WO2024011843A1 - 一种垂直温度梯度凝固制备磷化铟晶体的装置及方法 - Google Patents

一种垂直温度梯度凝固制备磷化铟晶体的装置及方法 Download PDF

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WO2024011843A1
WO2024011843A1 PCT/CN2022/138863 CN2022138863W WO2024011843A1 WO 2024011843 A1 WO2024011843 A1 WO 2024011843A1 CN 2022138863 W CN2022138863 W CN 2022138863W WO 2024011843 A1 WO2024011843 A1 WO 2024011843A1
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crucible
injection
thermocouple
indium phosphide
melt
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PCT/CN2022/138863
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English (en)
French (fr)
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党冀萍
孙聂枫
王书杰
徐森锋
史艳磊
刘峥
邵会民
姜剑
李晓岚
王阳
张晓丹
康永
刘惠生
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中国电子科技集团公司第十三研究所
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    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/10—Inorganic compounds or compositions
    • C30B29/40—AIIIBV compounds wherein A is B, Al, Ga, In or Tl and B is N, P, As, Sb or Bi
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B11/00—Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method
    • C30B11/003—Heating or cooling of the melt or the crystallised material
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B11/00—Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method
    • C30B11/006—Controlling or regulating
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B11/00—Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method
    • C30B11/008—Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method using centrifugal force to the charge
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B11/00—Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method
    • C30B11/04—Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method adding crystallising materials or reactants forming it in situ to the melt
    • C30B11/06—Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method adding crystallising materials or reactants forming it in situ to the melt at least one but not all components of the crystal composition being added
    • C30B11/065—Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method adding crystallising materials or reactants forming it in situ to the melt at least one but not all components of the crystal composition being added before crystallising, e.g. synthesis
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to the preparation of semiconductor materials, and in particular to a device and method for preparing indium phosphide crystals by vertical temperature gradient solidification.
  • InP indium phosphide
  • Si silicon
  • Ge germanium
  • GaAs gallium arsenide
  • the device has the characteristics of high frequency, low noise, high efficiency, and radiation resistance, and is widely used in 5G networks, space solar cells, terahertz communications, millimeter wave communications and detection and other fields. The faster InP is synthesized, the less external contamination there is, and the easier it is to prepare high-performance InP crystals.
  • the main synthesis methods of InP are: solute diffusion synthesis (SSD), horizontal Bridgman method (HB)/horizontal gradient solidification (HGF), and injection synthesis.
  • the injection synthesis method has the highest efficiency and is a method to achieve low-cost, high-quality polycrystalline industrialization.
  • Chinese authorized patents with application numbers 202010487276.2, 202110618242.7, 201911155615.0, and 202110145424.7 all disclose the use of gas injection devices to synthesize compound semiconductor materials.
  • the technical solution after heating and vaporizing the volatile gas source material, the vaporized elements are injected into the stationary or slowly rotating melt through the injection pipe to complete the synthesis.
  • the melt starts with pure indium, and as phosphorus atoms enter the indium melt, an indium-phosphorus melt is formed.
  • the temperature drops to the crystallization temperature (lower than the melting point of indium phosphide)
  • the phosphorus content reaches or exceeds 50 atomic percent
  • the solidified melt becomes indium phosphide, and the excess phosphorus will overflow; when the phosphorus content is less than atomic percent At 50%, the melt solidifies into indium phosphide and indium.
  • the synthesis time of indium phosphide mainly depends on the rate at which the melt absorbs phosphorus. At a constant temperature, the greater the difference between the saturated phosphorus concentration of the melt and the phosphorus concentration in the melt, the faster the melt absorbs phosphorus.
  • the concentration of phosphorus in the melt is very low, and the melt absorbs phosphorus elements very quickly; as the synthesis proceeds, the concentration of phosphorus in the melt becomes higher and higher, and the melt's ability to absorb phosphorus increases. As the temperature gets worse, the absorption of phosphorus by the melt will become slower and slower.
  • the present invention proposes a method, which speeds up the synthesis speed and realizes the in-situ growth of single crystals.
  • a device for preparing indium phosphide crystals by vertical temperature gradient solidification including a furnace body, a crucible placed on a support bracket, a seed crystal tank set at the bottom of the crucible, a multi-section heater around the crucible, a motor, and a connection between the support bracket and the motor.
  • the motor is a centrifugal motor
  • the device also includes an isolation cover covering the central opening of the crucible
  • the injection system includes an injection tank, a transversely arranged injection pipe, and a connecting injection tank
  • the transmission pipe and the injection pipe, the auxiliary heating system arranged on the periphery of the injection tank, the transmission pipe passes through the isolation cover, and the injection pipe is arranged inside the crucible.
  • the top of the injection system is connected to a detachable moving rod, and the moving rod is connected to a driving device.
  • the outlet of the injection pipe is close to the side wall of the crucible.
