JP3855650B2 - Cleaning device for single crystal pulling device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cleaning apparatus for a single crystal pulling apparatus in which a crucible is installed in a closed container and a semiconductor single crystal is pulled from a semiconductor melt in the crucible using a CZ method (Czochralski method).
[0002]
[Prior art]
In general, a single crystal pulling apparatus using a CZ method is known as one of means for growing a semiconductor single crystal such as silicon (Si) or gallium arsenide (GaAs).
This single crystal pulling apparatus has a cylindrical shape in which, for example, a silicon melt is stored in a quartz crucible disposed on a carbon susceptor inside a chamber, which is a sealed container, and the silicon melt is disposed around the quartz crucible. The silicon semiconductor single crystal is pulled up from the silicon melt by heating control to a predetermined temperature with a carbon heater.
[0003]
Inside the single crystal pulling apparatus, a carbon fiber (carbon fiber) heat insulating cylinder and a carbon plate as a support plate are arranged on the inner surface of the heat insulating cylinder around the heater. The chamber is provided with a water cooling tube for cooling, and an intermediate portion of the chamber is provided with a window for observing the inside and a transmission sensor for confirming the silicon single crystal to be pulled up. Yes.
[0004]
By the way, in this single crystal pulling apparatus, most of the internal parts are made of carbon, and carbon dust is generated due to deterioration of these carbon members. Further, during crystal growth and during growth cooling, foreign matters such as Si and SiO ₂ adhere to these parts and the inner wall of the apparatus. When these dusts and foreign substances (hereinafter referred to as foreign substances) are peeled off, they have an effect on pulling growth, causing dislocation of the single crystal and deteriorating crystal pulling characteristics.
For this reason, conventionally, the inside of the chamber has been suction-cleaned by a vacuum cleaner or the like before the pulling-up growth.
[0005]
[Problems to be solved by the invention]
However, the following problems remain in the cleaning means of the conventional single crystal pulling apparatus. That is, even if cleaning is performed by a vacuum cleaner or the like, the dust collecting force by suction is weak, and it is difficult to sufficiently discharge foreign matter from the inside of the apparatus. Further, even if the carbon member is taken out and cleaned, a large amount of carbon dust is generated due to contact of the carbon member or the like when the carbon member is assembled or the raw material is charged. Furthermore, foreign matter that adheres during crystal growth or after cooling does not adhere uniformly in the device, but tends to adhere depending on the location, and it is troublesome to clean the entire interior of the device uniformly. It was inefficient and inefficient.
[0006]
The present invention has been made in view of the above-described problems, and provides a cleaning device for a single crystal pulling apparatus that can sufficiently and efficiently remove foreign matter inside without removing a member inside the apparatus. For the purpose.
[0007]
[Means for Solving the Problems]
The present invention employs the following configuration in order to solve the above problems. That is, the cleaning device of the single crystal pulling apparatus of the present invention is an apparatus for cleaning the inside of the single crystal pulling apparatus that pulls up the semiconductor single crystal from the semiconductor melt in the crucible by installing the crucible in a sealed container, A lid body that can be placed in a sealed state in the upper opening of the sealed container with the top removed, and an air that is installed on the inner surface side of the lid body and that can blow air into the sealed container in the previously described state An air outlet mechanism, and the air outlet mechanism includes an air outlet rotating mechanism that rotates an air outlet around the central axis of the sealed container.
[0008]
In this cleaning device, since the air blowing mechanism includes a blower outlet rotating mechanism that rotates the air outlet around the central axis of the sealed container, the lid body is placed on the sealed container in a sealed state, By rotating the air outlet by the air outlet rotating mechanism, air was concentrated on the surface of the member arranged on the circumference around the central axis in the pulling device and the inner wall of the device, and adhered. Foreign matter can be efficiently blown away.
[0009]
The cleaning device of the single crystal pulling apparatus according to the present invention includes an air supply pipe in which the air blowing mechanism is rotatably held on the central axis of the lid body and supplies air to the blowout outlet, and the air supply A blowing member having the outlet at a position eccentric from the central axis of the lid body, and the outlet rotating mechanism tilts the outlet of the blowing member toward the circumferential side. It is preferable to arrange them. That is, in this cleaning device, the air blown out from the air outlet can be used as a rotational driving force by inclining the air outlet of the blowing member toward the circumferential side, and a drive source such as a motor can be used. There is no need for attachment, and the configuration becomes simple.
