A low-temperature continuous synthesis device and method for compounds

Abstract

A low-temperature continuous synthesis device and method for a compound, belonging to the field of compound semiconductor technology, comprises a constant temperature chamber, a rotating flywheel system, a gas supply system, and a metal droplet system. The method comprises: placing the materials required for synthesis in the metal droplet system and the gas supply system, respectively; raising and maintaining the temperature of the constant temperature chamber; injecting atmospheric elements into the constant temperature chamber; starting the rotating flywheel system; heating the metal droplet system; and injecting metal droplets into the constant temperature chamber to achieve compound synthesis. The synthesis temperature of the present invention is far below the melting point of the compound, reducing contact contamination between the compound and the container. The synthesis achieves high purity, reduces equipment manufacturing difficulty, and minimizes gas source loss, enabling high-purity, low-cost synthesis of compound polycrystalline materials.

Description

Technical Field

[0001] The present invention belongs to the technical field of compound semiconductors, and in particular relates to a device and method for continuously synthesizing semiconductor compounds by increasing the surface area of ​​metal droplets. Background Art

[0002] Compound semiconductor materials are one of the important basic supporting technologies for the development of the electronic information industry technology system. They are widely used in optical fiber communications, mobile communications, navigation, detection and other fields, and have become a hot spot for development in various countries.

[0003] Compound semiconductor materials mainly involve material synthesis and single crystal growth, and the methods of material synthesis mainly include diffusion method and injection method.

[0004] In the preparation process of indium phosphide, gallium arsenide, gallium phosphide, gallium arsenide, zinc germanium phosphide and other materials, due to the characteristics of the materials, the injection method is generally used for synthesis. For example, Chinese authorized patents with application numbers 202010487276.2, 202110618242.7, 201911155615.0, and 202110145424.7 all disclose technical solutions for synthesizing compound semiconductor materials using a gas injection device: after the volatile gas source material is heated and vaporized, the vaporized elements are injected into the melt through the injection tube to complete the synthesis.

[0005] Current technology has the following problems:

[0006] 1. Slow reaction rate. In practice, we've found that the rate of compound synthesis depends on the contact area between the volatile element gas and the melt. Calculations show that the primary reaction opportunities in the injection method occur at the tube orifice and within the tube. The diameter of the injection tube pins typically ranges from 8 to 20 mm. Even with a double-tube synthesis method, the contact area between the volatile element and the melt is limited. While bubbles may absorb gas during their rise, the rise time is short, and the amount absorbed is very limited.

[0007] 2. Waste of gas source material. Theoretically, if the vaporization rate of the volatile element is equal to its reaction rate with the melt, bubbles will not form. However, in actual process operation, it is difficult to match the vaporization rate and reaction rate. When the vaporization rate of the volatile element is lower than the reaction rate, the melt will be sucked into the pin, causing pin blockage and leading to synthesis process failure. When the vaporization rate of the volatile element is higher than the reaction rate, excess volatile element will be ejected as bubbles. The time from the bubble's emergence in the melt to its overflowing onto the melt surface is very short, making it almost unabsorbed by the melt. Moreover, in actual processes, to prevent pin back suction, the vaporization rate of the volatile element is often increased (by increasing the power of the volatile element heater), which increases the amount of volatile element overflow. During their rise, bubbles will react with the melt, but because the bubbles rise so quickly, only a very small amount is absorbed by the melt. Since the melt surface is often covered with a covering agent such as boron oxide, which isolates the substances involved in the synthesis, escaping bubbles will not participate in the synthesis process.

[0008] 3. Traditional compound synthesis techniques require high synthesis temperatures, often exceeding the compound's melting point. For example, indium phosphide, both horizontal and injection synthesis temperatures range from 1070°C to 1150°C. During the synthesis process, the high-temperature melt comes into contact with the crucible, reacting and causing contamination. Therefore, synthesis contamination is a pressing issue in compound synthesis technology. Summary of the Invention

[0009] The purpose of the present invention is to realize the synthesis of compound polycrystalline materials at low temperature.

[0010] To achieve the above-mentioned object, the present invention provides a low-temperature continuous synthesis device for a compound and a synthesis method using the device.

[0011] A low-temperature continuous synthesis device for compounds comprises a constant temperature chamber, a rotating flywheel system, an air source supply system and a metal dripping system.

