CN112813490A

CN112813490A - High-frequency heating doping coil of zone-melting single crystal furnace

Info

Publication number: CN112813490A
Application number: CN202110138407.0A
Authority: CN
Inventors: 王遵义; 刘凯; 吴磊; 边智学; 孙健; 孙晨光; 王彦君
Original assignee: Tianjin Zhonghuan Advanced Material Technology Co Ltd; Zhonghuan Advanced Semiconductor Materials Co Ltd
Current assignee: Tianjin Zhonghuan Advanced Material Technology Co Ltd; Zhonghuan Advanced Semiconductor Materials Co Ltd
Priority date: 2021-02-01
Filing date: 2021-02-01
Publication date: 2021-05-18

Abstract

The invention provides a high-frequency heating doping coil of a zone-melting single crystal furnace, which comprises a coil body and a doping pipeline for feeding doping gas into a melting zone, wherein the doping pipeline is arranged inside the coil body, a gas outlet of the doping pipeline is arranged on a cutting edge at the inner side of the coil body, and the doping pipeline is arranged along the radial direction of the coil body. The high-frequency heating doping coil of the zone-melting single crystal furnace concentrates doping gas inside the coil and directly sends the doping gas into a melting zone through a doping pipeline.

Description

High-frequency heating doping coil of zone-melting single crystal furnace

Technical Field

The invention belongs to the technical field of zone-melting gas-doped single crystals, and particularly relates to a high-frequency heating doped coil of a zone-melting single crystal furnace.

Background

The growth of the monocrystalline silicon mainly comprises a Czochralski method and a zone melting method. In the growth process of the zone-melting silicon single crystal, the single crystal and the melt are not in direct contact with the auxiliary materials, and other impurities are hardly introduced. During the crystal growth by the zone melting method, impurities are volatilized outwards through the concentration difference between the melt and the environment in the furnace, so that the purification effect is achieved. The float-zone silicon single crystal is far superior to the Czochralski silicon single crystal in quality, and therefore, is also applied to medium and high-end power electronic devices; the uniformity of the axial resistivity of the single crystal is reasonably controlled, the qualification rate of the single crystal can be improved, and the cost is reduced; the uniformity of the radial resistivity can improve the quality of the single crystal and the competitiveness of the product.

The gas phase doping is adopted for the zone-melting silicon, the resistivity is influenced by the single crystal rotation speed, the gas convection and the doping amount fluctuation, so that the fluctuation of the uniformity of the axial resistivity and the radial resistivity of the single crystal is large, and the key for improving the uniformity of the axial resistivity of the zone-melting silicon single crystal is to avoid or reduce the influence of the single crystal rotation speed, the gas convection and the doping amount fluctuation.

Disclosure of Invention

In view of the above, the present invention is directed to a high-frequency heating doped coil for a zone-melting single crystal furnace.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a high-frequency heating doping coil of a zone-melting single crystal furnace comprises a coil body and a doping pipeline used for sending doping gas into a melting zone, wherein the doping pipeline is arranged inside the coil body, a gas outlet of the doping pipeline is arranged at a cutting edge at the inner side of the coil body, and the doping pipeline is arranged along the coil body in the radial direction.

Furthermore, an annular cooling water path convenient for heat dissipation of the coil body is further arranged inside the coil body.

Furthermore, the outer edge of the coil body is also provided with a fixing part for fixing the coil body, and the fixing part is provided with a water inlet and a water outlet communicated with a cooling water path.

Furthermore, the fixed part comprises two fixed blocks, wherein one fixed block is provided with a water inlet communicated with one end of the cooling water path, and the other fixed block is provided with a water outlet communicated with the other end of the cooling water path;

and bolt holes for fixing the fixing blocks are formed in the two fixing blocks.

Furthermore, the cooling water path comprises an annular groove formed in the front face of the coil body and an annular cover plate used for sealing the annular groove, and the annular cover plate is fixedly connected with the coil body.

Furthermore, an annular concave platform corresponding to the annular cover plate is further arranged on the coil body, the depth of the annular concave platform is the same as the thickness of the annular cover plate, and the annular cover plate is fixedly arranged in the annular concave platform.

Further, the air inlet of the doping pipeline is arranged at the edge position of the coil body;

the position that cooling water route and doping pipeline contacted is buckled to the coil body back and is formed the surrounding part, the back of coil body is equipped with and is used for the sealed connection apron of surrounding part, the surrounding part forms the U-shaped water route of circumventing the doping pipeline with the connection apron cooperation.

Compared with the prior art, the high-frequency heating doped coil of the zone-melting single crystal furnace has the following advantages:

the high-frequency heating doping coil of the zone-melting single crystal furnace concentrates doping gas inside the coil and directly sends the doping gas into a melting zone through a doping pipeline. The advantages are that: firstly, the influence of the convection of argon in the furnace on the concentration of the doping gas can be reduced, the consistency of the impurity concentration on the surface of the melt is improved, and the uniformity of the axial resistivity is improved; secondly, the doping concentration difference between the center and the edge of the surface of the free melt is reduced, and the uniformity of the radial resistivity is improved; thirdly, the local doping concentration is increased, the doping efficiency is improved, the doping gas is saved, and the cost is reduced.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a front structural view of a coil body according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a back structure of a coil body according to an embodiment of the invention;

FIG. 3 is a cross-sectional view of a coil body according to an embodiment of the present invention;

fig. 4 is a schematic diagram illustrating a coil body and a crystal according to an embodiment of the invention.

