TW202229665A - Crystal growth apparatus - Google Patents

Abstract

A crystal growth apparatus is provided. The crystal growth apparatus comprises a reflector comprising an inner tube, an outer tube and a thermal insulating material positioned therebetween. The thermal insulating material comprises a tube-shaped solid felt. Fibers of the tube-shaped solid felt are wound around in a direction that is closed to a normal direction of an inner wall of the inner tube, and then an extending direction of the fibers is closed to the direction parallel to the inner wall of the inner tube of the reflector. When heat energy transmits from a crucible or silicon melt, passing the inner wall and to an inner side of the reflector, thermal insulating effect may be maximum because of decreasing efficiency of heat conduction affected by arrangement of heat transmitting direction and extending direction of the fibers perpendicular to each other.

Description

crystal pulling device

The present invention relates to the technical field of semiconductor manufacturing, in particular to a crystal pulling device.

Czochralski (Cz) is an important method for preparing silicon single crystals for semiconductors and solar energy. The high-purity silicon material put into the crucible is heated and melted by a thermal field composed of carbon materials. The seeds are immersed in the melt and go through a series of processes (melting, temperature stabilization, seeding, shoulder placement, equal diameter, finishing, cooling) to finally obtain a single crystal rod.

In the ingot growth of semiconductor monocrystalline silicon or solar monocrystalline silicon using the CZ method, the temperature distribution of the ingot and silicon melt directly affects the quality and growth rate of the ingot. During the growth of the CZ crystal rod, the guide tube (or reflective screen), as an important component in the crystal pulling heat field, prevents the heat of the silicon melt liquid level and the quartz crucible from radiating to the crystal rod, thus improving the crystal pulling effect. The role of speed and defects in controlling crystals.

Referring to FIG. 1 , a schematic structural diagram of a crystal pulling device is shown. As shown in FIG. 1 , the crystal pulling device includes a furnace body 1 , a crucible 11 is arranged in the furnace body 1 , a heater 12 for heating the crucible 11 is arranged outside the crucible 11 , and a silicon melt 13 is accommodated in the crucible 11 . The top of the furnace body 1 is provided with a pulling device 14 . Driven by the pulling device 14 , the crystal seed is pulled out from the liquid surface of the silicon melt to pull out the crystal rod 10 . There are also a driving device 15 for driving the crucible 11 to rotate and move up and down, and a magnetic field applying device 17 arranged outside the furnace body for applying a magnetic field to the silicon melt in the crucible. Meanwhile, continue to refer to FIG. 1 , the crystal pulling device further includes a heat shield device arranged around the crystal ingot 10 . The heat shield device includes a guide tube 16, and the guide tube 16 is set to a barrel shape. On the one hand, as a heat shield device, it is used to isolate the quartz crucible and the silicon melt in the crucible from the surface of the crystal rod during the growth of the crystal rod. The generated thermal radiation increases the cooling rate and the axial temperature gradient of the ingot, and increases the growth rate of the ingot. The difference is too large to ensure stable growth between the crystal rod and the liquid level of the silicon melt; at the same time, the guide tube is also used to guide the inert gas introduced from the upper part of the crystal rod growth furnace, so that it passes through the silicon melt at a large flow rate. The surface of the body can be controlled to control the oxygen content and impurity content in the crystal rod. During the growth of the semiconductor crystal rod, driven by the pulling device 14 , the crystal rod 10 passes through the guide tube 16 vertically upward.

Referring to FIG. 2 , a schematic cross-sectional structure diagram of a guide tube is shown. As shown in FIG. 2 , the guide tube is arranged in an annular cylindrical structure, and is composed of an outer tube 161 , an inner tube 162 , and a heat insulating material 163 between the inner and outer tubes. The function of the heat insulating material is to prevent the heat entering the outer cylinder from being transferred to the inner cylinder, to prevent the temperature of the inner cylinder from rising, and to make the heat of the crystal facing the inner cylinder difficult to transfer out, so that the temperature gradient of the crystal rod is small. Since the opposing surfaces between the guiding tube 16 and the crucible 11 and the silicon melt 13 in the crucible are constantly changing during the crystal pulling process, as shown in FIG. 2 , at the bottom of the guiding tube, the crucible and the inner The heat of the silicon melt needs to be transferred to the inner cylinder 162 through the thick insulating material 163 at the bottom. At the upper position of the guide cylinder, the heat of the crucible and the silicon melt in the crucible needs to pass through the upper thin insulating material. 163 is passed to the inner barrel 162.

