Seed chuck for Czochralski method monocrystalline silicon production
By setting up a main gas channel and an argon negative pressure exhaust system in the seed crystal chuck, the problem of gas and impurities in the seed crystal chuck that cannot be effectively discharged is solved, thereby improving the stability and quality of monocrystalline silicon production.
Patent Information
- Application Number
- CN202520274730.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-20
- Publication Date
- 2026-02-13
- Estimated Expiration
- 2035-02-20
AI Technical Summary
In the existing technology, when the seed crystal chuck is heated and expands in a high-temperature environment, gas and impurities cannot be effectively discharged, resulting in impurity deposition, which affects the quality of the single crystal rod and the smooth progress of production.
Design a seed crystal chuck for Czochralski single crystal silicon production, including an outer sleeve, an inner sleeve, and a fixing rod. The outer sleeve has a main gas channel, and the fixing rod is threaded to the outer sleeve. The extension part has an air inlet and an air outlet. Argon negative pressure is used to discharge the gas inside the chuck and prevent external gas from entering.
It effectively removes gas and impurities from the seed crystal chuck, ensuring smooth production of single crystal rods, preventing impurities from entering molten silicon, and improving the quality of single crystals.
Smart Images
Figure CN223906993U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a seed crystal chuck for Czochralski monocrystalline silicon production. BACKGROUND
[0002] In the process of Czochralski monocrystalline silicon production, in order to grow a single crystal ingot with a specific crystal orientation, a seed crystal with the specific crystal orientation is fixed in the seed crystal chuck as a seed, and the seed crystal is prevented from deviating during the pulling process. The specific production method is as follows: after high-purity monocrystalline silicon is melted in a crucible, the end of the seed crystal is immersed in the high-temperature melt as a nucleation center of the single crystal ingot, and then the single crystal ingot is slowly pulled upward to obtain a single crystal ingot.
[0003] Since the production of the single crystal ingot is carried out in a high-temperature environment, and the seed crystal chuck is above the high-temperature melt, the volume of the gas in the seed crystal chuck will expand rapidly under the heat. If the purity of the material of the seed crystal chuck is low, a large amount of impurity gas will also be emitted under high temperature. Under the above double effects, the seed crystal chuck may burst and cause the silicon material to be scrapped, and the production of the single crystal ingot cannot be carried out smoothly. In the prior art, the seed crystal chuck includes an outer sleeve, an inner sleeve, and a fixing rod. In order to discharge the heated gas and the impurity gas outward, a plurality of exhaust holes are formed in the outer sleeve. However, the actual exhaust capacity of the exhaust holes is limited due to the assembly between the fixing rod and the outer sleeve. Even if there is a partial exhaust effect, some external gas will also enter the seed crystal chuck at the same time, so that the gas and impurities in the seed crystal chuck cannot be completely discharged. Long-term use will cause deposition, resulting in the solidification of the seed crystal and the seed crystal chuck, the formation of impurity solidification blocks, the influence on the assembly effect of the seed crystal chuck and the normal use effect of the crystal orientation, and the serious falling of the impurity solidification blocks in the seed crystal chuck into the molten silicon during repeated heating and cooling, which reduces the quality of the single crystal ingot. SUMMARY
[0004] In order to solve the problem that the heated gas and the impurity gas are discharged outward through the exhaust holes at the same time, and some external gas enters the seed crystal chuck, the utility model provides a seed crystal chuck for Czochralski monocrystalline silicon production, which avoids the entry of external gas into the seed crystal chuck, ensures the complete emission of the gas and impurities in the seed crystal chuck, and enables the production of the single crystal ingot to proceed smoothly.
[0005] The utility model discloses a seed crystal chuck for the production of single crystal silicon by the Czochralski method, which comprises an outer sleeve, an inner sleeve slidably arranged in the outer sleeve, and a fixing rod detachably connected with the outer sleeve.
[0006] As a further optimization of the utility model, the extension direction of the main gas channel forms an angle with the axis of the fixing rod.
[0007] As a further optimization of the utility model, the extension direction of the main gas channel forms an angle with the axis of the fixing rod.
