A polycrystalline synthesis apparatus

Abstract

This utility model relates to the field of polycrystalline material synthesis technology and discloses a polycrystalline synthesis apparatus, comprising: a pressure vessel having a receiving cavity; an ampoule disposed in the receiving cavity, the ampoule including a first heating section, a connecting section, and a second heating section connected in sequence, the diameter of the connecting section being smaller than the diameters of the first heating section and the second heating section; a loading boat with a nozzle at its head, the loading boat being disposed within the first heating section, one end of the nozzle extending downwards into the connecting section; a first heater located in the receiving cavity and surrounding the outer periphery of the first heating section; and a second heater located in the receiving cavity and surrounding the outer periphery of the second heating section; wherein the heating temperature of the first heater is higher than the heating temperature of the second heater. This utility model's polycrystalline synthesis apparatus improves product quality, reduces material loss, lowers production costs, and makes the polycrystalline synthesis process safer.

Description

Technical Field

[0001] This utility model relates to the field of polycrystalline material synthesis technology, and in particular to a polycrystalline synthesis apparatus. Background Technology

[0002] Currently, in the synthesis of polycrystalline indium phosphide and gallium arsenide, during the cooling stage, the crystal is prone to rapid, large-area supercooling due to the inability to form seed crystals or cold spots. This rapid cooling of the entire crystal rod results in chaotic crystal growth directions, hindering directional solidification for effective impurity removal. Consequently, the quality of the polycrystalline material is inconsistent, or the entire crystal rod surface is porous. This renders the polycrystalline material unusable as a raw material for single crystal preparation, significantly impacting single crystal growth. More seriously, the rapid cooling process releases a large amount of heat, causing a sudden pressure rise inside the ampoule. This pressure imbalance often leads to ampoule cracking, resulting in material waste, increased production costs, and environmental pollution from the cracked waste. Utility Model Content

[0003] The purpose of this invention is to provide a polycrystalline synthesis apparatus that improves product quality, reduces material loss, lowers production costs, and ensures the safety of the polycrystalline synthesis process.

[0004] To achieve the above objectives, this utility model provides a polycrystalline synthesis apparatus, comprising:

[0005] Pressure vessel, having a containing cavity;

[0006] An ampoule is disposed in the receiving cavity. The ampoule includes a first heating part, a connecting part, and a second heating part connected in sequence. The diameter of the connecting part is smaller than the diameters of the first heating part and the second heating part.

[0007] A loading boat with a feeding nozzle at its head is located inside the first heating section, and one end of the feeding nozzle extends downwards into the connecting section.

[0008] A first heater is located in the receiving cavity and surrounds the outer periphery of the first heating part; and

[0009] The second heater is located in the receiving cavity and surrounds the outer periphery of the second heating part;

[0010] The heating temperature of the first heater is higher than that of the second heater.

[0011] In some embodiments, the angle between the nozzle and the horizontal direction is 20-70°.

[0012] In some embodiments, the inner diameter of the nozzle is 4-10 mm.

[0013] In some embodiments, the nozzle has a first end and a second end, the first end of the nozzle being located at the middle of the head of the loading boat, and the second end of the nozzle being located within the connecting portion.

[0014] In some embodiments, the upper inner wall of the connecting portion is flush with the first end of the nozzle, and the second end of the nozzle is flush with the bottom of the loading boat.

[0015] In some embodiments, the first end of the nozzle is connected to the loading boat, and the second end of the nozzle is sealed.

[0016] In some embodiments, an insulation layer is included, which surrounds and covers the outer periphery of the connecting portion.

[0017] In some embodiments, the loading boat is made of quartz or PBN.

[0018] In some embodiments, the heating temperature of the first heater is 1000-1200°C, and the heating temperature of the second heater is 500-700°C.

[0019] In some embodiments, the diameters of the first heating part and the second heating part are equal, both being 'a', and the diameter of the connecting part is 'b', then 0.3b≤a≤0.5b is satisfied.

[0020] This invention provides a polycrystalline synthesis apparatus, which, compared with the prior art, has the following advantages:

[0021] An ampoule is disposed within the receiving cavity. The ampoule includes a first heating section, a connecting section, and a second heating section connected in sequence. The diameter of the connecting section is smaller than the diameters of the first and second heating sections. The head of the loading boat has a nozzle. The loading boat is disposed within the first heating section. One end of the nozzle extends downwards into the connecting section. The heating temperature of the first heating section by the first heater is higher than the heating temperature of the second heating section by the second heater. Thus, during the polycrystalline synthesis condensation process, indium phosphide / gallium arsenide crystals begin to condense from one end of the nozzle, acting as a seed crystal or cold spot. The connecting section is unaffected by the first and second heaters, allowing a temperature gradient to be formed between the nozzle and the loading boat. This ensures that the crystal nucleates at one end of the nozzle, preventing instantaneous large-area supercooling that could cause the ampoule to break. Therefore, this improves product quality, reduces material loss, lowers production costs, and makes the polycrystalline synthesis process safer. Attached Figure Description

[0022] Figure 1 This is a frontal axial side structural diagram of the polycrystalline synthesis apparatus provided in an embodiment of the present invention.