[0010]
Further, in the cleaning device for a single crystal pulling apparatus according to the present invention, the air outlet is provided on a member installed in the sealed container at the time of rotation, a portion where the member overlaps, or an inner wall portion of the sealed container. It is preferable that the position is set so as to pass through the vicinity of at least one surface of the window or the sensor. That is, in this cleaning device, a member installed in the sealed container, a portion where the members overlap, a window provided on the inner wall of the sealed container, or the vicinity of at least one surface of the sensor is passed through the outlet. By setting the position, air can be blown in a concentrated manner especially on a portion where foreign matters are easily attached, and foreign matters can be removed more efficiently.
[0011]
Furthermore, the cleaning device of the single crystal pulling apparatus of the present invention includes an air suction mechanism that sucks air in the sealed container through the suction port and discharges the air to the outside. It is preferable to be arranged in the vicinity of the outlet. That is, in this cleaning device, since the suction port of the air suction mechanism is arranged in the vicinity of the blowout port, the foreign matter blown off by the air blown out from the blowout port is immediately sucked from the nearby suction port. Can be discharged outside.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a cleaning device for a single crystal pulling apparatus according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2.
[0013]
FIG. 1 shows a state in which a cleaning device for a single crystal pulling apparatus according to this embodiment is installed on a lower chamber (sealed container) 1 of the single crystal pulling apparatus. Is to clean. In this single crystal pulling apparatus, the chamber can be divided into a lower part, an intermediate part, and an upper part. In the lower chamber 1, a carbon susceptor 3 supported on a shaft 2 and a susceptor 3 are provided. The disposed quartz crucible 4, a cylindrical carbon heater 5 disposed around the quartz crucible 4, and a carbon fiber (carbon fiber) heat insulating cylinder 6 disposed around the heater 5 are installed. . Note that a carbon plate (not shown) is attached to the heat retaining cylinder 6 as a support plate on the inner surface.
[0014]
The cleaning device includes a lid main body 11 that can be placed in a sealed state on the lower chamber 1 with the upper and intermediate chambers removed, and is placed on the inner surface side of the lid main body 11 and placed in the lower chamber 1 in the placed state. An air blowing mechanism 12 capable of blowing clean air (air) and an air suction mechanism 13 that sucks air in the lower chamber 1 through the suction port 11a and discharges it to the outside.
[0015]
The lid body 11 is designed so as to obtain high hermeticity when placed on the lower chamber 1 and has high heat resistance so that it can be placed on the lower chamber 1 in the high temperature state after pulling growth. It has.
The air blowing mechanism 12 is rotatably held on a central axis of the lid body 11 by a rotary joint or the like, and supplies an air supply pipe 14 for supplying clean air to the outlet N. A lid provided at the lower part of the air supply pipe 14 A spray member 15 having a plurality of outlets N is provided at a position eccentric from the central axis of the main body 11.
[0016]
The air supply pipe 14 is connected to a high-pressure air supply source 16 through a switching valve (not shown) and a filter (not shown) on the base end side.
The open / close valve opens and closes the flow path in the air supply pipe 14, and the filter is for removing impurities in clean air to be supplied.
The blowing member 15 includes a rectangular pipe part 15A connected to the lower part of the air supply pipe 14, and an extended pipe part 15B extending radially outward from the upper part of the rectangular pipe part 15A. The rectangular pipe portion 15A is provided with one outlet N directed downward in the lower part and three outlets N directed outward in the radial direction on the outer side. Further, the extension pipe portion 15B is provided with two air outlets N facing downward.
[0017]
When the air outlet N provided at the lower part of the rectangular pipe part 15A is placed on the lower chamber 1, clean air can be blown toward the upper surface of the crucible lid member 17 placed on the crucible 4. Is arranged. Further, the three air outlets N provided on the outer side of the rectangular pipe portion 15A pass through the gap between the heater 5 and the heat retaining cylinder 6, the overlapping portion of the heat retaining cylinder 6, and the vicinity of the inner peripheral surface of the heat retaining cylinder 6 when rotating. The positions are set so that clean air can be blown toward them. Further, the position of the air outlet N provided in the extension pipe portion 15B is set so that it passes through the vicinity of the upper surface of the heat insulating cylinder 6 during rotation, and clean air can be sprayed toward the upper surface of the heat insulating cylinder 6. ing.
