Low-defect indium arsenide single crystal and preparation process thereof

Abstract

The invention discloses a low-defect indium arsenide single crystal and a preparation process thereof in the technical field of semiconductor materials. The core of the process is that two specific inorganic modified compounds, namely a nitrogen source polycrystal material containing lanthanum and arsenic and an indium arsenide polycrystal material containing europium, are cooperatively used in the growth process of the indium arsenide single crystal. According to the method, crystal growth is carried out by adopting a vertical gradient solidification method under strict arsenic overpressure protection through an accurate burdening and layered charging technology, and high-temperature in-situ annealing is combined. According to the method, formation and proliferation of intrinsic defects such as arsenic vacancy can be effectively inhibited, and the dislocation density of the crystal is remarkably reduced, so that the low-defect indium arsenide single crystal material with extremely high crystal integrity and excellent electrical and optical properties is prepared, and the method is suitable for preparing high-performance infrared detectors, lasers and high-speed electronic devices.

Description

Technical Field

[0001] This invention relates to the field of semiconductor materials technology, specifically to a low-defect indium arsenide single crystal and its preparation process. Background Technology

[0002] Indium arsenide (IAR) single crystals, as an important third-generation semiconductor material, play an indispensable role in cutting-edge technologies such as infrared detection, high-speed electronic devices, and quantum communication. Their extremely high electron mobility and superior narrow bandgap optoelectronic properties enable devices fabricated from this material to operate efficiently at room temperature, meeting the urgent needs of modern information technology for high-speed, high-frequency, and low-power devices. Particularly in long-wavelength infrared detection and laser applications, IAR single crystals are the core substrate material for fabricating high-performance photodiodes, laser arrays, and heterojunction transistors. With the rapid development of national defense, space exploration, and high-speed optical communication, the demand for large-area, high-quality, and low-defect IAR single crystal substrates is increasing. The quality of these substrates directly determines the performance limits and reliability of end devices; therefore, improving the crystal quality of IAR single crystals has become a crucial and highly challenging issue in the field of semiconductor materials.

[0003] However, the large-scale fabrication of indium arsenide single crystals still faces a series of severe technical bottlenecks, the most critical of which lies in the difficulty of effectively controlling intrinsic point defects and structural defects in the crystal. Traditional fabrication methods, such as liquid-sealed Czochralski or vertical gradient solidification, are prone to deviations in the melt stoichiometry during growth due to the high volatility of arsenic components, leading to the formation of high concentrations of intrinsic point defects such as arsenic and indium vacancies. These point defects not only act as non-radiative recombination centers, significantly reducing the quantum efficiency of optoelectronic devices, but also uncontrollably contribute charge carriers, degrading the electrical uniformity of the material. Simultaneously, the thermal stress generated during crystal cooling often induces high-density dislocations and grain boundaries, which become scattering centers and leakage channels for charge carriers, severely impairing the device's lifespan and stability. Although researchers have made improvements through optimizing thermal field design and applying component overvoltage, the defect density, especially the dislocation density, remains difficult to reduce to the ideal level required for high-end device applications. This fundamentally restricts the widespread application and industrialization of indium arsenide single crystals in high-performance devices.

[0004] To overcome the constraints imposed by the aforementioned material defects, the research focus in the industry has gradually shifted from simply optimizing process parameters to introducing specific "defect engineering" strategies into the growth system. Actively intervening in the formation and evolution of defects by adding trace amounts of dopants or modifiers with specific functions during crystal growth is considered a promising solution. Ideally, additives should function at the atomic scale, effectively suppressing or passivating harmful defects, for example, by occupying vacancies, pinning dislocations, or modulating local stress fields. In recent years, some studies have attempted to introduce rare earth elements or other elements with unique electronic structures into semiconductor materials, hoping to improve crystal quality through their interaction with the matrix material. However, how to design and prepare novel composite additives that can exist stably in high-temperature indium arsenide melts and precisely perform their intended defect control functions, while avoiding the introduction of secondary impurity defects, remains an unresolved problem in this field. Against this backdrop, this invention proposes an innovative material design and preparation process aimed at fundamentally improving the integrity of indium arsenide single crystals. Summary of the Invention

[0005] The purpose of this invention is to provide a low-defect indium arsenide single crystal and its preparation process, which solves the technical problems of high defect density and poor crystal quality when preparing indium arsenide single crystals using existing methods.

[0006] The present invention achieves the above objectives through the following technical solutions: A process for preparing low-defect indium arsenide single crystals, comprising the following steps: S1. By weight, in an argon-protected glove box, 950-1050 parts of polycrystalline InAs, 0.5-5.0 parts of nitrogen-source polycrystalline material containing lanthanum and arsenic, and 0.1-2.0 parts of polycrystalline material containing europium indium arsenide are placed into a quartz crucible with a pyrolytic boron nitride coating deposited on the inner wall to obtain a crucible containing the raw materials. S2. Place the crucible containing the raw materials into a single crystal furnace, evacuate to a high vacuum, fill with arsenic vapor and establish an arsenic overpressure of 1.2-1.8 atm, heat to 990-995℃ and hold; <100> Oriented InAs seed crystals induce vertical gradient solidification crystal growth; after growth, in-situ annealing is carried out in an arsenic vapor atmosphere of 880-920℃, and finally cooled to room temperature, followed by orientation, cutting, grinding and chemical mechanical polishing.

