Vertical alloy furnace tail gas treatment system and treatment method thereof

Abstract

The invention discloses a vertical alloy furnace tail gas treatment system and a treatment method thereof. The treatment system comprises a hydrogen combustion device, an oxygen concentration analyzer and a hydrogen concentration analyzer, the gas inlet end of the hydrogen combustion device is connected to a tail gas exhaust port of the process pipe through a pipeline b, a pipeline c is arranged at the gas exhaust end of the hydrogen combustion device, and the hydrogen combustion device is further connected with a pipeline a for conveying pure hydrogen, so that the pure hydrogen is conveyed into the hydrogen combustion device to be ignited; the oxygen concentration analyzer is connected to the pipeline b in parallel through a pipeline d and is used for detecting the oxygen content in the pipeline b so as to judge whether the hydrogen combustion device is ignited or not; the hydrogen concentration analyzer is connected to the pipeline b in parallel through a pipeline c and used for detecting the hydrogen content in the pipeline b so as to judge whether the hydrogen combustion device flames out or not. The tail gas treatment device has the characteristics of compact structure, convenience in operation, high safety, high reliability and the like, and the tail gas treatment efficiency of the vertical alloy furnace is improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing equipment technology, specifically to a vertical alloy furnace exhaust gas treatment system and its treatment method. Background Technology

[0002] In the semiconductor industry, surface treatment of silicon wafers takes various forms, with different process routes depending on different functional requirements. One such process route involves introducing a reducing gas, H2, to effectively reduce the contact resistance on the surface of the silicon wafer, thereby enhancing the adhesion between the metal and the silicon. The equipment used to implement this process route is called a vertical alloying furnace.

[0003] During the operation of vertical alloy furnaces, due to the use of pure hydrogen or mixed hydrogen processes, a high concentration of hydrogen remains in the process pipelines after production. Upon contact with air, this hydrogen can form an explosive mixture, posing a significant safety hazard. Therefore, the treatment of H2 after the process is completed becomes particularly important.

[0004] Currently, the common method for handling residual H2 is to reserve or install H2 treatment equipment during plant construction. Then, a sealed pipeline connects the outlet of the vertical alloy furnace's process pipe to the inlet of the H2 treatment equipment to complete the H2 treatment. Therefore, existing H2 treatment solutions rely heavily on the plant's existing H2 treatment equipment. In some plant sites, if there is no reserved space for installing an H2 treatment equipment, it is impossible to install a vertical alloy furnace. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a vertical alloy furnace tail gas treatment system and treatment method that is compact, easy to assemble and disassemble, and highly versatile, in order to overcome the shortcomings of the prior art.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A vertical alloy furnace tail gas treatment system includes a hydrogen combustion device, an oxygen concentration analyzer, and a hydrogen concentration analyzer. The inlet of the hydrogen combustion device is connected to the tail gas outlet of a process pipe via pipe b. The exhaust end of the hydrogen combustion device is equipped with pipe c, and the hydrogen combustion device is also connected to pipe a for transporting pure hydrogen, so as to realize the delivery of pure hydrogen to the hydrogen combustion device for ignition. The oxygen concentration analyzer is connected in parallel to pipe b via pipe d to detect the oxygen content in pipe b, thereby determining whether the hydrogen combustion device has ignited. The hydrogen concentration analyzer is connected in parallel to pipe b via pipe c to detect the hydrogen content in pipe b, thereby determining whether the hydrogen combustion device has been extinguished.

[0007] As a further improvement of the present invention, both the oxygen concentration analyzer and the hydrogen concentration analyzer are connected to the pipe c through the pipe f to realize the exhaust of waste gas.

[0008] As a further improvement of the present invention, control valves are provided on pipes b, c, d and e.

[0009] As a further improvement of the present invention, the hydrogen combustion device includes a rotary pipe, a combustion chamber, a transfer chamber and a water-cooled chamber. One end of the rotary pipe is connected to pipe b, and the other end of the rotary pipe is connected to the air inlet of the combustion chamber. The air inlet of the combustion chamber is also connected to pipe a. The exhaust end of the combustion chamber is connected to pipe c in sequence through the transfer chamber and the water-cooled chamber.

[0010] As a further improvement of the present invention, the combustion chamber sidewall is provided with a water-cooling jacket and the combustion chamber top is provided with a water-cooling plate.

[0011] As a further improvement of the present invention, the water-cooled plate is inclined.

[0012] As a further improvement of the present invention, the hydrogen combustion device further includes a venting pipe, which is connected to the rotary pipe and pipe c respectively; when the combustion chamber malfunctions, the exhaust gas from the process pipe is discharged to pipe c through the venting pipe.

