A semiconductor crystal growth tail gas recovery device

Abstract

The utility model relates to the technical field of crystal growth discloses a semiconductor crystal growth tail gas recovery device, including the cooling assembly, residual gas recovery assembly and waste gas treatment assembly that connect through pipeline in proper order, be equipped with the air inlet pipe on the cooling assembly, the other end of air inlet pipe is used for connecting the quartz tube for semiconductor crystal growth, realizes the arsenic or red phosphorus gas that the quartz tube inside discharged is introduced cooling assembly and cools to make arsenic or red phosphorus vapor solidify into solid particle, residual gas recovery assembly is used for carrying out chemical reaction recovery to the arsenic or red phosphorus gas that is not completely cooled in cooling assembly, waste gas treatment assembly is used for absorbing the exhaust gas that residual gas recovery assembly inside discharged, the device of the present application, not only realized the recovery of arsenic and red phosphorus, and direct cooling recovery, will not produce high temperature, avoided the explosion that red phosphorus self -ignition produced, improved the safety factor, also avoided the environmental pollution simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of crystal growth technology, and in particular to a semiconductor crystal growth tail gas recovery device. Background Technology

[0002] During the crystal growth process of compound semiconductor crystals, a small amount of intrinsic material (pure semiconductor free of impurities and lattice defects) is added as a pressure balancing agent to maintain pressure balance within the quartz tube during crystal growth. Common compound semiconductors include gallium arsenide (GaAs) and indium phosphide (IPT). In the growth of gallium arsenide single crystals, a small amount of elemental arsenic is added. At high temperatures, the arsenic sublimates into arsenic vapor, maintaining the pressure inside the quartz tube and preventing tube shrinkage and cracking due to insufficient pressure. Similarly, the growth of IPT single crystals also requires the addition of a small amount of red phosphorus to maintain pressure within the quartz tube.

[0003] However, after preparing gallium arsenide or indium phosphide crystals, some arsenic or red phosphorus residues often remain on the inner wall of the quartz tube. Existing technologies remove arsenic or red phosphorus residues from the inner wall of the quartz tube by corrosion with strong acid. Not only do the arsenic or red phosphorus react with the strong acid, making them unrecoverable, but the high temperature generated by the corrosion cleaning can also cause the red phosphorus to spontaneously combust and explode, increasing safety hazards; at the same time, it also pollutes the environment. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides a semiconductor crystal growth tail gas recovery device that recovers arsenic and red phosphorus, avoids the spontaneous combustion of red phosphorus and explosion, improves the safety factor, and avoids environmental pollution.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] A semiconductor crystal growth exhaust gas recovery device includes a cooling component, a residual gas recovery component, and an exhaust gas treatment component connected in sequence via pipes. The cooling component is equipped with an inlet pipe, the other end of which is used to connect to a quartz tube for semiconductor crystal growth, so as to introduce arsenic or red phosphorus gas discharged from the quartz tube into the cooling component for cooling, so that the arsenic or red phosphorus vapor condenses into solid particles. The residual gas recovery component is used to recover the arsenic or red phosphorus gas that is not completely cooled in the cooling component through a chemical reaction. The exhaust gas treatment component is used to absorb the exhaust gas discharged from the residual gas recovery component.

[0007] Preferably, the cooling assembly includes a cooling tank, the interior of which is filled with coolant, the side wall of which is provided with an inlet pipe for replenishing coolant, the bottom wall of which is provided with a drain pipe, the upper end of which is provided with an exhaust pipe connected to the residual gas recovery assembly, and the end of the exhaust pipe connected to the cooling assembly extends through the outer wall of the cooling tank into the coolant.

[0008] Preferably, the bottom wall of the cooling tank is inclined towards the horizontal plane, with one side being the high end and the other side being the bottom end, and the drain pipe is located near the high end.

[0009] Preferably, the angle between the bottom wall and the horizontal plane is α, and the value of α ranges from 15° to 20°.

[0010] Preferably, the temperature of the coolant is 2 to 10°C.

[0011] Preferably, the residual gas recovery assembly includes a recovery tank, the upper end of which is provided with a recovery liquid inlet and a connecting pipe, the other end of which is connected to the waste gas treatment assembly, the inside of which is provided with recovery liquid, and the side wall of which is provided with a recovery liquid discharge port.

[0012] Preferably, the recovered liquid is concentrated nitric acid or aqua regia.

[0013] Preferably, the waste gas treatment assembly includes a treatment tank, and the interior of the treatment tank contains a treatment liquid.

[0014] Preferably, the treatment solution is pure water.