Description of reference numerals:

1. a coil body; 11. a fixed block; 1101. bolt holes; 2. doping a pipeline; 21. an air outlet; 22. an air inlet; 3. a cooling water path; 31. an annular cover plate; 32. a U-shaped waterway; 33. a water inlet; 34. a water outlet; 4. connecting the cover plate; 5. a silicon melt.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in fig. 1 to 4, the high-frequency heating doped coil of the zone-melting single crystal furnace comprises a coil body 1 and a doping pipeline 2 for feeding doping gas into a melting zone, wherein the doping pipeline 2 is arranged inside the coil body 1, an air outlet 21 of the doping pipeline 2 is arranged at a cutting edge at the inner side of the coil body 1, and the doping pipeline 2 is arranged along the radial direction of the coil body 1.

The coil body 1 is internally provided with an annular cooling water path 3 convenient for heat dissipation of the coil body 1.

The outer edge of the coil body 1 is also provided with a fixing part for fixing the coil body, and the fixing part is provided with a water inlet 33 and a water outlet 34 communicated with the cooling water channel 3.

The fixing part comprises two fixing blocks 11, wherein one fixing block 11 is provided with a water inlet 33 communicated with one end of the cooling water channel 3, and the other fixing block 11 is provided with a water outlet 34 communicated with the other end of the cooling water channel 3;

bolt holes 1101 used for fixing the fixing blocks 11 are formed in the two fixing blocks 11.

The cooling water path 3 comprises an annular groove formed in the front face of the coil body and an annular cover plate 31 used for sealing the annular groove, and the annular cover plate 31 is fixedly connected with the coil body 1.

The coil body 1 is further provided with an annular concave table corresponding to the annular cover plate 31, the depth of the annular concave table is the same as the thickness of the annular cover plate 31, the annular cover plate 31 is fixedly arranged in the annular concave table, and the front surface of the coil body 1 is smoother and smoother through the design of the annular concave table.

The gas inlet 22 of the doping pipeline 2 is arranged at the edge position of the coil body 1;

the position of cooling water route 3 and doping pipeline contact is buckled to coil body 1 back and is formed the surrounding part, the back of coil body 1 is equipped with and is used for the sealed connection apron 4 of surrounding part, the U-shaped water route 32 that the doping pipeline was walked around in the cooperation formation of surrounding part and connection apron 4. One of them design difficult problem of this scheme is exactly that there is the position conflict in doping pipeline 2 and cooling water route 3, through the structural design of annular portion and connection cover plate 4, makes the ingenious doping pipeline 2 of having avoided in cooling water route 3, both mutual noninterference. By changing the water path structure, the cooling water path 3 crosses over the doping pipeline, the doping gas is sprayed to the position near the silicon melt 5 through the doping pipeline, the doping gas is decomposed at high temperature, the doping impurities fall into the silicon melt 5, and the doping impurities are distributed in the whole melt along with the heat convection in the silicon melt 5, so that the consistency of the impurity concentration on the surface of the melt is improved.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. The high-frequency heating doping coil of the zone-melting single crystal furnace comprises a coil body and a doping pipeline used for feeding doping gas into a melting zone, and is characterized in that: the doping pipeline is arranged inside the coil body, an air outlet of the doping pipeline is arranged at a cutting edge inside the coil body, and the doping pipeline is arranged along the coil body in the radial direction.

2. The high-frequency heating doped coil of the zone-melting single crystal furnace according to claim 1, characterized in that: the coil body is internally provided with an annular cooling water path convenient for heat dissipation of the coil body.

3. The high-frequency heating doped coil of the zone-melting single crystal furnace of claim 2, characterized in that: the coil comprises a coil body and is characterized in that a fixing part used for fixing the coil body is further arranged at the edge of the outer side of the coil body, and a water inlet and a water outlet communicated with a cooling water path are formed in the fixing part.

4. The high-frequency heating doped coil of the zone-melting single crystal furnace of claim 3, characterized in that: the fixing part comprises two fixing blocks, one fixing block is provided with a water inlet communicated with one end of the cooling water path, and the other fixing block is provided with a water outlet communicated with the other end of the cooling water path;

5. The high-frequency heating doped coil of the zone-melting single crystal furnace of claim 3, characterized in that: the cooling water path comprises an annular groove formed in the front face of the coil body and an annular cover plate used for sealing the annular groove, and the annular cover plate is fixedly connected with the coil body.

6. The high-frequency heating doped coil of the zone-melting single crystal furnace of claim 5, characterized in that: the coil comprises a coil body and is characterized in that an annular concave platform corresponding to an annular cover plate is further arranged on the coil body, the depth of the annular concave platform is the same as the thickness of the annular cover plate, and the annular cover plate is fixedly arranged in the annular concave platform.

7. The high-frequency heating doped coil of the zone-melting single crystal furnace of claim 3, characterized in that: the air inlet of the doping pipeline is arranged at the edge position of the coil body;