Double-channel partitioned water cooling screen and single crystal growth device

Abstract

The invention provides a double-channel partitioned water cooling screen and a single crystal growth device, and belongs to the field of single crystal growth equipment. The water cooling screen comprises an upper bottom plate, a lower bottom plate, an inner conical barrel, an outer conical barrel, a water inlet, a first water inlet pipe, a second water inlet pipe, a water outlet, a first water outlet, a second water outlet, a first group of annular flow channels and a second group of annular flow channels; wherein the water inlet and the water outlet are formed in the edge of the upper bottom plate; the upper bottom plate, the lower bottom plate, the inner conical barrel and the outer conical barrel form a single crystal cooling drawing space; a first group of annular runners is arranged at the lower part in the cooling and drawing space, and a second group of annular runners is arranged at the upper part in the cooling and drawing space; the lowest part of the lowest runner of the first group of annular runners is communicated with the first water inlet pipe, and the highest part of the uppermost runner is communicated with the first water outlet pipe; the lowest part of the lowest runner of the second group of annular runners is communicated with the second water inlet pipe, and the highest part of the uppermost runner is communicated with the second water outlet pipe. According to the invention, the production energy consumption is reduced, the temperature controllability is improved, and the production yield and the production efficiency are improved.

Description

Technical Field

[0001] The invention belongs to the field of single crystal production equipment, and in particular relates to a double-channel partitioned water cooling screen and a single crystal growth device. Background Art

[0002] The Czochralski method is to prepare single crystals by placing polycrystalline raw materials into a crucible, heating and melting them, and then immersing the seed crystals into the molten raw materials. By controlling the temperature and pulling speed, the crystals gradually grow into rod-shaped single crystals. The most common equipment is a single crystal growth furnace. The single crystal growth furnace includes a host, a heating power supply, and a control system, etc. The host part includes a vertical frame, a water-cooled furnace body, a crystal lifting and rotating mechanism, etc. The water-cooled furnace body includes a furnace body and a water-cooled screen. The water-cooled screen is used to cool down single crystal rods with a certain diameter, thereby increasing the pulling speed and thus improving production efficiency.

[0003] In the prior art, the water cooling screen of a single crystal furnace generally includes a water inlet pipe, a water outlet pipe, an upper bottom plate, a lower bottom plate, an inner cone barrel, an outer cone barrel and an annular flow channel; the upper bottom plate, the lower bottom plate, the inner cone barrel and the outer cone barrel form a rotary closed space, in which a connected annular flow channel is distributed from bottom to top, and the water inlet extends from the upper bottom plate to the lower bottom plate, and the cooling water flows from bottom to top to cool the single crystal rod inside the rotary body. However, the temperature of the single crystal rod itself is not uniform, and the temperature field has the most significant effect on the quality of the single crystal rod on the contact surface between the single crystal rod and the mother liquid; at the same time, cooling the single crystal rod by cooling water is extremely energy-consuming, and a predetermined pressure is required to ensure that the water flows from bottom to top along the annular flow channel, and the cooling water flow rate needs to be controlled by comprehensively considering the cooling conditions of the upper and lower parts of the single crystal rod. Although the water cooling screen improves production efficiency, it also increases energy consumption and cost, and puts forward higher requirements for quality control. Summary of the invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, the present invention aims to provide a dual-channel partitioned water-cooling screen and a single crystal growth device, which increases the rate of pulling single crystal silicon rods by partitioning the annular flow channel in the water-cooling screen and cooling different areas with cooling water, while improving the temperature controllability and the production yield.