  • the present invention also proposes a method for preparing indium phosphide crystals by vertical temperature gradient solidification, which includes the following steps:
  • Step 1 Place the seed crystal into the seed crystal tank of the crucible. Place the metal indium and boron oxide in the crucible; place the red phosphorus in the injection tank and assemble the device.
  • Step 2 Fill the furnace body with pressure protection of 4.0-8.0MPa.
  • Step 3 Use the multi-stage heater to heat the crucible to 500-600°C to melt boron oxide and metal indium; the driving device drives the detachable moving rod, places the injection system on the isolation cover, and the limiter device is fitted; it can The detached mobile rod disengages the injection system.
  • Step 4 Start the centrifugal motor to drive the support rod crucible to rotate.
  • the rotation rate of the centrifugal motor is 500-5000 rpm.
  • Step 5 Use the multi-stage heater to heat the crucible to 30-200°C above the melting point of indium phosphide; start the auxiliary heating system to make the injection tank reach 600-900°C.
  • the red phosphorus in the injection tank sublimates, and the gas discharged from the injection pipe enters the metal melt.
  • the body was synthesized by centrifugal injection.
  • Step 6 After the synthesis is completed, adjust the power of each segment heater of the multi-segment heater so that the temperatures of thermocouple E, thermocouple A and thermocouple D are 500-800°C.
  • the synthesized indium phosphide solidifies into a cylindrical solid. , boron oxide is liquid.
  • Step 7 Insert thermocouple B and thermocouple C, and adjust the power of each segment heater of the multi-segment heater so that thermocouple E is 20-50°C lower than the melting point of indium phosphide, and thermocouple A and thermocouple D are higher than the melting point of indium phosphide.
  • the melting point of indium is 50-200°C.
  • the cylindrical solid indium phosphide melts again and the liquid flows to the bottom of the crucible to lift the injection system.
  • the indium phosphide melt in the crucible establishes a temperature gradient of 5-50cm/°C, and the temperature close to the seed crystal direction is the low temperature direction.
  • Step 8 Adjust the power of each segmented heater of the multi-segment heater to achieve the growth of indium phosphide single crystal. After the growth is completed, the system is cooled to room temperature and the single crystal is taken out.
  • the density of indium (7.3g/cm 3 ) in the melt is greater than the phosphorus atoms and indium atoms bonded together (can be approximately calculated based on the density of indium phosphide 4.787g/cm 3 ), as a covering agent
  • the density of boron oxide (1.8g/cm 3 ) is the lowest.
  • Centrifugal force can change the spatial distribution concentration in the indium-phosphorus melt: in the crucible, pure indium is at the outermost periphery, and the combined phosphorus atoms and indium atoms will move together. Inside the pure indium, the innermost part is boron oxide. The outlet of the injection tube is at the edge of the crucible. The melt around the injection area is filled with pure indium without bound phosphorus atoms. The phosphorus content is always the smallest among all melts, which can quickly absorb phosphorus.
  • the rotation of the crucible is stopped, and the melt comes into contact with the seed crystal for crystal growth.
  • Figure 1 is a schematic diagram of the assembled device.
  • Figure 2 is a status diagram of the device during centrifugal synthesis.
  • Figure 3 is the state diagram of the device when the synthesis is completed.
  • Figure 4 is a state diagram of the device when starting single crystal growth.
  • Figure 5 is a state diagram of the device during the start of single crystal growth.
  • Figure 6 is an embodiment diagram of the injection system.
  • 1 crucible; 1-1: isolation cover; 2: support bracket; 3: multi-section heater; 4: metal melt; 5: boron oxide; 6: support rod; 7: centrifugal motor; 8: auxiliary heating system ;9: Red phosphorus; 10: Injection system; 10-1: Injection tank; 10-2: Transfer pipe; 10-3: Injection pipe; 11: Bubbles; 14-1: Bump; 14-2: Groove; 15: Detachable moving rod; 16: Indium; 17: Driving device; 18-1, 18-2, 18-3, 18-4, 18-5: Thermocouple; 19: Seed crystal; 20: Indium phosphide Single crystal.
  • the device includes a furnace body, a crucible 1 placed on a support bracket 2 arranged in the furnace body, a seed crystal tank 1-2 arranged at the bottom of the crucible 1, a multi-section heater 3 on the periphery of the crucible 1, a centrifugal motor 7, a connecting support bracket 2 and Support rod 6 of centrifugal motor 7, injection system 10, thermocouple.
  • the device also includes an isolation cover 1-1 covering the central opening of the crucible 1;
  • the injection system 10 includes an injection tank 10-1, a transversely arranged injection pipe 10-3, and a connection between the injection tank 10-1 and the injection pipe 10-1.
  • the transmission pipe 10-2 of 3 and the auxiliary heating system 8 are arranged on the periphery of the injection tank 10-1.
  • the transmission pipe 10-2 passes through the isolation cover 1-1, and the injection pipe 10-3 is arranged inside the crucible 1.
  • the top of the injection system 10 is connected to a detachable moving rod 15 , and the moving rod 15 is connected to a driving device 17 .
