copper tube 42 and the negative electrode flange 41.

[0044] In which, the vaporizer 1 is also provided with a negative electrode flange 15, the negative electrode flange plate 41 is connected to the negative electrode flange 15 through a screw or a bolt 45, and a sealing gasket 44 is also provided between the negative electrode flange 15 and the negative electrode flange plate 41, one end of the negative electrode graphite electrode 102 is electrically connected to the graphite heating element 5, and the other end is electrically connected to the negative electrode copper tube 42.

[0045] The positive electrode flange assembly 3 has the same structure as the positive electrode flange assembly 4 and also includes: a positive electrode flange, a positive electrode copper tube inserted through the positive electrode flange, and a positive electrode graphite electrode 102 inserted through the positive electrode copper tube. The positive electrode copper tube is also fitted with an insulating washer for insulation between the positive electrode copper tube and the positive electrode flange. The vaporizer 1 is also provided with a positive electrode flange 14. The positive electrode flange is connected to the positive electrode flange 14, and a sealing washer is provided between the positive electrode flange 14 and the positive electrode flange. One end of the positive electrode graphite electrode 102 is electrically connected to the positive electrode copper tube, and the other end is electrically connected to the graphite heating element 5. The only difference between the positive electrode flange assembly 3 and the negative electrode flange assembly 4 is that the positive electrode flange assembly 3 contains the positive electrode graphite electrode 101, while the negative electrode flange assembly 4 contains the negative electrode graphite electrode 102.

[0046] Specifically, the outer end of the negative copper tube 42 is further provided with a threaded end 422, and the outer wall of the inner end is provided with a thread 421. The negative copper tube 42 can be screwed to the negative flange 15 of the vaporizer 1 via the thread 421. Similarly, the structure of the positive copper tube of the positive flange assembly 3 is the same as that of the negative copper tube 42.

[0047] Among them, a pad 6 is also provided at the bottom end of the graphite heating element 5, and the pad 6 is connected to the bottom of the vaporizer 1. The pad 6 not only supports the graphite heating element 5, but also has the function of heat insulation between the graphite heating element 5 and the vaporizer 1.

[0048] The bottom of the vaporizer 1 is also provided with a drain port 16 for draining residue from the vaporizer 1. The sidewall of the vaporizer 1 is also provided with a nitrogen inlet channel 12, which requires nitrogen ventilation for internal cleaning before and after vaporization. The gasket 6 is an annular structure with a plurality of radial through holes 61 formed therein.

[0049] The chlorosilane vaporizer for HCVD in this embodiment adopts graphite material for the heating element and has an innovative structural design to increase the heating area. The surface temperature of the heating element is constant, so that the incoming gas mixture is vaporized better. The chlorosilane treated by the chlorosilane vaporizer for HCVD can be fed into the HCVD in an effectively measured and constant temperature gas phase state, ensuring that the gas field of the chemical vapor deposition furnace is uniform and stable.

[0050] See also Figure 6 , which is a schematic diagram of the structure of the HCVD chlorosilane vaporizer applied to a complete vaporization system, and the vaporization process is as follows:

[0051] High-pressure hydrogen is provided with pipeline heating. Methyltrichlorosilane droplets are extracted from the metering tank through the atomizing injector 9 and splashed onto the high-temperature surfaces inside and outside the graphite heating element 5 along with the hydrogen, thereby vaporizing the methyltrichlorosilane. To ensure that it does not liquefy after vaporization, a heating vest 2 is provided on the outer wall of the HCVD chlorosilane vaporizer to provide a constant temperature and compensate for heat loss. The heating vest 2 is provided with its own temperature monitoring function. The vaporized methyltrichlorosilane and hydrogen mixture is pumped from the gas phase outlet of the HCVD chlorosilane vaporizer (i.e., the mixed gas outlet 13) to the HCVD for chemical vapor deposition. The pipeline is provided with insulation and heating, thereby realizing the gas phase delivery of the chlorosilane.

[0052] The entire HCVD chlorosilane vaporizer adopts a constant temperature control function. The spray volume of methyltrichlorosilane is measured by a mass flow meter on the outlet pipe of the metering box. The heating element can be increased or decreased in load according to the spray volume of chlorosilane, thereby realizing the constant temperature control function. Once the temperature exceeds the limit, the alarm interlock will stop the operation.

[0053] The HCVD chlorosilane vaporizer is equipped with a nitrogen purge port. Nitrogen purges are required before and after commissioning and after shutdown to ensure the vaporizer is clear of scale and maintain high heat transfer efficiency. The HCVD chlorosilane vaporizer is equipped with a drain port 16, which automatically discharges the gas into the environmental treatment system through a pneumatic valve at regular intervals.