[0018]
Moreover, as shown in FIG. 2, all the blower outlets N of the blowing member 15 are all inclined slightly toward the same circumferential direction side. That is, since all the air outlets N are inclined toward the circumferential side, clean air blown from the air outlets N can be used as a driving force for rotation, and the air outlets N are the central axis of the lower chamber 1. It functions as an outlet rotation mechanism that rotates the blowing member 15 around C.
[0019]
The air suction mechanism 13 includes a cover member 18 provided on the upper surface of the lid body 11 so as to cover a plurality of suction ports 11a opened near the center of the lid body 11, and a vacuum pump connected to the inside of the cover member 18. And a suction device 19 such as a vacuum cleaner.
[0020]
Next, a cleaning method using the cleaning device of the single crystal pulling apparatus of this embodiment will be described.
[0021]
First, the crucible 4 containing the raw material is placed on the susceptor 3 with each member (susceptor 3, heater 5, heat retaining cylinder 6, etc.) installed in the lower chamber 1 from which the upper and middle chambers are removed. Note that the crucible lid member 17 is placed on the crucible 4 so as to be covered.
Next, the lid body 11 of the cleaning device is placed on the upper opening of the lower chamber 1 and covered, that is, in a sealed state.
[0022]
While maintaining the above-mentioned sealed state, high-pressure air is sent from the high-pressure air supply source 16 of the air blowing mechanism 12 to the air supply pipe 14, and high-pressure clean air is blown out from each outlet N of the blowing member 15 through the filter and the open / close valve. . At this time, since all the air outlets N are inclined toward the same circumferential direction, the blowing member 15 is rotated around the central axis C of the lower chamber 1 by the thrust of the clean air that is blown out. Clean air is blown over.
[0023]
The position of the blowout port N is set so as to pass through the upper surface of the crucible lid member 17, the gap between the heater 5 and the heat retaining cylinder 6, the overlapping portion of the heat retaining cylinder 6, and the vicinity of the inner peripheral surface of the heat retaining cylinder 6. Therefore, clean air is intensively blown over the circumferential direction along with the rotation, and the foreign matters attached to these are blown off.
In addition, since the inside of the lower chamber 1 is sealed by the lid body 11, the soaring foreign matter is not scattered outside. At this time, the suction device 19 of the air suction mechanism 13 is driven, and the air in the lower chamber 1 is sucked together with the foreign matter soared through the suction port 11a and discharged to the outside.
[0024]
After the foreign matter in the lower chamber 1 has been sufficiently removed in this way, the crucible lid member 17 is removed, and the flow tube, the middle and upper chambers, etc. are set to perform pulling growth.
[0025]
In the present embodiment, while the lid body 11 is placed on the lower chamber 1 in a sealed state, high-pressure clean air is blown into the lower chamber 1 to raise the foreign matter, and the foreign matter that has raised the air in the lower chamber 1 At the same time, the foreign matter can be removed by discharging to the outside. That is, since the foreign matter is lifted by blowing air and then sucked, it is easier to collect dust than the suction by the conventional suction cleaner, and the foreign matter is removed while the members are set in the lower chamber 1. be able to.
[0026]
Further, the air blowing mechanism 12 rotates the clean air outlet N about the central axis C of the lower chamber 1, so that the lid body 11 is placed on the lower chamber 1 in a sealed state in the pulling device. In addition, clean air can be intensively sprayed onto the surface of the member disposed on the circumference around the central axis C, and the adhered foreign matter can be efficiently blown away.
[0027]
In particular, the air outlet N rotates and passes near the gap between the heater 5 and the heat retaining cylinder 6, which is a part to which foreign matter easily adheres, the overlapping part of the heat retaining cylinder 6, and the inner peripheral surface of the heat retaining cylinder 6. Since air is blown onto these, foreign matter can be removed more efficiently. In addition, even if the blown-off foreign matter tries to adhere to the upper surface of the crucible lid member 17, clean air is blown onto this portion, so that the foreign matter can be prevented from adhering.
[0028]
Furthermore, since each blower outlet N of the blowing member 15 is inclined toward the same circumferential direction, clean air blown from the blower outlet N can be used as a driving force for rotation, such as a motor. There is no need to attach a drive source, and the configuration becomes simple.
[0029]
Next, a second embodiment of a cleaning apparatus for a single crystal pulling apparatus according to the present invention will be described with reference to FIG.