[0015] This invention discloses a semiconductor crystal growth tail gas recovery device. Compared with existing technologies, its advantages lie in the following: A cooling component, a residual gas recovery component, and a waste gas treatment component are sequentially connected by pipes. The cooling component is equipped with an inlet pipe, the other end of which is connected to a quartz tube used for semiconductor crystal growth. After the semiconductor crystal growth is complete, the arsenic or red phosphorus gas discharged from the quartz tube is introduced into the cooling component through the inlet pipe for cooling, causing the arsenic or red phosphorus vapor to condense into solid particles for recovery. The arsenic or red phosphorus gas that is not completely cooled in the cooling component enters the residual gas recovery component for chemical reaction recovery, avoiding the discharge of arsenic or red phosphorus-containing residual gas and environmental pollution. The waste gas discharged after the chemical reaction contains acidic chemical gases, which are absorbed in the waste gas treatment component, preventing the acidic chemical gases from being directly discharged into the air and polluting the environment. The entire process not only achieves the recovery of arsenic and red phosphorus but also directly cools and recovers them without generating high temperatures, avoiding the risk of spontaneous combustion of red phosphorus and explosion, thus improving the safety factor and preventing environmental pollution. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the semiconductor crystal growth tail gas recovery device of this utility model.

[0017] Figure 2 This is a schematic diagram of the cooling component of this utility model.

[0018] Figure 3This is a schematic diagram illustrating the application of the semiconductor crystal growth tail gas recovery device of this utility model.

[0019] Wherein: 1-Cooling component, 11-Cooling tank, 111-Bottom wall, 12-Coolant, 13-Inlet pipe, 14-Drain pipe, 2-Residual gas recovery component, 21-Recovery tank, 22-Recovery liquid inlet, 23-Recovery liquid, 24-Recovery liquid outlet, 3-Waste gas treatment component, 31-Treatment tank, 32-Treatment liquid, 4-Inlet pipe, 5-Exhaust pipe, 6-Connecting pipe, 100-Quartz tube. Detailed Implementation

[0020] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0021] like Figure 1-3 As shown in the preferred embodiment of this utility model, a semiconductor crystal growth tail gas recovery device includes a cooling component 1, a residual gas recovery component 2, and a waste gas treatment component 3 connected in sequence by pipes. The cooling component 1 is provided with an air inlet pipe 4, the other end of which is used to connect to a quartz tube 100 for semiconductor crystal growth, so as to introduce arsenic or red phosphorus gas discharged from the quartz tube 100 into the cooling component 1 for cooling, so that the arsenic or red phosphorus vapor condenses into solid particles. The residual gas recovery component 2 is used to chemically react and recover the arsenic or red phosphorus gas that is not completely cooled in the cooling component 1. The waste gas treatment component 3 is used to absorb the waste gas discharged from the residual gas recovery component 2.

[0022] The semiconductor crystal growth exhaust gas recovery device based on the above features comprises a cooling component 1, a residual gas recovery component 2, and an exhaust gas treatment component 3 connected sequentially by pipelines. The cooling component is equipped with an inlet pipe 4, the other end of which is connected to a quartz tube 100 used for semiconductor crystal growth. After the semiconductor crystal growth is completed, the arsenic or red phosphorus gas discharged from the quartz tube 100 is introduced into the cooling component 1 through the inlet pipe 4 for cooling, causing the arsenic or red phosphorus vapor to condense into solid particles for recovery. The arsenic or red phosphorus gas that is not completely cooled in the cooling component 1 enters the residual gas recovery component 2 for chemical reaction recovery, preventing the discharge of arsenic or red phosphorus-containing residual gas and environmental pollution. The exhaust gas discharged after the chemical reaction contains acidic chemical gases, which are absorbed in the exhaust gas treatment component 3, preventing direct discharge of acidic chemical gases into the air and environmental pollution. The entire process not only achieves the recovery of arsenic and red phosphorus but also directly cools and recovers them without generating high temperatures, avoiding the risk of spontaneous combustion and explosion of red phosphorus, thus improving the safety factor and preventing environmental pollution.

[0023] In this embodiment, the cooling assembly 1 includes a cooling tank 11, which is the main structure of the cooling assembly 1 and is made of materials such as quartz or ceramic. The cooling tank 11 contains a coolant 12. The side wall of the cooling tank 11 has an inlet pipe 13 for replenishing the coolant, serving as the channel for the coolant 12 to enter the cooling tank 11. The bottom wall of the cooling tank 11 has a drain pipe 14, serving as the channel for the coolant 12 to drain out. That is, the coolant 12 enters the cooling tank 11 through the inlet pipe 13 and exits through the drain pipe 14, achieving circulation of the coolant 12 and ensuring that the temperature of the coolant 12 remains between 2 and 10°C, such as 3°C, 4°C, 5°C, 6°C, 7°C, 8°C, or 9°C, thereby maintaining the cooling effect on arsenic or red phosphorus. The inlet pipe 13 and the drain pipe 14 can be connected via a pump, refrigeration equipment, etc., or they can be independent and operate independently.