[0012] The constant temperature chamber comprises a constant temperature sealed chamber, a constant temperature chamber heater and a heat preservation layer.

[0013] The rotating flywheel system includes a flywheel and a driving device connected to the flywheel. The flywheel is bowl-shaped and vertically arranged in the insulation layer. A curved baffle is arranged on the edge of the flywheel.

[0014] The gas source supply system includes a gas source bubble, a gas source heater and a gas source supply pipeline. One end of the gas source supply pipeline is connected to the gas source bubble, and the other end is provided with an outlet in the insulation layer.

[0015] The metal dripping system includes a metal liquid heater, a metal liquid dripping barrel, a metal liquid dripping nozzle, and a connecting rod. The metal dripping system is positioned on a constant temperature closed cavity through the connecting rod, and the metal liquid dripping nozzle is aligned with a baffle at the edge of a flywheel.

[0016] A method for low-temperature continuous synthesis of a compound using the above-mentioned device comprises the following steps:

[0017] Step 1: Calculate the amount of metal material and non-metallic volatile material required for synthesis, place the metal material in the metal droplet barrel, place the non-metallic volatile material in the gas source bubble, and assemble the device.

[0018] Step 2: Evacuate the constant temperature sealed chamber to 100 Pa, start the constant temperature chamber heater, heat the constant temperature sealed chamber to 300-700°C and maintain the temperature; the temperature is higher than the melting point of the metal material and lower than the melting point of the compound.

[0019] Step 3: Start the gas source heater to gasify the non-metallic volatile material and inject it into the constant temperature closed cavity through the gas source supply pipeline and outlet.

[0020] Step 4: Start the drive device to rotate the flywheel until the speed reaches 2000 rpm.

[0021] Step 5: Start the molten metal heater to melt the metal material into a molten metal.

[0022] Step 6: Start the molten metal propulsion mechanism to discharge the molten metal droplets from the molten metal drop barrel through the molten metal drop nozzle until the molten metal in the molten metal drop barrel is completely discharged.

[0023] Step 7: Stop the driving device, stop heating to room temperature, dismantle the device, and take out the compound.

[0024] The present invention utilizes a rotating flywheel to greatly extend the liquid metal material in the compound semiconductor, so that it can fully contact and combine with the atmospheric elements in the environment to form a solid compound material with a higher melting point.

[0025] Beneficial Effects: A key feature of this invention is that the synthesis temperature is far below the melting point of the compound, significantly reducing contact contamination between the compound and the container. In this case, only the thin layer of compound in contact with the flywheel will be slightly contaminated, and subsequent materials will only come into contact with the solidified compound material, avoiding material contamination and further improving the purity of the compound. The large-area contact between the metal material and the atmosphere elements increases the synthesis speed. The device and method proposed in this invention achieve high synthesis purity, low equipment manufacturing difficulty, and minimal gas source loss, enabling high-purity, low-cost synthesis of compound polycrystalline materials and easy engineering and automation.

[0026] The present invention will be further described below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a top view of the synthesis device,

[0028] Figure 2 This is a front view of the synthesis device, which lacks the metal dripping system.

[0029] Figure 3 is a front view of the synthesis device,

[0030] Figure 4 is the state diagram of the synthesis device during the synthesis process,

[0031] Figure 5 A state diagram of a synthesis device during synthesis in another embodiment is shown.

[0032] Figure 6 A top view of another embodiment of a synthesis device

[0033] Figure 7 This is the state diagram of the synthesis device after the synthesis is completed.

[0034] Among them, 1-1: constant temperature closed chamber, 1-2: constant temperature chamber heater, 1-3 insulation layer, 2-1: flywheel, 2-2: driving device, 2-3: baffle, 3-1: gas source bubble, 3-2: gas source heater, 3-3: gas source supply pipeline, 3-4: outlet, 4-1: molten metal heater, 4-2: molten metal droplet barrel, 4-3: molten metal droplet nozzle, 4-4: propulsion motor, 4-5: propulsion rod, 4-6: propulsion head, 4-7: connecting rod, 5-1: connecting column, 5-2: dispersion head, 6: non-metallic volatile material, 7: metal melt, 7-1: metal droplets, 7-2: thin layer of metal liquid, 7-3: broken up metal droplets, 8: compound. DETAILED DESCRIPTION

[0035] A low-temperature continuous synthesis device for compounds comprises a constant temperature chamber, a rotating flywheel system, an air source supply system and a metal dripping system.

