A bubbler
By setting a sedimentation section at the bottom of the bubbler barrel and optimizing the air inlet direction, combined with a bubble diffuser, the problem of reduced monocrystalline silicon quality caused by the accumulation of metal impurities was solved, achieving efficient, clean, and high-quality monocrystalline silicon production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZING SEMICON CORP
- Filing Date
- 2025-05-27
- Publication Date
- 2026-07-24
AI Technical Summary
During use, existing bubblers are prone to accumulating metallic impurities, which leads to a decline in the crystal quality and electrical properties of monocrystalline silicon. Furthermore, traditional cleaning methods are costly and ineffective.
A settling section is set at the bottom of the bubbler barrel to hold the precipitated metal impurities, which are then discharged through a drain pipe. The liquid inlet is located outside the opening of the settling section, and the air inlet is vertical or obliquely upward. Combined with a bubble diffuser, the bubble dispersion is increased and the impurity tumbling is reduced.
It effectively reduces the metal ion content in the mixed gas, reduces defects in the monocrystalline silicon generation process, improves product quality and generation efficiency, and avoids the need for complete replacement.
Smart Images
Figure CN224541766U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor manufacturing, and more particularly, to a bubbler. Background Art
[0002] Monocrystalline silicon is an essential material in the semiconductor manufacturing process. In the process of producing monocrystalline silicon, a common process is to react trichlorosilane with hydrogen. Usually, through methods such as chemical vapor deposition (CVD), a mixture of trichlorosilane gas and hydrogen undergoes a chemical reaction on the surface of a high-temperature silicon wafer. During the reaction, trichlorosilane decomposes at high temperature, and silicon atoms deposit on the silicon wafer surface, gradually growing into monocrystalline silicon while generating hydrogen chloride gas. In actual production, a bubbler is usually used to introduce hydrogen into liquid trichlorosilane to obtain a mixture of trichlorosilane and hydrogen for the subsequent monocrystalline silicon production process. During use, metal particles shed from the inner wall of the pipeline enter the liquid to form metal impurities, which continuously flow into the bubbler with the liquid. Therefore, after a period of use, a large amount of metal impurities will accumulate in the bubbler, causing the output mixture gas to contain excessive metal ions, thereby reducing the crystal quality and electrical properties of monocrystalline silicon, especially shortening the lifetime of minority carriers in monocrystalline silicon. In severe cases, it may even lead to the complete scrapping of the product.
[0003] However, existing bubblers usually lack effective impurity collection and discharge means, so usually only the entire bubbler can be replaced, which not only consumes manpower and material resources but also has a high cost. Although some bubblers may have a discharge port at the bottom for discharging metal impurities, during the use of these bubblers, the metal impurities inside are easily tumbled by the trichlorosilane liquid flow, thus spreading in the trichlorosilane liquid, on the one hand increasing the contact between metal impurities and trichlorosilane, making the output mixture gas contain more metal ions, and on the other hand, it is also easy to cause incomplete discharge of metal impurities, resulting in a high content of metal impurities in the bubbler. Therefore, the overall effect is not ideal. Summary of the Utility Model
[0004] The purpose of the embodiment of this application is to provide a bubbler, with a precipitation part provided at the bottom of its barrel body for centrally accommodating the metal impurities precipitated in liquid trichlorosilane, and the impurities can be discharged through a discharge pipe. Since the projection of the liquid inlet on the bottom surface of the barrel body is located outside the opening of the precipitation part, the trichlorosilane liquid flow injected into the bubbling barrel will not impact the impurities in the precipitation part, thereby reducing the tumbling of impurities and effectively reducing the content of metal ions in the output mixture gas.
[0005] The present application provides a bubbler, which includes a bubbling barrel, a liquid inlet pipe, a gas inlet pipe, an air outlet pipe and a discharge pipe. Among them, the bubbling barrel includes a barrel cover and a hollow barrel body. The center of the bottom surface of the barrel body bulges downward partially to form a precipitation part for accommodating precipitated impurities. The opening of the precipitation part is smaller than the bottom surface of the barrel body. The liquid inlet pipe penetrates the barrel cover from top to bottom. The central axis of the liquid inlet pipe is parallel to the central axis of the barrel body. The end of the liquid inlet pipe is provided with a liquid inlet, and the projection of the liquid inlet on the bottom surface of the barrel body is located outside the opening of the precipitation part. The gas inlet pipe penetrates the barrel cover from top to bottom, and the end of the gas inlet pipe is provided with a gas inlet. The air outlet pipe penetrates the barrel cover from top to bottom. One end of the discharge pipe is connected to the bottom of the precipitation part. A discharge valve is also provided on the discharge pipe.
