KR101353477B1 - Apparatus for pulling single crystal and apparatus for supporting crucible - Google Patents

Abstract

The single crystal pulling apparatus A1 moves the pulling shaft 3 and the shaft supporting portion 4 by moving the support 5 including the weight detecting means 541, so that the single crystal 1 in the hermetic container 2 is pulled out. The shaft support part 4 is provided with the main body part 41 which supports the impression shaft 3, and the to-be-supported part 43 connected with the main body part 41, and the support body 5 has the to-be-supported part ( The support part 54 which supports 43, and the extension part 53 arrange | positioned above the to-be-supported part 43 in the axial direction z are provided, The said single crystal pulling apparatus has the extension part 53 and the to-be-supported part 43 Between the first cylinder 71 and the pulling shaft 3, which are internally sealed, and which can be expanded and contracted in the axial direction z, and are expandable and contractable in the axial direction z. The second cylinder 72 communicates with the interior space of the hermetic container 2 while the upper end portion in the axial direction z is fixed to the main body portion 41 and the interior space is hermetically sealed. And it includes a first cylinder 71 and the pipe 74 which connects the second cylinder (72). By this structure, the weight of the single crystal 1 can be measured more accurately.

Description

Monocrystalline pulling device and crucible support device {APPARATUS FOR PULLING SINGLE CRYSTAL AND APPARATUS FOR SUPPORTING CRUCIBLE}

TECHNICAL FIELD This invention relates to the single crystal pulling apparatus and crucible support apparatus used when manufacturing single crystals, such as silicon and sapphire, by the Czochralski method.

Background Art Conventionally, a method is known in which the diameter of a single crystal is calculated from time to time on the pulling shaft and adjusted so that the diameter of the single crystal is a desired value based on the result of the calculation (for example, Japanese Laid-Open Patent Application). 2010-120789 and Japanese Patent Laid-Open No. 2005-231958. In order to carry out these methods, a single crystal pulling apparatus capable of pulling a single crystal while measuring weight is required. 5 shows an example of such a single crystal pulling apparatus.

The single crystal pulling apparatus X1 shown in FIG. 5 is for pulling up the single crystal 91 from the crucible 92a provided in the hermetic container 92. The single crystal pulling apparatus X1 supports the pulling shaft 93 and the holding shaft 93 supporting the pulling shaft 93. FIG. The branch part 94, the support part 95 which supports the axial support part 94, and the drive mechanism 96 which moves the support part 95 are provided. The support part 95 is provided with the load cell 95a which measures the weight added to the axial support part 94 at any time. Thus, when the load cell 95a is provided outside the hermetic container 92, there is an advantage that the structure of the hermetic container 92 can be simplified and the cost can be easily reduced.

In order to maintain the air pressure in the hermetic container 92, a sealing ring 92b is provided, for example, at the contact portion with the pulling shaft 93 of the hermetic container 92. The weight detected by the load cell 95a may be inaccurate due to the friction between the sealing ring 92b and the pulling shaft 93.

For this reason, for example, the single crystal pulling apparatus X2 as shown in FIG. 6 is sometimes used. The single crystal pulling apparatus X2 is provided with a cylinder 97 that can be stretched up and down, such as bellows, between the airtight container 92 and the shaft support portion 94. According to this structure, unlike the single crystal pulling apparatus X1, it is possible to prevent the frictional force in the axial direction from being applied to the pulling shaft 93.

However, when manufacturing a sapphire single crystal, for example, the air pressure in the airtight container 92 may be greatly reduced. In this case, in both of the single crystal pulling apparatuses X1 and X2, the shaft support portion 94 is applied with a force corresponding to the air pressure difference between the inside of the hermetic container 92 and atmospheric pressure, and detected by the load cell 95a. The weight which became may become inaccurate.

For example, in order to confirm how much raw material of the single crystal 91 remains in the crucible 92a, the crucible 92a may be supported by the crucible support apparatus which can measure a weight. Also in such a case, if the difference between the air pressure in the airtight container 92 and the air pressure outside is large, the same problem as that described above may occur.

In addition, when the long single crystal is to be pulled up in the axial direction, in the single crystal pulling apparatus X2, the cylinder 97 is elongated. At this time, the force to which the cylinder 97 pulls the shaft support part 94 may become the magnitude | size which cannot be ignored. Even in this case, there has been a problem that the weight detected by the load cell 95a becomes inaccurate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a single crystal pulling apparatus and a crucible support apparatus capable of measuring weight more accurately.

