JP7468339B2 - Dust collection device for use when cleaning parts of a single crystal pulling apparatus and method for cleaning parts of a single crystal pulling apparatus - Google Patents

Description

The present invention relates to a dust collection device used when cleaning parts of a single crystal pulling device, and a method for cleaning parts of a single crystal pulling device using the same.

A representative method for manufacturing a single crystal silicon ingot is the Czochralski method (CZ method). In the CZ method, a silicon single crystal pulling apparatus 1000 installed in a clean room as shown in FIG. 9 is used. During pulling of the single crystal, oxygen contained in the quartz crucible 116A reacts with the silicon melt to generate silicon oxide (SiO _x ). This silicon oxide vaporizes, and in the process of moving along the flow of inert gas in the main chamber 110, it cools and solidifies, and adheres to the inner wall surface of the main chamber 110 and the surfaces of each component (e.g., the heater 124) in the main chamber 110, and gradually accumulates over time. Therefore, after the pulling of the single crystal is completed, the silicon single crystal pulling apparatus 1000 is disassembled and cleaning is performed to remove the adhesions, that is, disassembly and cleaning is performed. At that time, the main chamber 110 and the pull chamber 111 are separated, and the space inside the chamber is opened to the atmosphere inside the clean room, and various parts to be cleaned are cleaned. That is, cleaning of the inner wall surface of the main chamber 110 and cleaning of each component (e.g., the heater 124) inside the main chamber 110 are performed in a clean room atmosphere. Therefore, the removed adherent matter becomes dust and flies around the components to be cleaned inside the clean room.

Generally, single crystal pulling devices such as silicon single crystal pulling devices are installed in a clean room as shown in Patent Document 1. A downflow is formed in the clean room to suppress the diffusion of dust and maintain cleanliness.

Japanese Patent Application Laid-Open No. 6-159751

However, when cleaning the components of the single crystal pulling apparatus described above, a much larger amount of dust is generated than that generated by a normal pulling apparatus, and this dust ends up floating around the components being cleaned. In such a situation where a large amount of dust is generated, it is difficult to prevent the dust from diffusing within the clean room using only the downflow of the clean room, and there is an issue of a decrease in the cleanliness within the clean room.

In view of the above problems, the present invention aims to provide a dust collection device capable of suppressing the scattering of dust in a clean room when cleaning parts of a single crystal pulling device, and a method of cleaning parts of a single crystal pulling device using the same.

The gist and configuration of the present invention are as follows.
[1] A dust collection device for use when cleaning parts of a single crystal pulling apparatus, comprising:
A dust collector having a suction surface;
a first panel and a second panel each having a vertical surface and located on either side of the suction surface of the dust collector;
and capable of realizing an open state in which the first panel and the second panel, together with the suction surface of the dust collector, are positioned around a part to be cleaned of the single crystal pulling apparatus, and a stored state in which the first panel and the second panel are positioned adjacent to a side surface of the dust collector.

[2] The dust collector further includes a pair of frames consisting of a first frame and a second frame located on both sides of the suction surface,
the first panel is connected to the first frame via a first hinge,
the second panel is connected to the second frame via a second hinge,
The dust collecting device according to [1] above, wherein the first and second hinges enable the open state and the stored state to be realized.

[3] The dust collecting device described in [2] above, in which the first and second hinges are horizontally movable hinges.

[4] A plurality of panels including the first panel are arranged on a side where the first panel is located relative to the suction surface, and adjacent panels are connected to each other via a third hinge, and/or a plurality of panels including the second panel are arranged on a side where the second panel is located relative to the suction surface, and adjacent panels are connected to each other via a fourth hinge,
The dust collector described in [2] or [3] above, wherein the first to fourth hinges enable an open state in which all of the panels, together with the suction surface of the dust collector, are positioned around the parts to be cleaned of the single crystal pulling apparatus, and a stored state in which all of the panels are folded and positioned adjacent to the sides of the dust collector.

[5] The dust collecting device described in [4] above, in which the third and fourth hinges are horizontally movable hinges.

[6] The dust collecting device described in [5] above, in which the hinge connecting the outermost panel located farthest from the suction surface to the panel adjacent to the outermost panel is a horizontally and vertically movable hinge.

[7] Further comprising a dolly for accommodating the dust collector,
The dust collecting device according to any one of the above [2] to [6], wherein the first frame and the second frame constitute a part of the cart.

[8] The dust collection device described in [7] above, in which casters are provided on the bottom of the dolly.

[9] The dust collection device described in [7] or [8] above, in which the cart is made of a non-magnetic material.

[10] Holding hooks are arranged on both sides of the dust collector on the carriage,
In the stored state, all of the panels are hooked and fixed by the retaining hooks,
The dust collecting device according to any one of claims [7] to [9], wherein when transitioning from the stored state to the open state, the outermost panel located furthest from the suction surface is released from the retaining hooks, and then all of the panels are moved horizontally.

[11] The dust collecting device according to any one of [1] to [10] above, in which the lower end of the suction surface is in the range of 50 mm to 150 mm from the floor.

[12] The dust collection device according to any one of [1] to [11] above, in which the frame constituting all of the panels is made of a non-magnetic material.

[13] The dust collecting device according to any one of [1] to [12] above, in which a dust-free cloth and/or an electrostatic vinyl sheet are attached to the vertical surfaces of all of the panels.

[14] The dust collecting device according to any one of [1] to [13] above, in which the outermost panel located furthest from the suction surface is provided with a stopper at its lower part for fixing the panel to the floor surface in the open state.

