Doping device for heavily doping Czochralski single crystal
By introducing a guide portion into the doping device to block and guide escaping gas molecules, the doping area is increased, solving the problem of low doping efficiency in the prior art and achieving efficient single crystal growth and long device life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HAINA SEMICON (SHANXI) CO LTD
- Filing Date
- 2025-05-12
- Publication Date
- 2026-05-01
AI Technical Summary
In the existing technology, unreasonable design of the doping device leads to dopant loss, low doping efficiency, and affects the yield of single crystal growth.
Design a doping device for heavily doped Czochralski single crystals, including a bell-shaped doping shroud and a guide portion. The guide portion extends radially outward and downward to block and guide escaping gas molecules, increase the doping area, and ensure non-contact doping.
It improves doping efficiency and single crystal growth yield, reduces impurity introduction, and extends the lifespan of the device.
Smart Images
Figure CN224186324U_ABST
Abstract
Description
Doping device for heavily doped Czochralski single crystals Technical Field
[0001] This utility model relates to the field of single-crystal silicon pulling technology, and in particular to a doping device for heavily doped Czochralski-grown single crystals. Background Technology
[0002] Currently, semiconductor silicon materials can be divided into heavily doped silicon single crystals and lightly doped silicon single crystals. The resistivity of a pulled single crystal is determined by the amount of dopant element selected; the higher the dopant element concentration, the lower the resistivity of the single crystal. Low-resistivity single crystals with a large dopant element concentration are called heavily doped silicon single crystals; conversely, those with a small dopant element concentration are called lightly doped silicon single crystals. Heavily doped silicon single crystals are the most ideal epitaxial substrate materials, and the main dopants currently used are arsenic, phosphorus, and antimony.
[0003] In related technologies, considering the high volatility of dopants, doping devices often employ a combination of doping hoods and doping bowls. However, this structural design is still not ideal, leading to dopant loss and resulting in low doping efficiency. Summary of the Invention
[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one objective of the present invention is to provide a doping device for heavily doped Czochralski single crystals, which has higher doping efficiency.
[0005] A doping apparatus for heavily doped Czochralski single crystals according to an embodiment of the present invention includes: a doping bowl adapted to hold a dopant; and a doping shield comprising: a doping shield body and a guide portion. The doping shield body is bell-shaped and extends axially in the vertical direction. The doping bowl is coaxial with the doping shield body and connected to the top of the inner wall of the doping shield body. The guide portion is connected to the bottom end of the doping shield body and is annular, extending radially outward and downward from the doping shield body. The guide portion is spaced apart from the silicon solution in the vertical direction.
[0006] Therefore, by connecting a guide part to the bottom of the doping cover body, the guide part is arranged to extend outward and downward in the radial direction of the doping cover body, and the guide part is spaced apart from the silicon solution in the vertical direction. In this way, under the premise of ensuring non-contact doping, the guide part can block and guide some of the escaping gas molecules, thereby increasing the doping area, which can not only improve the doping efficiency, but also improve the first-pass yield of single crystal growth.
[0007] In some examples of this utility model, the guide portion is an arc-shaped plate, which is bent downwards.
[0008] In some examples of this utility model, the guide portion is an inclined plate.
[0009] In some examples of this utility model, the radial projection of the doped cover body is L1, and the radial projection of the guide portion on the doped cover body is L2. L1 and L2 satisfy the following relationship: 278mm < L1 < 282mm, 8mm < L2 < 12mm.
[0010] In some examples of this utility model, the axial projection dimension of the doped cover body is L3, and the axial projection dimension of the guide portion of the doped cover body is L4. L3 and L4 satisfy the following relationship: 158mm < L3 < 162mm, 13mm < L4 < 18mm.
[0011] In some examples of this utility model, the distance between the top of the doping bowl and the top of the inner wall of the doping shield body in the vertical direction is D1, and D1 satisfies the relationship: 18mm < D1 < 22mm.
[0012] In some examples of this utility model, the distance between the guide portion and the silicon solution in the vertical direction is D2, and D2 satisfies the relationship: 5mm < D2 < 10mm.
[0013] In some examples of this utility model, the doping cover further includes: a first connecting part, which is disposed on the top of the inner wall of the doping cover body. The first connecting part is a hook, and the doping bowl is provided with a suspension beam. The hook and the suspension beam are connected.
[0014] In some examples of this utility model, the doping cover further includes: a second connecting part, which is disposed on the top of the outer wall of the doping cover body, and the second connecting part is provided with a hanging hole, which is adapted to be connected to a hanging device.
[0015] In some examples of this utility model, the doping bowl is a quartz bowl, and the doping cover is a quartz cover.
