Gas supply device for CVD (Chemical Vapor Deposition)

Abstract

The utility model discloses a gas supply device for CVD (Chemical Vapor Deposition), which comprises a raw material tank and a carrier gas pipeline, a carrier gas bubbling pipe is arranged at the bottom of an inner cavity of the raw material tank, the carrier gas bubbling pipe is communicated with the carrier gas pipeline, the top of the raw material tank is communicated with a gas outlet pipe, a lower heating coil is arranged at the lower part of the side wall of the raw material tank, and the gas outlet pipe is communicated with the gas outlet pipe. An upper heating coil is arranged at the upper part of the side wall of the raw material tank; a first temperature sensor is arranged at the lower part of the side wall of the raw material tank; a second temperature sensor is arranged at the upper part of the side wall of the raw material tank; at least two gas uniformizing plates are further arranged in the inner cavity of the raw material tank, the at least two gas uniformizing plates are arranged at intervals in the vertical direction, and a plurality of through holes are formed in the gas uniformizing plates; and gas flow meters are arranged on the gas outlet pipe and the carrier gas pipeline. According to the utility model, reliable, stable and accurate supply of solid raw materials is realized, the valve on the gas inlet pipe can be prevented from being blocked by arranging the first gas mixing tank and the second gas mixing tank, and the maintenance cost of equipment is reduced.

Description

Technical Field

[0001] The utility model relates to a gas supply device for CVD, belonging to the technical field of chemical vapor deposition (CVD) equipment. Background Art

[0002] CVD (Chemical Vapor Deposition) refers to a technology in which mixed gases react with each other or interact with the surface of a substrate, and a thin film coating of a metal or non-metal compound is formed on the surface of the substrate to modify the surface of the material to meet some special performance requirements.

[0003] In the process of producing and researching high-performance new materials, CVD technology has become an increasingly important method. In particular, CVD technology also plays an extremely important role in the field of semiconductor materials. In the CVD growth technology, the condensed state of the material precursor is divided into gaseous, liquid and solid states. For gaseous precursors, precise control can be achieved by using a gas flow meter. For liquid precursors, the bubbling method that has been developed and widely applied is to bring the liquid into the high-temperature reaction zone through carrier gas bubbling. However, for solid precursors (solid raw materials), how to ensure reliable, stable and precise feeding is a technical problem to be solved. Summary of the Utility Model

[0004] The utility model provides a gas supply device for CVD, which is beneficial to realizing reliable, stable and precise supply of solid raw materials. The specific technical solutions are as follows.

[0005] A gas supply device for CVD includes a raw material tank and a carrier gas pipeline. A carrier gas bubbling tube is arranged at the bottom of the inner cavity of the raw material tank. The carrier gas bubbling tube is communicated with the carrier gas pipeline. An air outlet pipe is communicated with the top of the raw material tank. It is characterized in that: a lower heating coil is arranged at the lower part of the side wall of the raw material tank, and an upper heating coil is arranged at the upper part of the side wall of the raw material tank; a first temperature sensor is arranged at the lower part of the side wall of the raw material tank, and a second temperature sensor is arranged at the upper part of the side wall of the raw material tank; at least two air distribution plates are arranged in the inner cavity of the raw material tank, and at least two air distribution plates are arranged at intervals in the vertical direction. A plurality of through holes are arranged on the air distribution plates; gas flow meters are arranged on both the air outlet pipe and the carrier gas pipeline.

[0006] By adopting the above technical solutions, the solid raw materials can be heated by the lower heating coil to be liquefied, and then the liquefied raw materials can be sent into the air outlet pipe by the carrier gas in the carrier gas bubbling tube. The upper heating coil can precisely control the temperature of the carrier gas in the raw material tank to prevent the raw materials from solidifying; the air distribution plates are helpful for the uniform distribution of the carrier gas; the above solutions are beneficial to relatively reliable and accurate metering control of solid raw materials, and ensure the accuracy and uniformity of solid raw material feeding.