[0054] The metering tank uses a constant-pressure nitrogen delivery method. A pneumatic diaphragm valve and a manual shut-off valve are installed between the metering tank and the vaporizer to cut off the material supply to the vaporizer at any time. The metering tank is equipped with nitrogen overpressure discharge and safety valve overpressure relief, and the exhaust gas is discharged to the environmental protection treatment system.

[0055] In practical applications, this vaporization system delivers chlorosilane to the HCVD in an effectively metered, constant-temperature vapor phase, ensuring a uniform and stable gas field within the chemical vapor deposition furnace. It is applicable to various silane vaporization processes, with significant demand for liquid-to-gas conversion applications in semiconductor specialty gas feeding, photovoltaic chemical vapor deposition, and other applications.

[0056] The above examples are merely provided to further illustrate the technical content of the present invention for easier understanding by the reader, but do not limit the embodiments of the present invention to these examples. Any extension or re-creation of the technology based on the present invention is protected by the present invention. The scope of protection of the present invention shall be determined by the claims.

Claims

1. A chlorosilane vaporizer for HCVD, characterized in that: include: A vaporizer, a heating vest arranged on the outside of the vaporizer, a graphite heating element arranged in the vaporizer, and an atomizing injector arranged on the top of the vaporizer; wherein, a mixed gas outlet and a positive flange assembly and a negative flange assembly are also provided on the side wall of the vaporizer, the atomizing injector is used to spray the gas to be vaporized to the graphite heating element, the positive flange assembly and the negative flange assembly are both electrically connected to the heating vest and the graphite heating element, and are used for an external power supply; the graphite heating element includes: a heating element body, a plurality of heat conducting plates connected to the outer wall of the heating element body, a through hole is also provided in the heating element body, an upper connecting hole and a lower connecting hole are provided on the heating element body, the upper connecting hole is used to connect the positive graphite electrode, and the lower connecting hole is used to connect the negative graphite electrode.

2. The chlorosilane vaporizer for HCVD according to claim 1, characterized in that The heating element body is a tubular body, and the heat conducting sheet extends axially along the side wall of the tubular body.

3. The chlorosilane vaporizer for HCVD according to claim 2, characterized in that The top of the vaporizer is further provided with a top flange, the atomizing injector is connected to the top flange, the atomizing injector is provided with a first air inlet pipe and a second air inlet pipe, the first air inlet pipe is used to transport hydrogen, and the second air inlet pipe is used to transport methyltrichlorosilane.

4. The chlorosilane vaporizer for HCVD according to claim 3, characterized in that The positive flange assembly includes: a positive flange, a positive copper tube passing through the positive flange, and a positive graphite electrode passing through the positive copper tube; wherein, an insulating gasket is also sleeved on the positive copper tube, and the insulating gasket is used to insulate between the positive copper tube and the positive flange.

5. The chlorosilane vaporizer for HCVD according to claim 4, characterized in that The vaporizer is also provided with a positive electrode flange, the positive electrode flange is connected to the positive electrode flange, and a sealing gasket is provided between the positive electrode flange and the positive electrode flange. One end of the positive electrode graphite electrode is electrically connected to the positive electrode copper tube, and the other end is electrically connected to the graphite heating element.

6. The chlorosilane vaporizer for HCVD according to claim 3, characterized in that The negative electrode flange assembly includes: a negative electrode flange, a negative electrode copper tube passing through the negative electrode flange, and a negative electrode graphite electrode passing through the negative electrode copper tube; wherein, an insulating gasket is also sleeved on the negative electrode copper tube, and the insulating gasket is used to insulate between the negative electrode copper tube and the negative electrode flange.

7. The chlorosilane vaporizer for HCVD according to claim 6, characterized in that The vaporizer is also provided with a negative electrode flange, the negative electrode flange plate is connected to the negative electrode flange, and a sealing gasket is provided between the negative electrode flange and the negative electrode flange plate. One end of the negative electrode graphite electrode is electrically connected to the graphite heating element, and the other end is electrically connected to the negative electrode copper tube.

8. The chlorosilane vaporizer for HCVD according to claim 3, characterized in that The top of the vaporizer is further provided with a flange, the top flange is connected to the flange, and a sealing gasket is further provided between the flange and the top flange.

9. The chlorosilane vaporizer for HCVD according to claim 1, characterized in that A pad is further provided at the bottom end of the graphite heating element, and the pad is connected to the bottom of the vaporizer.

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