[15] A method for cleaning parts of a single crystal pulling apparatus using the dust collecting device according to any one of [1] to [14] above, comprising the steps of:
The dust collector is arranged so that all of the panels, together with the suction surface of the dust collector, are located around the parts to be cleaned of the single crystal pulling apparatus;
The method for cleaning parts of a single crystal pulling apparatus includes cleaning the parts to be cleaned while the dust collector is in operation.

[16] The method for cleaning parts of a single crystal pulling apparatus described in [15] above, in which the part to be cleaned is a carbon member of the single crystal pulling apparatus.

[17] The method for cleaning components of a single crystal pulling apparatus described in [16] above, in which the carbon member is a heater of the single crystal pulling apparatus.

[18] The method for cleaning parts of a single crystal pulling apparatus described in [15] above, in which the part to be cleaned is a quartz component of the single crystal pulling apparatus.

[19] The method for cleaning parts of a single crystal pulling apparatus described in [15] above, in which the part to be cleaned is the main chamber of the single crystal pulling apparatus.

The dust collection device of the present invention and the method for cleaning parts of a single crystal pulling device using the same can prevent dust from scattering in a clean room when cleaning parts of a single crystal pulling device.

FIG. 1 is a perspective view of a dust collecting device 100 according to an embodiment of the present invention with four panels open. FIG. 1 is a perspective view of a dust collecting device 100 according to an embodiment of the present invention, with four panels stored. FIG. 1 is a schematic side view of a dust collecting device 100 according to an embodiment of the present invention with four panels open. 11 is a diagram showing the structure of a retaining hook 94 for fixing a panel in a stored state in the dust collecting device 100. FIG. 2 is a cross-sectional view showing the internal structure of a dust collector 10 used in the dust collecting device 100. FIG. 10 is a perspective view showing an installation state of the dust collecting device 100 relative to the heater 124 when the heater 124 is being cleaned. FIG. The upper figure is a top view showing the installation state of the dust collecting device 100 relative to the heater 124 when cleaning the heater 124, and the lower figure is a top view showing the storage state in which the four panels are folded when the dust collecting device 100 is not in use. 1 is a perspective view showing a state in which the dust collecting device 100 is installed relative to the main chamber 110 when the main chamber 110 is cleaned. FIG. FIG. 2 is a side view showing a dust collecting device 200 according to another embodiment of the present invention. FIG. 11 is a side view showing a dust collecting device according to still another embodiment of the present invention. 1 is a graph showing the measurement results of the number of airborne particles when cleaning a heater. 13 is a graph showing the measurement results of the number of airborne particles when the main chamber is cleaned. 1 is a cross-sectional view taken along a pulling axis X, showing a schematic configuration of a silicon single crystal pulling apparatus 1000. FIG.

(Single crystal pulling device)
First, with reference to FIG. 9, a configuration of a silicon single crystal pulling apparatus 1000, which is an example of a single crystal pulling apparatus to be disassembled and cleaned in one embodiment of the present invention, will be described.

The silicon single crystal pulling apparatus 1000 has a main chamber 110, a pull chamber 111, a crucible 116, a shaft 118, a shaft drive mechanism 120, a cylindrical heat shield 122, a cylindrical heater 124, a cylindrical insulator 126, a seed chuck 128, a pulling wire 130, a wire lifting mechanism 132, and a pair of electromagnets 134.

The main chamber 110 is a cylindrical chamber with a bottom that houses a crucible 116 inside. The pull chamber 111 is a cylindrical chamber with a smaller diameter than the main chamber 110, which has the same central axis as the main chamber 110 and is provided above the main chamber 110. A gate valve 112 is provided between the main chamber 110 and the pull chamber 111, and the spaces in the main chamber 110 and the pull chamber 111 are connected to each other or blocked by opening and closing this gate valve 112. A gas inlet 113 is provided at the top of the pull chamber 111 to introduce an inert gas such as Ar gas into the main chamber 110. In addition, a gas outlet 114 is provided at the bottom of the main chamber 110 to suck and exhaust gas from the main chamber 110 by driving a vacuum pump (not shown).

The crucible 116 is placed in the center of the main chamber 110 and contains silicon melt M. The crucible 116 has a double structure of a quartz crucible 116A and a graphite crucible 116B. The quartz crucible 116A directly supports the silicon melt M on its inner surface. The graphite crucible 116B supports the quartz crucible 116A on the outside of the quartz crucible 116A.

The shaft 118 passes vertically through the bottom of the main chamber 110 and supports the crucible 116 at its upper end. The shaft drive mechanism 120 raises and lowers the crucible 116 while rotating it via the shaft 118.

The thermal shield 122 is provided above the crucible 116 to surround the single crystal silicon ingot I being pulled up from the silicon melt M.

The cylindrical heater 124 is positioned within the main chamber 110 so as to surround the crucible 116. The heater 124 is generally a resistance heating heater made of carbon, which melts the silicon raw material fed into the crucible 116 to form silicon melt M, and also provides heating to maintain the formed silicon melt M.

The cylindrical insulator 126 is provided below the upper end of the thermal shield 122 and spaced apart from the outer circumferential surface of the heater 124, along the inner surface of the main chamber 110. The insulator 126 provides a heat retention effect to the area inside the main chamber 110, particularly below the thermal shield 122, and has the function of making it easier to maintain the silicon melt M in the crucible 116.