[0013] As a further improvement of the present invention, the combustion chamber is provided with an ignition assembly, which includes a resistance wire and a thermocouple, and the resistance wire is integrated with a temperature sensing element.

[0014] As a general technical concept, the present invention also provides a method for treating exhaust gas from a vertical alloy furnace, comprising the following steps: Step S1: Open the fourth pneumatic valve on pipe d. The oxygen concentration analyzer detects the O2 content in the exhaust gas emitted from the process pipe. If the O2 content is within the preset safety range, the exhaust gas treatment process begins. If the O2 content is not within the preset safety range, N2 is introduced into the process pipe through pipe g to reduce the O2 content until the O2 content reaches the safety range. Step S2: Open the first pneumatic valve on pipe b and the second pneumatic valve on pipe c. Introduce H2 into the hydrogen combustion device through pipe a and start ignition and combustion. The hydrogen-containing tail gas in the process pipe is transported to the hydrogen combustion device through pipe b for combustion treatment. The gas after combustion is discharged through pipe c.

[0015] As a further improvement of the present invention, it also includes step S3, after the exhaust gas combustion process is completed, N2 is introduced into the process pipe through pipe g to dilute the H2 content; Step S4: Open the third pneumatic valve on pipe e. The exhaust gas discharged from the process pipe enters the hydrogen concentration analyzer to detect whether the H2 content is within the preset safety range. If the H2 content is within the preset safety range, pipe a stops supplying H2 to the hydrogen combustion device, combustion stops, and the exhaust gas discharged from the process pipe enters pipe c for external discharge. If the H2 content is not within the preset safety range, the hydrogen combustion device continues to burn until the H2 content meets the standard.

[0016] Compared with the prior art, the advantages of the present invention are as follows: The vertical alloy furnace tail gas treatment system and method of the present invention connects the inlet of a hydrogen combustion device to the tail gas outlet of a process pipe via pipe b, and also connects the hydrogen combustion device to pipe a for transporting pure hydrogen. This enables the pure hydrogen to be transported to the hydrogen combustion device for ignition, thereby treating the hydrogen-containing tail gas discharged from the process pipe. Simultaneously, an oxygen concentration analyzer is connected in parallel to pipe b via pipe d to detect the oxygen content of the tail gas discharged from the process pipe. The oxygen content is then used to determine whether the hydrogen combustion device should ignite. The oxygen content in the tail gas and the timing of the hydrogen combustion device ignition are interlocked to effectively ensure the safety of ignition. Furthermore, a hydrogen concentration analyzer is connected in parallel to pipe b via pipe e to detect the hydrogen content of the tail gas discharged from the process pipe. The hydrogen content is then used to determine whether the hydrogen combustion device should be extinguished. The hydrogen content in the tail gas and the conditions for extinguishing the hydrogen combustion device are interlocked to effectively ensure that the hydrogen in the tail gas is completely treated, ensuring the safety of equipment operation. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the gas path principle of the vertical alloy furnace tail gas treatment system in a specific embodiment of the present invention; Figure 2 This is a three-dimensional structural principle diagram of the hydrogen combustion device in a specific embodiment of the present invention; Figure 3 This is a schematic diagram of the main structural principle of the hydrogen combustion device in a specific embodiment of the present invention; Figure 4 This is a schematic diagram of the structural principle of the ignition assembly in a specific embodiment of the present invention; Legend: 1. Hydrogen combustion device; 2. First pneumatic valve; 3. Second pneumatic valve; 4. Third pneumatic valve; 5. Fourth pneumatic valve; 6. Hydrogen concentration analyzer; 7. Oxygen concentration analyzer; 100. Process pipe; 101. Inlet flange; 102. Mounting plate; 103. Combustion chamber; 104. Water cooling jacket; 105. Transfer chamber; 106. Water cooling chamber; 107. Water cooling plate; 108. Manual valve; 109. Rotary pipe; 110. Fifth pneumatic valve; 111. Vent pipe; 112. Fifth pneumatic valve; 1031. Resistance wire; 1032. Thermocouple. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0019] In the description of this invention, it should be understood that the terms "side", "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0020] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more unless otherwise explicitly specified.

