An apparatus and method for synthesizing compounds by centrifugal diffusion

Abstract

A device and method for synthesizing compounds by centrifugal diffusion, belonging to the field of compound semiconductor technology, comprises a constant temperature chamber, a centrifugal diffusion 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 centrifugal diffusion system; heating the metal droplet system; and injecting metal droplets into the constant temperature chamber to synthesize the compound. 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 synthesizing semiconductor compounds by increasing the surface area of metal droplets through centrifugal force. 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 provide a solution to the above problems.

[0010] To achieve the purpose of the invention, the present invention provides a device for synthesizing compounds by centrifugal diffusion and a synthesis method using the device.

[0011] A device for synthesizing compounds by centrifugal diffusion comprises a constant temperature chamber, a centrifugal diffusion system, a gas source supply system and a metal droplet system.

[0012] The constant temperature chamber comprises a constant temperature sealed chamber, a constant temperature chamber heater, a discharge port and a discharge valve.

[0013] The centrifugal diffusion system includes a disc-shaped rotating wheel connected to a driving device and arranged inside a constant temperature closed chamber.

[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 connected to a circular arc-shaped gas supply disk. A plurality of air outlet holes are arranged on the disk surface of the gas supply disk; the circular arc surface of the gas supply disk matches the outer contour of the runner and is arranged close to the runner.

[0015] The metal dripping system is arranged at the top of the constant temperature closed chamber, and comprises a metal liquid heater, a metal liquid dripping barrel, a metal liquid dripping nozzle, and the metal liquid dripping nozzle is aligned with the center of the rotating wheel.

[0016] A method for synthesizing a compound by centrifugal diffusion using the above 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 500-700°C and maintain the temperature. This 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 pipe and the gas outlet.

[0020] Step 4: Start the driving device to rotate the wheel, and the speed reaches 1000 rpm.

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

[0022] Step 6: Start the propulsion motor of the molten metal propulsion mechanism, and the molten metal is discharged from the molten metal droplet barrel through the molten metal droplet nozzle as metal droplets. The metal droplets drip onto the runner under the action of gravity until the molten metal in the molten metal droplet 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 wheel 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: The present invention's greatest advantage lies in its synthesis temperature, which is far below the compound's melting point, 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, avoiding material contamination and further improving the compound's purity. 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 schematic diagram of the device of the present invention,

[0028] Figure 2 is a schematic diagram of another direction of the device of the present invention,

[0029] Figure 3 for Figure 1 A partial enlarged view of the dotted box in the middle.

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

[0031] Figure 5 This is the state diagram of the device after synthesis is completed.

[0032] Among them, 1-1: constant temperature closed chamber, 1-2: constant temperature chamber heater, 1-3: discharge port, 1-4: discharge valve, 1-5: vacuum port, 2-1: rotary wheel, 2-2: driving device, 3-1: gas source bubble, 3-2: gas source heater, 3-3: gas source supply pipeline, 3-4: gas supply plate, 3-5: main gas outlet, 3-6: auxiliary gas outlet, 3-7: bottom gas outlet, 4-1: metal liquid heater, 4-2: metal droplet barrel, 4-3: metal droplet nozzle, 4-4: propulsion motor, 4-5: propulsion rod, 4-6: propulsion head, 5: non-metallic volatile material, 6, compound, 7: metal melt, 7-1: metal droplet, 7-2: thin layer of metal liquid, 7-3: scattered metal droplets. DETAILED DESCRIPTION

[0033] A device for synthesizing compounds by centrifugal diffusion comprises a constant temperature chamber, a centrifugal diffusion system, a gas source supply system and a metal droplet system.

[0034] See Figure 1 、 Figure 2 .

[0035] The constant temperature chamber includes a sealed constant temperature chamber 1-1 and a chamber heater 1-2. The heater 1-2 is made of a resistance heating wire or graphite, and can maintain the temperature within the chamber 1-1 at a constant temperature of 300-700°C. The chamber 1-1 is made of dense corundum, capable of achieving a vacuum of 100 Pa and withstanding a gas pressure of 0.2 MPa at a constant temperature of 700°C.

[0036] The centrifugal diffusion system includes a disc-shaped rotor 2-1 connected to a drive device 2-2 and disposed within a constant-temperature, sealed chamber 1-1. Drive device 2-2 connects to the rotor 2-1 via a shaft, driving the rotor 2-1 to rotate at a speed of 1,000 to 3,000 rpm. The rotor 2-1 is made of stainless steel and has a diameter of 300 to 10,000 mm.