[0016] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0017] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:
[0018] Figure 1 is a schematic diagram of a doping device for heavily doped Czochralski single crystals according to an embodiment of the present invention.
[0019] Figure label:
[0020] 100. Doping apparatus;
[0021] 10. Mixed bowl; 11. Suspended beam;
[0022] 20. Doped cover; 21. Doped cover body; 22. Guide part; 23. First connecting part; 24. Second connecting part; 241. Suspension hole. Detailed Implementation
[0023] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present invention are described in detail below.
[0024] The doping apparatus 100 for heavily doped Czochralski single crystals according to an embodiment of the present invention is described below with reference to FIG1.
[0025] As shown in Figure 1, the doping device 100 for heavily doped Czochralski single crystals according to this invention mainly includes: a doping bowl 10 and a doping cover 20.
[0026] The doping bowl 10 is suitable for holding dopants. The doping cover 20 may include a doping cover body 21 and a guide portion 22. The doping cover body 21 is bell-shaped and its axial direction extends in the vertical direction. The doping bowl 10 is coaxial with the doping cover body 21 and connected to the top of the inner wall of the doping cover body 21. The guide portion 22 is connected to the bottom end of the doping cover body 21. The guide portion 22 is annular and extends outward and downward in the radial direction of the doping cover body 21. The guide portion 22 is spaced apart from the silicon solution in the vertical direction.
[0027] Specifically, by making the doping cover body 21 bell-shaped, extending the axial direction of the doping cover body 21 in the vertical direction, and placing the doping bowl 10 inside the doping cover body 21, so that the doping bowl 10 is connected to the top of the inner wall of the doping cover body 21, and the doping bowl 10 is coaxially arranged with the doping cover body 21, the basic structure of the doping device 100 can be formed.
[0028] When the doping device 100 is operating, the dopant is placed in the doping bowl 10, and the doping cover body 21 is spaced apart from the silicon solution in the vertical direction. Under the influence of the high-temperature thermal field of the silicon solution (above 1000°C), the dopant sublimates, and the gas molecules rapidly volatilize and move continuously in all directions at high temperature. After encountering the inner wall of the doping cover 20, they rush back towards the silicon solution and dope the silicon solution. The dopant includes, but is not limited to, phosphorus or arsenic.
[0029] In this way, non-contact doping can be achieved, and the doping cover 20 does not need to enter the silicon solution. This not only avoids the introduction of impurities, but also avoids the reaction between the doping cover 20 and the silicon solution, reducing the introduction of impurities and improving the service life of the doping device 100.
[0030] Considering that when the gas molecules of the dopant rush towards the silicon solution, a large portion of the gas molecules that have not yet been incorporated into the silicon solution can easily escape from the gap between the doping shield 20 and the liquid surface, this will reduce the doping efficiency.
[0031] By connecting the guide portion 22 to the bottom of the doping cover body 21, it can be understood that the bottom of the doping cover body 21 is circular, and by making the guide portion 22 annular, the guide portion 22 can be adapted to the shape of the bottom of the doping cover body 21. Furthermore, the guide portion 22 is arranged radially outward and downward from the doping cover body 21, and is spaced apart from the silicon solution in the vertical direction. This allows the guide portion 22 to block and guide some of the escaping gas molecules, enabling them to enter the silicon solution and be doped, while ensuring non-contact doping. This increases the contact area between the gas molecules and the silicon solution, i.e., increases the doping area, which not only improves the doping efficiency but also increases the first-pass yield of single crystal growth.
[0032] Therefore, by connecting the guide portion 22 to the bottom of the doping cover body 21, the guide portion 22 is arranged to extend outward and downward in the radial direction of the doping cover body 21, and the guide portion 22 is spaced apart from the silicon solution in the vertical direction. In this way, under the premise of ensuring non-contact doping, the guide portion 22 can block and guide some of the escaping gas molecules, thereby increasing the doping area, which can not only improve the doping efficiency, but also improve the first-pass yield of single crystal growth.
[0033] In some embodiments of this utility model, as shown in Figure 1, the guide portion 22 is an arc-shaped plate that is bent downwards. Specifically, the guide portion 22 can be configured as an arc-shaped plate, with one end connected to the bottom of the doping cover body 21, and the other end extending radially outwards and downwards. The other end of the arc-shaped plate is spaced apart from the silicon solution. This allows gas molecules to gradually approach the silicon solution surface along the arc-shaped plate and move radially outwards, making the flow of gas molecules more stable and smooth, thereby further improving the doping efficiency and the first-pass yield of single crystal growth.