[0036] See Figure 1 、 Figure 2 .

[0037] The constant temperature chamber includes a sealed constant temperature chamber 1-1, a chamber heater 1-2, and an insulation layer 1-3. The heater 1-2 is made of a resistance heating wire or graphite, which allows the temperature within the sealed constant temperature chamber 1-1 to reach and remain constant at 300-700°C. The sealed constant temperature chamber 1-1 is made of dense corundum material, capable of achieving a vacuum of 100 Pa and withstanding a gas pressure of 0.2 MPa at a constant temperature of 700°C. The insulation layer 1-3 is made of fluffy corundum insulation material.

[0038] The rotating flywheel system includes a flywheel 2-1 and a drive device 2-2 connected to flywheel 2-1. Flywheel 2-1 is bowl-shaped and vertically positioned within insulation layer 1-3. Curved baffles 2-3 are located along the edge of flywheel 2-1. Drive device 2-2 is connected to flywheel 2-1 via a shaft, driving flywheel 2-1 at a speed of 1,000 to 3,000 rpm. Flywheel 2-1 is made of stainless steel and has a diameter of 300 to 10,000 mm, depending on the raw material availability.

[0039] The gas source supply system includes a gas source bubble 3-1, a gas source heater 3-2 and a gas source supply pipeline 3-3. One end of the gas source supply pipeline is connected to the gas source bubble 3-1, and the other end is provided with an outlet 3-4 in the insulation layer; the gas source bubble 3-1 is made of high-purity quartz or stainless steel, and the gas source supply pipeline 3-3 is made of quartz or stainless steel. The atmosphere can be evenly delivered into the constant temperature closed chamber 1-1 through 4-8 outlets 3-4. The gas source heater 3-2 is made of nickel-chromium resistance wire, molybdenum wire or induction coil, and the heating power is 2000W~10000W.

[0040] The gas source bubble 3-1 is arranged outside the constant temperature cavity, and the gas source supply pipe 3-3 passes through the constant temperature closed cavity 1-1 and enters the interior of the insulation layer 1-3.

[0041] See Figure 1 、 Figure 3 .

[0042] The metal dripping system includes a molten metal heater 4-1, a metal dripping barrel 4-2, a metal dripping nozzle 4-3, and a connecting rod 4-7. The metal dripping system is positioned on the inner wall of the constant-temperature, sealed chamber 1-1 via connecting rod 4-7, with the metal dripping nozzle 4-3 aligned with the center of the baffle 2-3 at the edge of the flywheel. The molten metal heater 4-1 is made of nickel-chromium resistance wire, molybdenum wire, or an induction coil. The metal dripping barrel 4-2 is made of high-purity quartz or boron nitride, with a volume of 3,000 to 10,000 ml, depending on the amount of raw materials. The diameter of the metal dripping nozzle 4-3 is 1 to 5 mm.

[0043] The metal droplets can drip freely by their own weight. In order to accurately control the discharge amount of the metal droplets, this embodiment also provides a metal liquid propulsion mechanism, including a propulsion motor 4-4, a propulsion rod 4-5 made of stainless steel, and a propulsion head 4-6 connected in sequence. The propulsion head 4-6 is arranged in the metal droplet barrel 4-2.

[0044] In order to increase the surface area of ​​the metal droplets during the reaction process, this embodiment also provides a metal droplet dispersion mechanism on the flywheel 2-1, including a connecting column 5-1 connected to the flywheel and a comb-shaped dispersion head 5-2 provided at the end of the connecting column. The dispersion head is in the same vertical position as the metal droplet nozzle 4-3 and is provided with 2-6 teeth.

[0045] During operation, the metal droplet dispersion mechanism rotates together with the flywheel 2-1, and the metal droplets are broken up by the dispersion head 5-2 during the falling process.

[0046] In the device, an atomizing device can be provided at the metal droplet nozzle 4-3.

[0047] Liquid metal atomization is an existing technology. For example, an atomizing disk is connected to the metal droplet nozzle 4-3, and the metal droplets are dispersed into tiny particles by rotating the atomizing disk to achieve atomization.