[0024] The upper end of the cooling tank 11 is provided with an exhaust pipe 5 connected to the residual gas recovery assembly 2, which is used to introduce the arsenic or red phosphorus gas that is not completely cooled in the cooling assembly 1 into the residual gas recovery assembly 2. One end of the air inlet pipe 4 connected to the cooling assembly 1 passes through the outer wall of the cooling tank 11 and extends into the coolant 12, so that the exhaust gas is directly introduced into the coolant 12, thereby achieving rapid cooling and solidification of the arsenic or red phosphorus in the exhaust gas.

[0025] In this embodiment, to facilitate the collection of cooled arsenic or red phosphorus while ensuring the cooling effect of the coolant 12, the bottom wall 111 of the cooling tank 11 is inclined towards the horizontal plane, with one side being the high end and the other side being the low end. The drain pipe 14 is positioned close to the high end, allowing the solidified arsenic or red phosphorus to concentrate at the lowest point of the cooling tank 11, preventing it from being drained away with the cooling water and thus uncollectible. Specifically, if the angle between the bottom wall 111 and the horizontal plane is α, then the value of α ranges from 15 to 20°, such as 16°, 16.5°, 17°, 17.5°, 18°, 18.5°, 19°, 19.5°, etc. If the inclination angle α is designed to be too large, it will hinder the circulation and cooling of the coolant, resulting in a higher water temperature at the bottom of the cooling tank 11 and a reduced cooling effect. If the inclination angle α is designed to be too small, the solidified arsenic or red phosphorus particles will not be able to quickly slide down to the lowest point of the cooling tank 11, and some particles will be drained away with the cooling water. Setting the value of 'a' in the range of 15 to 20° can ensure both good cooling effect and complete collection of cooled arsenic or red phosphorus.

[0026] In this embodiment, the residual gas recovery component 2 includes a recovery tank 21, which is the main structure of the residual gas recovery component 2 and is made of materials such as quartz and ceramic. The upper end of the recovery tank 21 is provided with a recovery liquid inlet 22 and a connecting pipe 6. The other end of the connecting pipe 6 is connected to the waste gas treatment component 3. The waste gas discharged after the chemical reaction is introduced into the waste gas treatment component 3 through the connecting pipe 6 and absorbed. The recovery tank 21 contains a recovery liquid 23, and the side wall of the recovery tank 21 is provided with a recovery liquid discharge port 24. That is, the recovery liquid 23 enters the recovery tank 21 through the recovery liquid inlet 22 and is discharged through the recovery liquid discharge port 24 when it needs to be discharged. The recovery liquid 23 uses different chemicals depending on the different waste gas substances being recovered; for example, aqua regia is used to recover arsenic waste gas, and concentrated nitric acid is used to recover red phosphorus. One end of the exhaust pipe 5, connected to the recovery tank 21, extends into the recovery liquid 23 to ensure good recovery of residual gas.

[0027] In this embodiment, the waste gas treatment component 3 includes a treatment tank 31, inside which a treatment liquid 32 is provided. One end of the connecting pipe 6, which is connected to the treatment tank 31, extends into the treatment liquid 32. The treatment tank 31 is made of materials such as quartz or ceramic, and its top is open to directly discharge the treated gas.

[0028] In addition, since the exhaust gas discharged after the chemical reaction mainly contains acidic chemical gases, which can be directly dissolved in water, the treatment liquid 32 can be made of pure water.

[0029] To illustrate the technical effects of this application, two specific embodiments are listed below:

[0030] Example 1

[0031] Step 1: The exhaust gas from the growth of gallium arsenide single crystal is heated to 630°C, so that the arsenic-containing vapor enters the cooling component 1 from the quartz tube 100 through the inlet pipe 4.

[0032] Step 2: Coolant 12 is introduced through inlet pipe 13 and coolant 12 is drained through outlet pipe 14 to circulate coolant 12 and maintain water temperature at 2-4℃; arsenic-containing exhaust gas forms arsenic particles after passing through coolant 12 and is concentrated at the bottom of cooling tank 11 of cooling component 1.