Above the crucible 116, a pulling wire 130 is arranged coaxially with the shaft 118, and the pulling wire 130 holds at its lower end a seed chuck 128 that holds a seed crystal S. A wire lifting mechanism 132 raises and lowers the pulling wire 130 while rotating it at a predetermined speed in the opposite direction to or in the same direction as the shaft 118.

The pair of electromagnets 134 are positioned symmetrically with respect to the pulling axis X outside the main chamber 110, in a height range that includes the crucible 116. By passing a current through the coils of the pair of electromagnets 34, a horizontal magnetic field that forms a horizontal magnetic field distribution on the silicon melt M can be generated. Although a pair of electromagnets 34 that generate a horizontal magnetic field is shown in FIG. 1, electromagnets that generate a cusp magnetic field that forms a cusp-shaped magnetic field distribution on the silicon melt M may be placed instead. If no magnetic field is applied to the silicon melt M during crystal growth, the electromagnets are not necessary.

As described above, during the pulling of the single crystal, deposits made of silicon oxide (SiO _x ) gradually accumulate on the inner wall surface of the main chamber 110 and on the surfaces of each component (e.g., the heater 124) in the main chamber 110. Therefore, after the pulling of the single crystal is completed, the silicon single crystal pulling apparatus 1000 is disassembled and cleaning is performed to remove the deposits, that is, disassembly and cleaning is performed. At that time, the main chamber 110 and the pull chamber 111 are separated, the space inside the chamber is opened to the atmosphere inside the clean room, and various parts to be cleaned are cleaned. In other words, the cleaning of the inner wall surface of the main chamber 110 and the cleaning of each component (e.g., the heater 124) inside the main chamber 110 are performed in the atmosphere inside the clean room. Therefore, the removed deposits become dust and fly around the parts to be cleaned in the clean room. The dust collector according to one embodiment of the present invention is intended to suppress the diffusion of dust flying around the parts to be cleaned in the clean room when the parts of the silicon single crystal pulling apparatus 1000 are cleaned.

(Dust collection device)
A dust collector 100 according to an embodiment of the present invention will be described with reference to Figures 1A to 1D, 2, and 3A and 3B. The dust collector 100 is used when cleaning parts of the silicon single crystal pulling apparatus 1000, for example, when dismantling and cleaning the silicon single crystal pulling apparatus 1000. The dust collector 100 has a dust collector 10, a dolly 40, and four panels 50, 60, 70, and 80 as main components.

In the present invention, a "horizontally movable hinge" refers to a single-axis hinge that has a single rotation axis, and when the rotation axis is installed so that it is vertical, it has a degree of freedom in the horizontal direction. Also, a "horizontally-up-down movable hinge" refers to a hinge that has a single rotation axis and can slide in both directions along the rotation axis, and when the rotation axis is installed so that it is vertical, it has a degree of freedom in the up-down direction (vertical direction) in addition to the horizontal direction. Note that a horizontally-up-down movable hinge is a type of horizontally movable hinge, and is included in horizontally movable hinges.

[Dust collector]
The internal structure of the dust collector 10 will be described with reference to Fig. 2. The dust collector 10 has a housing 12 and a blower fan 22 located therein, and has a structure in which three stages of filters 14, 16, and 28 are installed from the upstream side of the airflow formed by the blower fan 22.

A prefilter 14 is installed in front of the dust collector 10 as a first stage filter. The prefilter 14 has the function of capturing dust particles with a particle size of approximately 5 μm or more. This prefilter 14 becomes the suction surface along the vertical direction in front of the dust collector 10.

Downstream of the prefilter 14, a medium-performance filter 16 is installed in parallel to the prefilter 14 via a filter packing 18 as a second-stage filter. The medium-performance filter 16 has the function of capturing dust particles with a particle size of approximately 1 μm or more. Downstream of the medium-performance filter 16 in the housing 12, there is a first internal space 20, in which a blower fan 22 is located. The blower fan 22 converts the airflow formed by sucking air through the prefilter 14 into an upward direction. Above the blower fan 22, there is a partition plate 12A as part of the housing 12, and above that, there is a second internal space 26. The airflow converted into an upward direction by the blower fan 22 is sent to the second internal space 26 via a connecting member 24.

At the most downstream of the second internal space 26, a HEPA filter 28 is installed horizontally via a filter packing 30 as a third stage filter. The HEPA filter 28 has the function of capturing dust particles with a particle size of approximately 0.3 μm or more.

The dust collector 10 sucks in dust-containing air from the suction surface (pre-filter 14) located on its front, captures the dust with three stages of filters 14, 16, and 28, and releases clean air that does not contain dust particles with a particle size of 0.3 μm or more from the top (HEPA filter 28). When cleaning the parts of the silicon single crystal pulling device 1000, the suction surface (pre-filter 14) of the dust collector 10 is located close to the parts to be cleaned. From the viewpoint of achieving efficient dust capture, it is preferable that the suction surface (pre-filter 14) has a rectangular shape with a length (height): 600 to 1000 mm x width (width): 600 to 1200 mm.

It is preferable that four or more casters 32 are provided on the bottom of the dust collector 10. This allows the dust collector 10 to be freely moved around the clean room together with the dolly 40 described below.

The lower end of the suction surface is preferably in the range of 50 mm to 150 mm from the floor. If the suction surface is close to the floor, there is a risk that dirty air with a high particle density, such as dust and dirt, will be sucked up from the underground pit in a manner that counter-flows the downflow of the clean room. By separating the lower end of the suction surface from the floor by a specified distance, it is possible to suppress the sucking up of dirty air from the underground pit.