[0023] In the diagram: 1. Pressure vessel; 11. Receiving cavity; 2. Ampoule; 21. First heating section; 22. Connecting section; 23. Second heating section; 3. Loading boat; 31. Feeding nozzle; 4. First heater; 5. Second heater; 6. Insulation layer. Detailed Implementation

[0024] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0025] It should be understood that in the description of this application, the terms "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. That is, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Furthermore, unless otherwise stated, "a plurality of" means two or more.

[0026] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0027] like Figure 1 As shown, the polycrystalline synthesis apparatus of this embodiment includes: a pressure vessel 1, an ampoule 2, a loading boat 3, a first heater 4, and a second heater 5. The pressure vessel 1 is configured to regulate the internal air pressure. The loading boat 3 is used to synthesize polycrystalline materials. The first heater 4 and the second heater 5 are used to heat the ampoule 2.

[0028] Pressure vessel 1 has a receiving cavity 11. Specifically, when synthesizing polycrystalline material using the horizontal Bridgman process, to prevent the ampoule 2 from bursting due to excessive internal pressure, inert gas is introduced into the receiving cavity 11 of pressure vessel 1 outside the ampoule 2 through the vent, ensuring that the external pressure of the ampoule 2 is greater than its internal pressure. After the synthesis reaction is completed, staged cooling is performed according to the principle of directional solidification. Throughout the cooling process, the inert gas in the receiving cavity 11 of pressure vessel 1 needs to be continuously discharged through the vent to reduce the external pressure of the ampoule 2.

[0029] Ampoule 2 is disposed in receiving cavity 11. Ampoule 2 includes a first heating part 21, a connecting part 22 and a second heating part 23 connected in sequence. The diameter of the connecting part 22 is smaller than the diameter of the first heating part 21 and the second heating part 23.

[0030] The loading boat 3 has a nozzle 31 at its head. The loading boat 3 is located inside the first heating section 21, and one end of the nozzle 31 extends downwards into the connecting section 22. The first heater 4 is located in the receiving cavity 11 and surrounds the outer periphery of the first heating section 21. The second heater 5 is located in the receiving cavity 11 and surrounds the outer periphery of the second heating section 23. Thus, the interior of the connecting section 22 where the nozzle 31 is located is not directly heated by the first heater 4 and the second heater 5.

[0031] In this embodiment, the heating temperature of the first heater 4 is higher than that of the second heater 5.

[0032] Based on the above structural configuration, during the crystal synthesis and condensation process, the indium phosphide / gallium arsenide crystal begins to condense from one end of the nozzle 31, acting as a seed crystal or a cold spot. The connecting part 22 is not affected by the first heater 4 and the second heater 5, allowing the nozzle 31 and the charging boat 3 to form a temperature gradient, ensuring that the crystal nucleates at one end of the nozzle 31, preventing instantaneous large-area supercooling and causing the ampoule 2 to break. Therefore, the quality of the product is improved, material loss is reduced, production costs are lowered, and the polycrystalline synthesis process is made safe.

[0033] In some embodiments, the angle between the nozzle 31 and the horizontal direction is 20-70°. If the angle between the nozzle 31 and the horizontal direction exceeds 70°, the nozzle 31 will be too short, and one end of the nozzle 31 will be too close to the loading boat 3, failing to function as a seed crystal or cold point. If the angle between the nozzle 31 and the horizontal direction is less than 70°, the liquid indium phosphide / gallium arsenide inside the nozzle 31 will easily become clogged in the middle of the nozzle 31 due to liquid surface tension, failing to fill the entire nozzle 31, and the nozzle 31's function as a seed crystal or cold point will be greatly reduced.

[0034] In some embodiments, the inner diameter of the nozzle 31 is 4-10 mm. If the inner diameter of the nozzle 31 is greater than 10 mm, crystal nucleation is not easy. If the inner diameter of the nozzle 31 is less than 4 mm, the middle of the nozzle 31 is easily blocked, making it impossible to start nucleation from the first end of the nozzle 31, thus reducing the effectiveness of the nozzle 31 as a seed crystal or cold point.

[0035] In some embodiments, the nozzle 31 has a first end and a second end. The first end of the nozzle 31 is located at the middle of the head of the loading boat 3, and the second end of the nozzle 31 is located inside the connecting portion 22. In some embodiments, the upper inner wall of the connecting portion 22 is flush with the first end of the nozzle 31, and the second end of the nozzle 31 is flush with the bottom of the loading boat 3. This allows the nozzle 31 to better function as a seed crystal or a cold point. The loading boat 3 has a head and a tail, and the crystal growth direction is from the head to the tail.

[0036] In some embodiments, the first end of the nozzle 31 is connected to the loading boat 3, and the second end of the nozzle 31 is sealed. This facilitates the flow of material within the nozzle 31 and prevents material leakage from the nozzle 31.