[0037] The gas supply system includes a gas source bubble 3-1, a gas source heater 3-2 and a gas source supply pipe 3-3. One end of the gas source supply pipe is connected to the gas source bubble 3-1, and the other end is connected to the arc-shaped gas supply disk 3-4. A plurality of gas outlet holes are set on the disk surface of the gas supply disk 3-4: the main gas outlet hole 3-5 is set on the arc concave surface of the gas supply disk 3-4, and the auxiliary gas outlet hole 3-6 is set on the arc convex surface. The bottom end of the gas supply disk 3-4 is also provided with a bottom auxiliary gas outlet hole 3-7. Figure 3 shown.

[0038] The gas source bubble 3-1 is made of high-purity quartz or stainless steel, the gas source supply pipe 3-3 is made of quartz or stainless steel, the gas supply disk 3-4 is made of high-purity quartz or stainless steel, and the gas source heater 3-2 is made of nickel-chromium resistance wire, molybdenum wire or induction coil, with a heating power of 2000W~10000W.

[0039] The gas source bubble 3-1 is arranged outside the constant temperature chamber, and the gas source supply pipe 3-3 enters the constant temperature closed chamber 1-1.

[0040] The length of the air supply disk 3-4 is greater than 1 / 4 of an arc and less than a semicircle. The edge of the top is close to the vertical direction of the metal droplet nozzle 4-3, and the horizontal distance between the two is less than 10 mm. The rotation direction of the runner 2-1 is from the top to the bottom of the air supply disk 3-4. The width of the air supply disk 3-4 is greater than the width of the runner 2-1.

[0041] The arc surface of the air supply disc 3-4 matches the outer contour of the runner 2-1 and is arranged close to the runner 2-1 with a spacing of less than 10 mm.

[0042] The metal dripping system includes a metal heater 4-1, a metal dripping tank 4-2, and a metal dripping nozzle 4-3, which is aligned with the center of the rotating wheel 2-1. The metal heater 4-1 is made of nickel-chromium resistance wire, molybdenum wire, or an induction coil. The metal dripping tank 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 dripping system is arranged outside the constant temperature sealed chamber 1-1, and the metal dripping nozzle 4-3 penetrates through the shell of the constant temperature sealed chamber 1-1 and penetrates into the interior of the constant temperature sealed chamber 1-1.

[0044] 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.

[0045] The method for synthesizing a compound by centrifugal diffusion based on the above device comprises the following steps:

[0046] 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 5 in the gas source bubble 3-1, and assemble the device.

[0047] In this embodiment, the metal material is indium, and the volatile metal material 5 is phosphorus.

[0048] Step 2: evacuate the constant temperature sealed chamber 1-1 to 100 Pa through the vacuum port 1-5, start the constant temperature chamber heater 1-2, heat the constant temperature sealed chamber 1-1 to 500-700°C and maintain the temperature.

[0049] 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.

[0050] Step 3: Activate gas source heater 3-2 to vaporize non-metallic volatile material 5. The vaporized non-metallic volatile material 5 is then injected into constant temperature sealed chamber 1-1 through gas source supply pipe 3-3, main gas outlet 3-5, auxiliary gas outlet 3-6, and bottom gas outlet 3-7. After a period of time, constant temperature sealed chamber 1-1 is filled with vaporized non-metallic volatile material 5.

[0051] Step 4: Start the driving device 2-2 to rotate the wheel 2-1, and the speed reaches 1000 rpm.

[0052] Step 5: Start the molten metal heater 4 - 1 to melt the metal material into a metal melt 7 .

[0053] Step 6: Start the propulsion motor 4-5 of the molten metal propulsion mechanism to discharge the molten metal droplets 7-1 from the molten metal drop barrel 4-2 through the molten metal drop nozzle 4-3. The molten metal droplets 7-1 drip onto the runner 2-1 under the action of gravity until the molten metal 7 in the molten metal drop barrel 4-2 is completely discharged.

[0054] The discharge rate of the metal droplets 7-1 is 5-50 ml / min.

[0055] 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.

[0056] See Figure 4 After the metal droplets 7-1 are discharged, they fall onto the surface of the runner 2-1. The metal droplets are stretched tangentially by the rotating runner 2-1. The metal droplets 7-1 are sufficiently flattened and extended. The extension of the metal liquid forms a thin metal liquid layer 7-2, which greatly increases the exposed surface area of the metal liquid.

[0057] The arc concave surface of the gas supply disk 3-4 is provided with a main gas outlet 3-5. The gap between the gas supply disk 3-4 and the runner 2-1 is filled with non-metallic volatile material 5 gas, and the metal materials are quickly combined to form a compound.