  • the bottom of the injection system 10 and the top of the isolation cover 1-1 have mutually matching limiting devices.
  • the injection system 10 rotates synchronously with the crucible 1 and remains relatively stationary to prevent the injection pipe 10-3 from stirring the melt in the crucible 1.
  • the injection system 10 can have a separate driving system to rotate synchronously with the crucible 1, or the injection system 10 can be limited on the isolation cover 1-1.
  • a limiting device composed of a groove 14-2 provided on the top of the isolation cover 1-1 and a convex block 14-1 provided at a corresponding position on the bottom of the injection tank 10-1 is used.
  • the injection system 10 and the isolation cover 1-1 are limited together.
  • the isolation cover 1-1 and the crucible 1 are firmly connected (such as welded) together, and the injection system 10 and the crucible 1 can rotate synchronously.
  • the pure indium in the crucible 1 is distributed on the side wall of the crucible 1.
  • the outlet of the injection pipe 10-3 is close to the side wall of the crucible 1.
  • the vicinity of the outlet, that is, the injection area is always in an indium-rich state.
  • the distance between the outlet of the injection pipe 10-3 and the side wall of the crucible 1 is 1-5 mm.
  • the injection pipe 10-3 is set horizontally or both ends form an angle of 1-5° downward with the horizontal direction.
  • the injection pipe 10-3 is horizontally Setting, when all the phosphorus is vaporized, the melt will enter the injection pipe 10-3, and will solidify in the injection pipe 10-3 after cooling, resulting in waste of raw materials, and the injection pipe 10-3 cannot be reused.
  • both ends of the injection pipe 10-3 form an angle of 1-5° downward with the horizontal direction.
  • Figure 6 when the injection system 10 lifts out the melt, a small amount of liquid inside the injection pipe 10-3 The melt will flow out without the above problems.
  • the present invention also proposes a method embodiment for preparing indium phosphide crystals by vertical temperature gradient solidification, which includes the following steps:
  • Step 1 Place the metal materials required for synthesis in the crucible, and place the non-metallic volatile materials required for synthesis in the injection device.
  • Step 1 Place the seed crystal 19 into the seed crystal tank 1-2 of the crucible 1. Place the metal indium 16 and boron oxide 5 in the crucible 1; place the red phosphorus 9 in the injection tank 10-1. Assemble the device: Injection The cover plate on the upper part of the tank 10-1 can be separated, and the red phosphorus 9 is placed and then welded; insert the injection pipe 10-3 into the center air of the isolation cover 1-1, and weld the injection pipe 10-3 and the transmission 10-2 together. After the weld seam cools, the upper edge of the crucible 1 and the isolation cover 1-1 are welded together.
  • the connection method can be a robot hand. Seal the furnace body.
  • Step 2 Fill the furnace body with 4.0-8.0MPa inert gas to provide pressure protection, as shown in Figure 1.
  • Step 3 Separate thermocouple B18-2 and thermocouple C18-3 and place them in crucible 1. Rotation will cause obstruction and damage; use multi-stage heater 3 to heat crucible 1 to 500-600°C to make boron oxide 5 and metal indium 16 is melted; the driving device 17 drives the detachable moving rod 15 to place the injection system 10 on the isolation cover 1-1, and the limiting device is fitted, that is, the bump 14-1 of the injection tank 10-1 sinks into the isolation cover 1 The top of -1 corresponds to the groove 14-2.
  • the manipulator is released, and the detachable moving rod 15 is detached from the injection system 10 .
  • the heating temperature of the crucible 1 is low, and the purpose is to prevent the loss of phosphorus in the injection system 10 before the injection synthesis.
  • Step 4 Start the centrifugal motor 7 to drive the support rod 6 and the crucible 1 to rotate.
  • the rotation rate of the centrifugal motor 7 is 500-5000 rpm. Since the detachable moving rod 15 has been separated from the injection system 10 and the thermocouple B18-2 and the thermocouple C18-3 have been separated, the rotation of the crucible 1 will not be affected by the outside world.
  • the metal indium melt is distributed on the inner wall of the crucible 1 and separated from the seed crystal 19, and the boron oxide 5 is distributed on the inner surface of the metal indium melt.
  • Step 5 Use the multi-stage heater 3 to heat the crucible 1 to 30-200°C above the melting point of indium phosphide;
  • the auxiliary heating system 8 starts the auxiliary heating system 8 to make the injection tank 10-1 reach 600-900°C, the red phosphorus 9 in the injection tank 10-1 sublimates, the injection pipe 10-3 discharges the bubbles 11 into the metal melt 4 for centrifugal injection synthesis, as shown in the figure 2 shown.
  • Step 6 After the synthesis is completed, that is, after all phosphorus gasification injection is completed, adjust the power of each segment heater of the multi-segment heater 3 so that the temperature of thermocouple E18-5, thermocouple A18-1 and thermocouple D18-4 is 500 -800°C, the synthesized indium phosphide solidifies into a cylindrical solid, and the boron oxide 5 becomes a liquid; gradually reduce the speed of the centrifugal motor 7 until it stops, and all the boron oxide 5 flows to the bottom of the crucible 1, see Figure 3.