The single crystal pulling apparatus provided by the first aspect of the present invention includes an airtight container, an impression shaft for pulling up a single crystal grown in the airtight container, a shaft support for supporting the impression shaft, and a weight applied to the shaft support. A single crystal pulling apparatus comprising a support for supporting the shaft support and having a weight detecting means for detecting the above, wherein the support supports are moved along the axial direction of the pulling shaft to pull out the single crystal. A main body portion supporting the pulling shaft, a supported portion connected to the main body portion, the supporting portion supporting the supported portion, and a directing portion arranged above the axial direction than the supported portion. The single crystal pulling apparatus is provided between the directing portion and the supported portion, and the shaft Direction and at the same time, an inner space is hermetically sealed, and is configured to surround the pulling shaft, and is expandable in the axial direction, and an upper end in the axial direction is fixed to the main body portion, The space is hermetically sealed, and further includes a second cylinder communicating with the interior space of the hermetic container, and a pipe connecting the first cylinder and the second cylinder.

In a preferred embodiment of the present invention, the first cylinder has a first fixed ring fixed to the supported portion, the second cylinder has a second fixed ring fixed to the body portion, and the first fixed ring and The inner diameter of the second fixed ring is the same.

In a preferred embodiment of the present invention, the support has a mount having an opening through which the pulling shaft is inserted and passed, and a lower end portion in the axial direction of the second cylinder is fixed to the mount. And a third cylinder provided between the godfather and the hermetic container and configured to surround the pulling shaft, and communicating with an inner space of the hermetic container.

In preferable embodiment of this invention, the said piping is provided so that the said extension part and the said 2nd fixed ring may be connected.

In a preferred embodiment of the present invention, the third cylinder has a third fixing ring fixed to the large portion, and the pipe is provided to connect the directing portion and the third fixing ring.

In preferable embodiment of this invention, the said 1st cylinder is arrange | positioned in the position which overlaps with the said pulling shaft as seen from the said axial direction.

The single crystal pulling apparatus provided by the second aspect of the present invention is applied to an airtight container, a crucible accommodated in the airtight container, a support shaft for supporting the crucible, a shaft support portion for supporting the support shaft, and a shaft support portion. A crucible support device comprising a support for supporting the shaft support portion, the apparatus comprising a support for supporting the shaft support portion, wherein the shaft support portion includes a body portion for supporting the support shaft, and a supported portion connected to the body portion. The support includes a supporting portion for supporting the supported portion, and a extending portion disposed downward in the axial direction from the supported portion, and the crucible supporting device is provided between the extending portion and the supported portion, It can be stretched to the inside and the inner space is configured to surround the first cylinder and the support shaft is airtight And a second cylinder which is expandable and contractible in the axial direction, the lower end portion in the axial direction is fixed to the main body portion, and the inner space is hermetically sealed and communicates with the inner space of the hermetic container. A pipe further connecting the cylinder and the second cylinder is further included.

In a preferred embodiment of the present invention, the first cylinder has a first fixed ring fixed to the supported portion, the second cylinder has a second fixed ring fixed to the body portion, and the first fixed ring and The inner diameter of the second fixed ring is the same.

In a preferred embodiment of the present invention, the support has a portion having an opening through which the support shaft is inserted and passed, and an upper end portion in the axial direction of the second cylinder is fixed to the portion. The crucible support device is provided between the said large part and the said airtight container, and is comprised so that the said support shaft may be enclosed and further contains the 3rd cylinder which communicates with the internal space of the said airtight container.

In preferable embodiment of this invention, the said piping is provided so that the said extension part and the said 2nd fixed ring may be connected.

In a preferred embodiment of the present invention, the third cylinder has a third fixing ring fixed to the large portion, and the pipe is provided to connect the directing portion and the third fixing ring.

In preferable embodiment of this invention, the said 1st cylinder is arrange | positioned in the position which overlaps with the said support shaft as seen from the said axial direction.

Other features and advantages of the present invention will become more apparent from the following description of embodiments of the invention.

1 is a block diagram showing a single crystal pulling apparatus according to a first embodiment of the present invention;
2 is a block diagram showing a single crystal pulling apparatus according to a second embodiment of the present invention;
3 is a block diagram showing a crucible support device according to a third embodiment of the present invention;
4 is a configuration diagram showing a crucible support device according to a fourth embodiment of the present invention;
5 is a configuration diagram showing an example of a conventional single crystal pulling apparatus;
6 is a configuration diagram showing another example of a conventional single crystal pulling apparatus.

Fig. 1 shows a single crystal pulling apparatus according to the first embodiment of the present invention. The single crystal pulling apparatus A1 shown in FIG. 1 includes an airtight container 2, an pulling shaft 3, a shaft support 4, a support 5, a drive mechanism 6, a first cylinder 71, and a second cylinder. 72, a third cylinder 73, and a pipe 74 are provided. The z direction in FIG. 1 is the axial direction of the pulling shaft 3, and the single crystal pulling apparatus A1 pulls up the single crystal 1 via the pulling shaft 3 along the z direction which is perpendicular. The x direction is a direction orthogonal to the z direction, and there is a base 8 that holds the single crystal pulling apparatus A1 at the right end in the x direction in FIG. 1. The base 8 is fixed to the large base material which can move the single crystal pulling apparatus A1 around a z-axis direction, or horizontally, for example. In this embodiment, the case where the single crystal 1 is a sapphire single crystal will be described.