[0033] Step 3: The exhaust gas after passing through the cooling component 1 is discharged into the recovery liquid 23 of the residual gas recovery component 2 through the exhaust pipe 5. The recovery liquid 23 is aqua regia composed of hydrochloric acid and nitric acid in a 3:1 ratio. The aqua regia reacts with the arsenic-containing exhaust gas that has not been completely cooled to remove the residual arsenic.

[0034] Step 4: The exhaust gas from the residual gas recovery component 2 is discharged into the pure water of the exhaust gas treatment component 3 through the connecting pipe 6. Since the residual gas recovery component 2 contains aqua regia, the gas discharged into the exhaust gas treatment component 3 will contain acidic gas. The acidic gas is mixed with the pure water, which can directly remove the acidic gas.

[0035] Example 2

[0036] Step 1: The tail gas from the growth of indium phosphide single crystals is heated to 420°C, so that the vapor containing red phosphorus enters the cooling component 1 from the quartz tube 100 through the air inlet pipe 4.

[0037] Step 2: Coolant 12 is introduced through inlet pipe 13 and coolant 12 is drained through outlet pipe 14 to circulate coolant 12 and maintain water temperature at 2-4℃; the exhaust gas containing red phosphorus forms red phosphorus particles after passing through coolant 12 and is concentrated at the bottom of cooling tank 11 of cooling component 1.

[0038] Step 3: The exhaust gas after passing through the cooling component 1 is discharged into the recovery liquid 23 of the residual gas recovery component 2 through the exhaust pipe 5. The recovery liquid 23 is nitric acid with a concentration of 68-70%. The nitric acid reacts with the incompletely cooled exhaust gas containing red phosphorus to remove the residual red phosphorus.

[0039] Step 4: The exhaust gas from the residual gas recovery component 2 is discharged into the pure water of the exhaust gas treatment component 3 through the connecting pipe 6. Since the residual gas recovery component 2 contains nitric acid, the gas discharged into the exhaust gas treatment component 3 will contain acidic gas. The acidic gas is mixed with pure water, which can directly remove the acidic gas.

[0040] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A semiconductor crystal growth tail gas recovery device, characterized in that: The device includes a cooling assembly, a residual gas recovery assembly, and an exhaust gas treatment assembly connected in sequence via pipes. The cooling assembly is equipped with an air inlet pipe, the other end of which is used to connect to a quartz tube for semiconductor crystal growth. This allows arsenic or red phosphorus gas discharged from the quartz tube to be introduced into the cooling assembly for cooling, so that the arsenic or red phosphorus vapor condenses into solid particles. The residual gas recovery assembly is used to chemically recover any arsenic or red phosphorus gas that has not been completely cooled in the cooling assembly. The exhaust gas treatment assembly is used to absorb the exhaust gas discharged from the residual gas recovery assembly.

2. The semiconductor crystal growth tail gas recovery device as described in claim 1, characterized in that: The cooling assembly includes a cooling tank containing coolant. The cooling tank has an inlet pipe on its side wall for replenishing coolant, a drain pipe on its bottom wall, and an exhaust pipe at its upper end that is connected to the residual gas recovery assembly. One end of the exhaust pipe connected to the cooling assembly passes through the outer wall of the cooling tank and extends into the coolant.

3. The semiconductor crystal growth tail gas recovery device as described in claim 2, characterized in that: The bottom wall of the cooling tank is inclined towards the horizontal plane, with one side being the high end and the other side being the bottom end, and the drain pipe is located near the high end.

4. The semiconductor crystal growth tail gas recovery device as described in claim 3, characterized in that: The angle between the bottom wall and the horizontal plane is α, and the value of α ranges from 15° to 20°.

5. The semiconductor crystal growth tail gas recovery device as described in claim 2, characterized in that: The temperature of the coolant is 2 to 10°C.

6. The semiconductor crystal growth tail gas recovery device according to any one of claims 1-5, characterized in that: The residual gas recovery assembly includes a recovery tank, the upper end of which is provided with a recovery liquid inlet and a connecting pipe, the other end of which is connected to the waste gas treatment assembly, the inside of which is provided with recovery liquid, and the side wall of which is provided with a recovery liquid discharge port.

7. The semiconductor crystal growth tail gas recovery device as described in claim 6, characterized in that: The recovered liquid is concentrated nitric acid or aqua regia.

8. The semiconductor crystal growth tail gas recovery device according to any one of claims 1-5, characterized in that: The waste gas treatment assembly includes a treatment tank, and the interior of the treatment tank contains a treatment liquid.

9. The semiconductor crystal growth tail gas recovery device as described in claim 8, characterized in that: The treatment solution is pure water.

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