The current insulation materials are divided into soft felt and solid felt. Solid felt is widely used in the thermal field of semiconductor crystal growth due to its stable shape and stable performance. The heat insulating material is wound by graphite fibers into a cylindrical solid felt according to the required shape, and finally made after surface wrapping treatment. In the guide cylinder, the graphite felt is provided between the outer guide cylinder and the inner guide cylinder for thermal insulation. Since the solid felt is formed by entanglement of fibers, its thermal conductivity and thermal expansion properties are anisotropic according to its fiber direction. In terms of thermal conductivity, the thermal conductivity along the direction of extension of the fibers is 2-3 times higher than along the normal direction perpendicular to the direction of extension of the fibers. As shown in FIG. 2 , the insulating material 163 is formed by winding the fibers in one direction to form a whole (the lines of the insulating material 163 in FIG. 2 are shown as fibers), wherein, in the bottom area of the guide tube, the heat flows along the fibers. The extending direction is transferred to the inner barrel 162 through the insulating material 163, and in the upper region of the guide barrel, the heat is transferred to the inner barrel 162 through the insulating material 163 along the normal direction perpendicular to the extending direction of the fibers. Since the thermal conductivity along the extension direction of the fiber is larger than the thermal conductivity along the normal direction perpendicular to the extension direction of the fiber, the temperature at the bottom of the inner cylinder is higher, and the average temperature reaches 1050 ° C, which limits the temperature of the crystal rod. It is transmitted through the inner cylinder, so that the temperature gradient of the crystal is small, which reduces the crystal pulling speed and affects the crystal pulling quality.

In order to solve the problems in the prior art, the present invention provides a crystal pulling device.

A series of concepts in simplified form have been introduced in the Summary section, which are described in further detail in the Detailed Description section. The Summary of the Invention section of the present invention is not intended to attempt to limit the key features and essential technical features of the claimed technical solution, nor is it intended to attempt to determine the protection scope of the claimed technical solution.

In order to solve the problems in the prior art, the present invention provides a crystal pulling device, which includes a guide tube. The guide tube includes an inner tube, an outer tube, and a heat insulating material disposed between the inner tube and the outer tube. The heat insulating material includes a cylindrical solid felt formed by winding a fibrous material, wherein the fibrous material The winding direction is close to the normal direction perpendicular to the side wall of the inner cylinder, so that the extending direction of the fiber material is close to the direction parallel to the side wall of the inner cylinder of the guide cylinder.

Exemplarily, the guide tube includes a first part and a second part from top to bottom, the outer tube includes an upper part of the outer tube and a lower part of the outer tube, the inner tube includes an upper part of the inner tube and a lower part of the inner tube, the The upper part of the inner cylinder and the upper part of the outer cylinder and the first solid felt located between the upper part of the inner cylinder and the upper part of the outer cylinder constitute the first part, the lower part of the inner cylinder and the lower part of the outer cylinder and the The second solid felt between the lower part of the inner cylinder and the lower part of the outer cylinder constitutes the second part

Exemplarily, the second portion protrudes toward the inner side of the guide tube relative to the first portion.

Exemplarily, the first portion and the second portion have different winding directions of the fibrous material.

Exemplarily, the first portion is provided as a cylindrical drum, and the winding direction of the fiber material of the first solid felt in the first portion is along a direction close to a normal line perpendicular to the upper portion of the outer drum.

Exemplarily, the lower part of the inner cylinder comprises a horizontally arranged plane or an inclined plane inclined downward in the radial direction, and the winding direction of the fiber material of the second solid felt in the second part is along a direction close to the vertical direction. The normal direction of the lower part of the inner cylinder.

Exemplarily, the range of the included angle between the extending direction of the fiber material of the first solid felt in the first part and the normal line perpendicular to the side wall of the upper part of the inner cylinder is 75-105°.

Exemplarily, the range of the included angle between the extending direction of the fiber material of the second solid felt in the second part and the normal line perpendicular to the lower part of the inner cylinder is 75-105°.

Exemplarily, the extending direction of the fiber material of the first solid felt in the first part is parallel to the side wall of the upper part of the inner cylinder.