[0048] The low-temperature continuous synthesis method of a compound based on the above-mentioned low-temperature continuous synthesis device for a compound comprises the following steps:

[0049] Step 1: Calculate the amount of metal material and non-metal volatile material required for synthesis, place the metal material in the metal droplet barrel 4-2, place the non-metal volatile material 6 in the gas source bubble 3-1, and assemble the device.

[0050] In this embodiment, the metal material is indium, and the non-metallic volatile material 6 is phosphorus.

[0051] Step 2: Evacuate the constant temperature sealed chamber 1-1 to 100 Pa, start the constant temperature chamber heater 1-2, heat the constant temperature sealed chamber 1-1 to 300-700°C and maintain the temperature.

[0052] Vacuuming is a conventional technical means, and in this embodiment, no related devices are shown in the figure.

[0053] One of the key points of the present invention is low-temperature synthesis, that is, the temperature in the reaction chamber is lower than the melting point of the compound. On this basis, the temperature setting should take into account the following factors: the temperature in the constant temperature closed chamber 1-1 should be higher than the melting point of the metal material (such as the melting point of indium is 156.51°C), otherwise the metal droplet 7-1 will solidify in the constant temperature closed chamber 1-1. In addition, the synthesis speed of the compound should be considered.

[0054] Step 3: Start the gas source heater 3-2 to vaporize the non-metallic volatile material 6 and inject it into the constant temperature sealed chamber 1-1 through the gas source supply pipe 3-3 and the outlet 3-4. After a period of time, the constant temperature sealed chamber 1-1 is filled with the vaporized non-metallic volatile material 6.

[0055] Step 4: Start the driving device 2-2 to rotate the flywheel 2-1, and the speed reaches 2000 rpm.

[0056] Step 5: Start the molten metal heater 4 - 1 to melt the metal material into a metal melt 7 .

[0057] Step 6: Start the propulsion motor 4-4 of the metal liquid propulsion mechanism to drive the propulsion rod 4-5 and the propulsion head 4-6 to discharge the metal droplets 7-1 from the metal droplet barrel 4-2 through the metal droplet nozzle 4-3 until the metal melt 7 in the metal droplet barrel 4-2 is completely discharged.

[0058] The discharge rate of the metal droplets 7-1 is 5-50 ml / min.

[0059] The discharge rate of metal droplets 7-1 is related to the synthesis rate of the compound, specifically the material being synthesized and the temperature within the constant-temperature sealed chamber 1-1. The temperature within the constant-temperature sealed chamber 1-1 and the discharge rate of metal droplets 7-1 are adjusted based on the material being synthesized. Experimental results show that a constant-temperature sealed chamber 1-1 temperature of 600°C and a discharge rate of 10 ml / min of metal droplets 7-1 are sufficient to produce polycrystalline materials such as indium phosphide, gallium arsenide, gallium phosphide, gallium arsenide, and zinc germanium phosphate. Adjusting process parameters can accelerate synthesis time.

[0060] See Figure 4 After the metal droplet 7-1 is discharged, if the device lacks a metal droplet dispersion mechanism, the metal droplet 7-1 will fall directly into the baffle 2-3 at the edge of the flywheel 2-1. Due to the rotation, the metal droplet 7-1 will be stretched into a thin layer of liquid metal 7-2, increasing its surface area. Because the constant temperature sealed chamber 1-1 is filled with non-metallic volatile material 6, the two materials react rapidly and combine to form a compound. Because the temperature within the constant temperature sealed chamber 1-1 is far below the melting point of the compound, the formed compound 8 solidifies within the baffle 2-3.

[0061] During the entire reaction process, the compound 8 in the baffle 2-3 gradually thickens, and its surface is partially covered with a thin metal liquid layer 7-2. After the reaction is completed, the thin metal liquid layer 7-2 is converted into a solid compound 8.

[0062] See Figure 5 If the device is provided with a metal droplet dispersion mechanism, the metal droplet 7-1 will be dispersed by the dispersion head 5-2 during the falling process, and the total surface area of ​​the dispersed metal droplets 7-3 is larger than the surface area of ​​the metal droplet 7-1, and the time for the metal droplet 7-1 to drip in the constant temperature closed chamber 1-1 filled with the non-metallic volatile material 6 is longer than the time for the metal droplet 7-1 to drip directly, so that the reaction is more complete.