The single crystal 1 is formed by growing a seed crystal attached to the tip of the pulling shaft 3, and the shoulder portion 11 whose diameter gradually increases as it moves away from the pulling shaft 3. ) And a straight body portion 12 having a substantially constant diameter.

The airtight container 2 has the opening part 21 for passing the pulling shaft 3, and accommodates the crucible 22. As shown in FIG. The crucible 22 is made of iridium, for example, and is filled with alumina, which is a raw material of sapphire. The crucible 22 is heated by the resistance heating apparatus 25 installed in the airtight container 2, for example, and it becomes 2000-2200 degreeC which exceeds the melting point of alumina. The resistance heating device 25 is connected to, for example, a computing device (not shown) and is controlled according to the weight of the single crystal 1. This arithmetic unit adjusts the temperature of the alumina melt 23 in the crucible 22 so that the diameter of the shoulder part 11 and the straight trunk | drum 12 of the single crystal 1 may become desired value. The pressure inside the hermetic container 2 is, for example, 0.1 kPa to 3 kPa.

The pulling shaft 3 is for pulling up while rotating the single crystal 1, and a large diameter portion 31 formed to be thicker than the lower portion is provided at the upper end in the z direction. The large diameter portion 31 is connected to the rotary motor 311 via a belt 312. In addition, the large diameter portion 31 is supported by the shaft support portion 4. The rotary motor 311 is also controlled by the calculation means described above.

The shaft support portion 4 includes a main body portion 41 formed in a plate shape along a plane orthogonal to the z direction, a connecting portion 42 standing up from the main body portion 41 in the z direction, and a z of the connecting portion 42. It is provided with the to-be-supported part 43 which protrudes in an x direction from a direction upper end. The main body portion 41 has a through hole 411 through which the thin portion of the pulling shaft 3 is inserted and passed. The inner diameter of this through hole 411 is formed so that it may become a diameter smaller than the outer diameter of the large diameter part 31 of the impression shaft 3, and the main-body part 41 supports the impression shaft 3 rotatably. . The connection part 42 is a plate-shaped or rod-shaped member formed so that the left end part in FIG. 1 and the left end part in FIG. 1 of the to-be-supported part 43 in the x direction of the main-body part 41 may be connected. The supported portion 43 is formed in a plate shape parallel to the main body portion 41.

The support 5 includes a large portion 51 connected to the drive mechanism 6, a support 52 standing up in the z-direction from the support 51, a lead portion 53 extending from the upper end of FIG. The support part 54 which supports the branch part 4 is provided. The opening part 511 for passing the pulling shaft 3 is formed in the large part 51. The large part 51 moves up and down in the z direction according to the operation of the drive mechanism 6. The lower end part in the z direction of the support | pillar 52 is being fixed to the big part 51, and the support | pillar 52 is integrated with the big part 51, and moves up and down. The extension part 53 is formed in the plate shape which opposes the to-be-supported part 43 in a z direction. The extension part 53 is formed with the first thin hole 531 penetrating in the z direction. The support part 54 is formed in the plate shape which opposes the main-body part 41 at the lower side, and the to-be-supported part 43 at the upper side, and as shown in FIG. Part. The load cell 541 is mounted on the upper surface of the support part 54. The load cell 541 is a weight detecting means in the present invention, and measures the weight applied to the body portion 41 constituting the shaft support portion 4 at any time. The arithmetic unit described above performs control of the heat generating resistor 25 or the like using the weight measured by the load cell 541.

The drive mechanism 6 has a screw shaft rotated by a servomotor, for example, and is provided with the movable part 61 which moves up and down in a z direction according to rotation of a screw shaft. The movable portion 61 is connected to the support 5. In such a drive mechanism 6, the rising speed of the support body 5 can be freely adjusted by controlling the operation of the servomotor. The arithmetic unit mentioned above also adjusts the operation | movement of the drive mechanism 6 so that the diameter of the straight trunk | drum 12 may become a desired value.

The 1st cylinder 71 is a bellows, for example, and is provided between the extension part 53 and the to-be-supported part 43. A fixing ring 711 is provided at the upper end portion in the z-direction of the first cylinder 71, and is fixed to maintain the airtightness on the lower surface of the extension portion 53. A fixing ring 712 is provided at the lower end of the first cylinder 71 in the z-direction, and is fixed to maintain the airtightness on the upper surface of the supported portion 43. The first cylinder 71 is configured such that a portion between the fixed rings 711 and 712 is stretchable up and down. Moreover, the 1st cylinder 71 should just be stretchable by the length by which the load cell 541 deforms in a z direction, and specifically, the stretch width is about 1-2 mm.