[0034] In some other embodiments of this utility model, the guide portion 22 is an inclined plate. Specifically, the guide portion 22 can be configured as an inclined plate, with one end of the inclined plate connected to the bottom of the doping cover body 21, and the other end of the inclined plate extending radially outward and downward. The other end of the inclined plate is spaced apart from the silicon solution. This ensures that the doping area can be increased while also simplifying the structure of the guide portion 22.
[0035] As shown in Figure 1, the radial projection of the doped cover body 21 is L1, and the radial projection of the guide portion 22 on the doped cover body 21 is L2. L1 and L2 satisfy the following relationship: 278mm < L1 < 282mm, 8mm < L2 < 12mm.
[0036] Specifically, by setting the radial projection dimensions of the doped cover body 21 and the radial projection dimensions of the guide portion 22 on the doped cover body 21 within reasonable ranges, the overall axial structural design of the doped cover 20 can be optimized. Under the premise that the doped cover 20 can be placed in the furnace and spaced apart from the silicon solution in the vertical direction, not only can the axial dimensions of the doped cover body 21 be guaranteed to ensure that the dopant gas molecules diffuse fully inside the doped cover body 21, but also the axial dimensions of the guide portion 22 can be guaranteed to ensure that the guide portion 22 can guide the dopant gas molecules to the silicon solution in the axial direction, thus ensuring doping efficiency.
[0037] As shown in Figure 1, the axial projection dimension of the doped cover body 21 is L3, and the axial projection dimension of the guide portion 22 on the doped cover body 21 is L4. L3 and L4 satisfy the following relationship: 158mm < L3 < 162mm, 13mm < L4 < 18mm.
[0038] Specifically, by setting the dimensions of the projection of the doped cover body 21 in the axial direction and the dimensions of the projection of the guide portion 22 in the axial direction of the doped cover body 21 within a reasonable range, the overall radial structural design of the doped cover 20 can be optimized. Under the premise of ensuring that the doped cover 20 can be placed in the furnace without interfering with the container holding the silicon solution, not only can the radial dimensions of the doped cover body 21 be guaranteed to ensure that the dopant gas molecules diffuse fully inside the doped cover body 21, but also the radial dimensions of the guide portion 22 can be guaranteed to guide the dopant gas molecules further in the radial direction, reduce the amount of gas molecule escape, increase the doping area, and thus ensure the doping efficiency.
[0039] As shown in Figure 1, the distance between the top of the doped bowl 10 and the top of the inner wall of the doped cover body 21 in the vertical direction is D1, and D1 satisfies the relationship: 18mm < D1 < 22mm.
[0040] This configuration allows for a more reasonable height of the doping bowl 10 within the doping cover body 21, enabling the dopant gas molecules to be evenly distributed within the doping cover body 21 before flowing into the silicon solution and doping with it. Consequently, under the same doping time and conditions, the doping efficiency can be improved, and the first-pass yield of single crystal growth can be increased.
[0041] Furthermore, the distance between the guide portion 22 and the silicon solution in the vertical direction is D2, and D2 satisfies the relationship: 5mm < D2 < 10mm.
[0042] Specifically, when the vertical distance between the guide portion 22 and the silicon solution is too large, even though the guide portion 22 can block and guide gas molecules, a large portion of the gas molecules will still escape through the gap between the guide portion 22 and the silicon solution before reaching the silicon solution, resulting in low doping efficiency. When the vertical distance between the guide portion 22 and the silicon solution is too small, the silicon solution is more likely to come into contact with the guide portion 22, leading to the introduction of impurities.
[0043] By setting the distance between the guide portion 22 and the silicon solution in the vertical direction to be greater than 5 mm and less than 10 mm, this distance can be made more reasonable, which can not only more reliably avoid the introduction of impurities, but also ensure doping efficiency.
[0044] As shown in Figure 1, the doping cover 20 may further include: a first connecting part 23, which is disposed on the top of the inner wall of the doping cover body 21. The first connecting part 23 is a hook, and the doping bowl 10 is provided with a suspension beam 11. The hook and the suspension beam 11 are connected.
[0045] Specifically, by setting the hook on the top of the inner wall of the doping cover body 21 and setting the suspension beam 11 on the top of the doping bowl 10, the connection between the doping bowl 10 and the doping cover 20 can be achieved simply by hooking the hook onto the suspension beam 11, ensuring the stable setting of the doping bowl 10 in the doping cover 20, and making the doping device 100 simpler and more reliable.
[0046] Furthermore, it is understandable that the connection between the hook and the suspension beam 11 is detachable, so that when the dopant needs to be replenished, the dopant bowl 10 can simply be removed from the dopant cover 20, and then placed back into the dopant cover 20 after the dopant has been replenished, thus facilitating the user's operation.