[0007] In this invention, the growth of low-defect indium arsenide single crystals begins with a gradient packing strategy of functionalized raw materials: a bottom indium arsenide buffer layer, a middle europium source functional layer, an upper lanthanum-nitrogen source functional layer, and a surface sealing layer constitute a spatial distribution system. The melting stage is carried out under an overpressure environment of arsenic vapor, effectively suppressing the volatilization of arsenic components. During vertical gradient solidification, nitrogen atoms released from the lanthanum-nitrogen source polycrystalline material act as isoelectronic traps, precisely occupying arsenic sites in the lattice and significantly suppressing arsenic vacancy generation; lanthanum selectively segregates to the grain boundary region, pinning dislocation movement and enhancing the stability of the interface structure. Simultaneously released europium ions act as deep-level centers, efficiently capturing charge carriers and passivating the electrical activity of point defects. After growth termination, thorough in-situ annealing is performed in an arsenic atmosphere to promote residual defect recombination and internal stress relaxation, followed by a gentle cooling process to avoid thermal shock. Finally, the crystal is obtained through precision machining. The synergistic effect of three elements constitutes the core mechanism for defect suppression: the nitrogen source suppresses intrinsic point defects, the lanthanum source enhances the integrity of the macroscopic structure, and the europium source optimizes the microscopic electrical environment. Together, they construct a high-quality single-crystal system with extremely low dislocation density and excellent carrier migration performance, providing key material support for high-end optoelectronic and infrared detection devices.

[0008] According to a preferred embodiment of the present invention, in step S1, the order of adding the crucible is as follows: first, add 30-50 parts of polycrystalline InAs to the bottom of the crucible, then add 0.1-2.0 parts of polycrystalline material containing europium indium arsenide, then add 870-920 parts of polycrystalline InAs, then add 0.5-5.0 parts of nitrogen source polycrystalline material containing lanthanum and arsenic, and finally add 50-80 parts of polycrystalline InAs.

[0009] According to a preferred embodiment of the present invention, in step S2, the heating to 990-995°C and the holding time is 10-12 hours.

[0010] According to a preferred embodiment of the present invention, the method for preparing the lanthanum and arsenic-containing nitrogen source polycrystalline material includes: A1. By weight, in an argon glove box, place 100 parts of indium granules, 5.2-5.5 parts of lanthanum shavings, and 48-52 parts of arsenic blocks into a quartz crucible liner with a pyrolytic boron nitride coating on the inner wall; place 31-33 parts of arsenic blocks as an arsenic vapor buffer source in a groove at the other end of the liner; place the liner into a quartz ampoule, evacuate, and then fill it with a mixed gas of 0.5-1.0 atm consisting of 95-97% argon and 3-5% ammonia by volume, and seal it to obtain a sealed ampoule; place the sealed ampoule in a dual-temperature zone tube furnace, heat it to 1000-1050℃ and hold it there, while controlling the temperature of the arsenic source zone at 610-620℃ to obtain the reaction product; A2. After the reaction is complete, cool the reaction product to room temperature; take out the reaction product in the glove box and ball mill the reaction product under argon protection.

[0011] In this invention, during the preparation of a nitrogen-source polycrystalline material containing lanthanum and arsenic, high-purity metallic indium, metallic lanthanum, and arsenic blocks are precisely mixed in an inert atmosphere and placed in a specially lined crucible, with a separate arsenic buffer zone simultaneously set up. After deep degassing, a trace amount of nitrogen-containing gas is introduced into the sealed ampoule. The main reaction zone in the zoned temperature-controlled furnace is raised to a suitable high temperature and maintained at a constant temperature, while the arsenic source zone maintains a stable vapor pressure. Multiple solid-phase reactions occur during this stage: indium and arsenic construct an indium arsenide matrix framework, lanthanum and arsenic form a lanthanum arsenide phase, and simultaneously, active nitrogen species generated from the pyrolysis of the nitrogen-containing gas combine with lanthanum to generate lanthanum nitride micro / nano structures. Through the synergistic control of the atmosphere and temperature field, nitrogen is effectively captured in the thermodynamically stable form of lanthanum nitride and uniformly dispersed in the composite matrix, avoiding high-temperature volatilization loss. The product is then finely ground in an inert environment after gradient slow cooling to obtain a homogeneous powder. Its core mechanism lies in constructing a "nitrogen-lanthanum" dual-functional carrier: lanthanum nitride serves as a slow-release nitrogen source, and lanthanum arsenide serves as a lanthanum element reserve phase. Both can release active components as needed in the subsequent melt environment, providing a precise and controllable doping basis for single crystal growth.