The 2nd cylinder 72 is a bellows, for example, and is provided between the main-body part 41 and the large part 51 so that the impression shaft 3 may be enclosed. A fixing ring 721 is provided at the upper end portion in the z-direction of the second cylinder 72, and is fixed to maintain the airtightness on the lower surface of the main body portion 41. A fixing ring 722 is provided at the lower end of the second cylinder 72 in the z-direction, and is fixed to the base 51 so as to surround the opening of the base 51 and maintain airtightness. The portion between the fixed rings 721 and 722 is configured to be able to expand and contract up and down in the second cylinder 72. Moreover, the 2nd cylinder 72 should just be stretchable by the length by which the load cell 541 deform | transforms in a z direction, specifically, the stretch width is about 0.1 mm.

The four fixed rings 711, 712, 721, and 722 are all annular in view of the z direction, and their inner diameters preferably coincide with each other.

The 3rd cylinder 73 is a bellows, for example, and is provided between the airtight container 2 and the base 51 so that the impression shaft 3 may be enclosed. The third cylinder 73 has fixed rings 731 and 732 above and below in the z direction, and the portion between the fixed rings 731 and 732 is configured to be stretchable up and down. The third cylinder 73 can be stretched by the length of the single crystal 1 which can be pulled up from the crucible 22, and specifically, the stretch width is about 300 mm.

The fixed ring 731 fixed to the upper portion of the third cylinder 73 is fixed to maintain the airtightness on the lower surface of the large portion 51, and the fixed ring 732 fixed to the lower portion of the third cylinder 73 is airtight. The opening 21 of the container 2 is fixed to maintain airtightness. In the fixed ring 731 fixed to the upper part of the 3rd cylinder 73, the 2nd narrow hole 733 which penetrates radially and connects inside is formed. This second thin hole 733 is connected to the pipe 74.

The space inside the second cylinder 72 and the third cylinder 73 is blocked from the outside air, and becomes the same air pressure as the interior space of the airtight container 2.

The pipe 74 is provided so as to connect between the second thin hole 733 and the first thin hole 531. By this piping 74, the air pressure inside the cylinder 71 becomes equal to the space inside the cylinder 72 and the cylinder 73, that is, the air pressure in the hermetic container 2.

Next, the operation of the single crystal pulling apparatus A1 of the present embodiment will be described.

In such single crystal pulling apparatus A1, the second cylinder 72 and the third cylinder 73 are attached to the lower end of the shaft support 4, and the first cylinder 71 is attached to the upper end of the shaft support 4. Is attached, and the internal pressure of the 1st cylinder 71, the 2nd cylinder 72, and the 3rd cylinder 73 is the same by the piping 74. As shown in FIG. In this embodiment, the internal pressure of the 1st cylinder 71, the 2nd cylinder 72, and the 3rd cylinder 73 is the same as the air pressure in the airtight container 2 which can be 0.1 kPa-3 kPa, It is smaller than that. For this reason, the main body part 41 is exerted a force as much as z direction downwards by multiplying the contact area with the space inside the second cylinder 72 by the difference between atmospheric pressure and air pressure in the airtight container 2. . On the contrary, the force to which the support part 43 multiplies the contact area with the space inside the cylinder 71 by the difference between atmospheric pressure and the air pressure in the hermetic container 2 is applied upward in the z direction.

In this embodiment, since the fixed ring 712 provided in the lower part of the 1st cylinder 71 and the fixed ring 721 provided in the upper part of the 2nd cylinder 72 have the same inner diameter, they are added to these upper and lower sides. The force is of equal magnitude. Therefore, according to the present invention, the difference between the atmospheric pressure and the air pressure in the hermetic container 2 can cancel the z-direction force applied to the shaft support 4. As a result, unexpected load is applied to the load cell 541, and the weight of the single crystal 1 can be measured more accurately. The present invention is particularly useful when the air pressure in the hermetic container 2 changes.

According to this embodiment, the 1st cylinder 71 and the 2nd cylinder 72 are as much as the length of the quantity deformed so that the load cell 541 may shrink in the z direction by the weight applied to the to-be-supported body 43. It is stretched. This deformation amount is minute, and the force which the 1st cylinder 71 and the 2nd cylinder 72 exerts on the axial support part 4 is small, and does not interfere with the weight measurement of the single crystal 1. Since the third cylinder 73 is fixed to the large part 51 instead of the shaft support part 4, the shaft support part 4 does not receive a force by the deformation | transformation.

Since the single crystal pulling apparatus A1 provided by the present invention can accurately measure the weight of the single crystal 1 without affecting the air pressure in the hermetic container 2 or the expansion and contraction of the third cylinder 73, the single crystal ( The diameter of the shoulder part 11 and the straight trunk | drum 12 of 1) can be calculated correctly. For this reason, the temperature of the crucible 22 which influences the shape of the single crystal 1, the pulling speed by the drive mechanism 6, and the rotational speed of the pulling shaft 3 can be adjusted suitably, and the shape desired more reliably. It is possible to pull up the single crystal 1 of.