[0007] Furthermore, a pressure sensor is also provided on the raw material tank, which is used to detect and control the air pressure in the raw material tank to ensure safe production and accurate metering of solid raw materials.

[0008] Furthermore, the through holes on two adjacent air distribution plates are staggered in the vertical direction, that is, the through holes above do not align with the through holes below, which is beneficial to the uniformity of the bubbling gas.

[0009] Furthermore, the carrier gas bubbling tube is a circular pipe, and a number of air outlet holes are provided on its side wall. The circular carrier gas bubbling tube is beneficial to uniformly carry out the raw materials from the liquid phase. Since the carrier gas has a certain temperature, the circular carrier gas bubbling tube is beneficial to maintaining the temperature uniformity of the liquid raw materials and preventing local solidification of the liquid raw materials.

[0010] Preferably, the carrier gas pipeline is arranged in a spiral shape, which is beneficial to increasing the length of the carrier gas pipeline and ensuring that the carrier gas maintains an appropriate temperature when being transported into the raw material tank.

[0011] Furthermore, it further includes at least two intake air pipes. At least two of the intake air pipes are communicated with the first gas mixing tank, and the first gas mixing tank is communicated with the second gas mixing tank through a gas mixing inlet pipe; the outlet pipe is communicated with the second gas mixing tank; the second gas mixing tank is communicated with the downstream reaction tank. The provision of the first gas mixing tank upstream of the second gas mixing tank is beneficial to solving the problem that the valves on the intake air pipes are blocked.

[0012] Furthermore, the first gas mixing tank is provided with a side door that can be opened, and the second gas mixing tank is provided with a side door that can be opened. The side door can be fixed to the first gas mixing tank and the second gas mixing tank by means of flange connection, which is convenient for cleaning and troubleshooting of the first and second gas mixing tanks.

[0013] Preferably, stop valves are provided on both the gas mixing inlet pipe and the intake air pipe.

[0014] The utility model is beneficial to realizing reliable, stable and accurate supply of solid raw materials. By providing the first gas mixing tank and the second gas mixing tank, it can prevent the valves on the intake air pipes from being blocked and reduce the equipment maintenance cost. Brief Description of the Drawings

[0015] Figure 1 is a schematic diagram of the gas supply device of the utility model;

[0016] Figure 2 is a schematic diagram of the air distribution plate;

[0017] Figure 3 is a schematic diagram of the carrier gas bubbling tube.

[0018] In the figure: 1 - A intake air pipe, 2 - B intake air pipe, 3 - C intake air pipe, 4 - flowmeter, 5 - mixed gas intake pipe, 6 - outlet pipe, 7 - stop valve, 8 - side door, 9 - float observation window, 10 - float, 11 - pressure sensor, 12 - feeding port, 13 - raw material tank, 14 - upper heating coil, 15 - gas - distributing plate, 15.1 - through - hole, 16 - first temperature sensor, 17 - second temperature sensor, 18 - lower heating coil, 19 - solid raw material, 20 - carrier gas bubbling tube, 20.1 - air outlet hole, 21 - second mixed gas tank, 22 - first mixed gas tank, 23 - gas - distributing box, 24 - carrier gas pipeline. Detailed implementation mode

[0019] The following further describes the present utility model in detail with reference to the drawings.