[0008] As a further optimization of the utility model, the extension direction of the main gas channel forms an angle with the axis of the fixing rod.
[0009] As a further optimization of the utility model, the extension direction of the main gas channel forms an angle with the axis of the fixing rod.
[0010] As a further optimization of the utility model, the extension direction of the main gas channel forms an angle with the axis of the fixing rod.
[0011] As a further optimization of the utility model, the extension direction of the main gas channel forms an angle with the axis of the fixing rod.
[0012] As a further optimization of the utility model, the extension direction of the main gas channel forms an angle with the axis of the fixing rod.
[0013] As a further optimization of the seed crystal chuck for the production of single crystal silicon by the Czochralski method, the upper end of the outer sleeve is provided with a chamfer.
[0014] Compared with the prior art, the utility model has the beneficial effects that:
[0015] The utility model discloses a fixed rod, transition part, the extension of the department, the outer sleeve, the inner sleeve, the recess, the seed crystal, the main gas channel, the gap, the gas channel, the notch, the protruding, the third channel, the counterbore, the mounting hole, the pin hole and the limiting space are connected, and the utility model discloses a seed crystal chuck for the production of single crystal silicon by the Czochralski method. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 It is one embodiment schematic diagram of the utility model;
[0017] Figure 2 It is the A place partial close -up of the utility model;
[0018] Figure 3 It is the cooperation schematic diagram of outer sleeve, inner sleeve, fixed rod, transition part and extension of the department;
[0019] Figure 4 It is another embodiment schematic diagram of the utility model;
[0020] Figure 5 It is the cooperation schematic diagram of outer sleeve, inner sleeve, fixed rod, connecting portion and extension of the department;
[0021] Mark in drawing: 1, fixed rod, 2, transition part, 3, extension of the department, 4, outer sleeve, 5, inner sleeve, 6, recess, 7, seed crystal, 8, main gas channel, 9, gap, 10, gas channel, 11, notch, 12, protruding, 13, third channel, 14, counterbore, 15, mounting hole, 16, pin hole, 17, limiting space, 18, first channel, 19, second channel. DETAILED DESCRIPTION
[0022] The technical scheme of the utility model will be further described in detail in combination with specific embodiments, and the parts not described and disclosed in the following embodiments of the utility model should be understood as the prior art known or known by the person skilled in the art, such as the specific structure of the seed crystal 7.
[0023] Embodiment 1
[0024] A seed crystal chuck for the production of single crystal silicon by the Czochralski method, such as Figure 2 、 Figure 3and Figure 5 As shown, it comprises a sheath 4, an inner sheath 5 arranged inside the sheath 4 and a fixing rod 1 detachably connected with the sheath 4, and the sheath 4 and the inner sheath 5 are both made of graphite material. The sheath 4 is internally provided with a limiting space 17 which is gradually reduced from top to bottom, the limiting space 17 can limit the position of the inner sheath 5 to avoid the inner sheath 5 from escaping from the sheath 4, and there is a certain distance between the top of the inner sheath 5 and the top of the sheath 4 to connect the fixing rod 1 with the sheath 4. In order to ensure the purity of the material, the fixing rod 1 is made of high-purity molybdenum material, and the molybdenum fixing rod 1 also plays a role of counterweight to ensure the perpendicularity of the soft shaft; if a hard shaft is used as the fixing rod 1, the upper end of the sheath 4 is provided with a chamfer, which can achieve the purpose of convenient assembly on the one hand; and the design of the chamfer can form a release space with the fixing rod 1, which can provide a release space for the volatilization of impurities inside different materials when it is in the upper part of the melt.
