CN210856407U - Gallium arsenide single crystal crystallization latent heat release device - Google Patents

Abstract

The utility model discloses a gallium arsenide single crystal crystallization latent heat releasing device. The device comprises a quartz ampoule bottle, a supporting base and a supporting platform; the quartz ampoule bottle is arranged at the upper end of the supporting base, and the supporting base is arranged on the supporting platform and is fixedly connected with the supporting platform; the furnace core is arranged in the supporting base, the furnace core is provided with a heat dissipation rod, the heat dissipation rod is inserted into the furnace core and is detachably connected with the supporting platform, the upper end of the heat dissipation rod keeps a distance from a bottle opening at the lower end of the quartz ampoule bottle during furnace charging, and the heat dissipation rod is in contact with the bottle opening at the lower end of the quartz ampoule bottle during upward movement. In the stage of equal-diameter growth, when the diameter is equal to 50mm, the heat dissipation rod is upwards contacted with the bottle mouth at the lower end of the quartz ampoule bottle, the heat dissipation rod is used for slowly releasing redundant heat of latent heat of crystallization in a heat radiation and heat conduction mode, and after the crystal growth is finished, in-situ annealing is not needed to reduce the thermal stress of the crystal.

Description

Gallium arsenide single crystal crystallization latent heat release device

Technical Field

The utility model relates to a single crystal growth field, concretely relates to gallium arsenide single crystal crystallization latent heat release device.

Background

Important semiconductor materials such as Si, GaAs and InP are typically prepared using melt growth techniques such as: pull-up (Cz), partial Liquid Encapsulation (LEC), and Vertical Gradient Freeze (VGF), among others. The properties of the crystal defects in the crystal are closely related to the selected growth technology, and crystals grown by different growth technologies or methods often have specific crystal defects, so that the diversity of the crystal defects of the crystal is formed. For example: for the crystal grown by the Bridgman method, the inclusion is the main crystal defect and comprises the inclusion of heteroplasmon, the cavity left in the crystal by the sublimation of the included substance at high temperature, and the like; for crystals grown by the melt-seeded Czochralski method, inclusions are no longer the predominant crystalline defect, but are replaced by threading dislocations, edge dislocations, grain boundaries (present only in polycrystalline bodies), and the like. Each method or technique has a separate relationship to the thermodynamics and kinetics of crystal growth.

The crystal growth can be generally divided into three stages: a kinetic phase, a bulk diffusion phase and a latent heat release phase. For GaAs single crystal growth, the latent heat release at the third stage is a key factor for determining the growth rate of the crystal and is also an important factor influencing the solid-liquid interface angle. The latent heat release stage refers to the release of heat generated during the crystallization process by radiation, heat conduction, and the like. The VGF single crystal is heated by a furnace body, the edge of the melt is close to the heater, the temperature is higher, the middle part of the melt is far from the heater, and the temperature is low; however, in the process of releasing latent heat, the heat in the middle of the melt is more difficult to release, and relative heat accumulation can be formed. Therefore, the solid-liquid interface angle of crystal growth depends on the equilibrium of these two trends. After the temperature of the lower part of the crucible is gradually reduced, the local supercooling area of the crucible wall forms crystal nuclei and releases latent heat of crystallization. Generally, crystals grow normally when the supercooling degree is low, latent heat of crystallization is easy to form when the supercooling degree is high, and if the latent heat of crystallization cannot be effectively released, the defects of branch growth, twin crystal or star-shaped structure and the like are easy to occur. The use of Vertical Bridgman (VB), Bridgman and VGF for crystal production all require in-situ annealing after crystal growth to reduce thermal stress. The commonly adopted annealing mode is that after the melt is completely crystallized, the PBN crucible is moved to a constant temperature removing area, the temperature is kept for dozens of hours within the range of 900-1100 ℃ to eliminate the stress in the crystal, then the cooling rate is controlled to be 30-70 ℃/h, the temperature is reduced to the room temperature, and the period is longer. Therefore, how to effectively release the latent heat of crystallization is a difficulty in the growth of gallium arsenide single crystals.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the shortcomings of the prior art and provide a gallium arsenide single crystal latent heat releasing device, which has simple structural design and can conveniently and effectively release the latent heat of crystallization.