Exemplarily, the extending direction of the fiber material of the second solid felt in the second portion is parallel to the lower portion of the inner cylinder.

According to the crystal pulling device of the present invention, the winding direction of the fiber material used to form the solid mat of the heat insulating material is set close to the normal direction perpendicular to the side wall of the inner cylinder, so that the extending direction of the fiber material is close to the In the direction parallel to the side wall of the inner cylinder of the guide tube, when the heat is transferred from the crucible or the silicon melt in the crucible to the inside through the side wall of the guide tube, the heat conduction direction is perpendicular to the extension direction of the fiber material, thereby reducing the heat. The efficiency of heat conduction is reduced, so that the heat resistance effect of the thermal insulation material is maximized.

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without one or more of these details. In other instances, some technical features known in the art have not been described in order to avoid obscuring the present invention.

For a thorough understanding of the present invention, a detailed description will be set forth in the following description to illustrate the crystal pulling apparatus of the present invention. Obviously, the practice of the present invention is not limited to the specific details familiar to those skilled in the art of semiconductor technology. Preferred embodiments of the present invention are described in detail below, however, the present invention may have other embodiments in addition to these detailed descriptions.

It should be noted that the terminology used herein is for the purpose of describing specific embodiments only, and is not intended to limit the exemplary embodiments in accordance with the present invention. As used herein, the singular forms are also intended to include the plural forms unless the context clearly dictates otherwise. Furthermore, it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they indicate the presence of stated features, integers, steps, operations, elements and/or components, but do not exclude the presence or Addition of one or more other features, integers, steps, operations, elements, components and/or combinations thereof.

Now, exemplary embodiments according to the present invention will be described in more detail with reference to the accompanying drawings. These exemplary embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of these exemplary embodiments to those skilled in the art. In the drawings, the thicknesses of layers and regions are exaggerated for clarity, and the same reference numerals are used to denote the same elements, and thus their descriptions will be omitted.

In order to solve the problems in the prior art, the present invention provides a crystal pulling device, comprising a guide tube, the guide tube includes an inner tube, an outer tube, and a heat insulating material disposed between the inner tube and the outer tube, the The thermal insulation material includes a cylindrical solid felt formed by winding a fiber material, wherein the winding direction of the fiber material is close to the normal direction perpendicular to the side wall of the inner cylinder, so that the extending direction of the fiber material is close to the direction of the normal line. The direction in which the side walls of the inner cylinder of the guide cylinder are parallel.

An exemplary description of a crystal pulling device according to the present invention will be given below with reference to FIG. 3 and FIGS. 4A-4C. 3 is a schematic structural diagram of a crystal pulling device according to an embodiment of the present invention; FIG. 4A is a structural schematic diagram of a guide tube in a crystal pulling device according to an embodiment of the present invention; FIG. 4B is another embodiment of the present invention FIG. 4C is a schematic structural diagram of the flow guide tube in the crystal pulling device according to another embodiment of the present invention.

As shown in FIG. 3 , the crystal pulling device includes a furnace body 2 , a crucible 21 is arranged in the furnace body 2 , a heater 22 for heating the crucible 21 is arranged outside the crucible 21 , and a silicon melt 23 is accommodated in the crucible 21 . A pulling device 24 is arranged on the top of the furnace body 2 . Driven by the pulling device 24 , the crystal seed is pulled out from the liquid surface of the silicon melt to pull out the crystal rod 20 . There are also a driving device 25 for driving the crucible 21 to rotate and move up and down, and a magnetic field applying device 27 arranged outside the furnace body for applying a magnetic field to the silicon melt in the crucible. Meanwhile, continue to refer to FIG. 3 , the crystal pulling device further includes a heat shield device arranged around the crystal ingot 20 . The heat shield device includes a guide tube 26, and the guide tube 26 is set in a barrel shape. On the one hand, as a heat shield device, it is used to isolate the quartz crucible 21 and the silicon melt 23 in the crucible 21 during the growth process of the crystal rod 20. The thermal radiation generated on the surface of the crystal rod 20 increases the cooling rate and the axial temperature gradient of the crystal rod 20, and increases the growth rate of the crystal rod 20. On the other hand, it affects the thermal field distribution on the surface of the silicon melt 23 and avoids the crystal rod. The axial temperature gradient difference between the center and the edge of the crystal rod 20 is too large to ensure stable growth between the crystal rod 20 and the liquid level of the silicon melt 23; at the same time, the guide tube 26 is also used for the inert gas introduced from the top of the crystal rod growth furnace. The flow is diverted so that it passes through the surface of the silicon melt 23 at a relatively large flow rate, so as to achieve the effect of controlling the oxygen content and impurity content in the crystal rod 20 . During the growth process of the semiconductor crystal rod 20 , the crystal rod 20 vertically passes through the guide tube 26 under the driving of the pulling device 24 .

