Indium phosphide polycrystal high-pressure synthesis furnace

Abstract

An indium phosphide polycrystal high-pressure synthetic furnace relates to the technical field of semiconductor materials and comprises a furnace body, a quartz tube is arranged in the furnace body, a first quartz boat for containing red phosphorus is arranged at one end in the quartz tube, and a second quartz boat for containing indium is arranged at the other end in the quartz tube. A reaction transition device is arranged in the quartz tube between the first quartz boat and the second quartz boat, the reaction transition device comprises an outer tube, the outer tube is in close fit with the quartz tube, small-caliber passing openings are reserved in the two ends of the outer tube, separation blades which are uniformly distributed at intervals are arranged on the inner side of the outer tube, and a notch is reserved between each separation blade and the outer tube; and the phase angles of the gaps of the adjacent separation blades differ by 180 degrees. The reaction transition device provided by the utility model can effectively control the pressure change in the quartz tube and the synthesis process, and prevents furnace explosion and the conditions of rich indium, holes and the like caused by insufficient reaction in the synthesis process. Compared with a Bridgman method, the synthesis quality of the indium phosphide polycrystal is greatly improved, and a reliable foundation is laid for subsequent single crystal growth.

Description

Technical Field

[0001] The utility model belongs to the technical field of semiconductor materials, and in particular relates to an indium phosphide polycrystalline high-pressure synthesis furnace. Background Art

[0002] Indium phosphide single crystal material belongs to the second generation of semiconductor materials, has a zinc blende crystal structure, and its melting point is 1070 degrees Celsius. Because of its many electrochemical properties, it is currently widely used in optical communications, millimeter wave devices, integrated circuits, space exploration, solar cells, etc. It has an objective market prospect.

[0003] The growth of InP single crystals is inseparable from the synthesis of polycrystals. Qualified polycrystalline materials are the basis for growing high-quality single crystal materials. Therefore, the preparation of polycrystalline materials is particularly important.

[0004] The commonly used method for synthesizing indium phosphide polycrystals is the horizontal Bridgman method. Due to its high synthesis pressure, generally 2-4 MPa, and synthesis temperature of about 1100 degrees Celsius, the traditional Bridgman method cannot synthesize large quantities of low-cost polycrystals, has a high risk of furnace explosion, and the product has unstable electrical properties, is rich in indium, and has many holes. Utility Model Content

[0005] In order to solve the problems in the background technology, the utility model provides an indium phosphide polycrystalline high-pressure synthesis furnace. The reaction transition device in the utility model can effectively control the pressure change and the synthesis process in the vacuum tube to prevent the furnace from exploding. The indium-rich and pores caused by insufficient reaction during the synthesis process are also basically improved.

[0006] The utility model provides a technical solution: an indium phosphide polycrystalline high-pressure synthesis furnace, comprising a temperature control system, a pressure control system, an electric heating system and a furnace body, wherein a quartz tube is arranged in the furnace body, an electric heating body is arranged outside the quartz tube, the electric heating body comprises a high temperature zone and a low temperature zone, a first quartz boat for containing red phosphorus is arranged at one end of the quartz tube, a second quartz boat for containing indium is arranged at the other end of the quartz tube, a reaction transition device is arranged in the quartz tube between the first quartz boat and the second quartz boat, the reaction transition device comprises an outer tube, the outer tube is tightly matched with the quartz tube, two ends of the outer tube are provided with through openings with a diameter smaller than the diameter of the outer tube, the inner side of the outer tube is provided with baffles arranged at even intervals, the baffles are arranged perpendicularly to the axis of the outer tube, each baffle has a gap between the outer tube, and the phase angles of the gaps of adjacent baffles differ by 180 degrees; the low temperature zone corresponds to the position of the first quartz boat, and the high temperature zone corresponds to the position of the second quartz boat.

[0007] The quartz reaction transition device placed in the middle of the quartz tube is particularly critical in the process of polycrystal synthesis. It not only blocks the large amount of red phosphorus from entering the high-temperature zone during the synthesis process, causing uncontrollable pressure, but also transports an appropriate amount of red phosphorus to the high-temperature zone through the reaction transition device.

[0008] A further technical solution is: the indium phosphide polycrystalline high-pressure synthesis furnace also includes a cooling water circulation system, the furnace body is a double-wall structure with a cavity, the upper end of the cavity is connected to the cooling water outlet, and the lower end of the cavity is connected to the cooling water inlet.

[0009] A further technical solution is that the reaction transition device is made of quartz.

[0010] A further technical solution is that both ends of the outer tube are elliptical.

[0011] A further technical solution is that the axis of the quartz tube coincides with the axis of the electric heating element, and the axis of the electric heating element coincides with the axis of the furnace body.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] 1. Compared with the traditional Bridgman method, the present application can safely and stably synthesize large-mass indium phosphide polycrystalline materials, and the output of a single furnace can reach about 12 kilograms, which can provide sufficient qualified polycrystalline materials for subsequent single crystal growth.

[0014] 2. Compared with the traditional Bridgman method, the reaction transition device in the present application can effectively control the pressure change and synthesis process in the quartz tube, and prevent the explosion of the furnace and the generation of indium-rich and holes due to insufficient reaction during the synthesis process.

[0015] 3. The present application can effectively reduce the synthesis failure rate through pressure control, temperature control and water temperature control. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0017] Figure 2 It is a structural schematic diagram of a reaction transition device in the utility model.

[0018] In the figure: 1, furnace body; 2, electric heating element; 3, quartz tube; 4, second quartz boat; 5, first quartz boat; 6, baffle; 7, notch; 8, outer tube; 9, through port. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0020] This embodiment includes a temperature control system, a pressure control system, an electric heating system and a furnace body 1, which are structures already existing in the prior art and will not be described in detail here.