[0020] See Figures 1 - 3 , a gas supply device for CVD, comprising a raw material tank 13 and a carrier gas pipeline 24. A carrier gas bubbling tube 20 is arranged at the bottom of the inner cavity of the raw material tank 13. The carrier gas bubbling tube 20 is communicated with the carrier gas pipeline 24. The top of the raw material tank 13 is communicated with an outlet pipe 6. A lower heating coil 18 is arranged at the lower part of the side wall of the raw material tank 13, and an upper heating coil 14 is arranged at the upper part of the side wall of the raw material tank 13; a first temperature sensor 16 is arranged at the lower part of the side wall of the raw material tank 13, and a second temperature sensor 17 is arranged at the upper part of the side wall of the raw material tank 13; at least two gas - distributing plates 15 are further arranged in the inner cavity of the raw material tank 13. The at least two gas - distributing plates 15 are arranged at intervals in the vertical direction. A plurality of through - holes 15 - 1 are arranged on the gas - distributing plate 15; gas flowmeters 4 are arranged on both the outlet pipe 6 and the carrier gas pipeline 24; stop valves 7 are arranged on both the mixed gas intake pipe 5 and the intake air pipe.

[0021] Among them, a pressure sensor 11 is further arranged on the raw material tank 13, which is used to detect and control the air pressure in the raw material tank 13 to ensure safe production and accurate metering of solid raw materials.

[0022] Preferably, the through - holes 15 - 1 on two adjacent gas - distributing plates 15 are staggered in the vertical direction. That is, the through - holes 15 - 1 above do not align with the through - holes 15 - 1 below, which is beneficial to the uniformity of the bubbling gas.

[0023] As Figure 3 shown, the carrier gas bubbling tube 20 is a circular pipe, and a plurality of air outlet holes 20 - 1 are arranged on its side wall. The carrier gas bubbling tube 20 being a circular pipe is beneficial to uniformly carry out the raw materials from the liquid phase. Since the carrier gas has a certain temperature, the circular carrier gas bubbling tube 20 is beneficial to maintaining the temperature uniformity of the liquid raw materials and preventing local solidification of the liquid raw materials.

[0024] Preferably, the carrier gas pipeline 24 is arranged in a spiral shape. This is beneficial to increasing the length of the carrier gas pipeline 24 and ensuring that the carrier gas maintains an appropriate temperature when being transported into the raw material tank 13.

[0025] Among them, there are three intake air pipes, namely intake air pipe A 1, intake air pipe B 2, and intake air pipe C 3. The reaction gas and / or inert gas are transported in the intake air pipes. The intake air pipes are communicated with the first gas mixing tank 22. The first gas mixing tank 22 is communicated with the second gas mixing tank 21 through a gas mixing inlet pipe 5; the outlet pipe 6 is communicated with the second gas mixing tank 21; the second gas mixing tank 21 is communicated with the downstream gas distribution box 23, and the gas distribution box 23 is communicated with the downstream reaction tank (not shown). Arranging the first gas mixing tank 22 upstream of the second gas mixing tank 21 is beneficial to solving the problem that the valves on the intake air pipes are blocked during misoperation. After the reaction in the reaction tank is completed, when the valves on intake air pipe A 1, intake air pipe B 2, and intake air pipe C 3 are first closed, or these valves are not closed, but the ventilation has stopped, but at this time the heating of the raw material tank 13 has not stopped and the stop valve 7 of the outlet pipe 6 of the raw material tank has not been closed in time, then the gasified gas of the raw material tank 13 will flow back to the first gas mixing tank 22. Since there is no high-temperature gas input from the intake air pipes, the solid raw materials flowing back into the first gas mixing tank 22 will condense into solids, which can effectively prevent the solid raw material gas from entering intake air pipe A 1, intake air pipe B 2, and intake air pipe C 3, resulting in pipeline blockage and valve blockage.

[0026] Preferably, an openable side door 8 is provided on the first gas mixing tank 22. An openable side door 8 is provided on the second gas mixing tank 21. The side door 8 can be fixed to the first gas mixing tank 22 and the second gas mixing tank 21 by means of flange connection, which is convenient for cleaning and troubleshooting the first and second gas mixing tanks 21.

[0027] A float 10 and a float observation window are also provided in the raw material tank 13, which can provide a rough estimate of the remaining amount of the raw materials. When the raw materials are insufficient, they can be filled in time. A feeding port 12 is provided on the raw material tank 13. In order to maintain the gas temperature, all pipelines and tanks need to be heated and insulated.