[0012] According to a preferred embodiment of the present invention, in step A1, the time for holding the temperature at 1000-1050°C is 48-50 hours.

[0013] According to a preferred embodiment of the present invention, in step A2, the cooling rate is 48-52°C / h.

[0014] According to a preferred embodiment of the present invention, the method for preparing the europium indium arsenide polycrystalline material includes: B1. By weight, in an argon glove box, place 100 parts of indium granules, 48-56 parts of arsenic blocks, and 1.5-1.7 parts of europium shavings into a quartz crucible liner with a carbonized inner wall; place 24-32 parts of arsenic blocks as an arsenic vapor buffer source in a groove at the other end of the liner; place the liner into a quartz ampoule, evacuate and seal it to obtain a sealed ampoule; place the sealed ampoule in a dual-temperature zone tube furnace, heat the main reaction zone to 1000-1050℃ and hold, and control the arsenic source zone at 600-610℃ to obtain the reaction product; B2. Cool the reaction product to 280-320℃, then cool it to room temperature in the furnace; remove the reaction product under argon protection and ball mill the reaction product.

[0015] In this invention, the synthesis of europium-containing indium arsenide polycrystalline material relies on the precise combination of high-purity raw materials within a carbonized protective liner. Due to its strong reducing properties, metallic europium preferentially reacts with arsenic to form europium arsenide compounds, while indium and arsenic simultaneously construct a continuous indium arsenide matrix. Under zoned temperature control and dynamic equilibrium of arsenic vapor pressure, the system spontaneously forms a eutectic structure of indium arsenide and europium arsenide. Europium is highly dispersed and embedded in the matrix as a second phase of europium arsenide, effectively circumventing the solid solubility limit of europium in the indium arsenide lattice. The carbonized liner effectively blocks side reactions between europium and the quartz container, ensuring the chemical purity of the product. The product is then finely pulverized under programmed cooling and an inert atmosphere to obtain a powder with a highly uniform europium distribution. The design mechanism focuses on "stable encapsulation and controllable release of europium": europium arsenide, as a thermodynamically stable carrier, gradually dissolves in the single crystal melt, allowing europium ions to be smoothly integrated into the growth interface, avoiding volatilization, segregation or sudden concentration fluctuations, and providing a continuous and uniform europium source supply for crystal defect passivation.

[0016] According to a preferred embodiment of the present invention, in step B1, the main reaction zone is heated to 1000-1050°C and held at that temperature for 36-40 hours.

[0017] According to a preferred embodiment of the present invention, in step B2, the cooling rate for cooling the reaction product to 280-320°C is 28-32°C / h.

[0018] The present invention also provides a low-defect indium arsenide single crystal prepared according to the preparation process of the low-defect indium arsenide single crystal described above.

[0019] The beneficial effects of this invention are as follows: The low-defect indium arsenide single-crystal preparation process provided by this invention achieves significant technical effects in improving the overall performance of the crystal by introducing two carefully designed functionalized polycrystalline materials and optimizing the growth and post-processing procedures. The most crucial effect lies in the effective suppression of internal crystal defects and the comprehensive optimization of the material's intrinsic properties. This process intervenes at the source of defect formation through the synergistic effect of nitrogen-source polycrystalline materials containing lanthanum and arsenic, and europium-containing indium arsenide polycrystalline materials. Lanthanum and its associated nitrogen components help stabilize the lattice structure near the crystal growth interface, filling or suppressing the formation of arsenic vacancies, while the introduction of europium can modulate the local stress field and potentially passivate certain deep-level defect centers. Combined with a precisely controlled arsenic overpressure environment, this composite doping strategy fundamentally ensures the stability of the crystal's stoichiometry and significantly reduces the intrinsic point defect concentration caused by component volatilization deviations. The final prepared single-crystal material exhibits extremely high structural integrity, with a dislocation density reduced by orders of magnitude and a more uniform stress distribution within the crystal, laying a solid material foundation for optimal electrical and optical properties.

[0020] From the perspective of process controllability and reproducibility, the technical solution of this invention also exhibits outstanding advantages. The entire process route is rigorously designed with clear parameter windows, demonstrating high operability and repeatability. The preparation methods for the two key additives both employ sealed ampoules and dual-temperature zone precise temperature control technology, ensuring that the synthesis reaction is carried out in a controlled stoichiometric atmosphere. The resulting polycrystalline material has uniform composition and stable properties, providing a reliable raw material guarantee for the reproducible growth of the subsequent main crystal. In the main crystal growth stage, from the layered loading of raw materials, the establishment and maintenance of arsenic overpressure, to the gradient control of vertical gradient solidification, the adjustment of growth rate, and the in-situ annealing of the system after growth, a complete and interconnected precision control system is formed. This comprehensive control effectively avoids the random proliferation of defects common in traditional processes, ensuring that the quality of each batch of grown single crystals remains highly consistent. This meets the stringent requirements of industrial production for product consistency and stability, greatly enhancing the feasibility of this advanced material moving from the laboratory to practical applications.