[0006] In an implementable solution, the opening direction of the gas inlet is vertically upward or obliquely upward.
[0007] In an implementable solution, the opening direction of the gas inlet forms an angle of 45°-90° with the horizontal plane.
[0008] In an implementable solution, a bubble diffuser is provided on the gas inlet for increasing the dispersion degree of the bubbles formed by hydrogen in liquid trichlorosilane.
[0009] In an implementable solution, the bubble diffuser is a conical diffuser with openings at both ends.
[0010] In an implementable solution, the bubble diffuser is a box-shaped diffuser with multiple small holes on its surface.
[0011] In an implementable solution, a sealing layer is provided between the barrel cover and the barrel body of the bubbling barrel, and sealing members are respectively provided at the positions where the liquid inlet pipe, the gas inlet pipe and the air outlet pipe contact the barrel cover.
[0012] In an implementable solution, a pressure regulating valve is provided on the gas inlet pipe, and the pressure regulating valve is used to regulate the pressure of the gas introduced into the bubbling barrel by the gas inlet pipe.
[0013] In an implementable solution, the controller is signal-connected to the discharge valve for controlling the discharge valve to automatically discharge the deposited impurities to the outside.
[0014] Compared with the prior art, the beneficial effects of the present application at least include:
[0015] The present application provides a bubbler. By providing a precipitation part at the bottom of the barrel body, it can centrally accommodate the metal impurities precipitated in liquid trichlorosilane. And after the impurity amount accumulates to a certain extent, the discharge valve can be opened to discharge the impurities through the discharge pipe, realizing the cleaning of the inside of the bubbling barrel, without the need for overall replacement like some traditional bubbling barrels. In addition, since the opening of the precipitation part is smaller than the bottom surface of the barrel body, and the projection of the liquid inlet on the bottom surface of the barrel body is located outside the opening of the precipitation part, the trichlorosilane liquid flow injected into the bubbling barrel from the liquid inlet will not impact the impurities accumulated in the precipitation part, which helps to avoid the dispersion of impurities in liquid trichlorosilane due to tumbling, thereby effectively reducing the metal ion content in the mixed gas output by the bubbler and ensuring the product quality of the subsequent single-crystal silicon production process.
[0016] Furthermore, the air inlet direction of the bubbler provided by the present application is vertically upward or obliquely upward, which also helps to prevent the air flow from impacting the precipitated impurities, better avoiding the tumbling of impurities and reducing the metal ion content in the mixed gas. In addition, by providing a bubble diffuser on the air inlet, it helps to inject hydrogen more dispersedly into liquid trichlorosilane, forming more bubbles with smaller sizes, thereby increasing the contact area between hydrogen and trichlorosilane, making the mixed gas output by the bubbler contain more trichlorosilane and improving the efficiency of the subsequent single-crystal silicon production process. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.
[0018] Figure 1 It is a side view of the bubbler shown according to an embodiment of the present application.
[0019] In the figure: 1, bubbling barrel; 2, liquid inlet pipe; 3, air inlet pipe; 4, air outlet pipe; 5, discharge pipe; 6, liquid trichlorosilane; 7, metal impurities; 101, barrel cover; 102, barrel body; 103, precipitation part; 201, liquid inlet; 301, air inlet; 302, bubble diffuser; 303, pressure regulating valve; 501, discharge valve. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all of them. Usually, the components of the embodiments of this application described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.
[0021] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of this application that is claimed, but merely represents selected embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts fall within the scope of protection of this application.