Referring to FIG. 4A , there is shown a schematic structural diagram of the guide tube 26 in a crystal pulling device according to the present invention. The guide tube 26 is disposed around the silicon ingot 20 as a cylindrical structure with upper and lower openings, which is symmetrical with respect to the central axis. 4A shows a schematic cross-sectional structure diagram of the guide tube 26 on one side of the silicon ingot 20 .

Exemplarily, cylindrical shapes include, but are not limited to, cylindrical cylindrical structures, conical cylindrical structures, and the like.

As shown in FIG. 4A , the guide tube 26 is configured as a cylindrical cylindrical structure.

The guide tube 26 includes a first part (the part in the dashed frame 26a ) and the second part (the part in the dashed frame 26b ). The inner cylinder includes an inner cylinder upper part 262a and an inner cylinder lower part 262b, and the insulating material includes a solid felt formed by winding a fiber material, including a first solid felt 263a and a second solid felt 263b.

As shown in FIG. 4A , the upper part 261a of the outer cylinder, the upper part 262a of the inner cylinder and the first solid felt 263a located between the upper part 261a of the outer cylinder and the upper part 262a of the inner cylinder constitute the first part of the guide cylinder 26 (the part in the dashed frame 26a ) The lower part 261b of the outer cylinder, the lower part 262b of the inner cylinder and the second solid felt 263b between the lower part 261b of the outer cylinder and the lower part 262b of the inner cylinder constitute the second part of the guide cylinder 26 (the part in the dashed frame 26b).

Exemplarily, the material of the inner cylinder 162 and the outer cylinder 161 is set to be graphite.

In the present invention, the heat insulating material 163 is provided as a cylindrical solid felt formed by winding a fibrous material.

Exemplary, fibrous materials of which the insulating material is wound include glass fibers, graphite fibers, and the like.

In this embodiment, a cylindrical solid felt is formed by winding graphite fibers as the heat insulating material.

Exemplarily, as shown in FIG. 4A , the second part (the part in the dashed frame 26 b ) protrudes toward the inner side of the guide tube 26 relative to the part in the dashed frame 26 a of the first part.

On the one hand, the guide tube 26 is used as a heat shielding device to shield the heat radiated from the crucible 21 and the silicon melt 23 to the silicon ingot 20. By setting the guide tube 26 so that the second part 26b is opposite to the first part 26a protrudes toward the inner side of the guide tube 26, which can further shield the heat radiated from the silicon melt 23 and the crucible 21 at the bottom of the guide tube 26 to the silicon crystal rod 20, thereby improving the shielding effect. The second aspect of the guide tube 26 is as an argon guide device. During the crystal pulling process, the argon gas introduced into the crystal pulling chamber is guided, and the second part 26b is directed toward the first part 26a relative to the first part 26a. The inner side of the guide tube 26 is protruded, which effectively reduces the passage of the argon gas flowing through the guide tube 26 to the liquid level of the silicon melt 23, so that the flow from the top of the furnace body 2 flows back to the silicon melt through the guide tube 26 The flow rate of the argon gas at the position of the liquid level of 23 increases, and the shear force of the liquid level of the silicon melt 23 increases. Accordingly, the flow structure of the silicon melt 23 is further adjusted, so that the flow state of the silicon melt 23 is along the circumferential direction. more uniform, which further improves the uniformity of the rate of crystal growth and improves the quality of crystal pulling.

Exemplarily, the first portion 26a and the second portion 26b have different winding directions of the fiber material.

Since the solid mat is formed by winding the fiber material, the thermal conductivity and thermal expansion properties of the solid mat are anisotropic according to the direction of the fiber material. In terms of thermal conductivity, the thermal conductivity along the extension direction of the fiber material is 2-3 times higher than along the normal direction perpendicular to the extension direction of the fiber material.