[0021] Based on the comprehensive improvement in material properties and processing technology, the low-defect indium arsenide single crystal prepared in this invention exhibits broad and significant application value in the field of high-end semiconductor devices. The extremely low defect density means a significant reduction in carrier scattering centers within the material, resulting in a substantial increase in the crystal's electron mobility. This makes it highly suitable for fabricating microwave and terahertz electronic devices requiring extremely high operating frequencies and speeds. Simultaneously, the excellent crystal quality and reduced concentration of non-radiative recombination centers contribute to the material's outstanding performance in photoelectric conversion, particularly beneficial for manufacturing high-sensitivity, low-noise infrared detectors and high-efficiency semiconductor lasers. The photoresponsivity and quantum efficiency of these devices are expected to improve significantly. Furthermore, the good crystal integrity extends the carrier diffusion length, enhancing device reliability and lifetime. Therefore, this invention not only provides an advanced material preparation technology but also powerfully promotes the research and development of next-generation high-performance optoelectronic and microelectronic devices that rely on high-quality indium arsenide substrates, possessing significant technological promotion value and market application prospects. Detailed Implementation

[0022] The following detailed embodiments are only used to further illustrate this application and should not be construed as limiting the scope of protection of this application. Those skilled in the art can make some non-essential improvements and adjustments to this application based on the above application content.

[0023] Example 1 To prepare a nitrogen-source polycrystalline material containing lanthanum and arsenic, 100.0 g of high-purity indium granules with a particle size of 3-5 mm, 5.3 g of high-purity lanthanum shavings cleaned and dried with dilute acid, and 50.0 g of blocky high-purity arsenic were accurately weighed using an analytical balance with an accuracy of 0.001 g in an argon glove box with an oxygen content of less than 0.1 ppm. These were placed in the main reaction zone of a quartz crucible liner that had been baked at high temperature and had its inner wall uniformly coated with a pyrolytic boron nitride coating. Separately, 32.0 g of high-purity arsenic blocks were weighed as an arsenic vapor buffer source and placed separately in a specially designed groove at the other end of the liner. The crucible liner containing the materials was transferred to a quartz ampoule with a wall thickness of 2 mm. The ampoule was connected to a molecular pump system for vacuuming, and a dynamic vacuum was applied at room temperature until the system pressure was below 5.0 × 10⁻⁶. -4 Pa, then through a precision valve, a mixed gas consisting of 96% argon and 4% ammonia by volume is introduced into the ampoule until the pressure reaches 0.8 atm. The neck of the ampoule is immediately sealed with an oxyhydrogen flame. The sealed ampoule is placed horizontally in the isothermal zone of a dual-temperature zone tube furnace. The main reaction zone is programmed to heat to 1025°C at a rate of 100°C / h and held at this temperature for 49 hours, while the temperature of the independently controlled arsenic source zone is precisely stabilized at 615°C. After the holding period, the heating power is turned off, and the ampoule is slowly cooled to room temperature along with the furnace at a set cooling rate of 50°C / h. The ampoule is broken in a glove box, and the grayish-black blocky product obtained from the reaction is removed. It is placed in a planetary ball mill jar filled with high-purity argon and ball-milled at 300 rpm for 2 hours. After passing through a 400-mesh sieve, a uniform powder with a particle size D50 of less than 50 μm is obtained and stored in an argon-filled vacuum bag for later use.

[0024] To prepare polycrystalline europium indium arsenide, 100.0 g of high-purity indium granules, 52.0 g of high-purity arsenic blocks, and 1.6 g of high-purity europium metal chips were accurately weighed and placed together in the main reaction zone of a quartz crucible liner whose inner wall had undergone high-temperature pyrolysis and carbonization treatment. Separately, 28.0 g of high-purity arsenic blocks were weighed and placed in a separate groove at the other end of the liner as an arsenic source. This liner was then placed in another quartz ampoule, and a vacuum system was connected to evacuate the pressure to below 5.0 × 10⁻⁶. -4 After Pa, the ampoule was directly sealed. The sealed ampoule was placed in a dual-temperature zone furnace, with the main reaction zone heated to 1025℃ at a rate of 50℃ / h and held at that temperature for 38 hours, while the arsenic source zone temperature was controlled at 605℃. After the reaction, the temperature was first programmed to decrease to 300℃ at a rate of 30℃ / h, and then the power was cut off to allow the ampoule to cool naturally to room temperature with the furnace. The silvery-gray product was removed under argon protection, initially crushed by a jaw crusher, and then ball-milled in an argon-atmosphere glove box to obtain a dark gray powder with a particle size D50 of less than 100μm, which was then sealed and stored.

