阅读说明：本技术 硅芯线 (Silicon core wire ) 是由 星野成大 冈田哲郎 石田昌彦 于 2020-04-13 设计创作，主要内容包括：本发明涉及的第一方式的硅芯线中,形成于第一硅细棒的一端的外螺纹部与形成于第二硅细棒的一端的内螺纹部相互螺合后紧固。此外,本发明涉及的第二方式的硅芯线中,形成于第一硅细棒的一端的螺纹部与形成于第二硅细棒的一端的螺纹部通过在两端部形成有螺纹部的接合器相互螺合后紧固。(In the silicon core wire according to the first aspect of the present invention, the external thread portion formed at one end of the first thin silicon rod and the internal thread portion formed at one end of the second thin silicon rod are screwed together and fastened. In the silicon core wire according to the second aspect of the present invention, the threaded portion formed at one end of the first thin silicon rod and the threaded portion formed at one end of the second thin silicon rod are fastened by being screwed together by an adaptor having threaded portions formed at both ends.)

1. A silicon core wire, characterized in that:

the external thread part formed at one end of the first thin silicon rod and the internal thread part formed at one end of the second thin silicon rod are screwed with each other and then fastened.

2. A silicon core wire, characterized in that:

the screw portion formed at one end of the first thin silicon rod and the screw portion formed at one end of the second thin silicon rod are fastened by being screwed together by an adaptor having screw portions formed at both ends.

3. The silicon core wire of claim 2, wherein:

wherein the adapter is composed of a silicon member.

4. The silicon core wire of claims 1 to 3, wherein:

wherein the first and second thin silicon rods are thin silicon rods extracted from a polycrystalline silicon rod or a single crystal silicon rod.

Technical Field

The present invention relates to a structure of a silicon core wire used in manufacturing polycrystalline silicon.

Background

Polycrystalline silicon is a raw material for monocrystalline silicon for semiconductor production or silicon for solar cell production. As a method for producing polycrystalline silicon, the siemens method is generally known, in which a silane-based source gas is brought into contact with a heated silicon core wire (silicon slim rod), and polycrystalline silicon is deposited on the surface of the silicon core wire by a cvd (chemical Vapor deposition) method.

In the siemens method, after two thin silicon rods in the vertical direction and one thin silicon rod in the horizontal direction are assembled into an inverted U shape, the lower end portions of the two thin silicon rods in the vertical direction are connected to a core wire bracket and fixed to a pair of metal electrodes arranged on a base plate. Generally, a plurality of sets of inverted U-shaped silicon core wires are arranged in a reaction furnace.

When a silicon core wire is heated to a deposition temperature by means of energization and a raw material gas (for example, a mixed gas of trichlorosilane and hydrogen) is supplied, polycrystalline silicon is vapor-grown on the surface of the silicon core wire by a CVD reaction, and a polycrystalline silicon rod having a desired diameter is formed into an inverted U shape.

When single crystal silicon is produced by the FZ method, both end portions of two polysilicon rods in the vertical direction of the inverted U-shaped polysilicon are cut to form columnar polysilicon rods, and the columnar polysilicon rods are used as a raw material to grow single crystal silicon. Naturally, since the length of the single-crystal silicon pulled up at a time is long, it is better to make the length of the columnar polycrystalline silicon rod as a raw material longer. Therefore, it is a prerequisite that the silicon core wires have a sufficient length in the rail-type direction.

Although the silicon thin rod constituting the inverted U-shaped silicon core wire is extracted from the polycrystalline silicon rod or the single crystal silicon rod, a part of the silicon thin rod is cut off when the silicon thin rod is taken out from the reactor, and thus the corresponding length is shortened. As a result, when a silicon core wire having a sufficient length in the forward direction is obtained, the length of the thin silicon rod may be insufficient, and the thin silicon rod having a short length must be lengthened.

In view of the above, japanese patent application laid-open No. 2011-116634 discloses a silicon wafer manufacturing apparatus and manufacturing method capable of manufacturing high-quality silicon seed crystals with few defects, which are easy to control, and in brief, obtains one long thin silicon rod by fusing the end portions of two thin silicon rods and then adhering them together.

Such a method of integrating two thin silicon rods by fusion is also disclosed in japanese patent laid-open nos. 2012 and 62243 and 2018 and 122340.

Further, U.S. Pat. No. 2003/014202 discloses a method in which one end of a silicon thin rod is tapered, and then the tapered end is press-fitted into a hole provided in an adapter to integrate the two silicon thin rods. Japanese patent application laid-open publication No. 2011-195441 discloses a method of integrating two thin silicon rods with a disk made of a material having a lower resistivity than silicon material.

However, when the integration is performed by welding as disclosed in japanese patent laid-open nos. 2011 and 116634, 2012 and 62243, and 2018 and 122340, contamination during welding is involved. In the case of fixing by an adapter described in U.S. Pat. No. 2003/014202, since the thin silicon rod must be strongly pressed into the hole of the adapter, there is a possibility that the thin silicon rod is broken or the connection portion is unstable, and the thin silicon rod collapses when assembled in an inverted U shape. Next, when a member different from a silicon member is used for integration as in U.S. patent publication No. 2003/014202 and japanese patent application laid-open publication No. 2011-195441, contamination in a process of depositing polycrystalline silicon by the siemens method is involved.

