CN117626399A - Single crystal growth apparatus - Google Patents

Abstract

The application discloses single crystal growth equipment relates to the technical field of crystal growth. The single crystal growth equipment comprises a furnace body, a supporting component, a lifting driving mechanism, a flow stabilizing plate and a cooling ring. The furnace body forms the furnace chamber, and the inboard of furnace body is provided with heating element. The supporting component comprises an objective table and a supporting shaft, wherein the objective table is positioned in the furnace chamber and is used for placing the crucible. The lifting driving mechanism is used for driving the furnace body and/or the supporting component so as to enable the furnace body to lift relative to the supporting component. The cooling ring is internally provided with a cooling channel for the flow of a refrigerant, and the cooling ring is communicated with the outside of the furnace body through a first pipeline and a second pipeline. The cooling ring can effectively control the temperature field in the furnace chamber, provide proper temperature gradient for crystal growth, and ensure the crystal growth quality. Due to the arrangement of the steady flow plate, the convection of gas is reduced, the quality of crystals is guaranteed, and meanwhile, the power required by the temperature of the space where the crucible is located is reduced.

Description

Single crystal growth apparatus

Technical Field

The application relates to the technical field of crystal growth, in particular to single crystal growth equipment.

Background

In the process of preparing large-size crystals, the single crystal growth equipment adopting the descent method needs to form a temperature field with a certain temperature gradient in a furnace body, slowly descends a crucible containing raw material melt, and moves from a high-temperature area to a low-temperature area to realize crystallization. The existing single crystal growth equipment has the defects of unreasonable structure, poor control effect on a temperature field, wide impurity distribution of grown crystals and poor quality, so that large-size crystals are difficult to prepare.

In view of this, the present application is specifically proposed.

Disclosure of Invention

The object of the present application consists in providing a single crystal growth apparatus which grows crystals of better quality, which is advantageous for growing large-size crystals.

Embodiments of the present application may be implemented as follows:

the present application provides a single crystal growth apparatus comprising:

the furnace body forms a furnace chamber, and a heating component is arranged on the inner side of the furnace body;

the support assembly comprises an objective table and a support shaft, the objective table is positioned in the furnace chamber and used for placing the crucible, one end of the support shaft is connected to the bottom of the objective table, and the other end of the support shaft extends out of the furnace chamber from the lower end of the furnace body;

the lifting driving mechanism is used for driving the furnace body and/or the supporting component so as to enable the furnace body to lift relative to the supporting component;

the steady flow plates are positioned in the furnace chamber and are arranged above the objective table at intervals, and can lift relative to the furnace body along with the objective table;

the cooling ring is arranged in the furnace chamber, a through hole is formed in the middle of the cooling ring and used for allowing the object stage and the supporting shaft to pass through, a cooling channel for cooling medium to flow is formed inside the cooling ring, and the cooling ring is communicated with the outside of the furnace body through a first pipeline and a second pipeline.

In an alternative embodiment, the single crystal growing apparatus includes a cold source coupled to the first conduit.

In an alternative embodiment, the cold source is connected to the cooling circuit via a first line, a second line and a cooling ring.

In an alternative embodiment, the refrigerant may be water, and the cold source includes a chiller.

In an alternative embodiment, the heating assembly comprises a first heating assembly and a second heating assembly, the first heating assembly being disposed above the second heating assembly at intervals, and the cooling ring being disposed between the first heating assembly and the second heating assembly.

In an alternative embodiment, be provided with first heat preservation spare in the furnace body, the inner wall of furnace chamber is located to first heat preservation spare is protruding to extend along the circumference of furnace chamber and form the cyclic annular, the middle part of first heat preservation spare forms the through-hole that supplies objective table and back shaft to pass, first heat preservation spare is located between first heating element and the second heating element in vertical direction, the cooling ring is located first heating element's lower extreme, first heat preservation spare is located second heating element's upper end, the cooling ring sets up in first heat preservation spare top with the interval.

In an alternative embodiment, a second heat-insulating member is arranged in the furnace body, the second heat-insulating member is convexly arranged on the inner wall of the furnace chamber and extends along the circumferential direction of the furnace chamber to form a ring shape, a through hole for the object stage and the supporting shaft to pass through is formed in the middle of the second heat-insulating member, and the second heat-insulating member is arranged below the second heating component.