[0025] To prepare low-defect indium arsenide single crystals, an 80mm quartz crucible with a 200μm thick pyrolytic boron nitride coating was placed in a glove box. The materials were loaded in a strict sequence: first, 40.0g of polycrystalline InAs raw material was placed at the bottom of the crucible as a buffer layer; then, 1.0g of europium-containing indium arsenide polycrystalline material powder was evenly sprinkled onto the surface of the buffer layer using a spatula; next, 895.0g of polycrystalline InAs bulk raw material was carefully added; then, 2.0g of lanthanum and arsenic-containing nitrogen source polycrystalline material powder was evenly dispersed above the main raw material; finally, 65.0g of polycrystalline InAs was added to cover and seal the loading area. The crucible, containing a total of 1000.0g of InAs main material and 3.0g of modifier, was removed from the glove box and quickly installed into the growth chamber of a vertical gradient solidification single crystal furnace and sealed. The vacuum unit was activated to evacuate the growth chamber to a high vacuum state. High-purity arsenic vapor was then introduced into the chamber through an external independent arsenic source evaporator, and the arsenic overpressure within the chamber was precisely stabilized at 1.5 atm using a pressure sensor and feedback system. The heating program was then initiated, causing the material in the crucible to uniformly heat to 992°C over 12 hours, and held at this temperature for 11 hours to ensure complete melting and homogenization. The seed crystal rod was then lowered, allowing… <100> Oriented InAs seed crystals are in contact with the melt surface, and crystal growth is carried out under computer program control at a pulling rate of 0.6 mm / h and an axial temperature gradient of 15 °C / cm. The entire growth process takes about 7 days. After growth, the ingot is annealed in situ for 24 hours in an arsenic vapor atmosphere at 900 °C. After annealing, the temperature is programmed to drop to room temperature at a rate of 20 °C / h. The furnace is closed, the ingot is removed, and after X-ray orientation, it is cut along the (100) plane using an internal circular cutter. After grinding and chemical mechanical polishing, a low-defect indium arsenide single crystal polished wafer with a diameter of 75 mm and a thickness of 1 mm is finally obtained.

[0026] Example 2 The specific implementation method is the same as in Example 1, except that a nitrogen source polycrystalline material containing lanthanum and arsenic is prepared. In an argon-filled glove box, 100.0 g of high-purity indium granules, 5.4 g of high-purity lanthanum shavings, and 49.0 g of high-purity arsenic blocks are accurately weighed and placed in the main area of ​​a pBN-coated quartz liner. Separately, 31.0 g of high-purity arsenic blocks are weighed and placed in a separate recess. The liner is then placed into a quartz ampoule, and a vacuum is applied to 5.0 × 10⁻⁶. -4 After Pa, a mixed gas consisting of 95% argon and 5% ammonia (by volume) was introduced to a pressure of 0.6 atm and then sealed. The ampoule was placed in a dual-temperature zone furnace, with the main zone heated to 1010°C at a rate of 100°C / h and held at that temperature for 48 hours, while the arsenic source zone temperature was controlled at 612°C. After the reaction was completed, the ampoule was cooled to room temperature at a rate of 49°C / h. The product was removed from the glove box, ball-milled and sieved under argon protection to obtain a powder for later use.

[0027] To prepare a polycrystalline material containing europium indium arsenide, accurately weigh 100.0 g of high-purity indium granules, 50.0 g of high-purity arsenic blocks, and 1.5 g of high-purity europium chips in a glove box and place them into the main area of ​​a carbonized quartz liner. Separately weigh 25.0 g of high-purity arsenic blocks and place them in a recess. Place the liner into an ampoule and evacuate to 5.0 × 10⁻⁶. -4 After Pa, the ampoule was sealed. It was placed in a dual-temperature zone furnace, with the main reaction zone heated to 1010℃ at a rate of 50℃ / h and held at that temperature for 36 hours. The arsenic source zone temperature was controlled at 602℃. After the holding period, it was cooled to 290℃ at a rate of 29℃ / h, and then cooled to room temperature with the furnace. The product was removed under argon protection and obtained as powder through crushing and ball milling.

[0028] To prepare low-defect indium arsenide single crystals, in a glove box, 35.0 g of polycrystalline InAs, 0.5 g of the aforementioned europium-containing indium arsenide polycrystalline material, 900.0 g of polycrystalline InAs, 1.0 g of the aforementioned lanthanum and arsenic-containing nitrogen source polycrystalline material, and finally 70.0 g of polycrystalline InAs were added sequentially to a quartz crucible with a pBN coating deposited on its inner wall. The crucible was then placed in a single-crystal furnace, evacuated to a high vacuum, and then filled with arsenic vapor to establish an overpressure of 1.3 atm. The furnace was heated to 991 °C and held at that temperature for 10 hours. <100> Oriented InAs seed crystals were used to induce vertical gradient solidification growth. After growth, the crystals were annealed in situ at 890℃ in an arsenic atmosphere, and finally cooled to room temperature. After post-processing, single-wafer crystals were obtained.