[Trolley]
1A and 1C, the dolly 40 has a rectangular parallelepiped skeleton formed by a plurality of frames, and houses the dust collector 10 therein. On the front surface of the dolly 40, a pair of frames consisting of a first vertical frame 42A and a second vertical frame 42B extending in the vertical direction are arranged as a first frame and a second frame located on both sides of the suction surface (prefilter 14) of the dust collector 10, respectively. The upper frame 42C connects the upper ends of the first vertical frame 42A and the second vertical frame 42B to each other. The lower frame 42D connects the lower ends of the first vertical frame 42A and the second vertical frame 42B to each other. The first vertical frame 42A, the second vertical frame 42B, the upper frame 42C, and the lower frame 42D form a rectangular skeleton. Furthermore, the middle frame 42E connects the middle parts of the first vertical frame 42A and the second vertical frame 42B to each other. The length of the first vertical frame 42A and the second vertical frame 42B is the same as the length of the panels 50, 60, 70, and 80 described later. The suction surface (prefilter 14) of the dust collector 10 is surrounded by the first vertical frame 42A, the second vertical frame 42B, the intermediate frame 42E, and the lower frame 42D. Therefore, the length of the lower frame 42D, the intermediate frame 42E, and the upper frame 42C is approximately the same as the width of the prefilter 14. It is preferable that a dust-free cloth or an electrostatic vinyl sheet is stretched above the suction surface (prefilter 14) of the dust collector 10, that is, the part surrounded by the first vertical frame 42A, the second vertical frame 42B, the intermediate frame 42E, and the upper frame 42C. This makes it easier to guide dust into the dust collector 10, and more sufficiently suppresses the dust from diffusing into the clean room. It should be noted that the "first frame and second frame" are not limited to rod-shaped frames such as the first vertical frame 42A and the second vertical frame 42B in this embodiment, but may have any shape that is strong enough to prevent the connected panels from falling over, and may be rod-shaped, ring-shaped, or even a wide plate-shaped frame that covers the dust collector 10.

The side lower frames 44A and 44B extend horizontally from both ends of the lower frame 42D at right angles to the lower frame 42D. As shown in FIG. 1C, casters 46 are preferably provided at both ends of the side lower frames 44A and 44B. This allows the dolly 40 to be freely moved within the clean room together with the dust collector 10 described above. At that time, the worker can easily move the dolly 40 by holding the grip 48 provided at the rear of the dolly 40.

[panel]
1A and 1C, the panel 50 as the first panel is connected to the first vertical frame 42A of the dolly 40 via horizontally movable hinges 58A and 58B as the first hinges, and has a vertical surface. The panel 50 has a pair of frames consisting of a first vertical frame 52A and a second vertical frame 52B extending in the vertical direction, an upper frame 52C connecting the upper ends of the first vertical frame 52A and the second vertical frame 52B, and a lower frame 52D connecting the lower ends of the first vertical frame 52A and the second vertical frame 52B, and these four frames form a rectangular skeleton. Furthermore, the intermediate frame 52E is of any configuration, but connects the intermediate portions of the first vertical frame 52A and the second vertical frame 52B. The panel 50 is connected to the trolley 40 by connecting the first vertical frame 52A to the first vertical frame 42A of the trolley 40 via a pair of upper and lower horizontally movable hinges 58A, 58B, and can move horizontally around the first vertical frame 42A of the trolley 40 by the action of the horizontally movable hinges 58A, 58B.

Referring to Figures 1A and 3B, a panel 70 serving as a second panel is disposed on the opposite side of the panel 50 with respect to the suction surface (prefilter 14) of the dust collector 10. The panel 70 is connected to the second vertical frame 42B of the cart 40 via a horizontally movable hinge serving as a second hinge, and has a vertical surface. The configuration of the panel 70 and the connection structure to the second vertical frame 42B of the cart 40 are similar to those of the panel 50 described in the previous paragraph, and therefore will not be described here.

1A and 1C, the panel 60 (third panel) is connected to the panel 50 via the horizontally movable hinges 68A and 68B as the third hinges, and has a vertical surface. The panel 60 has a pair of frames consisting of a first vertical frame 62A and a second vertical frame 62B extending in the vertical direction, an upper frame 62C connecting the upper ends of the first vertical frame 62A and the second vertical frame 62B, and a lower frame 62D connecting the lower ends of the first vertical frame 62A and the second vertical frame 62B, and these four frames form a rectangular skeleton. Furthermore, the intermediate frame 62E is of any configuration, but connects the intermediate portions of the first vertical frame 62A and the second vertical frame 62B. The panel 60 is connected to the panel 50 by connecting the first vertical frame 62A to the second vertical frame 52B of the panel 50 via a pair of horizontal and vertical movable hinges 68A, 68B, and the panel 60 is movable in the horizontal direction around the second vertical frame 52B of the panel 50 by the action of the horizontal and vertical movable hinges 68A, 68B. The panel 60 is also movable up and down (vertically) relative to the second vertical frame 52B of the panel 50 by the action of the horizontal and vertical movable hinges 68A, 68B.

Referring to Figures 1A and 3B, panel 80 (fourth panel) is disposed on the opposite side of panel 60 with respect to the suction surface (prefilter 14) of dust collector 10. Panel 80 is connected to panel 70 via a horizontally and vertically movable hinge serving as a fourth hinge, and has a vertical surface. The configuration of panel 80 and the connection structure to panel 70 are similar to those of panel 60 described in the previous paragraph, and therefore will not be described here.