  • the reason why the temperature inside the crucible 1 is lowered to solidify indium phosphide is that after the synthesis is completed, the temperature of the melt is relatively high. If the rotation of the centrifugal motor 7 is stopped at this time, the high-temperature melt will flow to the bottom of the crucible 1 and the seed crystal 19 will be melted.
  • Step 7 Insert thermocouple B18-2 and thermocouple C18-3, adjust the power of each segment heater of multi-segment heater 3, so that thermocouple E18-5 is 20-50°C lower than the melting point of indium phosphide, and thermocouple A18 -1 and thermocouple D18-4 are 50-200°C higher than the melting point of indium phosphide, and the cylindrical solid indium phosphide melts again and the liquid flows to the bottom of crucible 1; connect the detachable moving rod 15 and the injection system 10 to improve the injection system 10 is separated from the liquid level in crucible 1, as shown in Figure 4.
  • the indium phosphide melt in the crucible 1 establishes a temperature gradient of 5-50 cm/°C, and the temperature close to the direction of the seed crystal 19 is the low temperature direction.
  • the synthesized indium phosphide melt is higher than the melting point, and eventually a part of the seed crystal 19 will melt and establish an equilibrium state between the seed crystal 19 and the indium phosphide melt.
  • Step 8 Adjust the power of each segment heater of the multi-segment heater 3 to achieve the growth of indium phosphide single crystal, as shown in Figure 5; after the growth is completed, the system is cooled to room temperature, take out the crucible 1 from the crucible support 2, and use hydrogen The oxygen flame opens the weld; take out and crush the crucible 1, retain the injection system 10 and the isolation cover 1-1 for next use; take out the single crystal.
  • step 6 the injection system (10) will solidify into the indium phosphide solid, which may damage the injection tube (10-3).
  • improvements are as follows:
  • Step 6 After the synthesis is completed, adjust the power of each segment heater of the multi-segment heater 3.
  • the thermocouple E18-5 is 20-50°C higher than the melting point of indium phosphide, and the thermocouple A18-1 and thermocouple D18-4 are higher than
  • the melting point of indium phosphide is 50-200°C; gradually reduce the speed of the centrifugal motor 7 until it stops, and all the boron oxide 5 and the melt slowly flow to the bottom of the crucible 1.
  • the rotational speed of the centrifugal motor 7 decreases at a rate of 10-100 revolutions per minute.
  • the rotation speed of the centrifugal motor 7 drops to 0, connect the detachable moving rod 15 and the injection system 10, and lift the injection system 10 away from the liquid level in the crucible 1, as shown in Figure 4.
  • Step 7 Insert thermocouple B18-2 and thermocouple C18-3, adjust the power of each segment heater of multi-segment heater 3, and the indium phosphide melt in crucible 1 establishes a temperature gradient of 5-50cm/°C. The temperature close to the direction of seed crystal 19 is the low temperature direction.
  • the crucible rotates, using centrifugal force to separate the melt and inject gaseous phosphorus into the side of the crucible; 2. In the single crystal growth stage, establish a vertical direction Temperature gradient.
  • the synthesis speed is increased by 20-30% compared with the traditional injection method, speeding up the single crystal production process. Due to the accelerated synthesis speed and reduced melt pollution, the carrier concentration of indium phosphide is ⁇ 2 ⁇ 10 15 cm -3 and the mobility is >4500cm 2 ⁇ V -1 ⁇ s -1 ; when using the same raw materials , the carrier concentration of traditional synthetic polycrystalline is >5 ⁇ 10 15 cm -3 , and the mobility is about 3000-4000cm 2 ⁇ V -1 ⁇ s -1 .

