CN110629282A

CN110629282A - Crucible assembly and installation method thereof

Info

Publication number: CN110629282A
Application number: CN201910978400.2A
Authority: CN
Inventors: 邓先亮
Original assignee: Zing Semiconductor Corp
Current assignee: Zing Semiconductor Corp
Priority date: 2019-10-15
Filing date: 2019-10-15
Publication date: 2019-12-31
Also published as: TW202117097A

Abstract

The present invention provides a crucible assembly and a method of installing the same, the crucible assembly comprising: the carbon-carbon crucible comprises a carbon-carbon crucible body, wherein at least three first through holes are distributed on the same height of the side wall of the carbon-carbon crucible body; the inner diameter of the hoisting ring is not smaller than the outer diameter of the carbon-carbon crucible, second through holes which correspond to the first through holes one by one are distributed on the side wall of the hoisting ring, and supporting legs for hoisting are arranged at the top of the hoisting ring; and the plug is inserted into the first through hole and the second through hole so as to relatively fix the carbon-carbon crucible and the hoisting ring. The crucible assembly and the installation method thereof can conveniently and quickly place the carbon-carbon crucible, the quartz crucible and the silicon material in the furnace; the level can be quickly adjusted, and the stability of a thermal field is ensured; the damage of the quartz crucible can be avoided, and the probability of accidents is reduced; the crucible can be taken and placed under the condition that the temperature of the crucible is higher after the furnace is stopped.

Description

Crucible assembly and installation method thereof

Technical Field

The invention relates to the technical field of semiconductors, in particular to a method for mounting a silicon single crystal.

Background

Currently, as the semiconductor industry continues to move toward higher integration and lower cost, raw material preparation is required to continuously improve yield and reduce production cost. Silicon wafers, being the most important semiconductor material, must be compatible with the cost reduction requirements of the semiconductor industry. Since the Czochralski method is currently the predominant method of single crystal silicon production, cost reduction during the Czochralski method of producing single crystal silicon is the most critical component in reducing the cost of silicon wafer manufacture. The method for reducing the production cost in the process of preparing the monocrystalline silicon by the Czochralski method mainly aims at the following three aspects: increase the feeding amount, reduce the loss of the thermal field and reduce the energy consumption of crystal growth.

The use of carbon-carbon crucibles is an essential key technology for the first two aspects. Firstly, in order to increase the feeding amount, a crucible with a larger size must be used, the crucible with the size of 36 inches or 40 inches is continuously put into use, and for the graphite material which is usually used, the graphite material is limited by raw materials and processing capacity, the market condition of the graphite industry can greatly influence the large-scale application process, and once the graphite material is in short supply, the large-scale mass production process must be influenced; secondly, since the graphite crucible has to have a longer life as a component having the shortest life in the entire thermal field and the life of a wearing part must be increased in order to reduce the loss of the thermal field, there is a tendency to replace the graphite crucible with a carbon-carbon crucible having a longer life. Meanwhile, after the carbon-carbon crucible is used, the purpose of light weight of a thermal field can be achieved due to high strength and light weight, and subsequent carrying and installation are facilitated.

The use of carbon-carbon crucibles differs from conventional graphite crucibles. Graphite crucibles are usually formed by separate processing and then assembled into an integral structure, carbon crucibles are usually woven integrally by carbon fibers, and the carbon crucibles have the characteristics of high strength, light weight and the like, but when the carbon crucibles are used in combination with a charging process, the carbon crucibles can be transported. The main difficulty is that the tray of the carbon-carbon crucible is small, and the carbon-carbon crucible cannot be arranged with a buckle for hoisting, so that the carbon-carbon crucible is difficult to install in a single crystal furnace.

Therefore, there is a need for a new crucible assembly and method of installation to solve the above problems.