[0005] In order to achieve the above purpose, the embodiment of the present invention adopts the following technical solution:

[0006] In the first aspect, an embodiment of the present invention provides a dual-channel partitioned water-cooling shield, the water-cooling shield comprising an upper base plate 21, a lower base plate 22, an inner cone barrel 23, an outer cone barrel 24, a water inlet 25, a first water inlet pipe 251, a second water inlet pipe 252, a water outlet 26, a first water outlet pipe 261, a second water outlet pipe 262, a first group of annular flow channels 27 and a second group of annular flow channels 28; wherein,

[0007] The water inlet 25 and the water outlet 26 are arranged at the edge of the upper bottom plate 21; the water inlet 25 is connected to the first water inlet pipe 251 and the second water inlet pipe 252; the water outlet 26 is connected to the first water outlet pipe 261 and the second water outlet pipe 262;

[0008] The upper base plate 21, the lower base plate 22, the inner cone barrel 23 and the outer cone barrel 24 form a cooling and pulling space for the single crystal; a first group of annular flow channels 27 are arranged in the lower area below h in the cooling and pulling space, and a second group of annular flow channels 28 are arranged in the upper area above h; the bottom layer of the first group of annular flow channels 27 is connected to the first water inlet pipe 251, and the top layer of the flow channels is connected to the first water outlet pipe 261; the bottom layer of the second group of annular flow channels 28 is connected to the second water inlet pipe 252, and the top layer of the flow channels is connected to the second water outlet pipe 262; h is the cooling dividing point of the single crystal rod.

[0009] As a preferred embodiment of the present invention, the inner wall of the inner cone barrel 23 whose portion is lower than h is used as the first inner wall 71, the portion higher than h is used as the second inner wall 72, and the outer wall of the outer cone barrel 24 and the lower bottom plate 22 are used as the outer wall 73;

[0010] The outer side surface of the first inner wall 71 facing the single crystal rod is a first inner wall outer surface 711 , and the inner side surface facing the inner part of the water-cooling shield 20 cavity is a first inner wall inner surface 712 .

[0011] As a preferred embodiment of the present invention, the outer wall 73 is a hollow structure, including an outer wall inner layer 731 , an outer wall air barrier layer 732 and an outer wall outer layer 733 .

[0012] As a preferred embodiment of the present invention, the first inner wall 71 is a thin-walled structure, and its thickness is 50-80% of the first inner wall 72 .

[0013] As a preferred embodiment of the present invention, the first inner wall 71 is a thickness gradient structure, which gradually becomes thinner from top to bottom, and the thickness at the bottom is 50-80% of the thickness at the top.

[0014] As a preferred embodiment of the present invention, a polishing layer / reflective layer 734 is attached to the outer layer 733 of the outer wall 73 .

[0015] As a preferred embodiment of the present invention, the exposed side of the outer layer 733 is polished.

[0016] As a preferred embodiment of the present invention, the water inlet 25 and the water outlet 26 are respectively set to two, the first water inlet and the first water outlet correspond to the first water inlet pipe 251 and the first water outlet pipe 261 respectively; the second water inlet and the second water outlet correspond to the second water inlet pipe 252 and the second water outlet pipe 262 respectively, forming two independent cooling water circulation systems.

[0017] As a preferred embodiment of the present invention, the first inner wall 71 and the second inner wall 72 are made of heat-conducting material, and the outer wall 73 is made of high thermal resistance or heat-insulating material.

[0018] In a second aspect, an embodiment of the present invention further provides a single crystal growth device, which includes the double-channel partitioned water cooling shield 20 as described above.

[0019] The technical solution provided by the embodiment of the present invention has the following beneficial effects:

[0020] The embodiments of the present invention provide a dual-channel partitioned water-cooling screen and a single crystal growth device, wherein the water-cooling screen comprises an upper base plate, a lower base plate, an inner cone barrel, an outer cone barrel, a water inlet, a first and a second water inlet pipe, a water outlet, a first and a second water outlet, and a first group and a second group of annular channels; wherein the water inlet and the water outlet are arranged at the edge of the upper base plate; the upper base plate, the lower base plate, the inner cone barrel and the outer cone barrel form a cooling and pulling space for the single crystal; a first group of annular channels is arranged at the lower part of the cooling and pulling space, and a second group of annular channels is arranged at the upper part; the lowest point of the lowermost channel of the first group of annular channels is connected to the first water inlet pipe, and the highest point of the uppermost channel is connected to the first water outlet pipe; the lowest point of the lowermost channel of the second group of annular channels is connected to the second water inlet pipe, and the highest point of the uppermost channel is connected to the second water outlet pipe. Aiming at the characteristic that the surface temperature distribution of the single crystal rod shows a two-stage change during the single crystal pulling process, the present invention proposes a double-channel partitioned water-cooling screen, which can effectively improve the pulling speed and production efficiency of the single crystal rod, increase the output of a single furnace, and reduce equipment investment and operating costs under the same production capacity conditions; at the same time, it improves the temperature controllability of the entire furnace, can optimize the single crystal growth environment, and thereby improves the production yield and product quality.