[0029] Example 3 The specific implementation method is the same as in Example 1, except that a nitrogen source polycrystalline material containing lanthanum and arsenic is prepared. In an argon-filled glove box, 100.0 g of high-purity indium granules, 5.5 g of high-purity lanthanum shavings, and 51.0 g of high-purity arsenic blocks are accurately weighed and placed in the main area of ​​a pBN-coated quartz liner. Separately, 33.0 g of high-purity arsenic blocks are weighed and placed in a separate recess. The liner is then placed into a quartz ampoule, and a vacuum is applied to 5.0 × 10⁻⁶. -4 After Pa, a mixed gas consisting of 97% argon and 3% ammonia (by volume) was introduced to a pressure of 1.0 atm and then sealed. The ampoule was placed in a dual-zone furnace, with the main zone heated to 1040°C at a rate of 100°C / h and held at that temperature for 50 hours, while the arsenic source zone temperature was controlled at 618°C. After the reaction was complete, the ampoule was cooled to room temperature at a rate of 52°C / h. The product was removed from the glove box, ball-milled and sieved under argon protection to obtain a powder for later use.

[0030] To prepare a polycrystalline material containing europium indium arsenide, accurately weigh 100.0 g of high-purity indium granules, 55.0 g of high-purity arsenic blocks, and 1.7 g of high-purity europium chips in a glove box and place them into the main area of ​​a carbonized quartz liner. Separately weigh 30.0 g of high-purity arsenic blocks and place them in a recess. Place the liner into an ampoule and evacuate to 5.0 × 10⁻⁶. -4After Pa, the ampoule was sealed. It was placed in a dual-temperature zone furnace, with the main reaction zone heated to 1040℃ at a rate of 50℃ / h and held at that temperature for 40 hours. The arsenic source zone temperature was controlled at 608℃. After the holding period, it was cooled to 310℃ at a rate of 31℃ / h, and then cooled to room temperature with the furnace. The product was removed under argon protection and obtained as powder through crushing and ball milling.

[0031] To prepare low-defect indium arsenide single crystals, in a glove box, 45.0 g of polycrystalline InAs, 1.5 g of the aforementioned europium-containing indium arsenide polycrystalline material, 880.0 g of polycrystalline InAs, 3.5 g of the aforementioned lanthanum and arsenic-containing nitrogen source polycrystalline material, and finally 75.0 g of polycrystalline InAs were added sequentially to a quartz crucible with a pBN coating deposited on its inner wall. The crucible was then placed in a single-crystal furnace, evacuated to a high vacuum, and then filled with arsenic vapor to establish an overpressure of 1.7 atm. The furnace was heated to 994 °C and held at that temperature for 12 hours. <100> Oriented InAs seed crystals were used to induce vertical gradient solidification growth. After growth, the crystals were annealed in situ at 910℃ in an arsenic atmosphere, and finally cooled to room temperature. After post-processing, single-wafer crystals were obtained.

[0032] Comparative Example 1 The specific implementation method is the same as in Example 1, except that, for preparing low-defect indium arsenide single crystals, 1000.0 g of polycrystalline InAs raw material is directly added to a pBN-coated quartz crucible in an argon-filled glove box, without adding nitrogen-source polycrystalline material containing lanthanum and arsenic or europium-containing indium arsenide polycrystalline material. The crucible is placed in a single crystal furnace, and after being evacuated to a high vacuum, arsenic vapor is introduced to establish an overpressure of 1.5 atm. The furnace is then heated to 992°C and held at that temperature for 11 hours. <100> Oriented InAs seed crystals were used to induce vertical gradient solidification growth. After growth, the crystals were annealed in situ at 900℃ in an arsenic atmosphere, and finally cooled to room temperature. After post-processing, single-wafer crystals were obtained.

[0033] Comparative Example 2 The specific implementation method is the same as in Example 1, except that a nitrogen source polycrystalline material containing lanthanum and arsenic is prepared. The preparation steps are exactly the same as in Example 1, yielding powder. Low-defect indium arsenide single crystals are prepared by adding 40.0g of polycrystalline InAs, 896.0g of polycrystalline InAs, 2.0g of the aforementioned nitrogen source polycrystalline material containing lanthanum and arsenic, and finally 65.0g of polycrystalline InAs to a pBN-coated crucible in a glove box. The total feed amount is 1000.0g of InAs and 2.0g of a single modifier. All parameters for subsequent crystal growth, annealing, and post-treatment steps are strictly consistent with those in Example 1.

[0034] Comparative Example 3 The specific implementation method is the same as in Example 1, except that the preparation steps for europium indium arsenide polycrystalline material are exactly the same as in Example 1, resulting in powder. To prepare low-defect indium arsenide single crystals, in a glove box, 40.0 g of polycrystalline InAs, 1.0 g of the aforementioned europium indium arsenide polycrystalline material, 897.0 g of polycrystalline InAs, and finally 65.0 g of polycrystalline InAs are added sequentially to a pBN-coated crucible. The total amount of material added is 1000.0 g of InAs and 1.0 g of a single modifier. All parameters for subsequent crystal growth, annealing, and post-treatment steps are strictly consistent with those in Example 1.