In order to achieve the purpose, the utility model adopts the following technical scheme:

a gallium arsenide single crystal crystallization latent heat release device comprises a quartz ampoule bottle, a supporting base and a supporting platform; the quartz ampoule bottle is arranged at the upper end of the supporting base, and the supporting base is arranged on the supporting platform and is fixedly connected with the supporting platform; a furnace core is arranged in the supporting base; the furnace core is provided with a heat dissipation rod, the heat dissipation rod is inserted into the furnace core and is detachably connected with the supporting platform, the upper end of the heat dissipation rod keeps a distance from the lower end bottle opening of the quartz ampoule bottle during furnace charging, and the heat dissipation rod is contacted with the lower end bottle opening of the quartz ampoule bottle during upward movement.

The device simple structure, the cost is lower, and when the crystal isodiametric growth reached 50mm, utilize the heat dissipation stick upwards to contact with the lower extreme bottleneck of quartz ampoule, slowly emit the unnecessary heat of crystallization latent heat through heat radiation and heat-conducting mode, the crystal bar thermal stress of acquisition is less, need not to carry out the normal position annealing after the crystal growth.

Preferably, the support base is a graphite support base.

Preferably, the support base is equipped with wick, interior quartz capsule, interior furnace jacket, outer quartz capsule and outer furnace jacket by interior cover in proper order to the outside, all be equipped with the clearance between interior quartz capsule and the interior furnace jacket, between interior furnace jacket and the outer quartz capsule, between outer quartz capsule and the outer furnace jacket. More preferably, the gap is 4-5 mm.

The utility model discloses a support base adopts furnace jacket and the double-deck combination in turn of quartz capsule to form, and the quartz capsule texture is harder, and the primary function is used for supporting quartzy ampoule and crucible. All be equipped with the space between quartz capsule and the furnace jacket, can prevent on the one hand that the quartz capsule expends with heat and contracts with cold, card pipe appears in the crucible decline in-process, stops the phenomenon that the crucible descends, and on the other hand unnecessary heat can slowly spread out with the form of convection current through the clearance, ensures thermal field and solid-liquid interface's stability, reaches good long brilliant effect.

Preferably, the distance between the upper end of the heat dissipation rod and the opening of the lower end of the quartz ampoule bottle is 50-60mm during furnace charging.

Preferably, the upper end of the supporting base is provided with quartz wool, the quartz ampoule bottle is arranged on the quartz wool, and the heat dissipation rod moves upwards to break the quartz wool and contact with a bottle opening at the lower end of the quartz ampoule bottle.

A quartz cotton plug is arranged between the lower end bottle mouth of the quartz ampoule bottle and the quartz tube, so that firstly, the quartz cotton plays a role in heat preservation and prevents heat from dissipating from the gap between the furnace sleeve and the quartz tube; and secondly, the quartz ampoule bottle is prevented from being damaged by collision of the quartz tube and is easily separated from the quartz tube playing a supporting role after growth is finished.

Preferably, the heat dissipation rod is a quartz rod or a ceramic rod. Quartz or ceramic has a suitable thermal conductivity, but ceramic rods are expensive.

Preferably, the supporting platform is provided with a fixing piece for fixing the heat dissipation rod, and the heat dissipation rod is connected with the fixing piece through an iron wire. The fixing piece can be a screw, a bolt or a fixing clamping piece. Fix the radiating rod through mounting and iron wire, simple structure, easy operation.

Preferably, the device further comprises a lifting hydraulic shaft, and the lifting hydraulic shaft is connected with the supporting platform.

Preferably, a crucible, preferably a PBN crucible, is placed in the quartz ampoule;

the quartz ampoule bottle comprises an equal-diameter part, a shouldering part and a seed crystal well which are sequentially connected, wherein the diameter of an upper port of the shouldering part is equal to that of a lower port of the equal-diameter part, the diameter of a lower port of the shouldering part is equal to that of an upper port of the seed crystal well, and the diameter of the shouldering part is gradually reduced from the upper port along the direction of the lower port.