[0021] Of course, it is not necessary to achieve all of the advantages described above at the same time to implement any product or method of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 is a schematic structural diagram of a single crystal growth device according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the analysis of the dual flow channel partition principle of an embodiment of the present invention;

[0025] Figure 3 It is a schematic diagram of the structure of the dual-channel partitioned water-cooling screen according to an embodiment of the present invention.

[0026] Description of reference numerals:

[0027] 10-single crystal furnace body; 20-water cooling screen; 21-upper bottom plate; 22-lower bottom plate; 23-inner cone barrel; 24-outer cone barrel; 25-water inlet; 251-first water inlet pipe; 252-second water inlet pipe; 26-water outlet; 261-first water outlet pipe; 262-second water outlet pipe; 27-first group of annular flow channels; 28-second group of annular flow channels; 30-heat screen; 40-single crystal rod; 50-silicon melt; 60-crucible; 71-first inner wall; 711-outer surface of the first inner wall; 712-inner surface of the first inner wall; 72-second inner wall; 73-outer wall; 731-inner layer of the outer wall; 732-air barrier of the outer wall; 733-outer layer of the outer wall; 734-polishing layer / reflective layer of the outer wall. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations. It should be noted that the embodiments of the present invention and the features in the embodiments can also be combined with each other without conflict.

[0029] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In the description of the present invention, the terms "first", "second", "third", "fourth", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0030] In the equipment for producing single crystal rods by the Czochralski method, the heat transfer intensity from the solid-liquid surface to the upper layer of the single crystal rod is different, and the corresponding amount of heat is also different. Among them, it is necessary to focus on strengthening the heat exchange at the solid-liquid surface. However, most of the current water-cooling screens do not partition the water-cooling screen area according to different heat transfer intensity areas, which will lead to low solid-liquid surface heat exchange intensity, thereby slowing down the single crystal growth rate. Based on this, the present invention provides a dual-channel partitioned water-cooling screen and a single crystal growth device, in which dual channels are partitioned in the water-cooling screen to increase the solid-liquid surface heat exchange intensity, increase the surface temperature gradient of the silicon rod, and thus increase the growth rate of the silicon rod.

[0031] like Figure 1-3As shown, the double-channel partitioned water-cooling shield provided in the embodiment of the present invention is applied to a single crystal growth device. The single crystal growth device comprises: a single crystal furnace body 10, a water-cooling shield 20, a heat shield 30 and a crucible 60, wherein the crucible 60 contains a melt 50, and inside the single crystal furnace body 10, from outside to inside, there are the heat shield 30, the water-cooling shield 20 and the single crystal rod 40.

[0032] The water cooling shield 20 includes an upper base plate 21, a lower base plate 22, an inner cone barrel 23, an outer cone barrel 24, a water inlet 25, a first water inlet pipe 251, a second water inlet pipe 252, a water outlet 26, a first water outlet pipe 261, a second water outlet pipe 252, a first group of annular flow channels 27 and a second group of annular flow channels 28; wherein, the water inlet 25 and the water outlet 26 are arranged on the edge of the upper base plate 21; the water inlet 25 is connected to the first water inlet pipe 251 and the second water inlet pipe 252; the water outlet 26 is connected to the first water outlet pipe 261 and the second water outlet pipe 262; the upper base plate 21, the lower base plate 22, the inner cone barrel 23 and the outer cone barrel 24 form a cooling and pulling space for a single crystal.