[0021] Example like Figure 1 As shown, the vertical alloy furnace tail gas treatment system of the present invention includes: a hydrogen combustion device 1, an oxygen concentration analyzer 7, and a hydrogen concentration analyzer 6. The inlet of the hydrogen combustion device 1 is connected to the tail gas outlet of the process pipe 100 via pipe b. A first pneumatic valve 2 is installed on pipe b. The exhaust end of the hydrogen combustion device 1 is connected to pipe c, and a second pneumatic valve 3 is installed on pipe c. The hydrogen combustion device 1 is also connected to pipe a, which transports pure hydrogen, to enable the pure hydrogen to be delivered to the hydrogen combustion device 1 for ignition, allowing the tail gas from the process pipe 100 to be incinerated within the hydrogen combustion device 1. The oxygen concentration analyzer 7 is connected in parallel to pipe b via pipe d, which has a fourth pneumatic valve 5, to detect the oxygen content in pipe b, thereby determining whether the hydrogen combustion device 1 should ignite. The oxygen content in the tail gas is interlocked with the ignition timing of the hydrogen combustion device 1, effectively ensuring the safety of ignition. The hydrogen concentration analyzer 6 is connected in parallel to the pipe b through the pipe e with the third pneumatic valve 4 to detect the hydrogen content in the pipe b, thereby determining whether the hydrogen combustion device 1 is shut down. The hydrogen content in the exhaust gas is interlocked with the conditions for the hydrogen combustion device to shut down, which effectively ensures that the hydrogen in the exhaust gas is completely treated and ensures the safety of equipment operation.

[0022] In this embodiment, the hydrogen combustion device 1 can be completely disassembled. When the vertical alloy furnace needs to perform tail gas treatment, it can be directly installed as a whole. When it needs to switch to other processes, it can be completely disassembled, which greatly reduces the requirements for the plant and improves the versatility and convenience of the equipment.

[0023] like Figure 1 As shown, both the oxygen concentration analyzer 7 and the hydrogen concentration analyzer 6 are connected to the pipe c via pipe f to achieve exhaust gas discharge. At the same time, the oxygen concentration analyzer 7 and the hydrogen concentration analyzer 6 are also connected to the pipe for conveying nitrogen (not shown in the figure). When the oxygen concentration analyzer 7 and the hydrogen concentration analyzer 6 need to be started, N2 is first introduced for purging and cleaning, and then the exhaust gas from the vertical alloy furnace is introduced.

[0024] like Figure 2 and Figure 3 As shown, the hydrogen combustion device 1 includes a mounting plate 102, a rotary pipe 109, a combustion chamber 103, a transition chamber 105, and a water-cooled chamber 106. The combustion chamber 103, transition chamber 105, and water-cooled chamber 106 are all fixed to the mounting plate 102. The inlet end of the rotary pipe 109 is connected to pipe b via an inlet flange 101, and the outlet end of the rotary pipe 109 is connected to the inlet end of the combustion chamber 103. Due to the light weight of hydrogen, the outlet end of the rotary pipe 109 is vertically upward connected to the combustion chamber 103 to ensure that the hydrogen in the exhaust gas enters the combustion chamber 103 smoothly and smoothly. Simultaneously, by setting the rotary pipe 109 to a multi-loop zigzag structure, the exhaust gas entering the combustion chamber 103 can also be buffered, preventing excessive fluctuations in the exhaust gas flow rate within the combustion chamber 103 that could affect combustion quality. In this embodiment, a fifth pneumatic valve 110 is also provided between the outlet end of the rotary pipe 109 and the inlet end of the combustion chamber 103. The fifth pneumatic valve 110 serves as an inlet switch for the residual H2 mixture to enter the combustion chamber 103, thereby controlling the flow rate of the mixture entering the combustion chamber 103. It is understood that the combustion chamber 103, as an apparatus for H2 combustion treatment, can adopt conventional settings in the art, and will not be described in detail here.

[0025] In this embodiment, the inlet of combustion chamber 103 is also connected to pipe a for delivering pure hydrogen, so as to deliver pure hydrogen into combustion chamber 103. The exhaust of combustion chamber 103 is connected to pipe c in sequence through transfer chamber 105 and water-cooling chamber 106. The combustion mixture discharged from combustion chamber 103 first enters transfer chamber 105 for buffering, then enters water-cooling chamber 106 for cooling, and then enters pipe c. A second pneumatic valve 3 is also provided between water-cooling chamber 106 and pipe c to control the flow rate of combustion mixture entering pipe c. A manual valve 108 is also provided at the outlet of pipe c. The manual valve 108 is normally open and closes in case of emergency backflow.

[0026] Furthermore, a water-cooling jacket 104 is provided on the side wall of the combustion chamber 103, and a water-cooling plate 107 is provided on the top of the combustion chamber 103. The water-cooling plate 107 is installed obliquely on the inner side of the top of the combustion chamber 103, serving a guiding function while providing cooling.