[0021] The innovation of this embodiment is that a quartz tube 3 is arranged in the furnace body 1, and an electric heating body 2 is arranged outside the quartz tube 3, and the electric heating body 2 includes a high temperature zone and a low temperature zone. A first quartz boat 5 for holding red phosphorus is arranged at one end of the quartz tube 3, and a second quartz boat 4 for holding indium is arranged at the other end of the quartz tube 3. A reaction transition device is arranged in the quartz tube 3 between the first quartz boat 5 and the second quartz boat 4. After the reaction material is loaded into the quartz tube 3, an end cap is welded to the end of the quartz tube 3, and then the quartz tube 3 is evacuated.

[0022] like Figure 2 As shown, the reaction transition device includes an outer tube 8, which is polished to fit tightly with the quartz tube 3, and through openings 9 with a diameter smaller than the diameter of the outer tube 8 are left at both ends of the outer tube 8. The inner side of the outer tube 8 is provided with evenly spaced baffles 6, and the baffles 6 are arranged perpendicular to the axis of the outer tube 8. Each baffle 6 has a gap 7 between it and the outer tube 8, and the phase angles of the gaps 7 of adjacent baffles 6 differ by 180 degrees.

[0023] The low temperature zone corresponds to the position of the first quartz boat 5 , and the high temperature zone corresponds to the position of the second quartz boat 4 .

[0024] The quartz reaction transition device placed in the middle of the quartz tube 3 is particularly critical in the process of polycrystalline synthesis. It is necessary to prevent a large amount of red phosphorus from entering the high temperature zone during the synthesis process, causing uncontrollable pressure, and to transport an appropriate amount of red phosphorus to the high temperature zone through the reaction transition device. The reaction transition device can effectively control the pressure change and synthesis process in the quartz tube 3, and prevent furnace explosion and indium-rich, pores, etc. caused by insufficient reaction during the synthesis process.

[0025] The indium phosphide polycrystalline high-pressure synthesis furnace also includes a cooling water circulation system. The furnace body 1 is a double-wall structure with a cavity. The upper end of the cavity is connected to the cooling water outlet, and the lower end of the cavity is connected to the cooling water inlet. After the furnace pressure and temperature are stable, the cooling water outlet temperature should be controlled below 60 degrees Celsius, and the next synthesis stage can be entered. The synthesis program is input into the temperature control system, and each temperature zone of the entire synthesis furnace will be slowly cooled down in an orderly manner according to the synthesis program. The pressure must be kept constant throughout the synthesis stage. If there is a change, the inflation or deflation must be adjusted at any time through the pressure control panel. The pressure must always be controlled at the initial value before synthesis. The cooling water temperature must also remain unchanged and be adjusted at any time if there is a change. Note that someone must be on duty throughout the synthesis process, and abnormal conditions must be restored to normal within 1 minute, otherwise the probability of furnace explosion is extremely high.

[0026] The reaction transition device is made of quartz, which is beneficial to improving the purity of polycrystalline synthesis.

[0027] Both ends of the outer tube 8 are elliptical, and the elliptical structure has a better pressure bearing capacity.

[0028] The axis of the quartz tube 3 coincides with the axis of the electric heating element 2 , and the axis of the electric heating element 2 coincides with the axis of the furnace body 1 , which is beneficial to improving the uniformity of heating the quartz tube 3 .

Claims

1. An indium phosphide polycrystalline high-pressure synthesis furnace, comprising a temperature control system, a pressure control system, an electric heating system and a furnace body (1), characterized in that: A quartz tube (3) is arranged in the furnace body (1), an electric heating element (2) is arranged outside the quartz tube (3), the electric heating element (2) comprises a high temperature zone and a low temperature zone, a first quartz boat (5) for containing red phosphorus is arranged at one end of the quartz tube (3), a second quartz boat (4) for containing indium is arranged at the other end of the quartz tube (3), a reaction transition device is arranged in the quartz tube (3) between the first quartz boat (5) and the second quartz boat (4), the reaction transition device comprises an outer tube (8), the outer tube (8) and the quartz tube (4) are connected to each other. The quartz tube (3) is tightly matched, and both ends of the outer tube (8) are provided with through openings (9) with a diameter smaller than the diameter of the outer tube (8). The inner side of the outer tube (8) is provided with baffles (6) arranged at even intervals, and the baffles (6) are arranged perpendicularly to the axis of the outer tube (8). Each baffle (6) has a gap (7) between it and the outer tube (8), and the phase angles of the gaps (7) of adjacent baffles (6) differ by 180 degrees. The low temperature zone corresponds to the position of the first quartz boat (5), and the high temperature zone corresponds to the position of the second quartz boat (4).

2. The indium phosphide polycrystal high pressure synthesis furnace according to claim 1, characterized in that: It also includes a cooling water circulation system. The furnace body (1) is a double-wall structure with a cavity. The upper end of the cavity is connected to the cooling water outlet, and the lower end of the cavity is connected to the cooling water inlet.

3. The indium phosphide polycrystal high pressure synthesis furnace according to claim 1, characterized in that: The reaction transition device is made of quartz.

4. The indium phosphide polycrystal high pressure synthesis furnace according to claim 1, characterized in that: Both ends of the outer tube (8) are elliptical.

5. The indium phosphide polycrystal high pressure synthesis furnace according to claim 1, characterized in that: The axis of the quartz tube (3) coincides with the axis of the electric heating element (2), and the axis of the electric heating element (2) coincides with the axis of the furnace body (1).

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