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Abstract

一种垂直温度梯度凝固制备磷化铟晶体的装置及方法，装置包括炉体、坩埚、离心电机、注入系统，在合成过程中，旋转坩埚，使坩埚中的熔体在离心力的作用下贴在坩埚侧壁上；将气泡注入金属熔体靠近坩埚侧壁位置；合成完毕后，控制垂直温度梯度，完成单晶生长。

Description

一种垂直温度梯度凝固制备磷化铟晶体的装置及方法 技术领域
本发明涉及半导体材料的制备，尤其涉及一种垂直温度梯度凝固制备磷化铟晶体的装置及方法。
背景技术
InP(磷化铟)是继硅(Si)、锗(Ge)、砷化镓(GaAs)之后的一种重要化合物半导体材料，是制备高频和高速器件的首选材料之一，InP基微电子器件具有高频、低噪声、高效率、抗辐照等特点，广泛应用于5G网络、空间太阳能电池、太赫兹通信、毫米波通信与探测等领域。InP合成的越快，外界沾污就越少，越容易制备高性能InP晶体。
InP的主要合成方法有：溶质扩散法合成(SSD)、水平布里奇曼法(HB)/水平梯度凝固法(HGF)、注入合成法。其中注入合成法的效率最高，是实现低成本、高品质多晶产业化的方法，如申请号分别为202010487276.2、202110618242.7、201911155615.0、202110145424.7等中国授权专利中都公开了采用气体注入装置合成化合物半导体材料的技术方案：将挥发性气源材料加热气化后，通过注入管将气化的元素注入到静止或缓慢转动的熔体中完成合成。
熔体中开始是纯铟，随着磷原子进入铟熔体，形成铟-磷熔体。温度下降到结晶温度时(低于磷化铟熔点)，当磷的成分达到或超过原子百分比50％时凝固的熔体变为磷化铟，多余的磷会溢出；当磷的成分小于原子百分比50％时，熔体凝固为磷化铟和铟。
磷化铟合成的时间主要取决于熔体吸收磷元素的速度。在恒定温度下，熔体饱和磷浓度与熔体中磷的浓度差越大，熔体吸收磷元素的速度就越快。
在磷进入熔体初期，熔体中磷的浓度很低，熔体吸收磷元素的速度很快；随着合成的进行，熔体中磷的浓度越来越高，熔体吸收磷的能力越来越差，熔体吸收磷的速度会越来越慢。
发明内容
针对现有技术存在的问题，本发明提出了一种方法，加快了合成速度，并实现单晶的原位生长。
为实现上述目的，本发明采用以下技术方案：
一种垂直温度梯度凝固制备磷化铟晶体的装置，包括炉体、放置在支撑托上的坩埚、设置在坩埚底部的籽晶槽、坩埚外围的多段加热器、电机、连接支撑托和电机的支撑杆、注入系 统、热电偶，关键是：所述电机为离心电机，所述装置还包括覆盖坩埚的中心开口的隔离盖，所述注入系统包括注入罐、横向设置的注入管、连接注入罐和注入管的传输管、设置在注入罐外围的辅助加热系统，传输管穿过隔离盖，注入管设置在坩埚内部。
所述注入系统顶部连接可脱离的移动杆，所述移动杆连接驱动装置。
注入系统底部与隔离盖的顶部有相互配合的限位装置。
进一步地，所述注入管的出口接近坩埚侧壁。
基于上述装置，本发明还提出了一种垂直温度梯度凝固制备磷化铟晶体的方法，包括以下步骤：
步骤1、将籽晶放置进入坩埚的籽晶槽中，金属铟和氧化硼放置于坩埚中；将红磷放置在注入罐中，组装装置。
步骤2、给炉体充入4.0-8.0MPa的压力保护。
步骤3、通过多段加热器给坩埚加热至500-600℃，使得氧化硼和金属铟熔化；驱动装置驱动可脱离的移动杆，将注入系统放置在隔离盖上，且限位装置拟合；可脱离的移动杆脱离注入系统。
步骤4、启动离心电机，带动支撑杆坩埚转动，离心电机的转动速率为500-5000转/分。
步骤5、通过多段加热器给坩埚加热至磷化铟熔点以上30-200℃；启动辅助加热系统，使得注入罐达到600-900℃，注入罐内的红磷升华，注入管排出气体进入金属熔体进行离心注入合成。
步骤6、合成完毕后，调整多段加热器的各分段加热器的功率，使热电偶E、热电偶A和热电偶D温度为500-800℃，合成后的磷化铟凝固为筒状固体，氧化硼为液态。
逐渐降低离心电机的转速直至停止，氧化硼全部流至坩埚的底部。
步骤7、插入热电偶B和热电偶C，调整多段加热器的各分段加热器的功率，使热电偶E低于磷化铟熔点20-50℃，热电偶A和热电偶D高于磷化铟熔点50-200℃，筒状固体磷化铟再次熔化液态流至坩埚的底部，提升注入系统。
坩埚内的磷化铟熔体建立起5-50cm/℃的温度梯度，靠近籽晶方向的温度为低温方向。
步骤8、调整多段加热器的各分段加热器的功率，实现磷化铟单晶生长，生长完毕后系统降温至室温，取出单晶。
