A composite coil and quartz tube heating system for germanium zone melting

Abstract

The application relates to a composite coil and quartz tube heating system for germanium zone melting. The composite coil and quartz tube heating system for germanium zone melting comprises a quartz tube support, a quartz tube supported by the quartz tube support and provided with a sealing cover at one end, a heating coil sleeved outside the quartz tube and supported by a coil support, a sandwich layer arranged on the inner side of the upper inner wall of the quartz tube, the lower plane of the sandwich layer being parallel to a zone melting germanium ingot and uniformly provided with air outlet holes, and an air inlet pipe arranged outside the quartz tube and communicated with the inner cavity of the sandwich layer. The heating coil comprises a preheating coil, a main coil and an annealing coil, the main coil is arranged between the preheating coil and the annealing coil, and the preheating coil, the main coil and the annealing coil are independently controlled. The application can reduce the axial temperature gradient of the germanium ingot, form an ideal melting zone state, optimize the impurity removal efficiency and reduce the thermal stress in the crystal growth process.

Description

Technical Field

[0001] This application relates to the technical field of germanium zone melting heating devices, and more particularly to a composite coil and quartz tube heating system for germanium zone melting. Background Technology

[0002] In existing germanium zone melting purification technologies, the heating system typically employs a single main heating coil. This structure creates an excessively large axial temperature gradient, making it difficult to control the solid-liquid and liquid-solid interface morphology. This suboptimal melting zone morphology significantly reduces impurity removal efficiency and may also cause interaction between the molten germanium and the graphite boat, introducing a risk of secondary contamination. Simultaneously, the excessive temperature gradient generates high thermal stress within the material, increasing crystal defects. Regarding the reaction atmosphere, existing technologies use smooth-walled quartz tubes. When low-density hydrogen is introduced as a protective atmosphere, the hydrogen readily forms a laminar flow along the top of the quartz tube's inner wall. However, in the middle and bottom regions of the quartz tube, the gas flow is slow or even stagnant. This uneven atmosphere distribution results in significant differences in the local microenvironment of the germanium ingot at different axial positions within the quartz tube, disrupting the consistency of the zone melting process. This not only reduces impurity removal efficiency but may also cause localized oxidation of the germanium ingot, ultimately affecting the purity and quality of the product. Summary of the Invention

[0003] To address or partially address the problems existing in related technologies, this application provides a composite coil and quartz tube heating system for germanium zone melting, which can reduce the axial temperature gradient of germanium ingots, form an ideal melting zone state, optimize impurity removal efficiency, and reduce thermal stress during crystal growth.

[0004] This application provides a composite coil and quartz tube heating system for germanium zone melting, comprising: Quartz tube support 1; A quartz tube 2, which is mounted on and supported by the quartz tube support 1, has a sealing cap 3 at one end. The heating coil is supported and sleeved on the outside of the quartz tube 2 by the coil bracket; The interlayer 4 is set on the inner side of the upper inner wall of the quartz tube 2. The lower plane of the interlayer is parallel to the zone-melted germanium ingot 14 and has evenly distributed vent holes 5. An air inlet pipe 9 is located on the outside of the quartz tube and communicates with the inner cavity of the interlayer 4; The heating coil includes a preheating coil 6, a main coil 7, and an annealing coil 8. The main coil 7 is arranged between the preheating coil 6 and the annealing coil 8, and the preheating coil 6, the main coil 7, and the annealing coil 8 are controlled independently.

[0005] Optionally, in some embodiments, a linear module 10 is mounted on the quartz tube support 1, and a coil support is mounted on the movable slider of the linear module 10. Furthermore, the distance between the main coil 7 and the preheating coil 6 and the annealing coil 8 is adjustable, and the adjustment range is 1-20mm.

[0006] Optionally, in some embodiments, semi-circular protrusions 11 are evenly arranged on the inner wall of the quartz tube 2, and an exhaust pipe 12 is provided at the end of the quartz tube 2 away from the sealing cover 3.

[0007] Optionally, in some embodiments, an intake pipe valve 13 is provided on the intake pipe 9.