[0033] The pulling space of the single crystal rod 40 is much larger than the height of the water cooling screen. Figure 2 As shown, during the pulling process of the single crystal rod, as the distance from the melt 50 increases, the temperature becomes lower and lower, and active cooling is no longer required at a high point. Therefore, the water-cooling screen 20 is only provided in the area where the single crystal rod 40 needs to be cooled. In the cooling area, due to the different distances from the melt 50 and the growth of the single crystal rod 40, the cooling rates in different areas of the single crystal rod are different. In order to achieve continuous and rapid cooling without affecting the pulling quality of the single crystal rod, the embodiment of the present invention divides the annular flow channel in the water-cooling screen 20 into two areas through the cooling analysis of the single crystal rod, the area below h is the first group of annular flow channels, and the area above h is the second group of annular flow channels. Circulating coolant is introduced into the two areas respectively to achieve different cooling processes. The bottom channel of the first group of annular channels 27 is connected to the first water inlet pipe 251 , and the top channel is connected to the first water outlet pipe 261 ; the bottom channel of the second group of annular channels 28 is connected to the second water inlet pipe 252 , and the top channel is connected to the second water outlet pipe 262 .

[0034] like Figure 3 As shown, the inner wall of the inner cone barrel 23 whose portion is lower than h is used as the first inner wall 71, the portion higher than h is used as the second inner wall 72, and the outer wall of the outer cone barrel 24 and the lower bottom plate 22 are used as the outer wall 73. The outer side of the first inner wall 71 facing the single crystal rod is the first inner wall outer surface 711, and the inner side facing the cavity of the water cooling shield 20 is used as the first inner wall inner surface 712; the outer wall 73 is a hollow structure, including an outer wall inner layer 731, an outer wall air barrier 732 and an outer wall outer layer 733. The first inner wall 71 and the second inner wall 72 are generally made of heat conductive materials, and the outer wall 73 is generally made of high thermal resistance or insulation materials.

[0035] In a preferred embodiment, the first inner wall 71 is a thin-walled structure, and its thickness is 50-80% of the first inner wall 72. In another preferred embodiment, the first inner wall 71 is a thickness gradient structure, which gradually becomes thinner from top to bottom, and the thickness at the bottom is 30-50% of the thickness at the top.

[0036] In a preferred embodiment, a polishing layer / reflective layer 734 is attached to the outer layer 733 of the outer wall 73, or the exposed side of the outer layer 733 is polished.

[0037] In a specific embodiment, when the cooling water is circulated, in order to ensure the independence of the water temperature in the first group of annular flow channels 27 and the second group of annular flow channels 28, the water inlet 25 and the water outlet 26 can also be set to two respectively, such as, the first water inlet and the first water outlet correspond to the first water inlet pipe 251 and the first water outlet pipe 261 respectively; the second water inlet and the second water outlet correspond to the second water inlet pipe 252 and the second water outlet pipe 262 respectively, forming two independent cooling water circulation systems.

[0038] An embodiment of the present invention further provides a single crystal growth device, wherein the growth device includes the dual-channel partitioned water cooling screen.

[0039] When a single crystal is prepared by using a single crystal growth device including the dual-channel partitioned water-cooling screen, the crystal rod is arranged inside the single crystal furnace body 10, and cooling water is introduced into the first water inlet pipe 251 of the water-cooling screen 20, and the lower part of the single crystal rod 40 below the height h is cooled through the first group of annular flow channels 27, and then returned through the first water outlet pipe 261; at the same time, cooling water is introduced into the second water inlet pipe 252, and the upper part of the single crystal rod 40 above the height h is cooled through the second group of annular flow channels 28, and then returned through the second water outlet pipe 262; the cooling process of the lower and upper parts of the cooling area of ​​the single crystal rod 40 is completed respectively, thereby optimizing the thermal field, and the used single crystal rod can be cooled faster, thereby improving the pulling speed and production efficiency.

[0040] The bottom plate 22 of the water-cooled shield is adjacent to the bottom of the heat shield 30 corresponding to the melt 50 part, and is a heat-insulating layer, which will have a heat-insulating effect on the melt part. The surface of the melt 50 emits heat radiation to the heat shield, and when the heat exchange between the water-cooled shield 20 and the heat shield 30 is effectively reduced, the heat exchange between the melt 50 and the heat shield 30 can be indirectly controlled. Since the water-cooled shield includes the outer wall 73 of the bottom surface and the outer surface, it is set as a hollow structure, and a reflective layer, polishing layer or polishing treatment is added to the exposed side, the heat exchange between the water-cooled shield 20 and the heat shield 30 is further reduced, and the energy required to maintain the molten state of the melt is reduced, thereby saving production costs.