2 to 4 show another embodiment of the present invention. In addition, in these drawings, the same code | symbol as the said embodiment is attached | subjected to the element similar or similar to the said embodiment.

2, the single crystal pulling apparatus based on 2nd Embodiment of this invention is shown. In the single crystal pulling apparatus A2 shown in FIG. 2, the new 2nd cylinder 75 which replaces the 2nd cylinder 72 and the 3rd cylinder 73 in the above-mentioned single crystal pulling apparatus A1 of FIG. It is provided, and the other main structure is the same as that of the single crystal pulling apparatus A1. Hereinafter, the different part from the single crystal pulling apparatus A1 of the single crystal pulling apparatus A2 is demonstrated.

The 2nd cylinder 75 in this embodiment is a bellows, for example, and is provided between the main-body part 41 and the airtight container 2 so that the impression shaft 3 may be enclosed. The second cylinder 75 has fixed rings 751 and 752 above and below in the z direction, and the portion between the fixed rings 751 and 752 is configured to be stretchable up and down. The second cylinder 75 is stretchable by the length of the single crystal 1 that can be pulled out of the crucible 22, and specifically, the stretch width is about 1 to 2 mm.

The fixed ring 751 fixed to the upper portion of the second cylinder 75 is fixed to maintain the airtightness on the lower surface of the main body portion 41, and the fixed ring 752 fixed to the lower portion of the second cylinder 75 is The opening 21 of the hermetic container 2 is fixed to maintain hermeticity. In the fixed ring 751 fixed to the upper part of the 2nd cylinder 75, the 3rd fine hole 753 which penetrates radially and connects inside is formed. This third thin hole 753 is connected to the pipe 74. The fixed ring 751 is formed in an annular shape as viewed from the z direction, and its inner diameter preferably coincides with the inner diameter of the fixed ring 711 fixed to the upper portion of the first cylinder 71.

The pipe 74 is provided so as to connect between the third thin hole 753 and the first thin hole 531. By this piping 74, the air pressure inside the first cylinder 71 is equal to the space inside the second cylinder 75, that is, the air pressure in the hermetic container 2.

In this embodiment, not only the impression shaft 3 but the opening part 512 which inserts and passes the cylinder 75 is formed in the large part 51. As shown in FIG.

Also in such a structure, the internal pressure of the 1st cylinder 71 and the 2nd cylinder 75 is equal to the internal pressure of the airtight container 2. Therefore, the difference between the atmospheric pressure and the air pressure in the hermetic container 2 can cancel the force exerted on the shaft support portion 4, thereby preventing the load cell 541 from taking an unexpected force, thereby more accurately providing a single crystal ( The weight of 1) can be measured.

Such a single crystal pulling apparatus A2 is useful when, for example, pulling up a relatively short single crystal 1.

3, the crucible support apparatus based on 3rd Embodiment of this invention is shown. The crucible support device A3 shown in FIG. 3 may be used together with the above-mentioned single crystal pulling apparatus A1, A2, for example. The crucible support device A3 shown in FIG. 3 is for supporting while measuring the weight of the crucible 22 installed in the airtight container 2. The crucible support device A3 includes a support shaft 3 ', a shaft support 4', a support 5 ', a drive mechanism 6', a first cylinder 76, a second cylinder 77, and a pipe ( 74 '). This crucible support device A3 is fixed to the host 8, for example.

In addition to the structure of the airtight container 2 in the single crystal pulling apparatus A1, the airtight container 2 in this embodiment allows the support shaft 3 'for passing the crucible 22 to pass. The opening part 24 is provided. 3, the state before immersing the seed crystal | crystallization 13 supported by the pulling shaft 3 in the crucible 22 is shown. The seed crystal 13 is a sapphire single crystal, for example.

The support shaft 3 'is for supporting the crucible 22, and the flange 32 is provided in the lower end part in the z direction. This flange 32 is fixed to the shaft support part 4 'with a screw, for example.

The shaft supporting portion 4 'includes a main body portion 44 formed in a plate shape along a plane orthogonal to the z direction, a connecting portion 45 protruding from the main body portion 44 in the z direction, and a connecting portion 45 It is provided with the to-be-supported part 46 which protrudes in the x direction from a lower end part. The main body 44 has a through hole 441 through which the support shaft 3 'is inserted and passed, and the lower surface in the z direction is in contact with the upper surface in the z direction of the flange 32. The connection part 45 is a plate-shaped or rod-shaped member formed so that the left end part in FIG. 3 and the left end part of FIG. 3 of the to-be-supported part 46 in the x direction of the main-body part 44 may mutually connect. The supported portion 46 is formed in a plate shape parallel to the main body portion 44.