In this embodiment, the winding direction of the fiber material used to form the solid felt of the heat insulating material is set to be close to the normal direction perpendicular to the side wall of the inner cylinder 162, so that the extension direction of the fiber material is close to the direction of the fiber material. In the direction parallel to the side wall of the inner cylinder 162 of the guide cylinder 26, when the heat is transferred from the crucible 21 or the silicon melt 23 in the crucible 21 to the inside through the side wall of the guide cylinder 26, the conduction direction of the heat is different from that of the fiber material. The extending direction is vertical, thereby reducing the efficiency of heat conduction, so that the heat resistance effect of the heat insulating material 163 is maximized.

Exemplarily, the first portion 26a is configured as a cylindrical drum, and the winding direction of the fiber material of the first solid felt 263a in the first portion 26a is along a normal line that is close to perpendicular to the upper portion 261a of the outer drum. direction.

As shown in FIG. 4A , the first part of the guide tube 26 is configured as a cylindrical tube, wherein the cross section of the first part 26 a of the guide tube 26 shown in FIG. 4A is rectangular. Further, continuing to refer to FIG. 4A , the fiber material of the first solid felt 263a forming the first portion 26a of the guide tube 26 is wound along the normal direction perpendicular to the side wall of the inner tube 162 of the first portion 26a (ie, the upper portion 262a of the inner tube). It is made so that the extending direction of the fibrous material is parallel to the side wall of the inner cylinder 162 of the first portion 26a (ie, the inner cylinder upper part 262a).

Exemplarily, the lower part 262b of the inner cylinder includes a horizontally arranged plane or a downwardly inclined slope, and the winding direction of the fiber material of the second solid felt 263b in the second part 26b is along a direction that is close to perpendicular to the direction of winding. The normal direction of the inner cylinder lower part 262b.

As shown in FIG. 4A , the second part 26b of the guide tube 26 protrudes inwardly from the first part 26a, and at the same time, the lower part 262b of the inner tube is a horizontal plane, so that the inner diameter of the second part 26b of the guide tube 26 is larger than that of the first part 26b. A small portion of 26a is a cylindrical barrel.

Referring to FIG. 4B , there is shown a schematic structural diagram of the guide tube 26 in a crystal pulling apparatus according to another embodiment of the present invention. The structure of the guide tube 26 in FIG. 4B is similar to that of FIG. 4A , the difference is that the second part 26 b of the guide tube 26 in FIG. 4B protrudes inwardly from the first part 26 a , and at the same time, the lower part 262 b of the inner tube is at the inner side. The inclined surface is inclined downward in the radial direction, so that the inner diameter of the second part 26b of the guide tube 26 is smaller than that of the first part 26a, and the top is a cylindrical barrel whose top is inclined downward in the radial direction.

Referring to FIG. 4C , a schematic structural diagram of a flow guide tube 26 in a crystal pulling apparatus according to another embodiment of the present invention is shown. The structure of the guide tube 26 in FIG. 4C is similar to that in FIGS. 4A and 4B, the difference is that the second part 26b of the guide tube 26 in FIG. 262b is a downwardly inclined slope in the radial direction, so that the second portion 26b of the guide tube 26 is provided with a downwardly extending conical barrel.

Continuing to refer to FIG. 4A , the fibrous material of the second solid felt 263b forming the second portion 26b of the draft tube 26 is wound along a normal direction perpendicular to the side wall of the inner tube 162 of the second portion 26b (ie, the lower portion 262b of the inner tube). , so that the extending direction of the fiber material is parallel to the side wall of the inner cylinder 162 of the second part 26b (ie, the lower part 262b of the inner cylinder).

Since the extending direction of the fiber material of the first solid felt 263a of the first part is parallel to the upper part 262a of the inner cylinder, when the heat of the crucible 21 or the silicon melt 23 is transferred to the inner side of the guiding tube 26 through the first part 26a of the guiding tube 26 , the heat is transferred along the extension direction perpendicular to the fiber material, and the heat resistance effect is good due to the small thermal conductivity in the extension direction perpendicular to the fiber material.

Likewise, since the extending direction of the fiber material of the second solid felt 263b of the second part is parallel to the lower part 262b of the inner cylinder, when the heat of the crucible 21 or the silicon melt 23 passes through the second part 26b of the guide cylinder 26 to the guide cylinder 26 When the inner side of the fiber material is transferred, the heat is transferred along the extension direction perpendicular to the fiber material. Since the thermal conductivity coefficient is small in the extension direction perpendicular to the fiber material, the heat resistance effect is good.