[0030]
As shown in FIG. 3, the cleaning device of the second embodiment is provided with a window portion 20a, a permeation sensor 20b, a water-cooled tube (not shown), etc., and removes foreign matter adhering to the inner wall surface of the intermediate chamber 20 with many irregularities. To do. That is, the cleaning device of the present embodiment includes a lid body 21 that can be placed in a sealed state in the upper opening of the intermediate chamber 20 with the upper chamber removed, and a placed state that is placed on the inner surface side of the lid body 21. And an air blowing mechanism 22 capable of blowing clean air (air) into the intermediate chamber 20.
[0031]
In the cleaning device of the first embodiment, the lid body 11 is provided with the suction port 11 a of the air suction mechanism 13, whereas in the cleaning device of the second embodiment, the air suction mechanism 23 is located in the intermediate chamber 20. A receiving member 24 disposed at the lower end of a cylindrical member 20c attached to the bottom of the cylinder member 20 and a suction device 19 that sucks air in the intermediate chamber 20 through a suction port 24a provided in the receiving member 24 and discharges it to the outside. It differs in that it has.
Furthermore, in the cleaning device of the first embodiment, the spray member 15 is composed of the rectangular piping portion 15A and the extension piping portion 15B, whereas in the cleaning device of the second embodiment, the air supply pipe 14 is centered at the lower end. The difference is that a hollow columnar blowing member 25 having a plurality of outlets N on the peripheral surface is connected with the shaft aligned.
[0032]
In the cleaning device of the present embodiment, when the spray member 25 is rotated in a state of being placed on the intermediate chamber 20, the inner wall surface of the intermediate chamber 20, particularly the window portion 20a, the transmission sensor 20b, and the cylindrical member 20c. The positions of the air outlets N on the peripheral surface of the blowing member 22 are set so as to pass through the vicinity of the mounting portion.
In addition, the blower outlet N toward the inner wall surface of the intermediate chamber 20 and the window portion 20a employs a type that blows out clean air and removes foreign matter adhering to a relatively large area, and transmits the sensor 20b and the cylindrical member. As the air outlet N directed toward the mounting portion 20c, a spot type that removes foreign matters adhering to a relatively small area by blowing out without spreading clean air is adopted.
That is, in this cleaning device, clean air is blown in the vicinity of a portion where foreign matter is particularly likely to adhere while the blowout port N rotates, so that the foreign matter on the inner wall surface of the intermediate chamber 20 can be efficiently removed.
[0033]
Next, a third embodiment of a cleaning apparatus for a single crystal pulling apparatus according to the present invention will be described with reference to FIGS.
[0034]
The difference between the first embodiment and the third embodiment is that the blowing member 15 of the first embodiment is composed of a rectangular piping portion 15A and an extension piping portion 15B, whereas the air blowing in the third embodiment. As shown in FIGS. 4 and 5, the spray member 40 of the mechanism 39 is configured by a plurality of branch pipe portions 40 </ b> A that branch out in the radial direction and extend to the outlet N.
[0035]
The air suction mechanism 13 of the first embodiment is configured by connecting the suction device 19 to the cover member 18 provided on the upper surface of the lid body 11, whereas the air suction mechanism 41 of the third embodiment is configured. The cover body 42 is provided with a substantially cylindrical suction cover 43 that is rotatably held by the rotary joint or the like together with the air supply pipe 14 so as to cover the branch pipe portion 40A, and an upper cylinder of the suction cover 43 The suction device 19 is connected to the portion 43b.
[0036]
A plurality of suction ports 43a are formed on the outer peripheral surface and the bottom surface of the suction cover 43 of the present embodiment so as to open at the position of the air outlet N of the branch pipe portion 40A so as to surround the air outlet N.
Therefore, in the cleaning device of this embodiment, the suction port 43a of the suction cover 43 is arranged in the vicinity (periphery) of the blowout port N, so that the foreign matter blown off by the clean air blown out from the blowout port N is removed. The air can be immediately sucked from the suction port 43a in the vicinity without being raised and discharged to the outside.
[0037]
As another example of the third embodiment, as shown in FIG. 6, the suction cover 51 covering the spray member 40 is not a complete hollow member, and the suction port 51 a is formed in a cross-sectional fan shape and is connected to the suction device 19. It may be connected to the hollow portion 51b having a circular cross section at the center.
[0038]
The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, you may provide the air particle counter which measures the dust contained in the air of the inner surface side of a lid | cover main body.
Moreover, in the said 1st Embodiment, although the spraying member 15 is distribute | arranged to one direction of radial direction outward, you may distribute | arrange and provide in multiple other directions of radial direction outward. In this case, it is preferable to arrange the spray member symmetrically with respect to the rotation center in consideration of the balance during rotation.