[Panel open and closed states]
1A and 1B and 3A and 3B, in the dust collector 100 according to this embodiment, the horizontally movable hinges 58A, 58B and the horizontally and vertically movable hinges 68A, 68B can realize an open state (upper views of FIGS. 1A and 3B) in which all of the panels 50, 60, 70, 80, together with the suction surface (prefilter 14) of the dust collector 10, are positioned around the parts to be cleaned of the silicon single crystal pulling apparatus 1000 (heater 124 in FIGS. 3A and 3B), and a stored state (lower views of FIGS. 1B and 3B) in which all of the panels 50, 60, 70, 80 are folded and positioned adjacent to the sides of the dust collector 10. When cleaning the parts of the silicon single crystal pulling apparatus 1000, the dust collector 100 is positioned so that all of the panels 50, 60, 70, 80, together with the suction surface (pre-filter 14) of the dust collector 10, are positioned around the parts to be cleaned (heater 124 in Figs. 3A and 3B) of the silicon single crystal pulling apparatus 1000. This makes it possible to prevent dust particles floating around the parts to be cleaned from diffusing into the clean room when cleaning the parts of the silicon single crystal pulling apparatus 1000.

The vertical length (height) of the panels 50, 60, 70, and 80 is preferably 1000 mm or more, more preferably 1500 mm or more, and even more preferably 1800 mm or more, from the viewpoint of each panel being able to sufficiently block the air currents in the clean room, preventing the air currents in the clean room from entering around the parts to be cleaned, and making it easier to guide dust into the dust collector 10. In addition, the vertical length (height) of the panels 50, 60, 70, and 80 is preferably 2500 mm or less, and more preferably 2000 mm or less, from the viewpoint of the operability of each panel. In addition, it is preferable that the vertical lengths (heights) of the panels 50, 60, 70, and 80 are equal to each other.

In the present embodiment in which the number of panels is four, the horizontal length (width) of the panels 50, 60, 70, and 80 is preferably 600 mm or more, and more preferably 800 mm or more, from the viewpoint of each panel adequately surrounding the parts to be cleaned. Also, from the viewpoint of the operability of each panel, the horizontal length (width) of the panels 50, 60, 70, and 80 is preferably 1200 mm or less, and more preferably 1000 mm or less. Also, it is preferable that the horizontal lengths (widths) of the panels 50, 60, 70, and 80 are equal to each other.

Referring to FIG. 1D in addition to FIGS. 1A-C, retention hooks 94 are disposed on the lower part of the dolly 40 on both sides of the dust collector 10 (i.e., the lower side frames 44A, 44B). The retention hooks 94 have a plate 94A with a horizontal surface and a protrusion 94B that protrudes vertically upward from the tip of the plate 94A.

As described above, the outermost panel 60, which is located farthest from the suction surface, is connected to the adjacent panel 50 via the horizontal and vertical movable hinges 68A and 68B. Therefore, the horizontal and vertical movable hinges 68A and 68B allow the panel 60 to take a lower position where it is caught by the protruding portion 94B and an upper position where it is not caught by the protruding portion 94B. The lower position/upper position can be changed by the worker by holding the handle 92 provided on the middle frame 62E of the panel 60 and raising or lowering the panel 60. On the other hand, the panel 50 is located at a height where it is not caught by the protruding portion 94B because its lower frame 52D is located at the same height as the side lower frame 44A of the dolly 40. The panel 50 is connected to the dolly 40 by the horizontal movable hinges 58A and 58B, so it cannot move up or down. In addition, due to the presence of the casters 46, the lower side frame 44A of the cart 40 is located at a height of approximately 60 to 100 mm from the floor surface.

In the stored state, panels 50 and 60 are positioned on plate 94A. Panel 60, the outermost panel, is positioned in the lower position, and the movement of panel 60 is hindered by protrusion 94B, so panels 50 and 60 are fixed by retaining hooks 94. This is the state shown in Figure 1B and the lower diagram of Figure 3.

When moving from the stored state to the open state, the worker lifts up panel 60, which is the outermost panel, and in this state, the horizontally and vertically movable hinges 68A, 68B act to change panel 60 to the upper position, and the panel 60 is moved over protrusion 94B, removing panel 60 from retaining hook 94. Then, panels 50, 60 are moved horizontally.

Panel 60, the outermost panel, is provided with a spring-loaded fixing stopper 90 at its bottom. This allows panel 60 to be fixed to the floor surface in the open state. This is the state shown in Figure 1A and the upper diagram of Figure 3B.

Note that while the above describes the stored and open states of panels 50 and 60, the same applies to the stored and open states of panels 60 and 70.

[Panel and trolley material]
It is preferable that the frames and the carriage 40 constituting all the panels 50, 60, 70, 80 are made of a non-magnetic material, i.e., not attracted to a magnet. This ensures safety by preventing them from being attracted by the electromagnet 134 of the silicon single crystal pulling apparatus 1000. For example, the frames constituting each panel may be made of aluminum, and the carriage 40 may be made of stainless steel (SUS304).

[Vertical surface of panel]
It is preferable that one or both of a dust-free cloth and an electrostatic vinyl sheet are attached to the vertical surfaces of all the panels 50, 60, 70, 80. This makes it difficult for dust to adhere to each panel, and makes it easier to guide the dust into the dust collector 10, so that the dust can be more sufficiently prevented from diffusing into the clean room. For example, referring to Fig. 1C, a transparent electrostatic vinyl sheet can be attached to the upper panel parts 54, 64, and a dust-free cloth can be attached to the lower panel parts 56, 66. In this way, an operator can visually check the inside and outside of the panel parts 54, 64 through the upper panel parts 54, 64.