It should be understood that the above-mentioned fiber material of the first solid felt 263a of the first part 26a is wound along the normal direction perpendicular to the side wall of the inner cylinder 162 of the first part 26a (ie, the upper part 262a of the inner cylinder), and the second part The fiber material of the second solid felt 263b of the second portion 26b is wound along the normal direction perpendicular to the side wall of the inner cylinder 162 of the second portion 26b (ie, the lower part 262b of the inner cylinder), which is only an example. In the actual winding process, The fiber material winding directions of the first part 26a and the second part 26b are set to be different, and can be wound as close to the side wall of the inner cylinder 162 of the first part 26a or the side wall of the inner cylinder 162 of the second part 26b as possible, respectively, As long as the extension direction of the fiber material is as far as possible along the direction parallel to the plane of the inner wall of the guide tube 26, and the direction of heat transmission is perpendicular to the extension direction of the fiber material, the reduction of the thermal insulation material of the present invention can be realized. Thermal conduction effect, enhancing the technical effect of thermal insulation.

In an embodiment according to the present invention, the winding direction of the fiber material of the first solid felt 263a in the first part 26a is along a direction close to the normal line perpendicular to the upper part 262a of the inner cylinder, the first The range of the included angle between the extending direction of the fiber material of the first solid felt 263a in the part 26a and the normal line perpendicular to the side wall of the upper part 262a of the inner cylinder is 75-105°.

In an embodiment according to the present invention, the winding direction of the fiber material of the second solid felt 263b in the second part 26b is along a direction close to the normal line perpendicular to the lower part 262b of the inner cylinder, the The range of the included angle between the extending direction of the fiber material of the second solid felt 263b in the second portion 26b and the normal line perpendicular to the lower portion 262b of the inner cylinder is 75-105°.

In one embodiment, the guide cylinder 26 as shown in FIG. 2 is used, wherein the solid felt at the bottom of the guide cylinder 26 and the solid felt at the upper part of the guide cylinder 26 are wound in the same direction with fibrous material, so that the flow guide is wound in the same direction. The temperature at the bottom of the inner barrel 162 of the barrel 26 is relatively high, and the average temperature reaches 1050° C., and finally the average pulling speed of the crystal pulling process is 1.0 mm/min.

According to an embodiment of the present invention, the guide cylinder 26 as shown in FIG. 4A is used, wherein the solid felt at the bottom of the guide cylinder 26 and the solid felt at the upper part of the guide cylinder 26 are wound with fiber materials in different directions. The solid felt on the upper part of the guide cylinder 26 is wound with fiber material along the normal direction perpendicular to the side wall of the guide cylinder 26, so that the extension direction of the fiber material of the solid felt on the upper part of the guide cylinder 26 is parallel to the direction of the guide cylinder 26. The side wall of the tube 26, and the solid felt at the bottom of the guide tube 26 is wound with fiber material along the normal direction perpendicular to the bottom of the guide tube 26, so that the extension direction of the fiber material of the solid felt at the bottom of the guide tube 26 is parallel to the guide tube 26. At the bottom of the flow tube 26, the temperature at the bottom of the inner tube 162 of the flow tube 26 in FIG. 4A is finally lowered compared with the temperature at the bottom of the inner tube 162 of the flow tube 26 in the embodiment shown in FIG. 2, specifically to 1000° C. The average pulling speed of the crystal pulling process reaches 1.2 mm/min, and the pulling speed is increased by 20%.

The above is an exemplary introduction to a crystal pulling device according to the present invention. According to the crystal pulling device of the present invention, the winding direction of the fiber material used to form the solid mat of the insulating material is set close to perpendicular to the side wall of the inner cylinder. so that the extension direction of the fiber material is close to the direction parallel to the side wall of the inner cylinder of the guide cylinder, when the heat is transferred from the crucible or the silicon melt in the crucible to the inside through the side wall of the guide cylinder When the heat conduction direction is perpendicular to the extension direction of the fiber material, the efficiency of heat conduction is reduced, and the heat resistance effect of the thermal insulation material is maximized.