在多晶合成期间，熔体中，铟的密度(7.3g/cm 3)大于结合在一起的磷原子和铟原子 (可近似按磷化铟的密度4.787g/cm 3计算)，作为覆盖剂的氧化硼密度(1.8g/cm 3)最低。离心力可以改变铟磷熔体中空间分布浓度的变化：在坩埚内，纯铟在最外围，结合在一起的磷原子和铟原子会一起运动，在纯铟的内侧，最内侧为氧化硼。注入管的出口处于坩埚边缘，注入区域周围的熔体中遍布没有结合磷原子的纯铟，磷的含量总是所有熔体中最小的，可以快速吸收磷。
合成完毕后，停止旋转坩埚，熔体与籽晶接触，进行晶体生长。
有益效果：在离心力的作用下，密度较重的铟原子会向坩埚边缘方向运动，而密度较轻的磷原子会向坩埚中心运动，使得坩埚侧壁的铟原子较多。注入区域周围磷原子的浓度较低，因此合成速率较快，加速整体合成过程；离心快速合成和晶体生长结合，在单晶生长期间，精确控制垂直方向的温度梯度，进一步提高了注入合成后晶体生长的效率。
附图说明
图1为装配完成的装置示意图，
图2为离心合成时装置的状态图，
图3为合成完成时装置的状态图，
图4为开始单晶生长时装置的状态图，
图5为开始单晶生长过程中装置的状态图，
图6为注入系统实施例图。
其中，1：坩埚；1-1：隔离盖；2：支撑托；3：多段加热器；4：金属熔体；5：氧化硼；6：支撑杆；7：离心电机；8：辅助加热系统；9：红磷；10：注入系统；10-1：注入罐；10-2：传输管；10-3：注入管；11:气泡；14-1：凸块；14-2：凹槽；15：可脱离的移动杆；16：铟；17：驱动装置；18-1、18-2、18-3、18-4、18-5：热电偶；19：籽晶；20：磷化铟单晶。
具体实施方式
一种垂直温度梯度凝固制备磷化铟晶体的装置，参看图1。
装置包括炉体、炉体内设置的放置在支撑托2上的坩埚1、设置在坩埚1底部的籽晶槽1-2、坩埚1外围的多段加热器3、离心电机7、连接支撑托2和离心电机7的支撑杆6、注入系统10、热电偶。
所述装置还包括覆盖坩埚1的中心开口的隔离盖1-1；所述注入系统10包括注入罐10-1、横向设置的注入管10-3、连接注入罐10-1和注入管10-3的传输管10-2、设置在注入罐10-1外围的辅助加热系统8，传输管10-2穿过隔离盖1-1，注入管10-3设置在坩埚1内 部。
所述注入系统10顶部连接可脱离的移动杆15，移动杆15连接驱动装置17。
注入系统10底部与隔离盖1-1的顶部有相互配合的限位装置。
本发明中，注入系统10与坩埚1同步旋转，保持相对静止，避免注入管10-3搅动坩埚1内的熔体。
注入系统10可以单独设置驱动系统与坩埚1同步旋转，也可以将注入系统10限位在隔离盖1-1上。
本发明中，采用隔离盖1-1的顶部设置凹槽14-2、注入罐10-1底部对应位置设置凸块14-1组成的限位装置。
通过凹槽和凸块的配合，注入系统10与隔离盖1-1限位在一起。隔离盖1-1与坩埚1牢固连接(如焊接)在一起，注入系统10与坩埚1可以同步旋转。
由于离心力，坩埚1中的纯铟分布在坩埚1侧壁，注入管10-3的出口接近坩埚1侧壁，出口附近即注入区域周围始终处于富铟状态。本实施例中，注入管10-3的出口与坩埚1侧壁的距离为1-5mm。
由于注入系统10在合成结束后要提升出熔体，本实施例中，注入管10-3水平设置或两端与水平方向呈向下1-5°的夹角，在合成过程中，如果水平设置，当磷全部气化后，熔体会进入注入管10-3，降温后会凝固在注入管10-3中，造成原料浪费，且注入管10-3不能重复使用。本实施例中，注入管10-3两端与水平方向呈向下1-5°的夹角，如图6所示，当注入系统10提升出熔体时，注入管10-3内部少量的熔体会流出，不会产生上述问题。
基于上述垂直温度梯度凝固制备磷化铟晶体的装置，本发明还提出了一种垂直温度梯度凝固制备磷化铟晶体的方法实施例，包括以下步骤：
步骤1、将合成需要的金属材料置于坩埚中，将合成需要的非金属挥发性材料置于注入装置中。
步骤1、将籽晶19放置进入坩埚1的籽晶槽1-2中，金属铟16和氧化硼5放置于坩埚1中；将红磷9放置在注入罐10-1中，组装装置：注入罐10-1上部的盖板可以分离，放置红磷9后焊接；将注入管10-3插入隔离盖1-1的中心空中，将注入管10-3与传输10-2焊接在一起，待焊缝冷却后再将坩埚1的上沿与隔离盖1-1焊接在一起。
将坩埚1放入坩埚支撑托2中；将注入罐10-1外侧设置辅助加热系统8，连接注入系统10和可脱离的移动杆15，连接方式可以采用机械手。密封炉体。
步骤2、给炉体充入4.0-8.0MPa的惰性气体，起到压力保护作用，如图1所示。
步骤3、将热电偶B18-2和热电偶C18-3脱离，放置在坩埚1旋转是造成阻挡和损坏；通过多段加热器3给坩埚1加热至500-600℃，使得氧化硼5和金属铟16熔化；驱动装置17驱动可脱离的移动杆15，将注入系统10放置在隔离盖1-1上，且限位装置拟合，即注入罐10-1的凸块14-1陷入隔离盖1-1的顶部对应的凹槽14-2中。