[0063] In order to prevent the scattered metal droplets 7-3 from splashing, the metal droplet dispersion mechanism can be set in the baffle 2-3, such as Figure 6 shown.

[0064] After the synthesis is completed, the device status is as follows Figure 7 Stop driving device 2-2, stop heating to room temperature, dismantle the device, and take out compound 8.

Claims

1. A low-temperature continuous synthesis device for a compound, characterized in that: The device includes a constant temperature chamber, a rotating flywheel system, an air supply system, and a metal dripping system; The constant temperature chamber comprises a constant temperature sealed chamber (1-1), a constant temperature chamber heater (1-2) and a thermal insulation layer (1-3); The rotating flywheel system comprises a flywheel (2-1) and a driving device (2-2) connected to the flywheel (2-1); the flywheel (2-1) is bowl-shaped and vertically arranged in the insulation layer (1-3); a curved baffle (2-3) is arranged on the edge of the flywheel (2-1); The gas source supply system comprises a gas source bubble (3-1), a gas source heater (3-2) and a gas source supply pipeline (3-3); one end of the gas source supply pipeline is connected to the gas source bubble (3-1), and the other end is provided with an outlet (3-4) in the insulation layer; The metal dripping system comprises a metal liquid heater (4-1), a metal liquid dripping barrel (4-2), a metal liquid dripping nozzle (4-3), and a connecting rod (4-7); the metal dripping system is positioned on the inner wall of the constant temperature closed chamber (1-1) via the connecting rod (4-7); the metal liquid dripping nozzle (4-3) is aligned with a baffle (2-3) on the edge of the flywheel; The metal droplet system further comprises a metal liquid propulsion mechanism, which comprises a propulsion motor (4-4), a propulsion rod (4-5) connected to the propulsion motor (4-4), and a propulsion head (4-6) arranged in the metal liquid droplet barrel (4-2) and connected to the propulsion rod (4-5).

2. The low-temperature continuous synthesis device for compounds according to claim 1, characterized in that: The gas source bubble (3-1) is arranged outside the constant temperature chamber.

3. The low-temperature continuous synthesis device for compounds according to claim 1 or 2, characterized in that: The outlets (3-4) of the gas source supply pipeline (3-3) are provided in a number of 4 to 8.

4. The low-temperature continuous synthesis device for compounds according to claim 1, characterized in that: The device also includes a metal droplet dispersion mechanism arranged on the flywheel (2-1).

5. The low-temperature continuous synthesis device for compounds according to claim 4, characterized in that: The metal droplet dispersion mechanism comprises a connecting column (5-1) connected to a flywheel and a comb-shaped dispersion head (5-2) arranged at the end of the connecting column. The dispersion head (5-2) is in the same vertical position as the metal droplet nozzle (4-3) and is provided with 2-6 teeth.

6. A low-temperature continuous synthesis method for a compound, implemented based on the low-temperature continuous synthesis device for a compound according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: Step 1: Calculate the amount of metal material and non-metal volatile material required for synthesis, place the metal material in the metal droplet barrel (4-2), place the non-metal volatile material (6) in the gas source bubble (3-1), and assemble the device; Step 2: Evacuate the constant temperature sealed chamber (1-1) to 100 Pa, start the constant temperature chamber heater (1-2), heat the constant temperature sealed chamber (1-1) to 300-700°C and maintain the temperature; Step 3: Start the gas source heater (3-2) to gasify the non-metallic volatile material (6) and inject it into the constant temperature closed chamber (1-1) through the gas source supply pipe (3-3) and the outlet (3-4); Step 4: Start the driving device (2-2) to rotate the flywheel (2-1) to a speed of 2000 rpm; Step 5: Start the molten metal heater (4-1) to melt the metal material into a molten metal (7); Step 6: Start the propulsion motor (4-4) of the molten metal propulsion mechanism to discharge the molten metal droplets (7-1) from the molten metal droplet barrel (4-2) through the molten metal droplet nozzle (4-3) until the molten metal (7) in the molten metal droplet barrel (4-2) is completely discharged; Step 7: Stop the driving device (2-2), stop heating to room temperature, dismantle the device, and take out the compound (8).

7. The low-temperature continuous synthesis method of a compound according to claim 6, characterized in that: In step 6, the discharge rate of the metal droplets (7-1) is 5-50 ml / min.

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