Disclosure of Invention

In this summary, concepts in a simplified form are introduced that are further described in the detailed description. This summary of the invention is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

In view of the disadvantages of the prior art, an aspect of the present invention provides a crucible assembly, comprising:

the carbon-carbon crucible comprises a carbon-carbon crucible body, wherein at least three first through holes are distributed on the same height of the side wall of the carbon-carbon crucible body;

the inner diameter of the hoisting ring is not smaller than the outer diameter of the carbon-carbon crucible, second through holes which correspond to the first through holes one by one are distributed on the side wall of the hoisting ring, and supporting legs for hoisting are arranged at the top of the hoisting ring; and

and the plug is inserted into the first through hole and the second through hole so as to relatively fix the carbon-carbon crucible and the hoisting ring.

In one embodiment, the number of the first through holes and the second through holes is eight respectively.

In one embodiment, the number of legs is four.

In one embodiment, the support foot is connected with the hoisting ring through threads.

In one embodiment, the distance between any two adjacent first through holes is equal, and the distance between any two adjacent second through holes is equal.

In one embodiment, the support feet are evenly distributed on the top of the hoisting ring.

In one embodiment, the lifting ring is a carbon ring or a graphite ring.

In one embodiment, the crucible assembly further comprises a quartz crucible arranged inside the carbon-carbon crucible, and the quartz crucible is used for containing silicon materials.

Another aspect of the present invention provides a method for installing the crucible assembly, including:

sleeving a hoisting ring outside a carbon-carbon crucible, and aligning a first through hole on the carbon-carbon crucible with a second through hole on the hoisting ring;

inserting bolts into the first through hole and the second through hole so as to relatively fix the carbon-carbon crucible and the hoisting ring;

and hoisting the carbon-carbon crucible and the hoisting ring into the single crystal furnace through the support legs on the hoisting ring.

In one embodiment, before the hoisting ring is sleeved outside the carbon-carbon crucible, the hoisting ring further comprises:

placing a quartz crucible in the carbon-carbon crucible;

adjusting the level of the quartz crucible; and

and filling the quartz crucible with a silicon material.

The crucible assembly and the installation method thereof can conveniently and quickly place the carbon-carbon crucible, the quartz crucible and the silicon material in the furnace; the level can be quickly adjusted, and the stability of a thermal field is ensured; the damage of the quartz crucible can be avoided, and the probability of accidents is reduced; the crucible can be taken and placed under the condition that the temperature of the crucible is higher after the furnace is stopped.

Drawings

The following drawings of the invention are included to provide a further understanding of the invention. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

In the drawings:

FIG. 1 is a schematic view of a crucible assembly according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a carbon crucible in a crucible assembly provided by an embodiment of the present invention;

FIG. 3 is a schematic view illustrating the structure of a lifting ring in the crucible assembly according to an embodiment of the present invention;

fig. 4 is a flowchart illustrating a method of installing a crucible assembly according to an embodiment of the present invention.

Detailed Description

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 specific details. In other instances, well-known features have not been described in order to avoid obscuring the invention.

It is to be understood that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity. Like reference numerals refer to like elements throughout.

It will be understood that when an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it can be directly on, adjacent to, connected or coupled to the other elements or layers or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to" or "directly coupled to" other elements or layers, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.

Spatial relational terms such as "under," "below," "under," "above," "over," and the like may be used herein for convenience in describing the relationship of one element or feature to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, then elements or features described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary terms "under" and "under" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatial descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

Embodiments of the invention are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the invention should not be limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, an implanted region shown as a rectangle will typically have rounded or curved features and/or implant concentration gradients at its edges rather than a binary change from implanted to non-implanted region. Also, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation is performed. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of the present invention.

The main difficulty in installing the carbon-carbon crucible lies in that the tray of the carbon-carbon crucible is small, the buckle hoisting cannot be arranged, and the charging process can only be completed by the following two methods: the first method is that a carbon-carbon crucible is manually placed on a tray, and then a quartz crucible filled with polycrystalline silicon materials is placed in the carbon-carbon crucible, and the method has the main problems that the level of the quartz crucible is difficult to adjust and the risk of scratching the quartz crucible is high; the second method is to put the quartz crucible into the carbon-carbon crucible, adjust the level, load the material, and put the carbon-carbon crucible and the quartz crucible as a whole on the tray.