[0008] The technical solution provided in this application may include the following beneficial effects: (1) The temperature gradient and melting zone morphology have been optimized: a composite coil structure with independent control of three stages of preheating, main heating and annealing is adopted to replace the traditional single main heating coil, which effectively reduces the axial temperature gradient of germanium ingot, facilitates the control of solid-liquid and liquid-solid interface morphology, improves the efficiency of impurity removal, and reduces the risk of secondary pollution caused by contact between molten germanium and graphite boat. (2) Reduced crystal defects: The annealing treatment of the annealed coil, combined with the optimization of the temperature gradient, reduced the thermal stress inside the material, reduced the probability of crystal defects, and improved the quality of germanium crystals. (3) A uniform protective atmosphere is achieved: the interlayer and uniform vent design at the top of the quartz tube allow the protective gas to be discharged evenly; the semi-circular protrusion on the inner wall breaks the gas laminar flow and avoids the gas flow stagnation. Combined with the exhaust function of the tail gas pipe, the germanium ingots at different axial positions in the quartz tube are in a consistent local microenvironment, preventing local oxidation and ensuring the consistency of the zone melting process. (4) Improved process flexibility and precision: The position of the heating coil can be adjusted in the linear module, and the spacing between each coil can also be adjusted. The gas inlet valve can control the gas flow rate. The parameters can be flexibly adjusted according to the different germanium zone melting process requirements to further optimize the purification effect and adapt to diverse production needs.

[0009] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0010] The above and other objects, features and advantages of this application will become more apparent from the more detailed description of exemplary embodiments thereof in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments thereof.

[0011] Figure 1 This is a schematic diagram of the composite coil and quartz tube heating system for germanium zone melting shown in the embodiments of this application; Figure 2 This is a top view of the mezzanine arrangement structure shown in the embodiments of this application.

[0012] Figure label: 1-Quartz tube support, 2-Quartz tube, 3-Sealing cap, 4-Interlayer, 5-Exhaust vent, 6-Preheating coil, 7-Main coil, 8-Annealing coil, 9-Inlet pipe, 10-Linear module, 11-Semi-circular protrusion, 12-Exhaust pipe, 13-Inlet pipe valve, 14-Zone-melted germanium ingot, 15-Graphite boat. Detailed Implementation

[0013] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0014] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0015] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0016] To address the aforementioned issues, this application provides a composite coil and quartz tube heating system for germanium zone melting, which can reduce the axial temperature gradient of germanium ingots, form an ideal melting zone state, optimize impurity removal efficiency, and reduce thermal stress during crystal growth.

[0017] The technical solutions of the embodiments of this application are described in detail below with reference to the accompanying drawings.

[0018] See Figure 1-2 The composite coil and quartz tube heating system for germanium zone melting includes: Quartz tube support 1; A quartz tube 2, which is mounted on and supported by the quartz tube support 1, has a sealing cap 3 at one end. The heating coil is supported and sleeved on the outside of the quartz tube 2 by the coil bracket; The interlayer 4 is set on the inner side of the upper inner wall of the quartz tube 2. The lower plane of the interlayer is parallel to the zone-melted germanium ingot 14 and has evenly distributed vent holes 5. An air inlet pipe 9 is located on the outside of the quartz tube and communicates with the inner cavity of the interlayer 4; The heating coil includes a preheating coil 6, a main coil 7, and an annealing coil 8. The main coil 7 is arranged between the preheating coil 6 and the annealing coil 8, and the preheating coil 6, the main coil 7, and the annealing coil 8 are controlled independently.

[0019] During operation, the quartz tube support 1 first provides stable support for the quartz tube 2. The zone-melted germanium ingot 14 is placed inside the quartz tube 2 through the graphite boat 15. One end of the quartz tube 2 is sealed by the sealing cap 3, providing a closed reaction space for the germanium zone melting process. The protective gas enters the interlayer 4 on the upper inner wall of the quartz tube 2 through the gas inlet pipe 9. The lower plane of the interlayer 4 is parallel to the zone-melted germanium ingot 14 and has uniformly distributed gas outlet holes 5. The gas is evenly discharged from the gas outlet holes 5, forming a uniform protective atmosphere around the germanium ingot.

[0020] Simultaneously, the heating coils mounted on the outside of the quartz tube 2 begin to operate. The heating coils are divided into a preheating coil 6, a main coil 7, and an annealing coil 8. The main coil 7 is located between the preheating coil 6 and the annealing coil 8, and the three are controlled independently: first, the preheating coil 6 preheats the germanium ingot inside the quartz tube 2, gradually raising the temperature of the germanium ingot to near the molten state; then, the main coil 7 provides the core heating energy, causing the germanium ingot to form a melting zone and complete the main process of zone melting purification; finally, the annealing coil 8 anneals the germanium ingot that has completed the main zone melting, slowly lowering the temperature of the germanium ingot and reducing thermal stress; the preheating coil 6 is used to preheat the germanium ingot to 400-500℃, and the annealing coil 8 is used to anneal the germanium ingot at 500-600℃.