The support 5 'includes a large portion 55 connected to the drive mechanism 6', a support 56 protruding in the z direction from the support 55, and an extension portion 57 extending from the lower end of FIG. 3. And a support portion 58 for supporting the shaft support portion 4 '. The large part 55 is formed with the opening part 551 for passing the support shaft 3 '. The large part 55 moves up and down in the z direction according to the operation of the drive mechanism 6 '. The upper end part in the z direction of the strut 56 is being fixed to the large part 55, and the pillar 56 is integrated with the large part 55, and moves up and down. The extension part 57 is formed in the plate shape which opposes the to-be-supported part 46 on the upper side. In the extension section 57, a first thin hole 571 penetrating in the z direction is formed. The support part 58 is formed in the plate shape which opposes the to-be-supported part 46 below, and the load cell 581 is provided in the lower surface. The supporting portion 58 holds the supported portion 46 via the load cell 581. The load cell 581 is a weight detecting means in the present invention, and measures the weight applied to the suspended main body 44 at any time. From the weight measured by the load cell 581, the calculation means (not shown) can calculate the weight of the crucible 22 and can also calculate the amount of alumina remaining in the crucible 22.

The drive mechanism 6 'has a screw shaft rotated by a servomotor, for example, and is provided with the movable part 62 which moves up and down in a z direction according to rotation of a screw shaft. The movable portion 62 is connected to the support 5 '. In addition, when it is not necessary to move the crucible 22 up and down, you may fix the support body 5 'directly to a host without using the drive mechanism 6'.

The 1st cylinder 76 is a bellows, for example, and is provided between the extension part 57 and the to-be-supported part 46. A fixed ring 761 is provided at the upper end portion of the cylinder 76 in the z-direction, and is fixed to maintain the airtightness on the lower surface of the supported portion 46. A fixing ring 762 is provided at the lower end of the first cylinder 76 in the z-direction, and is fixed to maintain the airtightness on the upper surface of the extension part 57. The first cylinder 76 is configured such that a portion between the fixed rings 761 and 762 is stretchable up and down. In addition, the 1st cylinder 76 should just be able to expand and contract by the length by which the load cell 581 is deformed in a z direction, and the expansion width is about 1-2 mm specifically ,.

The 2nd cylinder 77 is a bellows, for example, and is provided between the airtight container 2 and the main-body part 44 so that the support shaft 3 'may be enclosed. The fixed ring 771 is provided in the z-direction upper end part of the 2nd cylinder 77, and the fixed ring 772 is provided in the lower end part. The fixed ring 771 is fixed to the outside of the opening 24 to maintain the airtight inside the hermetic container 2. The fixed ring 772 is fixed to the main body 44 to surround the through hole of the main body 44 to maintain airtightness. The portion between the fixed rings 771 and 772 is configured such that the second cylinder 77 is stretchable up and down. In addition, the expansion-contraction width of the 2nd cylinder 77 is determined according to the length to which the drive mechanism 6 'moves up and down. When the support body 5 'is directly fixed to the host 8 without using the drive mechanism 6', the load cell 581 may be stretchable by a length corresponding to the deformation in the z direction.

The four fixed rings 761, 762, 771, and 772 are all annular in view of the z direction, and their inner diameters preferably coincide with each other.

In the fixed ring 772 fixed to the lower portion of the second cylinder 77, a second thin hole 773 penetrating radially and connected therein is formed. This second thin hole 773 is connected to the pipe 74 '.

The pipe 74 'is provided so as to connect between the second thin hole 773 and the first thin hole 571. By this piping 74 ', the air pressure inside the first cylinder 76 is equal to the space inside the second cylinder 77, that is, the air pressure in the hermetic container 2.

Next, the effect | action of the crucible support apparatus A3 of this embodiment is demonstrated.

In such a crucible support device A3, the second cylinder 77 is attached to the upper end of the shaft support 4 ', and the first cylinder 76 is attached to the lower end of the shaft support 4'. The internal pressures of the first cylinder 76 and the second cylinder 77 are the same. In this embodiment, the internal pressure of the 1st cylinder 76 and the 2nd cylinder 77 is the same as the air pressure in the airtight container 2 which can be 0.1 kPa-3 kPa, and is small compared with atmospheric pressure. For this reason, the force to which the support part 46 multiplies the contact area with the space inside the 1st cylinder 76 multiplied by the difference between atmospheric pressure and the air pressure in the airtight container 2 is applied upwards in the z direction. . On the contrary, the main body 44 is exerted with a force equal to the area in contact with the space inside the second cylinder 77 multiplied by the difference between the atmospheric pressure and the air pressure in the hermetic container 2 toward the bottom in the z direction. . In the present embodiment, the fixed rings 771 and 772 provided respectively above and below the first cylinder 76, and the fixed rings 771 and 772 respectively provided above and below the second cylinder 77 have the same inner diameter. Because of this, the forces applied above and below these are of the same magnitude. Therefore, according to the present invention, the difference between the atmospheric pressure and the air pressure in the hermetic container 2 can cancel the z-direction force applied to the shaft support portion 4 'so that an unexpected force is applied to the load cell 581. The weight of the crucible 22 can be measured more accurately. The present invention is particularly useful when the air pressure in the hermetic container 2 changes.