[0028] The working principle of the present utility model is as follows: First, the solid raw materials 19 in the raw material tank 13 are heated and liquefied. All heating is turned on. After all pipelines reach the working temperature, ABC reaction gas and / or inert gas are introduced to mix the three gases in the first gas mixing tank 22. Gas A is introduced for bubbling. After bubbling, the gas is evenly distributed by the upper gas distribution plate 15 and then enters the second gas mixing tank 21 from the outlet pipe 6 of the raw material tank 13. At the same time, all valves are opened so that the reaction gas is mixed with the evaporated gas of the solid raw materials and then enters the gas distribution box 23 and the reaction tank for reaction. After the CVD process is completed, all valves and gas inflows are closed. The flow rate of the solid raw materials can be evaluated by subtracting the value of the flow meter of the carrier gas A entering the raw material tank from the flow meter of the outlet pipe 6 of the raw material tank 13.

[0029] The embodiments of the present utility model have been described above in conjunction with the accompanying drawings. Without conflict, the embodiments in the present utility model and the features in the embodiments can be combined with each other. The present utility model is not limited to the above specific embodiments. The above specific embodiments are merely illustrative rather than restrictive. Under the inspiration of the present utility model, those of ordinary skill in the art can also make many forms without departing from the purpose of the present utility model and the scope protected by the claims. All of these fall within the protection scope of the present utility model.

Claims

1. A gas supply device for CVD, comprising a raw material tank (13) and a carrier gas pipeline (24), wherein a carrier gas bubbling tube (20) is arranged at the bottom of the inner cavity of the raw material tank (13), the carrier gas bubbling tube (20) is connected to the carrier gas pipeline (24), and the top of the raw material tank (13) is connected to an outlet pipe (6), characterized in that: A lower heating coil (18) is arranged at the lower part of the side wall of the raw material tank (13), and an upper heating coil (14) is arranged at the upper part of the side wall of the raw material tank (13); a first temperature sensor (16) is arranged at the lower part of the side wall of the raw material tank (13), and a second temperature sensor (17) is arranged at the upper part of the side wall of the raw material tank (13); at least two gas-distributing plates (15) are also arranged in the inner cavity of the raw material tank (13), and at least two gas-distributing plates (15) are arranged at intervals in the vertical direction, and a plurality of through holes (15.1) are arranged on the gas-distributing plates; a gas flow meter (4) is arranged on both the gas outlet pipe (6) and the carrier gas pipe (24).

2. A gas supply device for CVD according to claim 1, characterized in that: The raw material tank (13) is also provided with a pressure sensor (11).

3. A gas supply device for CVD according to claim 1, characterized in that: The through holes (15.1) on adjacent gas-distributing plates (15) are staggered in the vertical direction.

4. A gas supply device for CVD according to claim 1, characterized in that: The carrier gas bubbling tube (20) is a circular tube, and a plurality of gas outlet holes (20.1) are arranged on its side wall.

5. A gas supply device for CVD according to claim 1, characterized in that: The carrier gas pipeline (24) is arranged in a spiral manner.

6. A gas supply device for CVD according to claim 1, characterized in that: It also comprises at least two air inlet pipes, at least two of the air inlet pipes are in communication with a first air mixing tank (22), the first air mixing tank (22) is in communication with a second air mixing tank (21) via an air mixing inlet pipe (5); the air outlet pipe (6) is in communication with the second air mixing tank (21); the second air mixing tank (21) is in communication with a downstream reaction tank.

7. A gas supply device for CVD according to claim 6, characterized in that: The first gas mixing tank (22) is provided with an openable side door (8).

8. A gas supply device for CVD according to claim 6, characterized in that: The second gas mixing tank (21) is provided with an openable side door (8).

9. A gas supply device for CVD according to claim 6, characterized in that: The mixed air intake pipe (5) and the air intake pipe are both provided with a stop valve (7).

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