In view of the above problems, an object of the present invention is to provide a long silicon core wire (silicon slim rod) which is simple and inexpensive, involves neither contamination nor collapse.

Disclosure of Invention

In order to solve the above problem, a silicon core wire according to a first aspect of the present invention is characterized in that: the external thread part formed at one end of the first thin silicon rod and the internal thread part formed at one end of the second thin silicon rod are screwed with each other and then fastened.

Further, a silicon core wire according to a second aspect of the present invention is characterized in that: the screw portion formed at one end of the first thin silicon rod and the screw portion formed at one end of the second thin silicon rod are fastened by being screwed together by an adapter having screw portions formed at both ends.

Ideally: the adapter is composed of a silicon member.

The first and second thin silicon rods are thin silicon rods extracted from, for example, a polycrystalline silicon rod or a single crystal silicon rod.

Effects of the invention

According to the present invention, a long silicon core wire (silicon slim rod) is provided which is simple and inexpensive, involves neither contamination nor collapse.

Drawings

Fig. 1 is a diagram for explaining a silicon core wire according to a first embodiment of the present invention.

Fig. 2 is a diagram for explaining a first example of a silicon core wire in a second embodiment according to the present invention.

Fig. 3 is a diagram for explaining a second example of the silicon core wire in the second embodiment according to the present invention.

Fig. 4 is a diagram for explaining a silicon core wire in comparative example 1.

Fig. 5 is a diagram for explaining a silicon core wire in comparative example 2.

Detailed Description

Hereinafter, modes for carrying out the present invention will be described with reference to the accompanying drawings.

Fig. 1 is a diagram for explaining a silicon core wire in a first embodiment according to the present invention, and fig. 1(a) shows an embodiment before integration, and fig. 1(B) shows an embodiment after integration. As shown in the drawing, an external thread portion 15 is formed at one end of the first thin silicon rod 10, an internal thread portion 25 is formed at one end of the second thin silicon rod 20, and the external thread portion 15 and the internal thread portion 25 are fastened and integrated after being screwed with each other, thereby forming one silicon core wire 100.

The thin silicon rod is extracted from, for example, a polycrystalline silicon rod or a single crystal silicon rod. The cross-sectional shape of the thin silicon rod is not particularly limited, but is generally rectangular.

The threaded portion of the thin silicon rod is formed by machining, but the thin silicon rod after machining is cleaned after etching treatment in order to remove contamination. However, since silicon in the threaded portion is slightly removed by the etching treatment, in order to screw the etched threaded portion, machining of the threaded portion is performed in consideration of a margin in the etching treatment.

According to the integration using the screw portion, since the screw portion is screwed by surface contact, it can be firmly fixed, and since the silicon core wire can be stably energized, abnormal heat generation or the like is less likely to occur in the screw portion.

Fig. 2 is a diagram for explaining a first example of a silicon core wire in a second embodiment according to the present invention, in which fig. 2(a) shows a state before integration, and fig. 2(B) shows a state after integration. In this embodiment, a male screw portion 15 is formed at one end of the first thin silicon rod 10, a male screw portion 25 is also formed at one end of the second thin silicon rod 20, and the male screw portions 15 and 25 are screwed together by an adaptor 30 having screw portions formed at both ends thereof, and then fastened and integrated to form one silicon core wire 100.

Fig. 3 is a diagram for explaining a second example of a silicon core wire in a second embodiment according to the present invention, in which fig. 3(a) shows a state before integration, and fig. 3(B) shows a state after integration. In this embodiment, a female screw portion 15 is formed at one end of the first slim silicon rod 10, a female screw portion 25 is also formed at one end of the second slim silicon rod 20, and the female screw portions 15 and 25 are screwed together by an adaptor 30 having screw portions formed at both ends thereof and then fastened and integrated to form one silicon core wire 100.

The thickness (width) a of the straight portion of the adapter 30 is set in consideration of the entire length of the silicon core wire 100, but may be 0. In the case where a is 0, the sum of the lengths of the first thin silicon rod 10 and the second thin silicon rod 20 is equal to the entire length of the silicon core wire 100. When the thickness a of the straight body of the adapter 30 is 0, the amount of use of the members for the adapter 30 is reduced, and the engagement portion is changed from two to one, and therefore, the present invention includes: the rigidity of the silicon core wire is improved, and the silicon core wire is not easy to bend during manufacturing.

The adapter 30 is not limited to the above-described embodiments, and may be formed with, for example, a male screw portion at one end and a female screw portion at the other end. The adapter 30 is preferably made of a silicon member from the viewpoint of preventing contamination or the like. Next, from the viewpoint of smooth screwing, a small hole portion may be provided in the adaptor 30 for exhausting air.