[0025] The fixing rod 1 is integrally connected with an extending part 3 extending into the sheath 4, and the extending part 3 is detachably connected with the sheath 4. In order to smoothly discharge the heated and expanded gas in the seed crystal 7 chuck and release stress, a main gas channel 8 is arranged on the extending part 3, one end of the main gas channel 8 penetrates through the side wall of the extending part 3 to form an air inlet towards the inner sheath 5, and the other end of the main gas channel 8 is in communication with the outside to form an air outlet. In the process of pulling the crystal, argon gas will be introduced, and the argon gas can carry away the generated volatile matter and cool the crystal bar, and the principle of introducing argon gas is the existing technology in the field, which will not be described in detail here. The gas can be discharged to the outside from the air outlet along the main gas channel 8 from the air inlet. Since the temperature inside the seed crystal 7 chuck is high and the temperature outside is low, and the argon atmosphere is maintained in a negative pressure state during the pulling process, the outside gas can be prevented from entering the seed crystal 7 chuck, so that the production of single crystal rods can be carried out smoothly. In order to facilitate the processing of the main gas channel 8 on the extending part 3, an angle is left between the extension direction of the main gas channel 8 and the axis of the fixing rod 1, and the appropriate main gas channel 8 can be processed directly at one time. The angle is set to 30°-45°.
[0026] The inner sleeve 5 comprises two half-pipes which are detachably connected. The two half-pipes are spliced to form a space for the seed crystal 7 to pass through, and a groove 6 and a protrusion 12 are respectively arranged on the mutually matched surfaces of the two half-pipes, wherein the protrusion 12 on one half-pipe can be inserted into the protrusion 12 of the other half-pipe, so that the two half-pipes form an integral whole, i.e., the inner sleeve 5 of the present application. The seed crystal 7 is installed along the upper part of the space. The groove 6 and the protrusion 12 of the two half-pipes are matched with a gap 9, which can release stress due to thermal expansion. The inner sleeve 5 is internally provided with a first channel 18, a second channel 19 and a third channel 13 from top to bottom, the second channel 19 gradually narrows from top to bottom, the second channel 19 is conical, the large end of the second channel 19 is in communication with the first channel 18, and the small end of the second channel 19 is in communication with the third channel 13, the first channel 18 is used for accommodating the head of the seed crystal 7, and the third channel 13 is used for the stem of the seed crystal 7 to pass through, so that the seed crystal 7 can pass through for crystal pulling, necking, shoulder turning and rod drawing after being fused with the silicon melt. The second channel 19 connects the first channel 18 and the third channel 13, and the second channel 19 can ensure that the head of the seed crystal 7 is located in the first channel 18, provides limiting for the assembly of the seed crystal 7, and further ensures the stability of the seed crystal 7 after installation and the sliding after bearing. The shapes of the first channel 18, the second channel 19 and the third channel 13 in the inner sleeve 5 can be adjusted and changed according to different shapes of the seed crystal 7. The outer surface of the inner sleeve 5 is matched with the inner surface of the outer sleeve 4, so as to ensure the stable installation of the inner sleeve 5 and prevent sliding due to excessive bearing.
[0027] The above is the basic embodiment of the present application, which can be further improved, optimized and limited on the basis of the above, so as to obtain the following embodiments:
[0028] Embodiment 2
[0029] This embodiment is an improved scheme based on embodiment 1, and the main structure is the same as that of embodiment 1, and the improvement point is that: Figure 1 and Figure 3As shown, the extending part 3 is threadedly connected with the inner wall of the sleeve 4, the circumferential wall of the extending part 3 is provided with a gap 9, and the gap 9 is communicated with the outside through the notch 11. The gas can enter the main gas channel 8 from the gas inlet, pass through the gas outlet of the main gas channel 8 to the notch 11, and then enter the gap 9 through the notch 11, and finally enter the outside. The extending part 3 is threadedly connected with the inner wall of the sleeve 4, so that the stress is mainly borne by the threaded part, i.e. the external thread on the extending part 3 and the internal thread of the sleeve 4, and the cooperation between the threads is more demanding. Therefore, the fixed rod 1 is connected with the extending part 3 through the transition part 2, the transition part 2 is tapered, the large end of the transition part 2 is connected with the fixed rod 1, and the small end of the transition part 2 is connected with the extending part 3. The transition part 2 forms a gas guiding channel 10 between the transition part 2 and the inner wall of the sleeve 4, and the gas guiding channel 10 is communicated with the gap 9 and the notch 11. When the external thread is machined on the extending part 3, the transition part 2 is first connected, the transition part 2 is integrally connected with the extending part 3, and the transition part 2 can ensure the center assembly of the seed crystal 7 chuck and the fixed rod 1.