By using such a crucible support device A3, since the weight of the crucible 22 can be measured accurately, the quantity of the material which remains in the crucible 22 can be calculated more accurately. For this reason, the quantity of the material in the crucible 22 does not become insufficient at the timing which exceeded the assumed range, and can grow a single crystal smoothly.

4, the crucible support apparatus based on 4th Embodiment of this invention is shown. The crucible support device A4 shown in FIG. 4 is provided with the new 2nd cylinder 78 and the 3rd cylinder 79 instead of the 2nd cylinder 77, The other main structure is the crucible support apparatus A3. Same as Hereinafter, the different part from the crucible support apparatus A3 of the crucible support apparatus A4 is demonstrated.

In this embodiment, the case where the silicon single crystal is grown in the airtight container 2 is illustrated. The crucible 22 is made of quartz, for example, and is filled with a silicon raw material melt. The seed crystal 13 attached to the pulling shaft 3 is silicon. Moreover, you may use single crystal pulling apparatuses A1 and A2 as a device for raising the pulling shaft 3.

The new 2nd cylinder 78 is a bellows, for example, and is provided between the main-body part 44 and the base part 55 so that the support shaft 3 'may be enclosed. A fixing ring 781 is provided at the upper end of the second cylinder 78 in the z-direction, and is fixed to surround the opening 551 of the large portion 55 to maintain airtightness. A fixing ring 782 is provided at the lower end of the second cylinder 78 in the z-direction, and is fixed to maintain the airtightness on the upper surface of the main body 44. The part between the fixed ring 781, 782 is comprised by this 2nd cylinder 78 so that it can expand and contract up and down. Moreover, the 2nd cylinder 78 should just be extensible by the length by which the load cell 581 is deformed in a z direction, and the extension width is about 0.1 mm specifically ,.

The 3rd cylinder 79 is a bellows, for example, and is provided between the airtight container 2 and the base 55 so that the support shaft 3 'may be enclosed. The third cylinder 79 has fixed rings 791 and 792 up and down in the z-direction, and a portion between the fixed rings 791 and 792 is configured to be stretchable up and down. In addition, the expansion-contraction width of the 3rd cylinder 79 is determined according to the length by which the drive mechanism 6 'moves up and down.

The fixed ring 791 provided at the upper end of the third cylinder 79 is fixed to maintain the airtight in the opening 24 of the airtight container 2, and the fixed ring 792 is installed at the lower end of the third cylinder 79. Is fixed to the upper surface of the large part 55 to keep it airtight. In the fixed ring 792 provided at the lower end of the third cylinder 79, a second thin hole 793 penetrating radially and connected to the inside is formed. This second thin hole 793 is connected to the pipe 74 '.

In the present embodiment, the four fixed rings 761, 762, 781, and 782 are all annular in view of the z direction, and their inner diameters preferably coincide with each other.

The space inside the second cylinder 78 and the third cylinder 79 is blocked from the outside air, and becomes the same air pressure as the interior space of the airtight container 2. In addition, since the space and the inner side of the cylinder 76 are connected via the pipe 74 ', the inner space of the first cylinder 76 also has the same air pressure as the interior of the hermetic container 2.

The crucible support device A4 of such a structure can cancel the pressure from the outside air applied to the axial support part 4 'similarly to the crucible support device A3, and unexpected force is applied to the load cell 581. The weight of the crucible 22 can be measured more accurately by preventing it from being applied.

According to the structure of this embodiment, when the drive mechanism 6 'moves to z direction, the 3rd cylinder 79 will deform | transform. The force according to the deformation of the third cylinder 79 is applied to the large portion 55 and not to the shaft support portion 4 '. For this reason, the load cell 581 can measure the weight of the crucible 22 correctly even when the drive mechanism 6 'is moved up and down.

The scope of the present invention is not limited to the above-described embodiment. The specific structure of each part of the single crystal pulling apparatus and crucible support apparatus which concerns on this invention can be variously changed design. For example, the above-described single crystal pulling apparatuses A1, A2 and crucible support apparatus A3 show the case where single crystals of sapphire are grown, but the present invention is also used in an apparatus for growing single crystals such as silicon. It is possible. The crucible support device A4 shows a case where a silicon single crystal is grown, but can also be used when growing other single crystals such as sapphire.

In addition, although only one load cell 541 is shown in FIG. 1 and FIG. 2 for simplicity, how many load cells may be arrange | positioned on the support part 54. As shown in FIG. The same applies to the load cell 581 in FIGS. 3 and 4.