The second method adopts an integrated installation and placement mode, is a relatively safe method, can effectively reduce the damage of the quartz crucible, but needs special design for the transportation of the carbon-carbon crucible. The currently common method is to wind the carbon-carbon crucible by a tension belt, and tie up the tension belt by a hanging belt, so as to integrally hoist the carbon-carbon crucible and the quartz crucible into the furnace. This method also suffers from difficulty in leveling and inability to easily place the crucible.

In order to solve the problems, the embodiment of the invention provides a crucible assembly and an installation method thereof, wherein the crucible assembly is additionally provided with a hoisting ring on the basis of a carbon-carbon crucible; the level can be quickly adjusted, and the stability of a thermal field is ensured; the damage of the quartz crucible can be avoided, and the probability of accidents is reduced; the crucible can be taken and placed under the condition that the temperature of the crucible is higher after the furnace is stopped.

In the following description, for purposes of explanation, specific details are set forth in order to provide a thorough understanding of the present invention. The following detailed description of the preferred embodiments of the invention, however, the invention is capable of other embodiments in addition to those detailed.

[ exemplary embodiment one ]

A crucible assembly according to an embodiment of the present invention will be described in detail with reference to fig. 1 to 3.

Referring first to fig. 1, the crucible assembly includes a carbon-carbon crucible 101 and a lifting ring 102.

Wherein the carbon-carbon crucible 101 is used for growing single crystal silicon by the czochralski method. Specifically, when the single crystal silicon is grown by the czochralski method, the polycrystalline silicon raw material is required to be put into a quartz crucible, the polycrystalline silicon raw material is heated and melted into a silicon melt in a single crystal furnace, then the silicon melt is given a certain supercooling degree, and a seed crystal is immersed into the solution, and silicon atoms in the solution can form regular crystals on a solid-liquid interface along a silicon atom arrangement structure of the seed crystal at a proper temperature; and lifting the seed crystal in a rotating way, driving the crucible to rotate by a crucible shaft below the crucible, continuously crystallizing silicon atoms in the solution on the single crystal at the moment, and continuing the regular atom arrangement structure, thereby growing the rod-shaped silicon single crystal. In the process of growing silicon single crystal, the temperature in the single crystal furnace is as high as about 1500 ℃, and at the moment, the quartz crucible becomes soft and needs to be supported by the carbon-carbon crucible 101.

The carbon-carbon crucible 101 is made of a carbon/carbon composite material. The carbon/carbon composite material is a carbon fiber reinforced carbon matrix composite material and has the outstanding characteristics of light weight, good ablation resistance, good thermal shock resistance, high damage tolerance, high-temperature strength, strong designability and the like. The strength of the carbon/carbon composite material is far greater than that of graphite, and compared with a graphite crucible, the carbon-carbon crucible 101 has the advantages of good dimensional stability, impact resistance, good thermal shock resistance and the like, the comprehensive mechanical property is superior to that of the graphite crucible, and a large-size crucible of 36 inches or 40 inches can be realized.

In one embodiment, the carbon-carbon crucible 101 is integrally formed by carbon fiber, and specifically includes the processes of carbon fiber interweaving, CVI (Chemical Vapor Infiltration) process for material Infiltration forming, high-temperature heat treatment, machining and polishing, and surface coating treatment. It should be noted that the above preparation process is only exemplary, and the carbon-carbon crucible 101 may be prepared in any suitable manner; the carbon-carbon crucible 101 is not limited to the integrated structure, and may be a vertically divided structure, a multi-lobed structure, or the like.