[0035] Performance testing The low-defect indium arsenide single crystals prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance testing according to the following method, which included the following steps: X-ray diffraction full width at half maximum (FWHM) measurement: A dual-crystal X-ray diffractometer equipped with a Ge monochromator and a Cu target Kα1 radiation source was used. The sample was fixed on a goniometer and aligned with the (004) crystal plane. The ω-scan mode was set, with a scan range of -200 arcsec to +200 arcsec, a scan step size of 0.5 arcsec, and a data acquisition time of 1 s per step. After acquisition, the FWHM was calculated by fitting the diffraction peaks using the Lorentz function, with the unit being arcseconds.

[0036] Dislocation density testing: Dislocation outcrops were visualized using a chemical preferential etching method. First, an etching solution was prepared, consisting of hydrofluoric acid, nitric acid, and deionized water in a volume ratio of 1:3:2. The sample was completely immersed in the etching solution at 25°C and etched for 300 seconds. After removal, the sample was rinsed with deionized water and dried with nitrogen. Subsequently, at least five different fields of view were randomly selected under a 200× magnification optical microscope for observation and pit counting. The average number of pits per square centimeter was calculated based on the area of ​​the field of view; this is the dislocation density, expressed in cm³. -2 .

[0037] Carrier concentration and electron mobility measurements: Hall effect measurements were performed using the van der Bauer method. The sample was cut into approximately 5mm × 5mm squares, and indium was soldered to the four vertices to form ohmic contact electrodes. The sample was placed between the poles of an electromagnet, and a magnetic field of 0.5T perpendicular to the sample surface was applied. A constant current of 10mA was passed between one pair of diagonal electrodes, and the Hall voltage generated at the other diagonal electrode and the resistance voltage between the electrodes on the same side were measured. The carrier concentration at room temperature (in cm³) was calculated using the formula. -3 ) and electron mobility (unit: cm) 2 / V·s).

[0038] Full width at half maximum (FWHM) of the main peak of photoluminescence at 77K: The sample was placed in a cryostat cooled by liquid nitrogen and stabilized at 77K. A helium-neon laser with a wavelength of 632.8 nm was used as the excitation source. The laser beam was focused and irradiated the sample surface in an approximately perpendicular direction, with a spot diameter of about 100 μm and a power density of about 50 W / cm². 2 The emission signal was collected using a grating spectrometer with a focal length of 0.5 m and a slit width of 100 μm. A liquid nitrogen-cooled silicon detector was used, and the spectrum was acquired by scanning in 0.1 nm steps within the wavelength range of 900 nm to 1700 nm. After background subtraction, the near-band edge emission peak located around 1550 nm was extracted, fitted with a Gaussian function, and its full width at half maximum (FWHM) was calculated in meV.

[0039] Test results: Table 1: Test results of each embodiment and comparative example ; As can be seen from Table 1, Examples 1-3 comprehensively and significantly solved the core technical problems of high defect density and poor crystal quality when preparing indium arsenide single crystals by using lanthanum and arsenic-containing nitrogen source polycrystalline materials and europium-containing indium arsenide polycrystalline materials in synergistic use.

[0040] Specifically, breakthrough improvements have been achieved in all key performance indicators: In terms of crystal structure integrity, the X-ray diffraction half-width of the embodiment is only 24-31 arcseconds, which is much lower than the 65 arcseconds of Comparative Example 1, indicating that the stress and long-range order inside the crystal have been greatly optimized. Regarding dislocation defect control, the dislocation density in Examples 1-3 is as low as 3.8-7.5 × 10⁻⁶. 3 cm -2 The magnitude is comparable to 1.5 × 10⁻⁶ in Comparative Example 1. 5 cm -2 This represents a reduction of nearly two orders of magnitude, demonstrating that the process effectively suppresses the multiplication and propagation of line dislocations. In terms of electrical performance, the carrier concentration in Examples 1-3 was reduced to 2.1-3.5 × 10⁻⁶. 16 cm -3 The electron mobility has increased to 24,000 cm⁻¹. 2 The concentration of / V·s is above 1, which is in stark contrast to the high concentration and low mobility of Comparative Example 1, indicating that the modifier effectively reduces point defects that serve as scattering centers and improves carrier transport efficiency.