[0022] As Figure 1 shown, this application provides a bubbler, which includes a bubbling barrel 1, a liquid inlet pipe 2, a gas inlet pipe 3, a gas outlet pipe 4, and a discharge pipe 5. Among them, the bubbling barrel 1 includes a barrel cover 101 and a hollow barrel body 102. A part at the center of the bottom surface of the barrel body 102 bulges downward to form a precipitation part 103 for accommodating precipitated impurities. The opening of the precipitation part 103 is smaller than the bottom surface of the barrel body 102. The liquid inlet pipe 2 penetrates the barrel cover 101 from top to bottom and is used to inject liquid trichlorosilane into the bubbling barrel 1. The central axis of the liquid inlet pipe 2 is parallel to the central axis of the barrel body 102. The end of the liquid inlet pipe 2 is provided with a liquid inlet 201, and the projection of the liquid inlet 201 on the bottom surface of the barrel body 102 is located outside the opening of the precipitation part 103. The gas inlet pipe 3 penetrates the barrel cover 101 from top to bottom and is used to introduce hydrogen gas into the liquid trichlorosilane inside the bubbling barrel 1 to form a mixture of trichlorosilane and hydrogen gas. The end of the gas inlet pipe 3 is provided with a gas inlet 301. The gas outlet pipe 4 penetrates the barrel cover 102 from top to bottom and is used to output the mixture gas to the outside of the bubbling barrel 1. One end of the discharge pipe 5 is connected to the bottom of the precipitation part 103. A discharge valve 501 is also provided on the discharge pipe 5.
[0023] During use, liquid trichlorosilane is injected into the bubbling barrel 1 through the liquid inlet pipe 2, and the gas inlet 301 is located below the liquid level of trichlorosilane. Hydrogen gas enters the liquid trichlorosilane through the gas inlet 301 to form bubbles. During the continuous rising of the bubbles, part of the liquid trichlorosilane forms trichlorosilane vapor and enters the bubbles, forming a mixture of trichlorosilane and hydrogen gas. The bubbles burst after rising to the liquid level of trichlorosilane, and the mixture gas is output to the outside of the bubbling barrel 1 through the gas outlet pipe 4 for carrying out the single-crystal silicon production process. Specifically, the mixture gas will be sent into a reaction chamber provided with a silicon substrate, and trichlorosilane and hydrogen gas will react at a high temperature (generally around 800°C - 1100°C) to generate elemental silicon and hydrogen chloride. Among them, the generated silicon atoms are deposited on the surface of the substrate in the reaction chamber and gradually accumulate and grow to form single-crystal silicon.
[0024] When liquid trichlorosilane flows in the metal inlet pipe 2, it may carry the metal particles peeled off from the inner wall of the pipe into the bubbling barrel 1. In addition, metal particles may also peel off from the part of the inlet pipe 2 below the trichlorosilane liquid level, forming metal impurities. The metal impurities will form some metal ions in trichlorosilane and enter the mixed gas. In the subsequent single-crystal silicon generation process, the metal ions may enter the silicon lattice, resulting in lattice distortion, and will also affect the deposition rate and growth direction of silicon atoms, resulting in uneven crystal growth or defects. In addition, the metal ions may become the recombination centers of electrons and holes, promoting the recombination of carriers, resulting in a significant reduction in the minority carrier lifetime, and thus affecting the performance of semiconductor devices. Therefore, as Figure 1 shown, when the metal impurities 7 accumulated in the precipitation part 103 reach a certain level, the discharge valve 501 is opened, and the impurities will be discharged to the outside of the bubbler through the discharge pipe 5 under the action of gravity and liquid flow. Since the impurities are concentrated in the precipitation part 103, compared with the traditional bubbler, the discharge speed of the impurities is faster and less trichlorosilane is carried out during discharge.
[0025] As Figure 1 shown, when the bubbler is operating stably, the liquid inlet 201 and the gas inlet 301 are both located below the liquid level of the liquid trichlorosilane 6, and the lower end opening of the gas outlet pipe 4 is located above the liquid level. Among them, the position of the gas inlet 301 should be as low as possible, that is, as far as possible from the liquid level of trichlorosilane, so as to extend the traveling distance of hydrogen in the liquid trichlorosilane and enhance the mixing effect of hydrogen and trichlorosilane. Preferably, the distance between the gas inlet 301 and the upper opening of the precipitation part 103 can be 1-3 cm.
[0026] The precipitation part 103 can usually adopt a cylindrical design, or other shapes can be adopted according to the situation, which is not limited here. In order to further facilitate the discharge of impurities, the bottom surface of the precipitation part 103 can be designed as a sunken type, that is, the bottom surface of the precipitation part 103 gradually sinks from the edge to the center. In this way, when discharging impurities, the impurities at the edge of the precipitation part 103 tend to move towards the middle, so that the impurities are discharged more thoroughly and efficiently. In addition, the precipitation part 103 can be detachably connected to the bottom of the barrel body 102. After the bubbler has been operating for a long time, there may be some impurities in the precipitation part 103 that are difficult to discharge through the discharge pipe 5. After the bubbler stops working, the precipitation part 103 can be removed for thorough cleaning to avoid having to replace the entire bubbler.