[0037] In some embodiments, an insulation layer 6 is included, which surrounds and covers the outer periphery of the connecting portion 22. Thus, the insulation layer 6 can insulate the connecting portion 22, further reducing the temperature impact of the first heater 4 and the second heater 5 on the connecting portion 22.

[0038] In some embodiments, the loading boat 3 is made of quartz or PBN (pyrolytic boron nitride). Both quartz and PBN materials are resistant to high temperatures.

[0039] In some embodiments, the heating temperature of the first heater 4 is 1000-1200°C, and the heating temperature of the second heater 5 is 500-700°C. This ensures that the heating temperature of the first heater 4 is higher than that of the second heater 5.

[0040] In some embodiments, the diameters of the first heating part 21 and the second heating part 23 are equal, both being 'a', and the diameter of the connecting part 22 is 'b', satisfying 0.3a ≤ b ≤ 0.5a. If b is less than 0.3a, the diameter of the connecting part 22 is too small, which is not conducive to the installation of the nozzle 31; if b is greater than 0.5a, the diameter of the connecting part 22 is too large, making it easily affected by the heating of the first heater 4 and the second heater 5.

[0041] An exemplary method for processing a polycrystalline synthesis apparatus according to an embodiment of the present invention is provided, the specific process of which is as follows:

[0042] Calculate the required amount of material for production, and fill the second heating section 23 of the ampoule 2 with phosphorus or arsenic, and fill the indium or gallium in the loading boat 3.

[0043] Adjust the position of the filling boat 3 so that the nozzle 31 of the filling boat 3 is fully inserted into the connecting part 22 of the ampoule 2.

[0044] Vacuum the ampoule 2 filled with the contents and seal its opening.

[0045] An insulating cotton layer 6 is wrapped around the outside of the connecting part 22 of the ampoule 2 so that the temperature of the connecting part 22 is not affected by the first heater 4 and the second heater 5.

[0046] Place the ampoule 2 inside the pressure vessel 1. Place the second heating section 23 containing phosphorus, arsenic, or phosphorus materials inside the first heater 4, and place the charging boat 3 containing indium or gallium materials inside the second heater 5.

[0047] Connect pressure vessel 1 to water, electricity, and gas.

[0048] Polycrystalline materials are synthesized using the horizontal Bridgman process. To prevent ampoule 2 from bursting due to excessive internal pressure, the pressure P at the corresponding temperature T is calculated based on the relationship between temperature and pressure in the Antoine equation for phosphorus or arsenic: lgP = AB(T+C). Then, inert gas at a pressure of P+1 atm is introduced into pressure vessel 1 outside ampoule 2 through the vent of pressure vessel 1, ensuring that the external pressure of ampoule 2 is greater than the internal pressure.

[0049] After the synthesis reaction is completed, the temperature is reduced in stages according to the principle of directional solidification. During the entire cooling process, the inert gas in the pressure vessel 1 needs to be continuously discharged through the vent to reduce the external pressure of the ampoule 2. The real-time pressure outside the ampoule 2 is still calculated by the Antoine equation.

[0050] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A polycrystalline synthesis apparatus, characterized in that, include: Pressure vessel, having a containing cavity; An ampoule is disposed in the receiving cavity. The ampoule includes a first heating part, a connecting part, and a second heating part connected in sequence. The diameter of the connecting part is smaller than the diameters of the first heating part and the second heating part. A loading boat with a feeding nozzle at its head is located inside the first heating section, and one end of the feeding nozzle extends downwards into the connecting section. A first heater is located in the receiving cavity and surrounds the outer periphery of the first heating part; and The second heater is located in the receiving cavity and surrounds the outer periphery of the second heating part; The heating temperature of the first heater is higher than that of the second heater.

2. The apparatus of claim 1, wherein The angle between the nozzle and the horizontal direction is 20-70°.

3. The apparatus of claim 1, wherein The inner diameter of the nozzle is 4-10 mm.

4. The apparatus of claim 1, wherein The nozzle has a first end and a second end. The first end of the nozzle is located in the middle of the head of the loading boat, and the second end of the nozzle is located inside the connecting portion.

5. The polycrystalline synthesis apparatus according to claim 4, characterized in that, The upper inner wall of the connecting part is flush with the first end of the nozzle, and the second end of the nozzle is flush with the bottom of the loading boat.

6. The polycrystalline synthesis apparatus according to claim 4, characterized in that, The first end of the nozzle is connected to the loading boat, and the second end of the nozzle is sealed.

7. The polycrystalline synthesis apparatus according to claim 1, characterized in that, It includes an insulation layer that surrounds and covers the outer periphery of the connecting portion.

8. The polycrystalline synthesis apparatus according to claim 1, characterized in that, The loading boat is made of quartz or PBN.

9. The polycrystalline synthesis apparatus according to claim 1, characterized in that, The heating temperature of the first heater is 1000-1200℃, and the heating temperature of the second heater is 500-700℃.

10. The polycrystalline synthesis apparatus according to claim 1, characterized in that, The diameters of the first heating part and the second heating part are equal, both being 'a', and the diameter of the connecting part is 'b', thus satisfying 0.3b≤a≤0.5b.

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