[0047] As shown in Figure 1, the doping cover 20 may further include a second connecting part 24, which is disposed on the top of the outer wall of the doping cover body 21. The second connecting part 24 is provided with a hanging hole 241, which is adapted to be connected to a Czochralski furnace.
[0048] Specifically, the doping cover 20 is spaced apart from the surface of the silicon solution, requiring control of the height of the doping cover 20. By setting the second connecting part 24 on the top of the outer wall of the doping cover body 21, and providing a hanging hole 241 on the second connecting part 24, the hanging hole 241 can be connected to the Czochralski furnace, allowing the Czochralski furnace to move the doping cover 20 and even the doping device 100 in the vertical direction, ensuring the normal operation of the doping device 100.
[0049] In some embodiments of this utility model, the doping bowl 10 is a quartz bowl, and the doping cover 20 is a quartz cover.
[0050] Specifically, considering that the doping device 100 operates in a high-temperature environment, by setting the doping bowl 10 as a quartz bowl and the doping cover 20 as a quartz cover, the high-temperature resistance of the doping bowl 10 and the doping cover 20 can be improved, ensuring that the two do not melt or deform at high temperatures and maintaining structural stability.
[0051] Furthermore, since the dopant vaporizes at high temperatures, both the doping bowl 10 and the doping cover 20 will come into contact with the dopant. By setting the doping bowl 10 as a quartz bowl and the doping cover 20 as a quartz cover, the chemical inertness of the doping bowl 10 and the doping cover 20 can be ensured, preventing chemical reactions between the doping cover 20 and the doping bowl 10 and the dopant. This not only avoids the introduction of additional impurities but also ensures the efficient release and uniform distribution of the dopant, reducing doping unevenness caused by material adsorption.
[0052] This can further improve doping efficiency and increase the first-pass yield of single crystal growth.
[0053] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0054] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.
[0055] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.
Claims
1. A doping device for heavily doped Czochralski-grown single crystals, characterized in that, include: A doping bowl, said doping bowl being adapted to hold a dopant; A doping shield, comprising: a doping shield body and a guide portion, the doping shield body being bell-shaped and extending axially in the vertical direction, the doping bowl being coaxial with the doping shield body and connected to the top of the inner wall of the doping shield body, the guide portion being connected to the bottom end of the doping shield body, the guide portion being annular and extending radially outward and downward in the doping shield body, the guide portion being spaced apart from the silicon solution in the vertical direction.
2. The doping apparatus for heavily doped Czochralski single crystals according to claim 1, characterized in that, The guide portion is an arc-shaped plate, which is bent downwards.
3. The doping apparatus for heavily doped Czochralski-grown single crystals according to claim 1, characterized in that, The guide section is an inclined plate.
4. The doping apparatus for heavily doped Czochralski-grown single crystals according to claim 2 or 3, characterized in that, The radial projection of the doped cover body is L1, and the radial projection of the guide portion on the doped cover body is L2. L1 and L2 satisfy the following relationship: 278mm < L1 < 282mm, 8mm < L2 < 12mm.
5. The doping apparatus for heavily doped Czochralski-grown single crystals according to claim 4, characterized in that, The axial projection of the doped cover body is L3, and the axial projection of the guide portion of the doped cover body is L4. L3 and L4 satisfy the following relationship: 158mm < L3 < 162mm, 13mm < L4 < 18mm.
6. The doping apparatus for heavily doped Czochralski-grown single crystals according to claim 5, characterized in that, The distance between the top of the doped bowl and the top of the inner wall of the doped cover body in the vertical direction is D1, and D1 satisfies the relationship: 18mm < D1 < 22mm.
7. The doping apparatus for heavily doped Czochralski-grown single crystals according to claim 1, characterized in that, The distance between the guide portion and the silicon solution in the vertical direction is D2, and D2 satisfies the relationship: 5mm < D2 < 10mm.
8. The doping apparatus for heavily doped Czochralski single crystals according to claim 1, characterized in that, The doping shield further includes: a first connecting part, which is disposed on the top of the inner wall of the doping shield body. The first connecting part is a hook. The doping bowl is provided with a suspension beam, and the hook and the suspension beam are connected.
9. The doping apparatus for heavily doped Czochralski-grown single crystals according to claim 1, characterized in that, The doping shield further includes a second connecting portion, which is disposed on the top of the outer wall of the doping shield body. The second connecting portion is provided with a suspension hole, which is adapted to be connected to a suspension device.
10. The doping apparatus for heavily doped Czochralski-grown single crystals according to claim 1, characterized in that, The doping bowl is a quartz bowl, and the doping cover is a quartz cover.