The present invention has been described by the above-mentioned embodiments, but it should be understood that the above-mentioned embodiments are only for the purpose of illustration and description, and are not intended to limit the present invention to the scope of the described embodiments. In addition, those skilled in the art can understand that the present invention is not limited to the above-mentioned embodiments, and more variations and modifications can also be made according to the teachings of the present invention, and these variations and modifications all fall within the protection claimed in the present invention. within the range. The protection scope of the present invention is defined by the appended claims and their equivalents.

1, 2: Furnace body 10, 20: Crystal Rod 11, 21: Crucible 12, 22: Heater 13, 23: Silicon Melt 14, 24: Lifting device 15, 25: Drives 16, 26: Guide tube 17, 27: Magnetic Field Applicator 26a: Part 1 26b: Part II 161: outer cylinder 162: inner cylinder 163: Thermal Insulation 261a: Upper part of outer cylinder 261b: lower part of outer cylinder 262a: Upper part of inner cylinder 262b: lower part of inner cylinder 263a: First solid felt 263b: Second solid felt

The following drawings of the present invention are incorporated herein as a part of the present invention for understanding of the present invention. The accompanying drawings illustrate the embodiments of the invention and their description, which serve to explain the principles of the invention. In the attached picture:

1 is a schematic structural diagram of a crystal pulling device according to an embodiment;

2 is a schematic structural diagram of a guide tube in a crystal pulling device according to an embodiment;

3 is a schematic structural diagram of a crystal pulling device according to an embodiment of the present invention;

4A is a schematic structural diagram of a guide tube in a crystal pulling device according to an embodiment of the present invention;

4B is a schematic structural diagram of a flow guide tube in a crystal pulling device according to another embodiment of the present invention;

FIG. 4C is a schematic structural diagram of a guide tube in a crystal pulling device according to another embodiment of the present invention.

none

161: outer cylinder

162: inner cylinder

163: Thermal Insulation

Claims (10)

A crystal pulling device, comprising: A guide tube, including: an inner cylinder; an outer cylinder; and an insulating material arranged between the inner cylinder and the outer cylinder, the insulating material comprising a cylindrical solid felt formed by winding a fibrous material, Wherein, the winding direction of the fiber material is close to the normal direction perpendicular to one side wall of the inner cylinder, so that the extension direction of the fiber material is close to the direction parallel to the side wall of the inner cylinder of the guide cylinder. The crystal pulling device according to claim 1, wherein the guide tube comprises a first part and a second part from top to bottom, the outer tube comprises an upper part of the outer tube and a lower part of the outer tube, and the inner tube includes An upper part of the inner cylinder and a lower part of the inner cylinder, the upper part of the inner cylinder and the upper part of the outer cylinder and a first solid felt between the upper part of the inner cylinder and the upper part of the outer cylinder constitute the first part, the lower part of the inner cylinder and the upper part of the outer cylinder The lower part of the cylinder and a second solid felt between the lower part of the inner cylinder and the lower part of the outer cylinder constitute the second part. The crystal pulling device of claim 2, wherein the second portion protrudes toward the inner side of the guide tube relative to the first portion. The crystal pulling device of claim 3, wherein the first portion and the second portion have different winding directions of the fiber material. The crystal pulling device according to claim 4, wherein the first part is configured as a cylindrical cylinder, and the winding direction of the fiber material of the first solid felt in the first part is along a method close to perpendicular to the upper part of the outer cylinder line direction. The crystal pulling device according to claim 5, wherein the lower part of the inner cylinder comprises a horizontally arranged flat surface or an inclined surface inclined downward in the radial direction, and the fiber material of the second solid felt in the second part is The winding direction is along the direction close to the normal line perpendicular to the lower part of the inner cylinder. The crystal pulling device according to claim 3, wherein the included angle between the extending direction of the fiber material of the first solid felt in the first part and the normal line perpendicular to the side wall of the upper part of the inner cylinder is in the range of 75-105 °. The crystal pulling device according to claim 3, wherein the included angle between the extending direction of the fiber material of the second solid felt in the second part and the normal line perpendicular to the lower part of the inner cylinder is in the range of 75-105 °. The crystal pulling device according to claim 2, wherein the extending direction of the fiber material of the first solid felt in the first part is parallel to the side wall of the upper part of the inner cylinder. The crystal pulling device according to claim 2, wherein the extending direction of the fiber material of the second solid felt in the second part is parallel to the lower part of the inner cylinder.

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