放开机械手，可脱离的移动杆15脱离注入系统10。
此时坩埚1加热温度较低，目的撒是防止注入合成以前，注入系统10中的磷损失。
步骤4、启动离心电机7，带动支撑杆6坩埚1转动，离心电机7的转动速率为500-5000转/。由于可脱离的移动杆15与注入系统10已脱离，热电偶B18-2和热电偶C18-3脱离，坩埚1的旋转不会受外界影响。
金属铟熔体分布在坩埚1内壁与籽晶19分离开，氧化硼5分布在金属铟熔体内侧表面。
步骤5、通过多段加热器3给坩埚1加热至磷化铟熔点以上30-200℃；
启动辅助加热系统8，使得注入罐10-1达到600-900℃，注入罐10-1内的红磷9升华，注入管10-3排出气泡11进入金属熔体4进行离心注入合成，如图2所示。
逐步增加辅助加热系统8的功率，保证注入管10-3排出气泡11稳定；同时，为保证注入系统10不从隔离盖1-1上脱离，可以再次注入惰性气体，增大炉体内、坩埚1外部的气体压力，使坩埚1外部压力大于等于内部压力。
步骤6、合成完毕，即所有磷气化注入完成后，调整多段加热器3的各分段加热器的功率，使热电偶E18-5、热电偶A18-1和热电偶D18-4温度为500-800℃，合成后的磷化铟凝固为筒状固体，氧化硼5为液态；逐渐降低离心电机7的转速直至停止，氧化硼5全部流至坩埚1的底部，参看图3。
降低坩埚1内部的温度使磷化铟凝固的原因，是合成完毕后，熔体的温度较高，如果此时停止离心电机7的旋转，高温熔体流向坩埚1底部，会融化籽晶19。
步骤7、插入热电偶B18-2和热电偶C18-3，调整多段加热器3的各分段加热器的功率，使热电偶E18-5低于磷化铟熔点20-50℃，热电偶A18-1和热电偶D18-4高于磷化铟熔点50-200℃，筒状固体磷化铟再次熔化液态流至坩埚1的底部；连接可脱离的移动杆15和注入系统10，提升注入系统10脱离坩埚1内的液面，如图4所示。
坩埚1内的磷化铟熔体建立起5-50cm/℃的温度梯度，靠近籽晶19方向的温度为低温方向。
由于籽晶19底部温度低与磷化铟熔点，被合成的磷化铟熔体高于熔点，最终将有一 部分籽晶19熔化并建立起籽晶19与磷化铟熔体的平衡态。
步骤8、调整多段加热器3的各分段加热器的功率，实现磷化铟单晶生长，如图5所示；生长完毕后系统降温至室温，从坩埚支撑2中取出坩埚1，利用氢氧焰打开焊缝；取出并破碎坩埚1，保留注入系统10和隔离盖1-1以便下次使用；取出单晶。
上述步骤中，在步骤6，注入系统(10)会凝固到磷化铟固体中，有可能损坏注入管(10-3)。为此，作为改进如下：
步骤6、合成完毕后，调整多段加热器3的各分段加热器的功率，热电偶E18-5高于磷化铟熔点20-50℃，热电偶A18-1和热电偶D18-4高于磷化铟熔点50-200℃；逐渐降低离心电机7的转速直至停止，氧化硼5和熔体全部缓慢流至坩埚1的底部。
离心电机7的转速每分钟降低速率为10-100转。当离心电机7的转速降为0后，连接可脱离的移动杆15和注入系统10，提升注入系统10脱离坩埚1内的液面，如图4所示。
步骤7、插入热电偶B18-2和热电偶C18-3，调整多段加热器3的各分段加热器的功率，坩埚1内的磷化铟熔体建立起5-50cm/℃的温度梯度，靠近籽晶19方向的温度为低温方向。
本发明中，关键有两点：1、在磷化铟合成阶段，坩埚旋转，利用离心力将熔体分离、将气态的磷注入到坩埚侧边；2、在单晶生长阶段，建立垂直方向的温度梯度。
实验表明，采用本发明提出的装置和方法，在磷化铟合成阶段，合成速度比传统的注入法提升20-30％，加快了单晶生产过程。由于加快了合成速度，减少了熔体污染，磷化铟的载流子浓度≤2×10 15cm -3，迁移率>4500cm 2·V -1·s -1；在使用相同原料的情况下，传统合成多晶的载流子浓度度>5×10 15cm -3，迁移率约3000-4000cm 2·V -1·s -1。

Claims (6)

  1. 一种垂直温度梯度凝固制备磷化铟晶体的装置，包括炉体、放置在支撑托(2)上的坩埚(1)、设置在坩埚(1)底部的籽晶槽(1-2)、坩埚(1)外围的多段加热器(3)、电机、连接支撑托(2)和电机的支撑杆(6)、注入系统(10)、热电偶，
    其特征在于：所述电机为离心电机(7)，所述装置还包括覆盖坩埚(1)的中心开口的隔离盖(1-1)，所述注入系统(10)包括注入罐(10-1)、横向设置的注入管(10-3)、连接注入罐(10-1)和注入管(10-3)的传输管(10-2)、设置在注入罐(10-1)外围的辅助加热系统(8)，传输管(10-2)穿过隔离盖(1-1)，注入管(10-3)设置在坩埚(1)内部；