(Method of cleaning parts of a single crystal pulling apparatus)
A method for cleaning parts of a silicon single crystal pulling apparatus 1000 according to an embodiment of the present invention will be described with reference to Figures 3A, 3B and 4. Figures 3A and 3B show a case where the part to be cleaned is the heater 124 of the silicon single crystal pulling apparatus 1000. Figure 4 shows a case where the part to be cleaned is the main chamber 110 of the silicon single crystal pulling apparatus 1000.

In the method for cleaning the parts of the silicon single crystal pulling apparatus 1000 according to the present embodiment, the dust collector 100 described above is used. As shown in FIGS. 3A, B and 4, the dust collector 100 is arranged so that all panels 50, 60, 70, 80, together with the suction surface (prefilter 14) of the dust collector, are located around the parts to be cleaned of the silicon single crystal pulling apparatus (heater 124 in FIGS. 3A and B, and main chamber 110 in FIG. 4). In the case of FIGS. 3A and B, the suction surface (prefilter 14) of the dust collector and the heater 124 are located at approximately the same height and face each other. In the case of FIG. 4, the main chamber 110 is cleaned in a state where it is suspended in midair so that its lower end is about 700 to 1000 mm above the floor surface. Therefore, the suction surface (prefilter 14) of the dust collector faces the space below the main chamber 110.

Then, while the dust collector 10 is in operation, the parts to be cleaned are cleaned. Specifically, in the case of Figs. 3A and 3B, an operator uses a brush with a suction function to scrub the heater 124 while sucking it in, at a position outside the heater 124 and inside the panels 50, 60, 70, and 80, to remove any deposits that have accumulated on the heater 124. In the case of Fig. 4, an operator enters the suspended main chamber 110 and uses a brush with a suction function to scrub the inner wall surface of the main chamber 110 while sucking it in, to remove any deposits that have accumulated on the inner wall surface. This makes it possible to prevent dust particles floating around the parts to be cleaned from diffusing into the clean room when cleaning the parts of the silicon single crystal pulling apparatus 1000.

In this embodiment, it is sufficient that each panel blocks the airflow in the clean room in the direction away from the suction surface (pre-filter 14) of the dust collector 10, making it easier to guide dust into the dust collector 10. From this perspective, it is not necessary to form an enclosed space around the parts to be cleaned, and the periphery of the parts to be cleaned can be an open system. In other words, the panels 50, 60, 70, and 80 do not need to surround the entire periphery of the heater 124. However, as shown in FIG. 3B, it is preferable that the panels 50, 60, 70, and 80 surround more than half of the heater 124, that is, when viewed from the vertically upward direction as in FIG. 3B, the center of the heater 124 is located closer to the dust collector 10 than the line connecting the tips of the panels 60 and 80. As shown in FIG. 3B, there may be no panels in the area facing the suction surface (pre-filter 14) of the dust collector 10. The contents of this paragraph also apply to the case where the main chamber 110 is used instead of the heater 124.

The parts to be cleaned are not limited to the heater 124 and the main chamber 110. In addition to the heater 124, the parts to be cleaned may be any carbon component of the single crystal pulling apparatus, such as the heat shield 122, the heat insulator 126, the graphite crucible 116B, the crucible pan, or the spill tray (not shown). The parts to be cleaned may also be any quartz component of the single crystal pulling apparatus, such as the purge tube (not shown).

(Modification of Dust Collection Device)
Referring to FIG. 5, a dust collector 200 according to another embodiment of the present invention is an embodiment in which the panel 50 in the dust collector 100 shown in FIG. 1C is divided into a plurality of panels 50A to G. The panel 70 on the opposite side of the panel 50 can be divided in the same manner. The plurality of panels 50A to G are connected to each other via a horizontally movable hinge as a third hinge. As in FIG. 1C, the panel 60, which is the outermost panel, is connected to the adjacent panel 50G via horizontally and vertically movable hinges 68A and 68B. In this way, regardless of the number of panels, if the horizontally movable hinge that connects the outermost panel located farthest from the suction surface and the horizontally movable hinge that connects the outermost panel to the adjacent panel is a horizontally and vertically movable hinge, the transition between the stored state and the open state as described above can be realized. In the embodiment shown in FIG. 5, the horizontal length (width) of each of the panels 50A to G can be about 150 to 250 mm, which is shorter than the horizontal length (width) of the panel 50 in FIG. 1C. This makes it easy to handle each panel when transitioning between the stored and open states.

The number of panels per side of the suction surface (prefilter 14) of the dust collector 10 is two in the dust collector 100 and eight in the dust collector 200, but is not particularly limited and may be at least one or more, and is preferably three to four. Regardless of the number of panels, the total horizontal length (width) of the panels per side is preferably 1200 mm or more, and more preferably 1600 mm or more, from the viewpoint of each panel fully surrounding the parts to be cleaned. In addition, the total horizontal length (width) of the panels per side is preferably 2400 mm or less, and more preferably 2000 mm or less, from the viewpoint of operability of each panel. The width of one panel is preferably 1200 mm or less, and more preferably 1000 mm or less, from the viewpoint of operability.