Preferably, the furnace core is provided with a temperature thermocouple comprising a temperature thermocouple Tc for measuring the temperature of the lower end of the seed crystal₁Temperature thermocouple Tc for measuring temperature of upper end of seed crystal₂And a temperature thermocouple Tc for measuring the temperature of the shoulder equal diameter position₃。

Compared with the prior art, the beneficial effects of the utility model are that:

the device of the utility model is simple in structure, easy to manufacture and low in cost. When the crystal grows to 50mm in the equal diameter, the heat dissipation rod is upwards contacted with the bottle mouth at the lower end of the quartz ampoule bottle, redundant heat of latent heat of crystallization is slowly released by the heat dissipation rod in a heat radiation and heat conduction mode, and after the crystal grows, in-situ annealing is not needed to reduce the thermal stress, so that the growth period is shortened, the energy is saved, the obtained crystal bar has small thermal stress, and the subsequent crystal bar processing, wafer processing and warehousing are facilitated.

Drawings

FIG. 1 is a schematic structural diagram of a gallium arsenide single crystal latent heat releasing device of the present invention;

fig. 2 is a schematic structural view of the support base of the present invention;

in the figure, 1-crucible, 2-quartz ampoule bottle, 3-quartz cotton, 4-radiating rod, 5-supporting base, 6-supporting platform, 7-fixing piece and 8-temperature thermocouple Tc₁9-temperature thermocouple Tc₂10-temperature thermocouple Tc₃11-lifting hydraulic shaft, 51-furnace core, 52-inner quartz tube, 53-inner furnace sleeve, 54-outer quartz tube and 55-outer furnace sleeve.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to specific embodiments. It will be understood by those skilled in the art that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

As shown in fig. 1, the gallium arsenide single crystal latent heat releasing device of the present invention comprises a quartz ampoule bottle 2, a supporting base 5 and a supporting platform 6; the quartz ampoule bottle 2 is arranged at the upper end of the supporting base 5, and the supporting base 5 is arranged on the supporting platform 6 and is fixedly connected with the supporting platform 6; a furnace core 51 is arranged in the supporting base 5; the furnace core 51 is equipped with the heat dissipation stick 4, and in the heat dissipation stick 4 inserted furnace core 51 to can dismantle with supporting platform 6 and be connected, the upper end of heat dissipation stick 4 kept the distance with the lower extreme bottleneck of quartz ampoule 2 during the dress stove, and the heat dissipation stick 4 contacts with the lower extreme bottleneck of quartz ampoule 2 during the upward movement. When the crystal grows to 50mm in the equal diameter, the heat dissipation rod 4 is upwards contacted with the bottle mouth at the lower end of the quartz ampoule bottle 2, redundant heat of latent heat of crystallization is slowly released in a heat radiation and heat conduction mode, the obtained crystal bar has small thermal stress, and in-situ annealing is not needed after the crystal grows.

In the present invention, the support base 5 is an integrated graphite base.

The utility model discloses in, support base 5 is equipped with wick 51, interior quartz capsule 52, interior furnace jacket 53, outer quartz capsule 54 and outer furnace jacket 55 by interior outside to overlapping in proper order, all be equipped with the clearance between interior quartz capsule 52 and the interior furnace jacket 53, between interior furnace jacket 53 and the outer quartz capsule 54, between outer quartz capsule 54 and the outer furnace jacket 55, the best preferred value in clearance is 4-5 mm.

The utility model discloses a support base 5 adopts furnace jacket and the double-deck combination in turn of quartz capsule to form, and the quartz capsule texture is harder, and the primary function is used for supporting quartzy ampoule 2 and crucible 1. All be equipped with the space between quartz capsule and the furnace jacket, can prevent on the one hand that the quartz capsule expends with heat and contracts with cold, card pipe appears in 1 decline in-process of crucible, stops the phenomenon that crucible 1 descends, and on the other hand unnecessary heat can slowly spread out with the form of convection current through the clearance, ensures thermal field and solid-liquid interface's stability, reaches good long brilliant effect.

In the utility model, the distance between the upper end of the heat dissipation rod 4 and the lower end bottle mouth of the quartz ampoule bottle 2 is preferably 50-60mm during charging.

The utility model discloses in, support 5 upper ends of base and be equipped with quartzy cotton 3, quartzy ampoule 2 is arranged in on the quartzy cotton 3, and the heat dissipation stick 4 upwards moves, punctures quartzy cotton 3 and contacts with the lower extreme bottleneck of quartzy ampoule 2. The quartz cotton 3 is arranged between the lower end bottle opening of the quartz ampoule bottle 2 and the quartz tube for blocking, so that firstly, the quartz cotton 3 plays a role in heat preservation and prevents heat from dissipating from a gap between the furnace sleeve and the quartz tube; secondly, prevent that quartz capsule collision from damaging quartz ampoule 2 and after the growth quartz ampoule 2 is easy to be separated with the quartz capsule that plays the supporting role.