[0058] During this process, some of the liquid metal will splash onto the gas supply plate 3-4, and the synthesized compound may also splash onto the gas supply plate 3-4. However, due to the high temperature inside the constant temperature sealed chamber 1-1, the metal material is in a liquid state, and the metal on the surface of the gas supply plate 3-4 will drip onto the rotor 2-1. The metal entering the main gas outlet 3-5 will be synthesized inside the gas supply plate 3-4. The unfinished liquid metal will drip from other main gas outlets 3-5 or from the bottom gas outlet 3-7 due to gravity, continuing to react during the dripping process. The synthesized compound, because its melting point is higher than the temperature inside the constant temperature sealed chamber 1-1, becomes a solid powder after synthesis and falls to the bottom of the constant temperature sealed chamber 1-1 due to gravity.

[0059] As the wheel 2-1 rotates, the liquid metal that is out of the coverage of the gas supply disk 3-4 will disperse to form dispersed metal droplets 7-3. The total surface area of the dispersed metal droplets 7-3 is larger than the surface area of a single metal droplet 7-1, and they fall into the constant temperature closed chamber 1-1 filled with non-metallic volatile material 5, allowing the reaction to proceed rapidly.

[0060] After the synthesis is completed, the device status is as follows Figure 5 Stop the driving device 2-2, stop heating to room temperature, open the discharge valve 1-4, and take out the synthesized compound 6 from the discharge port 1-3.

Claims

1. A device for synthesizing compounds by centrifugal diffusion, characterized in that: The device includes a constant temperature chamber, a centrifugal diffusion system, an air source 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), a discharge port (1-3) and a discharge valve (1-4); The centrifugal diffusion system comprises a disc-shaped rotating wheel (2-1) connected to a driving device (2-2) and arranged inside a constant temperature sealed chamber (1-1); The gas source supply system comprises a gas source bubble (3-1), a gas source heater (3-2) and a gas source supply pipe (3-3); one end of the gas source supply pipe is connected to the gas source bubble (3-1), and the other end is connected to an arc-shaped gas supply disk (3-4); a plurality of gas outlet holes are provided on the disk surface of the gas supply disk (3-4); the arc surface of the gas supply disk (3-4) matches the outer contour of the rotating wheel (2-1) and is provided close to the rotating wheel (2-1); The metal droplet system is arranged at the top of the constant temperature closed chamber (1-1), and comprises a metal liquid heater (4-1), a metal liquid droplet barrel (4-2), and a metal liquid droplet nozzle (4-3), wherein the metal liquid droplet nozzle (4-3) is aligned with the center of the rotating wheel (2-1).

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

3. The device for synthesizing compounds by centrifugal diffusion according to claim 1 or 2, characterized in that: The arc concave surface of the air supply disk (3-4) is provided with a main air outlet (3-5), and the arc convex surface is provided with an auxiliary air outlet (3-6).

4. The device for synthesizing compounds by centrifugal diffusion according to claim 3, characterized in that: The length of the gas supply disk (3-4) is greater than 1 / 4 of an arc and less than a semicircle, the edge of the top is close to the vertical direction of the metal droplet nozzle (4-3), and the rotation direction of the wheel (2-1) is from the top to the bottom of the gas supply disk (3-4).

5. The device for synthesizing compounds by centrifugal diffusion according to claim 4, characterized in that: The width of the air supply disc (3-4) is greater than the width of the rotating wheel (2-1).

6. The device for synthesizing compounds by centrifugal diffusion according to claim 1, characterized in that: The metal dripping system is arranged outside the constant temperature sealed chamber (1-1), and the metal dripping nozzle (4-3) penetrates the outer shell of the constant temperature sealed chamber (1-1) and protrudes into the constant temperature sealed chamber (1-1).

7. The device for synthesizing compounds by centrifugal diffusion according to claim 6, characterized in that: 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 droplet barrel (4-2) and connected to the propulsion rod (4-5).

8. A method for synthesizing a compound by centrifugal diffusion, based on the device for synthesizing a compound by centrifugal diffusion according to any one of claims 1 to 7, 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 bucket (4-2), place the non-metal volatile material (5) 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 500-700° C. and maintain the temperature; Step 3: Start the gas source heater (3-2) to gasify the non-metallic volatile material (5) and inject it into the constant temperature closed chamber (1-1) through the gas source supply pipe (3-3) and the gas outlet; Step 4: Start the driving device (2-2) to rotate the wheel (2-1) to a speed of 1000 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 metal liquid propulsion mechanism, and the metal melt (7) is discharged from the metal liquid drop barrel (4-2) through the metal liquid drop nozzle (4-3) as metal droplets (7-1). The metal droplets (7-1) drip onto the rotating wheel (2-1) under the action of gravity until the metal melt (7) in the metal liquid drop 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.

9. The method for synthesizing a compound by centrifugal diffusion according to claim 8, characterized in that: In step 6, the discharge rate of the metal droplets (7-1) is 5-50 ml / min.

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