In addition, when all panels are open, it is preferable that there be a gap of 50 mm to 150 mm between the panel (first panel or second panel) located immediately to the side of the suction surface of the dust collector and the floor. This makes it possible to suppress the suction of dirty air from the underground pit.

Referring to FIG. 6, it is also preferable to provide the dust collectors 100 and 200 with an upper panel 95 connected to the upper frame 42C of the dolly 40 via a horizontally movable hinge 96. The upper panel 95 is positioned horizontally in the open state (during cleaning) and vertically in the stored state. In this way, the upper panel 95 can adequately block the airflow in the clean room, making it easier to guide dust into the dust collector 10 more reliably.

(Dust collection device)
The dust collector shown in Figures 1A to 1D was prepared. The suction surface (prefilter) of the dust collector shown in Figure 2 has a rectangular shape with a vertical length (height): 1000 mm x horizontal length (width): 1000 mm. The four panels have a rectangular shape with a vertical length (height): 1700 mm x horizontal length (width): 800 mm. The height of the lower end of the suction surface from the floor and the height of the lower end of each panel from the floor in the open state are both 100 mm. The frame constituting each panel was made of aluminum, and the dolly was made of SUS304. A transparent electrostatic vinyl sheet was attached to the upper part of each panel, and a dust-free cloth was attached to the lower part of each panel. A transparent electrostatic vinyl sheet was also attached to the upper part of the prefilter.

(Cleaning the heater)
In the example of the invention, as shown in the upper diagrams of Figures 3A and 3B, a dust collector was placed relative to the heater. Then, with the dust collector in operation, an operator used a brush with suction function to scrub the heater while sucking it in, to remove the deposits that had accumulated on the heater. In the comparative example, a dust collector was not placed, and an operator similarly used a brush with suction function to scrub the heater while sucking it in, to remove the deposits that had accumulated on the heater. The heater had dimensions of an outer diameter of 1000 mm and a height of 900 mm.

For both the invention example and the comparative example, the particle count (maximum value) in the clean room during heater cleaning was measured. Specifically, when no dust collector was installed, the particle count was measured at one-minute intervals during heater cleaning at a position downwind of the airflow from the heater, and the maximum value among the measured values was used. The results are shown in Figure 7. As shown in Figure 7, the invention example was able to reduce the particle count significantly more than the comparative example, and in particular, the number of particles with a particle size of 0.3 μm or more and less than 0.5 μm was able to be suppressed to less than 500.

(Cleaning the main chamber)
In the invention example, as shown in Fig. 4, a dust collector was placed on the suspended main chamber. Then, while the dust collector was in operation, an operator entered the inside of the main chamber and used a brush with suction to scrub the inner wall surface of the main chamber while sucking it, thereby removing deposits accumulated on the inner wall surface. In the comparative example, a dust collector was not placed, and an operator similarly entered the inside of the main chamber and used a brush with suction to scrub the inner wall surface of the main chamber while sucking it, thereby removing deposits accumulated on the inner wall surface. The main chamber had an outer diameter of 1500 mm, and was suspended so that its lower end was 1000 mm above the floor.

For both the invention example and the comparative example, the particle count (maximum value) in the clean room when the main chamber was being cleaned was measured. Specifically, when no dust collector was installed, the particle count was measured at one-minute intervals while the main chamber was being cleaned in a position downwind of the airflow relative to the main chamber, and the maximum value among the measured values was used. The results are shown in Figure 8. As shown in Figure 8, the invention example was able to reduce the particle count significantly more than the comparative example, and in particular, the number of particles with a particle size of 0.3 μm or more and less than 0.5 μm was able to be kept to less than 200.

The dust collection device of the present invention and the method for cleaning parts of a silicon single crystal pulling device using the same can prevent dust from scattering in a clean room when cleaning parts of a silicon single crystal pulling device.

100 Dust collecting device 200 Dust collecting device 10 Dust collector 12 Housing 12A Partition plate 14 Pre-filter (suction surface)
16 Medium-performance filter 18 Filter packing 20 First internal space 22 Blower fan 24 Connecting member 26 Second internal space 28 HEPA filter 30 Filter packing 32 Caster 40 Dolly 42A First vertical frame 42B Second vertical frame 42C Upper frame 42D Lower frame 42E Intermediate frame 44A Lower side frame 44B Lower side frame 46 Caster 48 Grip portion 50 Panel (first panel)
52A First vertical frame 52B Second vertical frame 52C Upper frame 52D Lower frame 52E Middle frame 54 Upper panel portion 56 Lower panel portion 58A Horizontally movable hinge (first hinge)
58B Horizontally movable hinge (first hinge)
60 Panel (3rd Panel)
62A First vertical frame 62B Second vertical frame 62C Upper frame 62D Lower frame 62E Middle frame 64 Upper panel portion 66 Lower panel portion 68A Horizontal and vertical movable hinge (third hinge)
68B Horizontal and vertical movable hinge (third hinge)
70 Panel (2nd Panel)
80 Panel (4th Panel)
DESCRIPTION OF SYMBOLS 90 Fixing stopper 92 Handle 94 Holding hook 94A Plate 94B Protrusion 95 Upper panel 96 Horizontally movable hinge 1000 Silicon single crystal pulling apparatus 110 Main chamber 111 Pull chamber 112 Gate valve 113 Gas inlet 114 Gas outlet 116 Crucible 116A Quartz crucible 116B Graphite crucible 118 Shaft 120 Shaft drive mechanism 122 Heat shield 124 Heater 126 Insulator 128 Seed chuck 130 Pulling wire 132 Wire lifting mechanism 134 Electromagnet S Seed crystal M Silicon melt I Single crystal silicon ingot X Pulling shaft