In the present invention, the heat dissipation rod 4 is a quartz rod or a ceramic rod, preferably a quartz rod. Quartz or ceramic has a suitable thermal conductivity, but ceramic rods are expensive.

The utility model discloses in, supporting platform 6 is equipped with mounting 7 that is used for fixed radiating rod, radiating rod 4 is connected through the iron wire with mounting 7. The fixing piece 7 can be selected from screws, bolts or fixing clamping pieces, the heat dissipation rod is fixed through the fixing piece and an iron wire, and the heat dissipation rod is simple in structure and easy to operate.

The utility model discloses in, the device still includes lift hydraulic shaft 11, lift hydraulic shaft 11 is connected with supporting platform 6.

In the present invention, a crucible 1, preferably a PBN crucible, is placed in the quartz ampoule 2.

The utility model discloses in, quartz ampoule 2 is including the constant diameter part that connects gradually, shoulder the part and the seed crystal well, shoulder the lower port diameter that the upper port diameter of part equals the constant diameter part, shoulder the lower port diameter that the part equals the upper port diameter of seed crystal well, and shoulder the diameter of part and follow the upper port and reduce gradually along lower port direction. The quartz ampoule 2 has a shape corresponding to the shape of the PBN crucible.

In the present invention, the furnace core 51 is provided with a temperature thermocouple. The temperature thermocouple comprises a temperature thermocouple Tc₁8. Temperature thermocouple Tc₂9 and temperature thermocouple Tc₃10. Wherein, TC₁For determining the temperature, TC, of the lower end of the seed crystal₂For determining the temperature, TC, of the upper end of the seed crystal₃The temperature of the shoulder equal diameter position is measured.

The method for effectively releasing the crystallization latent heat of the gallium arsenide single crystal by using the device comprises the following steps:

(1) after gallium arsenide seed crystals, boron oxide and gallium arsenide polycrystalline materials are filled into a crucible 1, the crucible 1 is placed into a quartz ampoule bottle 2 with arsenic at the bottom, and the quartz ampoule bottle 2 is sealed under the vacuum-pumping condition;

(2) placing a supporting base 5 in the central area of a hearth, placing a quartz ampoule bottle 2 at the upper end of the supporting base 5, extending a heat dissipation rod 4 into a furnace core 51 and fixing the heat dissipation rod 4 on a supporting platform 6, and keeping a distance between the heat dissipation rod 4 and a bottle opening at the lower end of the quartz ampoule bottle 2;

(3) the process of melting, seeding and shouldering is completed in sequence, after the equal diameter grows to 50mm, the heat dissipation rod 4 is moved upwards, after the heat dissipation rod 4 is contacted with the lower end bottle mouth of the quartz ampoule bottle 2, the heat dissipation rod 4 is fixed on the supporting platform 6 again, and redundant heat of latent heat of crystallization is slowly released in a heat radiation and heat conduction mode;

(4) temperature Tc at the lower end of the seed crystal₁The temperature of the upper end of the seed crystal is reduced by 5-10 ℃, and the temperature Tc is₂The temperature Tc of the shoulder equal diameter position is reduced by 3-5 DEG C₃And reducing the temperature by 0.5-2 ℃, keeping one end of the heat dissipation rod in contact with the lower port of the quartz ampoule bottle, continuing to perform constant-diameter growth and cooling according to a set gradient, closing the furnace when the furnace temperature is reduced to below 300 ℃, and naturally cooling.

In the utility model, in the step (2), after the quartz wool 3 is laid on the upper end of the supporting base 5, the quartz ampoule bottle 2 is arranged on the quartz wool 3.

The utility model discloses in, interior furnace jacket 53 and outer furnace jacket 55 are the wet felt drum of the high temperature resistant cement of surface coating, and the external diameter of outer furnace jacket 55 is 5.0 inches, the internal diameter is 4.5 inches, and the external diameter of interior furnace jacket 53 is 4.0 inches, internal diameter 3.5 inches. The thickness of the inner quartz tube 52 and the outer quartz tube 54 is 4-6 mm, the length is 60-80 mm, and the inner diameter of the inner quartz tube 52 is 22 +/-1 mm larger than the maximum diameter of the crystal.