    所述注入系统(10)顶部连接可脱离的移动杆(15)，所述移动杆(15)连接驱动装置(17)；
    注入系统(10)底部与隔离盖(1-1)的顶部有相互配合的限位装置。
  2. 根据权利要求1所述的装置，其特征在于，所述注入管(10-3)的出口接近坩埚(1)侧壁。
  3. 根据权利要求1所述的装置，其特征在于，注入管(10-3)均匀设置2-8个，水平设置或与水平方向呈1-5°夹角。
  4. 根据权利要求1所述的装置，其特征在于，所述注入系统(10)底部与隔离盖(1-1)的顶部相互配合的限位装置为隔离盖(1-1)的顶部设置凹槽(14-2)，注入罐(10-1)底部对应位置设置凸块(14-1)。
  5. 一种垂直温度梯度凝固制备磷化铟晶体的方法，基于权利要求1-4任一项所述一种垂直温度梯度凝固制备磷化铟晶体的装置完成，其特征在于，所述方法包括以下步骤：
    步骤1、将籽晶(19)放置进入坩埚(1)的籽晶槽(1-2)中，金属铟(16)和氧化硼(5)放置于坩埚(1)中；将红磷(9)放置在注入罐(10-1)中，组装装置；
    步骤2、给炉体充入4.0-8.0MPa的压力保护；
    步骤3、通过多段加热器(3)给坩埚(1)加热至500-600℃，使得氧化硼(5)和金属铟(16)熔化；驱动装置(17)驱动可脱离的移动杆(15)，将注入系统(10)放置在隔离盖(1-1)上，且限位装置拟合；可脱离的移动杆(15)脱离注入系统(10)；
    步骤4、启动离心电机(7)，带动支撑杆(6)、坩埚(1)转动，离心电机(7)的转动速率为500-5000转/分；
    步骤5、通过多段加热器(3)给坩埚(1)加热至磷化铟熔点以上30-200℃；
    启动辅助加热系统(8)，使得注入罐(10-1)达到600-900℃，注入罐(10-1)内的红磷(9)升华，注入管(10-3)排出气体进入金属熔体(4)进行离心注入合成；
    步骤6、合成完毕后调整多段加热器(3)的各分段加热器的功率，使热电偶E(18-5)、热电偶A(18-1)和热电偶D(18-4)温度为500-800℃，合成后的磷化铟凝固为筒状固体，氧化硼(5)为液态；
    逐渐降低离心电机(7)的转速直至停止，氧化硼(5)全部流至坩埚(1)的底部；
    步骤7、插入热电偶B(18-2)和热电偶C(18-3)，调整多段加热器(3)的各分段加热器的功率，使热电偶E(18-5)低于磷化铟熔点20-50℃，热电偶A(18-1)和热电偶D(18-4)高于磷化铟熔点50-200℃，筒状固体磷化铟再次熔化液态流至坩埚(1)的底部，提升注入系统(10)；
    坩埚(1)内的磷化铟熔体建立起5-50cm/℃的温度梯度，靠近籽晶(19)方向的温度为低温方向；
    步骤8、调整多段加热器(3)的各分段加热器的功率，实现磷化铟单晶生长，生长完毕后系统降温至室温，取出单晶。
  6. 根据权利要求5所述的方法，其特征在于：
    步骤6、合成完毕后调整多段加热器(3)的各分段加热器的功率，热电偶E(18-5)高于磷化铟熔点20-50℃，热电偶A(18-1)和热电偶D(18-4)高于磷化铟熔点50-200℃；逐渐降低离心电机(7)的转速直至停止，氧化硼(5)和熔体全部缓慢流至坩埚(1)的底部；离心电机(7)停止后，提升注入系统(10)；
    步骤7、插入热电偶B(18-2)和热电偶C(18-3)，调整多段加热器(3)的各分段加热器的功率，坩埚(1)内的磷化铟熔体建立起5-50cm/℃的温度梯度，靠近籽晶(19)方向的温度为低温方向。
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US5650008A (en) * 1995-12-01 1997-07-22 Advanced Materials Processing, Llc Method for preparing homogeneous bridgman-type single crystals
CN115198370A (zh) * 2022-07-15 2022-10-18 中国电子科技集团公司第十三研究所 一种垂直温度梯度凝固制备磷化铟晶体的装置及方法

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CN115198370A (zh) * 2022-07-15 2022-10-18 中国电子科技集团公司第十三研究所 一种垂直温度梯度凝固制备磷化铟晶体的装置及方法

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