[0039]
Furthermore, in each said embodiment, although the mechanism which rotates a blowing member with the thrust of the clean air which blows off by inclining a blower outlet in the circumferential direction, you may use another rotating mechanism. For example, a drive source such as a motor may be attached. As described above, if a mechanism that rotates with the thrust of clean air is employed, it is not necessary to attach a motor or the like, and the number of members and the cost can be reduced.
[0040]
【The invention's effect】
According to the cleaning device of the single crystal pulling apparatus of the present invention, the air blowing mechanism includes the blower outlet rotating mechanism that rotates the air outlet around the central axis of the sealed container. By rotating the air outlet, air is intensively blown to the surface of the member arranged on the circumference in the pulling device and the inner wall of the device, and the adhered foreign matter is sufficiently removed without removing the member inside the device. And can be blown away efficiently. Therefore, the foreign matter affecting the single crystal pulling growth can be greatly reduced, the dislocation of the single crystal can be suppressed, the pulling characteristics can be improved, and the foreign matter removal work can be made efficient, and the periodic In addition, it is possible to greatly reduce the frequency of cleaning performed by removing the members and improve the throughput.
[Brief description of the drawings]
FIG. 1 is an overall cross-sectional view showing a cleaning device set on a lower chamber in a first embodiment of a cleaning device for a single crystal pulling device according to the present invention.
FIG. 2 is a schematic top view of a spray member for explaining the inclination of the air outlet in the first embodiment of the cleaning device for the single crystal pulling apparatus according to the present invention.
FIG. 3 is an overall cross-sectional view showing a cleaning device set on an intermediate chamber in a second embodiment of a cleaning device for a single crystal pulling device according to the present invention.
FIG. 4 is an overall sectional view showing a cleaning device in a third embodiment of a cleaning device for a single crystal pulling apparatus according to the present invention.
FIG. 5 is a side view showing a spray member in a third embodiment of a cleaning device for a single crystal pulling apparatus according to the present invention.
FIG. 6 is a top view of a suction cover showing another example of the cleaning device of the single crystal pulling apparatus according to the third embodiment of the present invention.
[Explanation of symbols]
1 Lower chamber 1 (sealed container)
4 Crucible 5 Heater 6 Insulating cylinder 11, 21, 42 Lid body 11a, 24a, 43a, 51a Suction port 12, 22, 39 Air blowing mechanism 14 Air supply pipes 15, 25, 40 Spray member 15A Rectangular piping part 15B Extension piping part 16 High-pressure air supply source 19 Suction device 20 Intermediate chamber (sealed container)
20a Window portion 20b Permeation sensor 23, 41 Air suction mechanism 40A, branch piping portion C Center axis N of air outlet

Claims (4)

A device for cleaning the inside of a single crystal pulling apparatus that pulls up a semiconductor single crystal from a semiconductor melt in a crucible by installing the crucible in a sealed container,
A lid body that can be placed in a sealed state in the upper opening of the sealed container with the top removed;
An air blowing mechanism installed on the inner surface side of the lid body and capable of blowing air into the sealed container in the above-described installation state,
The cleaning apparatus for a single crystal pulling apparatus, wherein the air blowing mechanism includes an air outlet rotating mechanism that rotates an air outlet around a central axis of the sealed container. In the cleaning apparatus of the single crystal pulling apparatus according to claim 1,
The air blowing mechanism is rotatably held on a central axis of the lid body, and an air supply pipe for supplying air to the outlet;
A blowing member provided at a lower portion of the air supply pipe and having the outlet at a position eccentric from a central axis of the lid body;
The cleaning device for a single crystal pulling apparatus, wherein the outlet rotating mechanism is formed by inclining the outlet of the blowing member toward the circumferential direction. In the cleaning apparatus of the single crystal pulling apparatus according to claim 1 or 2,
At the time of the rotation, the air outlet passes through at least one surface of a member installed in the sealed container, a portion where the member overlaps, a window provided in the inner wall of the sealed container, or a sensor. A cleaning apparatus for a single crystal pulling apparatus, wherein a position is set. In the cleaning apparatus of the single crystal pulling apparatus according to claim 3,
An air suction mechanism for sucking air in the sealed container through a suction port and discharging it to the outside;
The air suction mechanism is a cleaning device for a single crystal pulling apparatus, wherein the suction port is arranged in the vicinity of the air outlet.

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