Referring to fig. 2, at least three first through holes 1011 are formed on the circumference of the sidewall of the carbon crucible 101. The first through holes 1011 are arranged above the side wall of the carbon-carbon crucible 101 and close to the edge of the crucible, and are uniformly distributed along the same circumference, namely, the distance between any two adjacent first through holes 1011 is equal. The shape of the first through hole 101 includes, but is not limited to, a circle.

In one embodiment, in order to ensure stability during installation, the number of the first through holes 1011 is eight, and the eight first through holes 1011 are uniformly distributed on the same horizontal height, and the opening direction is along the horizontal direction.

Referring to fig. 3, the hoisting ring 102 has a circular ring structure, and the inner diameter of the ring structure is not smaller than the outer diameter of the carbon crucible 101, so that the ring structure can be sleeved outside the carbon crucible 101.

The hoisting ring 102 may be a carbon ring made of carbon-carbon composite material or a graphite ring made of graphite. The lifting ring 102 may also be made of other materials having better mechanical properties and thermal stability.

Second through holes 1021 corresponding to the first through holes 1011 one by one are distributed on the hoisting ring 102. After the lifting ring 102 is sleeved outside the carbon crucible 101 and the position of the lifting ring 102 relative to the carbon crucible 101 is adjusted, each first through hole 1011 and each corresponding second through hole 1021 are aligned to form a passage through which a plug pin can be inserted. The lifting ring 102 has sufficient thickness to ensure the stability of the latch.

It can be understood that the number of the second through holes 1021 is equal to the number of the first through holes 1011. When the number of the first through holes 1011 is eight, the number of the second through holes 1021 is also eight. Also, the first through hole 1011 and the second through hole 1021 have the same shape and size.

The top of the lifting ring 102 is provided with a plurality of feet 1022, see fig. 1. A plurality of feet 1022 are evenly distributed on the upper surface of the lifting ring 102 to maintain stability of the crucible assembly during lifting. The number of the support feet 1022 is not less than three, in this embodiment, four support feet 1022 are arranged on the hoisting ring 102, and two support feet 1022 on the diagonal are connected with each other at the top through a cross beam.

In one embodiment, the legs 1022 and the lifting ring 102 are threadably interconnected. The bottom of the feet 1022 is threaded and the lifting ring 102 is provided with matching threaded holes 1023, see fig. 3.

The crucible assembly further comprises a plug (not shown) for inserting into the first through hole 1011 and the second through hole 1021 to fix the carbon crucible 101 and the lifting ring 102 relatively. The number of pins corresponds to the number of the first through holes 1011 or the second through holes 1012. When lifting, the mechanical arm applies a pulling force to the lifting ring 102 through the legs 1022, and at the same time, is forced through the pins to lift the carbon-carbon crucible 101. Therefore, the plug is made of a material having sufficient rigidity and strength.

Further, the crucible assembly further includes a quartz crucible (not shown). As described above, the carbon-carbon crucible 101 is used to support the quartz crucible for containing the silicon material during the crystal growth. When the crucible assembly is installed, firstly, the quartz crucible is placed in the carbon crucible 101, the quartz crucible is adjusted to be horizontal, then the quartz crucible is loaded, then the hoisting ring 102 is sleeved outside the carbon crucible 101, the plug is inserted, and finally, the assembled crucible assembly is hoisted and loaded into a single crystal furnace and placed on a tray.

Compared with the existing carbon-carbon crucible, the crucible assembly provided by the embodiment of the invention can avoid the risk of damaging the quartz crucible by charging in the furnace, reduce the probability of accidents, and better adjust the level of the quartz crucible; compared with the mode of tensioning belt winding and hanging strip bundling, the lifting ring is more convenient and quicker to lift, the stability of the lifting process is greatly improved, and the level of the quartz crucible is convenient to guarantee. In addition, due to the fact that the melting points of the hoisting ring and the plug are high, the crucible assembly can be used for taking and placing the crucible under the condition that the temperature of the crucible is high after the crucible is shut down.

[ second exemplary embodiment ]

The method of installing the above crucible assembly will be described in detail with reference to fig. 1 to 4.