[0041] In terms of optical performance, Examples 1-3 showed a narrowed photoluminescence peak full width at half maximum (FWHM) of less than 7.2 meV at 77 K, significantly better than Comparative Example 1's 15.3 meV, revealing sharp band-edge emission and effective suppression of nonradiative recombination defects. Crucially, while Comparative Examples 2 and 3, using only a single modifier, outperformed the basic Comparative Example 1 in various aspects, they still showed a significant gap compared to the examples. This undeniably confirms the indispensable synergistic effect of the two functional compounds in the design. They work together through different mechanisms on the crystal growth interface and bulk phase, achieving comprehensive suppression of multiple defects, thereby systematically improving the crystal quality, electrical purity, and optical properties of indium arsenide single crystals, completely solving the bottleneck problems in the prior art.

[0042] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A process for preparing low-defect indium arsenide single crystals, characterized in that the steps include... include: S1. By weight, in an argon-protected glove box, 950-1050 parts of polycrystalline InAs, 0.5-5.0 parts of nitrogen-source polycrystalline material containing lanthanum and arsenic, and 0.1-2.0 parts of polycrystalline material containing europium indium arsenide are placed into a quartz crucible with a pyrolytic boron nitride coating deposited on the inner wall to obtain a crucible containing the raw materials. S2. Place the crucible containing the raw materials into a single crystal furnace, evacuate to a high vacuum, fill with arsenic vapor and establish an arsenic overpressure of 1.2-1.8 atm, heat to 990-995℃ and hold; <100> Oriented InAs seed crystals induce vertical gradient solidification crystal growth; after growth, in-situ annealing is carried out in an arsenic vapor atmosphere of 880-920℃, and finally cooled to room temperature, followed by orientation, cutting, grinding and chemical mechanical polishing.

2. The preparation process of low-defect indium arsenide single crystal according to claim 1, characterized in that, In step S1, the order of adding the crucible is as follows: first, add 30-50 parts of polycrystalline InAs to the bottom of the crucible, then add 0.1-2.0 parts of polycrystalline material containing europium indium arsenide, then add 870-920 parts of polycrystalline InAs, then add 0.5-5.0 parts of nitrogen source polycrystalline material containing lanthanum and arsenic, and finally add 50-80 parts of polycrystalline InAs.

3. The preparation process of low-defect indium arsenide single crystal according to claim 1, characterized in that, In step S2, the temperature is heated to 990-995℃ and held for 10-12 hours.

4. The preparation process of low-defect indium arsenide single crystal according to claim 1, characterized in that, The preparation method of the nitrogen source polycrystalline material containing lanthanum and arsenic includes: A1. By weight, in an argon glove box, place 100 parts of indium granules, 5.2-5.5 parts of lanthanum shavings, and 48-52 parts of arsenic blocks into a quartz crucible liner with a pyrolytic boron nitride coating on the inner wall; place 31-33 parts of arsenic blocks as an arsenic vapor buffer source in a groove at the other end of the liner; place the liner into a quartz ampoule, evacuate, and then fill it with a mixed gas of 0.5-1.0 atm consisting of 95-97% argon and 3-5% ammonia by volume, and seal it to obtain a sealed ampoule; place the sealed ampoule in a dual-temperature zone tube furnace, heat it to 1000-1050℃ and hold it there, while controlling the temperature of the arsenic source zone at 610-620℃ to obtain the reaction product; A2. After the reaction is complete, cool the reaction product to room temperature; take out the reaction product in the glove box and ball mill the reaction product under argon protection.

5. The preparation process of low-defect indium arsenide single crystal according to claim 4, characterized in that, In step A1, the temperature is raised to 1000-1050℃ and held for 48-50 hours.

6. The preparation process of low-defect indium arsenide single crystal according to claim 4, characterized in that, In step A2, the cooling rate is 48-52℃ / h.

7. The preparation process of low-defect indium arsenide single crystal according to claim 1, characterized in that, The preparation method of the europium-containing indium arsenide polycrystalline material includes: B1. By weight, in an argon glove box, place 100 parts of indium granules, 48-56 parts of arsenic blocks, and 1.5-1.7 parts of europium shavings into a quartz crucible liner with a carbonized inner wall; place 24-32 parts of arsenic blocks as an arsenic vapor buffer source in a groove at the other end of the liner; place the liner into a quartz ampoule, evacuate and seal it to obtain a sealed ampoule; place the sealed ampoule in a dual-temperature zone tube furnace, heat the main reaction zone to 1000-1050℃ and hold, and control the arsenic source zone at 600-610℃ to obtain the reaction product; B2. Cool the reaction product to 280-320℃, then cool it to room temperature in the furnace; remove the reaction product under argon protection and ball mill the reaction product.

8. The preparation process of low-defect indium arsenide single crystal according to claim 7, characterized in that, In step B1, the main reaction zone is heated to 1000-1050℃ and held at that temperature for 36-40 hours.

9. The preparation process of low-defect indium arsenide single crystal according to claim 7, characterized in that, In step B2, the cooling rate for cooling the reaction product to 280-320°C is 28-32°C / h.

10. A low-defect indium arsenide single crystal, characterized in that, The low-defect indium arsenide single crystal is prepared by the method for preparing low-defect indium arsenide single crystal according to any one of claims 1-9.