[0027] After the production process in process pipe 100 is completed, N2 is introduced through pipe g for purging to form positive pressure. The mixed gas containing H2 enters the combustion chamber 103 through rotary pipe 109. At this time, the second pneumatic valve 3 and the fifth pneumatic valve 110 are in the open state. The water cooling jacket 104, the water cooling chamber 106 and the water cooling plate 107 are connected in series through water pipes to cool the heat generated by the combustion chamber 103 when H2 is burned, and at the same time reduce the temperature of the gas. There is negative pressure at the tail outlet of pipe c to suck away the treated mixed gas.

[0028] like Figure 4 As shown, the combustion chamber 103 is equipped with an ignition assembly, which includes a resistance wire 1031 and a thermocouple 1032, and the resistance wire 1031 is integrated with the temperature sensing element.

[0029] At the start of the exhaust gas treatment process, the resistance wire 1031 begins to heat up. The temperature is detected and controlled by a temperature sensing element integrated on the resistance wire 1031. Heating stops when the H2 combustion temperature is reached. During the exhaust gas treatment process, the H2 in the pipeline burns in the combustion chamber 103, and the temperature is monitored and controlled by the thermocouple 1032. The temperature sensing element in the resistance wire 1031 and the thermocouple 1032 have overlapping functions. The simultaneous use of two temperature sensing components prevents temperature monitoring failure due to damage to the sensing components.

[0030] like Figure 2 As shown, the hydrogen combustion device 1 also includes a vent pipe 111 with a sixth pneumatic valve 112, which is connected to the rotary pipe 109 and pipe c. When the combustion chamber 103 malfunctions, the exhaust gas from the process pipe 100 is discharged to pipe c via the vent pipe 111. Simultaneously, a branch line with a one-way valve (not shown) can be installed on pipe c. When the combustion chamber 103 malfunctions and exhaust gas needs to be discharged from the vent pipe 111 and pipe c, N2 is introduced into pipe c through the branch line to dilute the exhaust gas before it is discharged, thereby improving the safety of exhaust gas discharge.

[0031] In this embodiment, a method for treating exhaust gas from a vertical alloy furnace is also provided, comprising the following steps: Step S1: Open the fourth pneumatic valve 5 on pipeline d. The oxygen concentration analyzer 7 detects the O2 content in the exhaust gas emitted from process pipe 100. If the O2 content is within the preset safety range, the exhaust gas treatment process begins. If the O2 content is not within the preset safety range, N2 is introduced into process pipe 100 through pipeline g to reduce the O2 content until it reaches the safety range. It can be understood that before the exhaust gas treatment process begins, N2 is introduced into pipeline g to purge the oxygen concentration analyzer 7 and clean it.

[0032] Step S2: Open the first pneumatic valve 2 on pipe b and the second pneumatic valve 3 on pipe c. Introduce H2 into the hydrogen combustion device 1 through pipe a and start ignition and combustion. The hydrogen-containing tail gas in the process pipe 100 is transported to the hydrogen combustion device 1 through pipe b for combustion treatment. The gas after combustion is discharged through pipe c.

[0033] Step S3: After the exhaust gas combustion process is completed, N2 is introduced into process pipe 100 through pipe g to dilute the H2 content.

[0034] Step S4: Open the third pneumatic valve 4 on pipeline e. The exhaust gas discharged from process pipe 100 enters the hydrogen concentration analyzer 6 to detect whether the H2 content is within the preset safety range. If the H2 content is within the preset safety range, pipeline a stops supplying H2 to the hydrogen combustion device 1, combustion stops, and the exhaust gas discharged from process pipe 100 enters pipeline c for external discharge. If the H2 content is not within the preset safety range, the hydrogen combustion device 1 continues to burn until the H2 content meets the standard.

[0035] In this embodiment, a reliable safety interlock exists during the exhaust gas treatment process: the exhaust gas treatment process can only begin when the O2 concentration meets the standard, ensuring that H2 will not spontaneously combust; simultaneously, combustion can only be stopped when the H2 content meets the standard, otherwise, excessively high H2 concentration in the residual gas will pose a risk of spontaneous combustion. Correspondingly, when the combustion chamber 103 in the hydrogen combustion device 1 malfunctions, pipe a stops supplying H2, the first pneumatic valve 2 and the second pneumatic valve 3 close, and the sixth pneumatic valve 112 opens. The gas in the process pipe 100 bypasses the combustion chamber 103 and directly enters the exhaust pipe c through the vent pipe 111. Simultaneously, N2 is introduced into a branch of the exhaust pipe c to dilute the H2 content in pipe c. The same steps are followed during power outages, aiming to ensure that H2 does not spontaneously combust under special circumstances.