[0041] The above description is only a preferred embodiment of the present invention and an explanation of the technical principles used. It is not intended to limit the scope of the invention claimed for protection, but only represents the preferred embodiment of the present invention. Those skilled in the art should understand that the scope of the invention involved in the present invention is not limited to the technical solution formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the inventive concept. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

Claims

1. A dual-channel partitioned water cooling screen, characterized in that: The water cooling shield comprises an upper base plate (21), a lower base plate (22), an inner cone barrel (23), an outer cone barrel (24), a water inlet (25), a first water inlet pipe (251), a second water inlet pipe (252), a water outlet (26), a first water outlet pipe (261), a second water outlet pipe (262), a first group of annular flow channels (27) and a second group of annular flow channels (28); wherein, The water inlet (25) and the water outlet (26) are arranged at the edge of the upper bottom plate (21); the water inlet (25) is in communication with the first water inlet pipe (251) and the second water inlet pipe (252); the water outlet (26) is in communication with the first water outlet pipe (261) and the second water outlet pipe (262); An upper base plate (21), a lower base plate (22), an inner cone barrel (23) and an outer cone barrel (24) form a cooling and drawing space for a single crystal; a first group of annular flow channels (27) is provided in a lower region below h in the cooling and drawing space, and a second group of annular flow channels (28) is provided in an upper region above h; the lowest layer of the first group of annular flow channels (27) is connected to a first water inlet pipe (251), and the highest layer of the flow channels is connected to a first water outlet pipe (261); the lowest layer of the second group of annular flow channels (28) is connected to a second water inlet pipe (252), and the highest layer of the flow channels is connected to a second water outlet pipe (262); h is a cooling dividing point for the single crystal rod.

2. The dual-channel partitioned water cooling screen according to claim 1 is characterized in that: The portion of the inner wall of the inner cone barrel (23) lower than h serves as a first inner wall (71), the portion higher than h serves as a second inner wall (72), and the outer wall of the outer cone barrel (24) and the lower bottom plate (22) serve as an outer wall (73); The outer side surface of the first inner wall 71 facing the single crystal rod is a first inner wall outer surface (711), and the inner side surface facing the water cooling shield (20) cavity is a first inner wall inner surface (712).

3. The dual-channel partitioned water cooling screen according to claim 2 is characterized in that: The outer wall (73) is a hollow structure, comprising an outer wall inner layer (731), an outer wall air barrier layer (732) and an outer wall outer layer (733).

4. The dual-channel partitioned water cooling screen according to claim 2 is characterized in that: The first inner wall (71) is a thin-walled structure, and its thickness is 50-80% of the second inner wall (72).

5. The dual-channel partitioned water cooling screen according to claim 2 is characterized in that: The first inner wall (71) has a thickness gradient structure, which gradually becomes thinner from top to bottom, and the thickness at the bottom is 50-80% of the thickness at the top.

6. The dual-channel partitioned water cooling screen according to claim 2 is characterized in that: The outer layer (733) of the outer wall (73) is also provided with a polishing layer / reflective layer (734).

7. The dual-channel partitioned water cooling screen according to claim 2 is characterized in that: The exposed side of the outer layer (733) is polished.

8. The dual-channel partitioned water cooling shield according to claim 1 or 2, characterized in that: The water inlet (25) and the water outlet (26) are respectively provided in two numbers, the first water inlet and the first water outlet respectively correspond to the first water inlet pipe (251) and the first water outlet pipe (261); the second water inlet and the second water outlet respectively correspond to the second water inlet pipe (252) and the second water outlet pipe (262), thereby forming two independent cooling water circulation systems.

9. The dual-channel partitioned water cooling screen according to claim 2 is characterized in that: The first inner wall (71) and the second inner wall (72) are made of high thermal conductivity material, and the outer wall (73) is made of high thermal resistance or thermal insulation material.

10. A single crystal growth device, characterized in that: The single crystal growth device comprises a dual-channel partitioned water cooling shield (20) as claimed in any one of claims 1 to 9.

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