In addition, in the above-described embodiment, the connecting portion 42 is formed to stand up from the main body portion 41, but the connecting portion 42 may extend horizontally from the main body portion 41. In this case, the supported portion 43 may be in the same height position as the main body portion 41. At this time, by providing the extension part 53 and the support part 54 in the position which does not overlap with the main body part 41 by looking at the z direction, it is possible to support the to-be-supported part 43 by the support part 54 preferably. Such a configuration is effective, for example, when it is desired to shorten the z-direction length of the support 5.

In addition, although the crucible support apparatus A3, A4 shows the case where a single crystal is grown by immersing the seed crystal 13 in the crucible 22, the crucible support apparatus which concerns on this invention is limited to this case. It is possible to use any structure that uses the crucible in the hermetic container.

Claims (12)

Airtight container;
An impression shaft for pulling up a single crystal grown in the hermetic container;
A shaft support part supporting the impression shaft; And
Comprising a weight detecting means for detecting the weight applied to the shaft support portion, including a support for supporting the shaft support portion,
A single crystal pulling apparatus for pulling up the single crystal by moving the support along the axial direction of the pulling shaft,
The shaft support portion includes a main body portion for supporting the pulling shaft and a supported portion connected to the main body portion,
The support body includes a support part for supporting the supported part, and a directing part disposed above the supported part in the axial direction,
The single crystal pulling apparatus,
A first cylinder provided between the directing portion and the supported portion, which is expandable and contractible in the axial direction and whose inner space is hermetically sealed;
A second structure configured to enclose the pulling shaft, which can be expanded and contracted in the axial direction, the upper end in the axial direction is fixed to the main body, and the inner space is hermetically sealed to communicate with the inner space of the hermetic container. Body; And
The single crystal pulling apparatus further includes a pipe connecting the first cylinder and the second cylinder. The said 1st cylinder is provided with the 1st fixed ring fixed to the said to-be-supported part,
The second cylinder has a second fixed ring fixed to the main body,
Single crystal pulling apparatus of the same inner diameter of the first fixed ring and the second fixed ring. The said support body is equipped with the base part which has an opening part which inserts and passes the said pulling shaft,
The lower end part in the said axial direction of the said 2nd cylinder is being fixed to the said base part,
The single crystal pulling apparatus is provided between the large portion and the hermetic container, and is configured to surround the pulling shaft, and further includes a third cylinder communicating with the inner space of the hermetic container. The single crystal pulling apparatus according to claim 2, wherein the pipe is provided to connect the directing portion and the second fixing ring. The said 3rd cylinder is provided with the 3rd fixed ring fixed to the said loan | column,
The pipe is a single crystal pulling apparatus that is provided to connect the directing portion and the third fixed ring. The single crystal pulling apparatus according to any one of claims 1 to 5, wherein the first cylinder is disposed at a position overlapping with the pulling shaft in the axial direction. Airtight container;
A crucible housed in the hermetic container;
A support shaft for supporting the crucible;
A shaft support part supporting the support shaft; And
A crucible support apparatus comprising weight support means for detecting a weight applied to the shaft support portion, and including a support for supporting the shaft support portion.
The shaft support portion includes a main body portion for supporting the support shaft, and a supported portion connected to the main body portion,
The support body includes a support part for supporting the supported part, and a directing part disposed below the supported axis in the axial direction of the support shaft,
The crucible support device,
A first cylinder provided between the directing portion and the supported portion, which is expandable and contractible in the axial direction and whose inner space is hermetically sealed;
A second structure configured to surround the support shaft, which is expandable and contractable in the axial direction, a lower end portion in the axial direction is fixed to the main body portion, and an inner space is hermetically sealed to communicate with the inner space of the hermetic container. Body; And
Crucible support device further comprises a pipe connecting the first cylinder and the second cylinder. The said 1st cylinder is provided with the 1st fixed ring fixed to the said to-be-supported part,
The second cylinder has a second fixed ring fixed to the main body,
Crucible support device that the inner diameter of the first fixed ring and the second fixed ring is the same. The said support body is equipped with the base part which has an opening part which inserts and passes the said support shaft,
The upper end part in the said axial direction of the said 2nd cylinder is being fixed to the said base part,
The crucible support device is a crucible support device which is provided between the large part and the hermetic container and is configured to surround the support shaft and further includes a third cylinder communicating with the inner space of the hermetic container. The crucible support apparatus according to claim 8, wherein the pipe is provided to connect the directing portion and the second fixing ring. The said 3rd cylinder is provided with the 3rd fixed ring fixed to the said loan,
The pipe is a crucible support device is installed to connect the directing portion and the third fixed ring. The crucible support device according to any one of claims 7 to 11, wherein the first cylinder is disposed at a position overlapping with the support shaft as viewed in the axial direction.

Images