[0036] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A vertical alloy furnace exhaust gas treatment system, characterized in that, include: The hydrogen combustion device (1), oxygen concentration analyzer (7), and hydrogen concentration analyzer (6) are provided. The inlet of the hydrogen combustion device (1) is connected to the exhaust port of the process pipe (100) through pipe b. The exhaust end of the hydrogen combustion device (1) is provided with pipe c. The hydrogen combustion device (1) is also connected to pipe a for transporting pure hydrogen so that pure hydrogen can be transported to the hydrogen combustion device (1) for ignition. The oxygen concentration analyzer (7) is connected in parallel to pipe b through pipe d to detect the oxygen content in pipe b and thus determine whether the hydrogen combustion device (1) is ignited. The hydrogen concentration analyzer (6) is connected in parallel to pipe b through pipe e to detect the hydrogen content in pipe b and thus determine whether the hydrogen combustion device (1) is extinguished.

2. The vertical alloy furnace tail gas treatment system according to claim 1, characterized in that, The oxygen concentration analyzer (7) and the hydrogen concentration analyzer (6) are both connected to the pipe c through the pipe f to achieve the discharge of waste gas.

3. The vertical alloy furnace tail gas treatment system according to claim 1, characterized in that, Control valves are installed on pipes b, c, d, and e.

4. The vertical alloy furnace tail gas treatment system according to any one of claims 1 to 3, characterized in that, The hydrogen combustion device (1) includes a rotary pipe (109), a combustion chamber (103), a transfer chamber (105), and a water-cooled chamber (106). One end of the rotary pipe (109) is connected to pipe b, and the other end of the rotary pipe (109) is connected to the air inlet of the combustion chamber (103). The air inlet of the combustion chamber (103) is also connected to pipe a. The exhaust end of the combustion chamber (103) is connected to pipe c in sequence through the transfer chamber (105) and the water-cooled chamber (106).

5. The vertical alloy furnace tail gas treatment system according to claim 4, characterized in that, The combustion chamber (103) has a water-cooled jacket (104) on its side wall and a water-cooled plate (107) on its top.

6. The vertical alloy furnace tail gas treatment system according to claim 5, characterized in that, The water-cooled plate (107) is set at an angle.

7. The vertical alloy furnace tail gas treatment system according to claim 4, characterized in that, The hydrogen combustion device (1) also includes a vent pipe (111), which is connected to the rotary pipe (109) and pipe c respectively; when the combustion chamber (103) malfunctions, the exhaust gas of the process pipe (100) is discharged to pipe c through the vent pipe (111).

8. The vertical alloy furnace tail gas treatment system according to claim 4, characterized in that, The combustion chamber (103) is equipped with an ignition assembly, which includes a resistance wire (1031) and a thermocouple (1032), and the resistance wire (1031) is integrated with a temperature measuring element.

9. A method for treating exhaust gas from a vertical alloy furnace, characterized in that, Includes the following steps: Step S1: Open the fourth pneumatic valve (5) on pipe d. The oxygen concentration analyzer (7) detects the O2 content in the exhaust gas emitted by the process pipe (100). If the O2 content is within the preset safe range, the exhaust gas treatment process is started. If the O2 content is not within the preset safe range, N2 is introduced into the process pipe (100) through pipe g to reduce the O2 content until the O2 content reaches the safe range. Step S2: Open the first pneumatic valve (2) on pipe b and the second pneumatic valve (3) on pipe c. Introduce H2 into the hydrogen combustion device (1) through pipe a and start ignition and combustion. The hydrogen-containing tail gas in the process pipe (100) is transported to the hydrogen combustion device (1) through pipe b for combustion treatment. The gas after combustion is discharged through pipe c.

10. The method for treating tail gas from a vertical alloy furnace according to claim 9, characterized in that, It also includes step S3, after the exhaust gas combustion process is completed, N2 is introduced into the process pipe (100) through pipe g to dilute the H2 content; Step S4: Open the third pneumatic valve (4) on pipe e. The exhaust gas discharged from the process pipe (100) enters the hydrogen concentration analyzer (6) to detect whether the H2 content is within the preset safety range. If the H2 content is within the preset safety range, pipe a stops supplying H2 to the hydrogen combustion device (1) and stops combustion. The exhaust gas discharged from the process pipe (100) enters pipe c for external discharge. If the H2 content is not within the preset safety range, the hydrogen combustion device (1) continues to burn until the H2 content meets the standard.

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