[0027] In summary, the bubbler of the present application can centrally accommodate the metal impurities precipitated in the liquid trichlorosilane by providing a precipitation part 103 at the bottom of the barrel body 102. After the amount of impurities accumulates to a certain extent, the discharge valve 501 can be opened to discharge the impurities through the discharge pipe 5, realizing the cleaning of the inside of the bubbling barrel 1, without the need for a complete replacement as some traditional bubbling barrels. In addition, since the opening of the precipitation part 103 is smaller than the bottom surface of the barrel body 102, and the projection of the liquid inlet 201 on the bottom surface of the barrel body 102 is located outside the opening of the precipitation part 103, the trichlorosilane liquid flow injected into the bubbling barrel 1 from the liquid inlet 201 will not impact the impurities accumulated in the precipitation part 103, which helps to prevent the impurities from being scattered in the liquid trichlorosilane due to tumbling, thereby effectively reducing the metal ion content in the mixed gas output by the bubbler 1 and ensuring the product quality of the subsequent single-crystal silicon production process.
[0028] In one embodiment, the opening direction of the air inlet 301 is vertically upward or obliquely upward. Preferably, the opening direction of the air inlet 301 can be at an angle of 45° - 90° upward with respect to the horizontal plane. Figure 1 As shown, this is the case where the opening direction of the air inlet 301 is at an angle of 90° upward with respect to the horizontal plane. Setting the air inlet direction to be vertically upward or obliquely upward helps to prevent the ejected air flow from impacting the impurities precipitated at the lower part of the bubbling barrel 1, thus better avoiding the tumbling of the impurities and helping to reduce the metal ion content in the final mixed gas. In addition, this design also enables hydrogen to enter the liquid trichlorosilane in a vertically upward or obliquely upward direction, which can effectively prevent bubbles from aggregating near the air inlet 301 to form larger bubbles. Therefore, it helps to keep the bubble distribution uniform and the bubble size small, increasing the contact area between hydrogen and trichlorosilane. And since the rising speed of small bubbles in the liquid is slower, the contact time between hydrogen and trichlorosilane can also be significantly increased, thereby effectively improving the mixing effect of trichlorosilane and hydrogen.
[0029] In one embodiment, as <着="0000068">As shown, a bubble diffuser 302 can be provided on the air inlet 301. The bubble diffuser 302 helps to inject hydrogen more dispersedly into liquid trichlorosilane, forming more bubbles with smaller sizes, thereby increasing the contact area between hydrogen and trichlorosilane, making the mixed gas output by the bubbler contain more trichlorosilane, and improving the efficiency of the subsequent single-crystal silicon production process. Preferably, the bubble diffuser 302 can be a conical diffuser with both ends open, and the small opening end of the bubble diffuser 302 is installed on the air inlet 301. The design of the conical diffuser enables hydrogen to be gradually dispersed during the diffusion process, reducing the aggregation of bubbles, thereby achieving a more uniform diffusion effect and improving the diffusion efficiency. In actual use, bubble diffusers 302 with various opening sizes can be designed according to different hydrogen flow rates to achieve precise control of the gas diffusion speed and distribution range. The bubble diffuser 302 can also be a box-type diffuser with multiple small holes on its surface. Specifically, the bubble diffuser 302 can be a hollow box with multiple small holes on its surface, and these small holes can be evenly distributed or arranged specifically according to specific requirements. In addition, the conical diffuser and the box-type diffuser can be combined. For example, the large opening end of the conical diffuser can be blocked with a perforated plate to better achieve the diffusion of hydrogen. According to specific requirements, the bubble diffuser 302 can also be in other structural forms, such as a tube-type diffuser, a microporous membrane-type diffuser, a nozzle-type diffuser, etc., which are not limited here. In addition, the end of the air inlet pipe 3 can be bifurcated to form multiple air inlets 301, and the multiple air inlets 301 are distributed at intervals in the liquid trichlorosilane, and a bubble diffuser is provided on each air inlet 301 to further enhance the gas dispersion effect.