Firstly, in step 401, the hoisting ring 102 is sleeved outside the carbon-carbon crucible 101, and the first through hole 1011 on the carbon-carbon crucible 101 is aligned with the second through hole 1022 on the hoisting ring 102.

The specific structures of the carbon-carbon crucible 101 and the hoisting ring 102 are described above with reference to fig. 1 to 3.

In one embodiment, before the hoisting ring 102 is sleeved outside the carbon-carbon crucible 101, the method further comprises: placing a quartz crucible in the carbon-carbon crucible 101; adjusting the level of the quartz crucible; and charging a silicon material into the quartz crucible.

Wherein the level of the quartz crucible is more easily adjusted before the crucible assembly is put into the single crystal furnace, and the quartz crucible is prevented from being damaged by the charging at this time.

In step 402, inserting pins into the first through hole 1011 and the second through hole 1012 to fix the carbon-carbon crucible and the hoisting ring relatively.

Wherein the shape of the latch matches with the first through hole 1011 and the second through hole 1012. After the plug is inserted, the hoisting ring 101 and the carbon-carbon crucible 102 are relatively fixed. The number of pins corresponds to the number of the first through holes 1011 or the second through holes 1012.

In step 403, the carbon-carbon crucible 101 and the hoisting ring 102 are hoisted into the single crystal furnace through the support feet 1022 on the hoisting ring 102.

In one embodiment, after the crucible assembly is lifted into the single crystal furnace and placed on the tray, the steps of removing the pins and removing the lifting ring 102 are included.

Thus, the description of the steps related to the method of mounting a silicon single crystal of the embodiment of the present invention is completed. It is to be understood that the mounting method of a silicon single crystal of the present embodiment includes not only the above-described steps but also other necessary steps before, during or after the above-described steps, all of which are included in the scope of the mounting method of the present embodiment.

Compared with the installation mode of placing the crucible firstly and then charging, the installation method of the crucible assembly provided by the embodiment of the invention can avoid the risk of damaging the quartz crucible by charging in the furnace, reduce the probability of accidents, and better adjust the level of the quartz crucible; compared with the mode of tensioning belt winding and hanging strip bundling, the lifting ring is more convenient and quicker to lift, the stability of the lifting process is greatly improved, and the level of the quartz crucible is convenient to guarantee. In addition, due to the fact that the melting points of the hoisting ring and the plug are high, the crucible assembly can be used for taking and placing the crucible under the condition that the temperature of the crucible is high after the crucible is shut down.

The present invention has been illustrated by the above embodiments, but it should be understood that the above embodiments are for illustrative and descriptive purposes only and are not intended to limit the invention to the scope of the described embodiments. Furthermore, it will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that many variations and modifications may be made in accordance with the teachings of the present invention, which variations and modifications are within the scope of the present invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A crucible assembly, comprising:

2. The crucible assembly of claim 1, wherein the number of the first through holes and the second through holes is eight, respectively.

3. The crucible assembly of claim 1, wherein the number of legs is four.

4. The crucible assembly of claim 1, wherein the support foot is threadably connected to the lifting ring.

5. The crucible assembly of claim 1, wherein a distance between any two adjacent first through holes is equal, and a distance between any two adjacent second through holes is equal.

6. The crucible assembly of claim 1, wherein the support feet are evenly distributed on top of the lifting ring.

7. The crucible assembly of claim 1, wherein the lifting ring is a carbon ring or a graphite ring.

8. The crucible assembly of claim 1, further comprising a quartz crucible disposed inside the carbon-carbon crucible, the quartz crucible being configured to hold a silicon material.

9. A method of installing a crucible assembly according to any one of claims 1 to 8, comprising:

10. The method of installing as defined in claim 9, further comprising, prior to placing the lifting collar outside the carbon-carbon crucible:

placing a quartz crucible in the carbon-carbon crucible;

adjusting the level of the quartz crucible; and

and filling the quartz crucible with a silicon material.