[0021] In some embodiments, a linear module 10 is mounted on the quartz tube support 1, a coil support is mounted on the movable slider of the linear module 10, and the distance between the main coil 7 and the preheating coil 6 and the annealing coil 8 is adjustable, with an adjustment range of 1-20mm.

[0022] During operation, the linear module 10 on the quartz tube support 1 plays an adjustment role. The coil support is installed on the movable slider of the linear module 10. When it is necessary to adjust the temperature distribution of the melting zone, the linear module 10 is controlled to move the coil support, which in turn moves the heating coil, changing the heating position. The distance between the main coil 7 and the preheating coil 6 and annealing coil 8 can be adjusted by the coil support (e.g., by screw adjustment). The adjustment range is 1-20mm. According to the process requirements of germanium zone melting, adjusting the distance between different coils can optimize the overlap of the heating areas of each coil, further precisely control the axial temperature gradient of the germanium ingot, and make the melting zone shape more in line with the purification requirements.

[0023] In some embodiments, semi-circular protrusions 11 are evenly arranged on the inner wall of the quartz tube 2, and an exhaust pipe 12 is provided at the end of the quartz tube 2 away from the sealing cap 3.

[0024] During operation, the semi-circular protrusions 11 on the inner wall of the quartz tube 2 will disturb the flow of the protective gas. When the protective gas is discharged from the vent 5 of the interlayer 4, the semi-circular protrusions 11 break the laminar flow state of the gas as it flows inside the quartz tube 2, preventing the gas from stagnating in the middle and bottom of the quartz tube 2. At the same time, the tail gas pipe 12 set at the end of the quartz tube 2 away from the sealing cover 3 is used to discharge the waste gas or excess protective gas after the reaction in a timely manner, ensuring the stable gas pressure inside the quartz tube 2 and forming a closed loop of gas flow, continuously providing a uniform and fresh protective atmosphere for germanium zone melting.

[0025] In some embodiments, an intake pipe valve 13 is provided on the intake pipe 9.

[0026] During operation, the inlet valve 13 on the inlet pipe 9 can control the amount and speed of protective gas in real time. According to the protective atmosphere requirements of different stages of germanium zone melting, the flow rate of gas entering the interlayer 4 can be precisely controlled by adjusting the opening of the inlet valve 13, ensuring that the gas flow rate and pressure discharged from the outlet 5 are stable, further ensuring the uniformity of the protective atmosphere in the quartz tube 2, and adapting to the atmosphere requirements of each process stage of germanium zone melting.

[0027] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A composite coil and quartz tube heating system for germanium zone melting, characterized in that: The composite coil and quartz tube heating system for germanium zone melting includes: Quartz tube support (1); A quartz tube (2) is mounted on a quartz tube support (1) and supported by the quartz tube support (1), and a sealing cap (3) is provided at one end. The heating coil is supported by a coil bracket and sleeved on the outside of the quartz tube (2); An interlayer (4) is set on the inner side of the upper inner wall of the quartz tube (2). The lower plane of the interlayer is parallel to the zone-melted germanium ingot (14) and has vent holes (5) evenly distributed. An air inlet pipe (9) is set on the outside of the quartz tube and communicates with the inner cavity of the interlayer (4); The heating coil includes a preheating coil (6), a main coil (7) and an annealing coil (8). The main coil (7) is arranged between the preheating coil (6) and the annealing coil (8), and the preheating coil (6), the main coil (7) and the annealing coil (8) are independently controlled.

2. The composite coil and quartz tube heating system for germanium zone melting according to claim 1, characterized in that: A linear module (10) is installed on the quartz tube support (1), and a coil support is installed on the movable slider of the linear module (10). The distance between the main coil (7) and the preheating coil (6) and the annealing coil (8) is adjustable, and the adjustment range is 1-20mm.

3. The composite coil and quartz tube heating system for germanium zone melting according to claim 1 or 2, characterized in that: The inner wall of the quartz tube (2) is evenly arranged with semi-circular protrusions (11), and the end of the quartz tube (2) away from the sealing cap (3) is provided with a tailpipe (12).

4. The composite coil and quartz tube heating system for germanium zone melting according to claim 3, characterized in that: An air intake valve (13) is provided on the air intake pipe (9).

Images