[0030] In one embodiment, a sealing layer is provided between the lid 101 and the barrel body 102 of the bubbling barrel 1, and seals (not shown in the figure) are provided at the positions where the liquid inlet pipe 2, the air inlet pipe 3, and the air outlet pipe 4 contact the lid 101 respectively to ensure that the gas in the barrel does not leak out and avoid the safety risks that may be caused by hydrogen leakage. Specifically, the sealing layer and the seals can generally use corrosion-resistant and high-temperature-resistant materials, such as rubber, silica gel or Teflon, etc. The seals can be in the form of O-rings, gaskets, etc., and are installed on the contact surfaces of each pipe and the lid 101 to ensure the sealing effect.
[0031] In one embodiment, as Figure 1 shown, a pressure regulating valve 303 can be provided on the air inlet pipe 3. The pressure regulating valve 303 is used to regulate the pressure of the gas introduced into the bubbling barrel 1 by the air inlet pipe 3. On the one hand, it can indirectly control the gas flow rate to make adaptive adjustments according to the progress of the subsequent process. On the other hand, it can prevent the internal pressure of the bubbling barrel 1 from being too high and protect the safe operation of each device.
[0032] In one embodiment, a controller (not shown in the figure) can also be provided for the bubbler. The controller is in signal connection with the discharge valve 501 and is used to control the discharge valve 501 to automatically discharge the deposited impurities to the outside. The controller can control the opening and closing of the discharge valve 501 in a timed manner, that is, it can be set to open the discharge valve 501 after the bubbler has been running for a preset duration. When various external conditions such as the flow rates of hydrogen and trichlorosilane are relatively stable, the accumulation rate of impurities is also relatively stable. This timed control method can discharge impurities more accurately, and since no additional sensors are required, it is relatively easy to implement. In addition, a sensor for detecting the accumulation amount of metal impurities, such as a weight sensor or an optical sensor, can also be provided inside the bubbler, and the sensor is in signal connection with the controller, so as to open the discharge valve 501 for discharge when the amount of metal impurities reaches a preset value.
[0033] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A bubbler, characterized in that, include: The bubbling tank (1) includes a lid (101) and a hollow tank body (102). A portion of the bottom center of the tank body (102) protrudes downward to form a sedimentation section (103) for accommodating sedimented impurities. The opening of the sedimentation section (103) is smaller than the bottom surface of the tank body (102). The liquid inlet pipe (2) runs through the bucket cover (101) from top to bottom; the central axis of the liquid inlet pipe (2) is parallel to the central axis of the bucket body (102), and the end of the liquid inlet pipe (2) is provided with a liquid inlet (201). The projection of the liquid inlet (201) on the bottom surface of the bucket body (102) is located outside the opening of the sedimentation part (103); An air inlet pipe (3) runs through the barrel lid (101) from top to bottom; an air inlet (301) is provided at the end of the air inlet pipe (3). The air outlet pipe (4) runs from top to bottom through the barrel lid (101). A discharge pipe (5) is provided at one end, which is connected to the bottom of the sedimentation section (103); a discharge valve (501) is also provided on the discharge pipe (5).
2. The bubbler according to claim 1, characterized in that, The air inlet (301) opens vertically upward or diagonally upward.
3. The bubbler according to claim 2, characterized in that, The opening direction of the air inlet (301) forms an angle of 45°-90° with the horizontal plane.
4. The bubbler according to claim 1, characterized in that, A bubble diffuser (302) is provided on the air inlet (301).
5. The bubbler according to claim 4, characterized in that, The bubble diffuser (302) is a cone-shaped diffuser with openings at both ends.
6. The bubbler according to claim 4, characterized in that, The bubble diffuser (302) is a box-type diffuser with multiple small holes on its surface.
7. The bubbler according to claim 1, characterized in that, A sealing layer is provided between the lid (101) and the body (102) of the bubbling tank (1), and the liquid inlet pipe (2), the air inlet pipe (3) and the air outlet pipe (4) are respectively provided with sealing elements at the positions that contact the lid (101).
8. The bubbler according to claim 1, characterized in that, A pressure regulating valve (303) is provided on the air inlet pipe (3), and the pressure regulating valve (303) is used to regulate the pressure of the gas introduced into the bubble barrel (1) by the air inlet pipe (3).
9. The bubbler according to claim 1, characterized in that, A controller is also provided, which is signal-connected to the discharge valve (501) and is used to control the discharge valve (501) to automatically discharge the deposited impurities to the outside.