[0030] Example 3
[0031] This embodiment is an improved scheme based on example 1, and the main structure is the same as that of example 1. The improvement lies in that, as shown in Figure 4 and Figure 5 As shown, the extending part 3 is fixedly connected with the sleeve 4 through a pin, the fixed rod 1 is provided with a pin hole 16 matched with the pin in the radial direction, the sleeve 4 is provided with two opposite mounting holes 15, the mounting hole 15 is communicated with the pin hole 16, the diameter of the mounting hole 15 is larger than that of the pin hole 16, the mounting hole 15 is communicated with the outside, and one of the mounting holes 15 is communicated with the main gas channel 8. This connection mode can also ensure that the extending part 3 is connected with the sleeve 4 without affecting the discharge of the gas in the head of the seed crystal 7. The gas enters the main gas channel 8 through the gas inlet, is discharged to one of the mounting holes 15 through the gas outlet of the main gas channel 8, and finally enters the outside. At least one counterbore 14 is formed on the outer wall of the sleeve 4 and communicated with the mounting hole 15.
[0032] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A seed crystal holder for use in the production of single crystal silicon by the Czochralski method, characterized by: The utility model relates to a fixed rod (1) and a fixed rod (1) are connected with the outer cover (4) can be dismantled, the outer cover (4) inside is provided with the limiting space (17) that gradually narrows from top to bottom, the fixed rod (1) is integrally connected with the extension part (3) that extends into the outer cover (4), the extension part (3) is provided with the main gas channel (8), one end of main gas channel (8) penetrates to the side wall of extension part (3) and forms the air inlet towards the inner cover (5), and the other end of main gas channel (8) is communicated with the outside and forms the air outlet.
2. The seed chuck for producing single crystal silicon by the Czochralski method according to claim 1, characterized by: The extension part (3) is screwed with the inner wall of the outer cover (4), the circumferential wall of the extension part (3) is provided with the notch (11) communicated with the main gas channel (8), and the gap (9) exists between the fixed rod (1) and the outer cover (4).
3. The seed chuck for single crystal silicon production by the Czochralski method according to claim 2, characterized in that: The fixed rod (1) is connected with the extension part (3) through the transition part (2), the transition part (2) is conical, the large end of the transition part (2) is connected with the fixed rod (1), the small end of the transition part (2) is connected with the extension part (3), the transition part (2) and the inner wall of the outer cover (4) form the air channel (10), and the air channel (10) is communicated with the gap (9) and the notch (11).
4. The seed chuck for producing single crystal silicon by the Czochralski method according to claim 1, characterized by: The extension part (3) and the outer cover (4) are fixedly connected through the pin, the fixed rod (1) is provided with the pin hole (16) matched with the pin in the radial direction, the outer cover (4) is provided with two opposite mounting holes (15), the mounting hole (15) is communicated with the pin hole (16), the diameter of the mounting hole (15) is larger than the diameter of the pin hole (16), the mounting hole (15) is communicated with the outside, and one of the mounting holes (15) is communicated with the main gas channel (8).
5. The seed chuck for producing single crystal silicon by the Czochralski method according to claim 1, characterized by: The inner cover (5) comprises two half pipes, and the two half pipes are detachably connected.
6. The seed chuck for single crystal silicon production by the Czochralski method according to claim 1, characterized in that: The inner cover (5) is sequentially provided with a first channel (18), a second channel (19) and a third channel (20) from top to bottom, the second channel (19) gradually narrows from top to bottom, the large end of the second channel (19) is communicated with the first channel (18), the small end of the second channel (19) is communicated with the third channel (20), the first channel (18) is used for accommodating the head of the seed crystal (7), and the third channel (20) is used for passing the stem of the seed crystal (7).
7. The seed chuck for single crystal silicon production by the Czochralski method according to claim 1, characterized in that: The extension direction of the main gas channel (8) and the axis of the fixed rod (1) leave an included angle.
8. The seed chuck for single crystal silicon production by the Czochralski method according to claim 7, characterized in that: The included angle is 30-45 degrees.
9. The seed chuck for single crystal silicon production by the Czochralski method according to claim 1, characterized in that: The upper end of the outer cover (4) is provided with a chamfer.