Claims (20)

A dust collection device for use when cleaning components of a single crystal pulling apparatus, comprising:
A dust collector having a suction surface;
a first panel and a second panel each having a vertical surface and located on either side of the suction surface of the dust collector;
an open state in which the first panel and the second panel, together with the suction surface of the dust collector, are positioned around a part to be cleaned of the single crystal pulling apparatus, and a stored state in which the first panel and the second panel are positioned adjacent to a side surface of the dust collector,
The dust collector further includes a pair of frames including a first frame and a second frame, the first frame and the second frame being located on both sides of the suction surface of the dust collector,
the first panel is connected to the first frame via a first hinge,
the second panel is connected to the second frame via a second hinge,
The dust collecting device is characterized in that the open state and the stored state can be realized by the first and second hinges. The dust collecting device according to claim 1, wherein the first and second hinges are horizontally movable hinges. a plurality of panels including the first panel are disposed on a side where the first panel is positioned relative to the suction surface, and adjacent panels are connected to each other via a third hinge ; a plurality of panels including the second panel are disposed on a side where the second panel is positioned relative to the suction surface, and adjacent panels are connected to each other via a fourth hinge;
3. The dust collector according to claim 1 or 2, wherein the first to fourth hinges enable an open state in which the plurality of panels including the first panel and all of the plurality of panels including the second panel , together with the suction surface of the dust collector, are positioned around a part to be cleaned of the single crystal pulling apparatus, and a stored state in which the plurality of panels including the first panel and all of the plurality of panels including the second panel are folded and positioned adjacent to a side of the dust collector. The dust collecting device according to claim 3, wherein the third and fourth hinges are horizontally movable hinges. The dust collecting device according to claim 4, wherein the hinge connecting the outermost panel located farthest from the suction surface to the panel adjacent to the outermost panel is a horizontally and vertically movable hinge. Further comprising a dolly for accommodating the dust collector;
The dust collecting device according to any one of claims 1 to 5, wherein the first frame and the second frame form a part of the carriage. The dust collection device according to claim 6, wherein casters are provided on the bottom of the dolly. The dust collection device according to claim 6 or 7, wherein the cart is made of a non-magnetic material. The carriage is provided with holding hooks on both sides of the dust collector;
In the stored state, all of the panels including the first panel and the second panel are hooked and fixed by the retaining hooks,
The dust collecting device according to any one of claims 6 to 8, wherein, when transitioning from the stored state to the open state, the outermost panel located furthest from the suction surface is disengaged from the retaining hooks, and then all of the panels are moved horizontally. The dust collecting device according to any one of claims 1 to 9, wherein the lower end of the suction surface is in the range of 50 mm to 150 mm from the floor. The dust collecting device according to any one of claims 1 to 10, wherein a frame constituting all of the panels including the first panel and the second panel is made of a non-magnetic material. The dust collecting device according to any one of claims 1 to 11, wherein one or both of a dust-free cloth and an electrostatic vinyl sheet are stretched on the vertical surfaces of all of the panels including the first panel and the second panel . The dust collecting device according to any one of claims 1 to 12, wherein the outermost panel located furthest from the suction surface has a stopper at its lower part for fixing the panel to the floor surface in the open state. A dust collection device for use when cleaning components of a single crystal pulling apparatus, comprising:
A dust collector having a suction surface;
a first panel and a second panel each having a vertical surface and located on either side of the suction surface of the dust collector;
an open state in which the first panel and the second panel, together with the suction surface of the dust collector, are positioned around a part to be cleaned of the single crystal pulling apparatus, and a stored state in which the first panel and the second panel are positioned adjacent to a side surface of the dust collector,
A dust collecting device, wherein a frame constituting the first panel and the second panel is made of a non-magnetic material. A dust collection device for use when cleaning components of a single crystal pulling apparatus, comprising:
A dust collector having a suction surface;
a first panel and a second panel each having a vertical surface and located on either side of the suction surface of the dust collector;
an open state in which the first panel and the second panel, together with the suction surface of the dust collector, are positioned around a part to be cleaned of the single crystal pulling apparatus, and a stored state in which the first panel and the second panel are positioned adjacent to a side surface of the dust collector,
A dust collecting device characterized in that a stopper is provided at a lower portion of an outermost panel located furthest from the suction surface to fix the panel to a floor surface in the open state. A method for cleaning parts of a single crystal pulling apparatus using the dust collector according to any one of claims 1 to 15, comprising the steps of:
The dust collector is disposed so that all panels including the first panel and the second panel , together with the suction surface of the dust collector, are positioned around the parts to be cleaned of the single crystal pulling apparatus;
The method for cleaning parts of a single crystal pulling apparatus includes cleaning the parts to be cleaned while the dust collector is in operation. The method for cleaning parts of a single crystal pulling apparatus according to claim 16, wherein the part to be cleaned is a carbon member of the single crystal pulling apparatus. The method for cleaning parts of a single crystal pulling apparatus according to claim 17, wherein the carbon member is a heater of the single crystal pulling apparatus. The method for cleaning a part of a single crystal pulling apparatus according to claim 16, wherein the part to be cleaned is a quartz member of the single crystal pulling apparatus. The method for cleaning a part of a single crystal pulling apparatus according to claim 16, wherein the part to be cleaned is a main chamber of the single crystal pulling apparatus.

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