The preparation method of the supporting base 5 specifically comprises the following steps:

1) selecting a wet felt with required size and thickness, smearing high-temperature-resistant cement on the surface of the wet felt to form a cylinder, and removing moisture to respectively obtain an inner furnace sleeve 53 and an outer furnace sleeve 55;

2) the furnace core 51, the inner quartz tube 52, the inner furnace jacket 53, the outer quartz tube 54 and the outer furnace jacket 55 are sleeved in sequence from inside to outside to form the supporting base 5.

The yield of the single crystal of 4 crystal bars produced by the device is about 75 percent, the warehousing rate reaches about 70 percent, and is about 15 percent higher than the yield of the single crystal produced generally at present; the performance parameters of the 4 bars produced are shown in table 1.

TABLE 1

Therefore, the device can effectively release the latent heat of crystallization, the prepared gallium arsenide single crystal has high yield, good crystal growth effect and small thermal stress of a crystal bar, and in-situ annealing is not needed to reduce the thermal stress in the cooling stage, so that the growth period is shortened and the energy is saved.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention can be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims (10)

1. A gallium arsenide single crystal crystallization latent heat release device is characterized by comprising a quartz ampoule bottle, a supporting base and a supporting platform; the quartz ampoule bottle is arranged at the upper end of the supporting base, and the supporting base is arranged on the supporting platform and is fixedly connected with the supporting platform; the furnace core is arranged in the supporting base, the furnace core is provided with a heat dissipation rod, the heat dissipation rod is inserted into the furnace core and is detachably connected with the supporting platform, the upper end of the heat dissipation rod keeps a distance from a bottle opening at the lower end of the quartz ampoule bottle during furnace charging, and the heat dissipation rod is in contact with the bottle opening at the lower end of the quartz ampoule bottle during upward movement.

2. The gallium arsenide single crystal latent heat of crystallization device of claim 1, wherein the support base is a graphite integral base.

3. The latent heat release device for gallium arsenide single crystal crystallization according to claim 1, wherein the supporting base is sleeved with a furnace core, an inner quartz tube, an inner furnace sleeve, an outer quartz tube and an outer furnace sleeve from inside to outside in sequence, and gaps are arranged between the inner quartz tube and the inner furnace sleeve, between the inner furnace sleeve and the outer quartz tube, and between the outer quartz tube and the outer furnace sleeve, and the gaps are 4-5 mm.

4. The latent heat releasing device for gallium arsenide single crystal according to claim 1, wherein the distance between the upper end of said heat sink rod and the opening of the lower end of the quartz ampoule bottle is 50-60mm during charging.

5. The latent heat release device for gallium arsenide single crystal according to any of claims 1 to 4, wherein quartz wool is provided on the upper end of the supporting base, the quartz ampoule is placed on the quartz wool, and the heat dissipation rod moves upwards to break through the quartz wool and contact with the lower end mouth of the quartz ampoule.

6. The gallium arsenide single crystal latent heat releasing device of claim 5, wherein the heat sink rod is a quartz rod or a ceramic rod.

7. The latent heat releasing device for gallium arsenide single crystal crystallization as claimed in claim 6, wherein the supporting platform is provided with a fixing member for fixing a heat dissipation rod, and the heat dissipation rod is connected with the fixing member by a wire.

8. The gallium arsenide single crystal latent heat release device according to any one of claims 1 to 4 and 6 to 7, further comprising a lifting hydraulic shaft, wherein the lifting hydraulic shaft is connected to the support platform.

9. The gallium arsenide single crystal latent heat of crystallization release device of claim 8, wherein a crucible is placed inside the quartz ampoule, said crucible being a PBN crucible;

the quartz ampoule bottle comprises an equal-diameter part, a shouldering part and a seed crystal well which are sequentially connected, wherein the diameter of an upper port of the shouldering part is equal to that of a lower port of the equal-diameter part, the diameter of a lower port of the shouldering part is equal to that of an upper port of the seed crystal well, and the diameter of the shouldering part is gradually reduced from the upper port along the direction of the lower port.

10. The gallium arsenide single crystal latent heat releasing device of claim 9, wherein said wick is provided with a temperature thermocouple.

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