In an alternative embodiment, the aperture of the through hole of the second insulating member is adjustable.

In an alternative embodiment, the outer peripheral side of the stabilizer plate is slidably connected to the inner wall of the furnace body, so that the stabilizer plate can be lifted and lowered relative to the furnace body.

In an alternative embodiment, the single crystal growing apparatus further comprises a rotary drive mechanism drivingly connected to the support shaft for driving the support shaft in rotation.

The beneficial effects of the embodiment of the application include, for example:

the single crystal growth equipment provided by the application comprises a furnace body, a supporting component, a lifting driving mechanism, a steady flow plate and a cooling ring. The furnace body forms the furnace chamber, and the inboard of furnace body is provided with heating element. The support assembly comprises an objective table and a support shaft, wherein the objective table is positioned in the furnace chamber and used for placing the crucible, one end of the support shaft is connected to the bottom of the objective table, and the other end of the support shaft extends out of the furnace chamber from the lower end of the furnace body. The lifting driving mechanism is used for driving the furnace body and/or the supporting component so as to enable the furnace body to lift relative to the supporting component. The steady flow plate is arranged in the furnace chamber and above the objective table at intervals, and can be lifted and lowered along with the objective table relative to the furnace body. The cooling ring is arranged in the furnace chamber, a through hole is formed in the middle of the cooling ring and used for allowing the object stage and the supporting shaft to pass through, a cooling channel for cooling medium to flow is formed inside the cooling ring, and the cooling ring is communicated with the outside of the furnace body through a first pipeline and a second pipeline. The cooling medium can be introduced into the cooling ring through the first pipeline, and the cooling medium is sent out of the furnace body from the second pipeline after taking heat away, so that a temperature field with a certain temperature gradient can be formed in the furnace chamber, and the temperature gradient can be controlled by controlling the flow of the cooling medium. Through the single crystal growth equipment of this application, can control the temperature field in the furnace chamber effectively, provide suitable temperature gradient for crystal growth, consequently can make the speed of crystallization be unlikely to too fast, and keep at a reasonable interval, be favorable to impurity row to the crystal top, guarantee crystal growth quality. Accordingly, the single crystal growth apparatus provided herein is advantageous for preparing large-sized crystals. In addition, due to the arrangement of the current stabilizer which can move along with the objective table, when the objective table descends, the current stabilizer can descend along with the objective table, so that the space above the crucible is not too large, the air flow is reduced, the temperature field is more stable, the distribution interval of impurities in the crystal is reduced, the crystal growth quality is improved, and good conditions are created for the growth of large-size crystals. In addition, due to the arrangement of the steady flow plate, the convection of gas is reduced, so that the power required for maintaining the temperature of the space where the crucible is positioned is also reduced, and the energy consumption of single crystal growth equipment is reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of a single crystal growing apparatus in one embodiment of the present application;

FIG. 2 is a cross-sectional view of a single crystal growth apparatus according to one embodiment of the present application;

FIG. 3 is a CNGS crystal grown without a cooling ring and a stabilizer plate;

FIG. 4 is a view showing the case of CNGS crystals grown by the single crystal growth apparatus according to the embodiment of the present application;

FIG. 5 is a TeO grown without a cooling ring and stabilizer ₂ A crystalline case;

FIG. 6 is a schematic diagram of a TeO grown by a single crystal growth apparatus according to an embodiment of the present application ₂ Crystalline case.

010-single crystal growth apparatus; 110-upper furnace body; 111-a first heating assembly; 120-lower furnace body; 121-a second heating assembly; 131-high temperature monitoring thermocouple; 132-a high temperature control thermocouple; 133-a first crystallization monitoring thermocouple; 134-a second crystallization monitoring thermocouple; 135-annealing monitoring thermocouple; 136-annealing a temperature-controlled thermocouple; 140-cooling ring; 141-a first line; 142-a second line; 150-a first thermal insulation member; 160-a second insulating member; 170-a current stabilizer; 200-a support assembly; 210-stage; 220-supporting shaft; 230-a rotary drive mechanism; 300-lifting driving mechanism; 310-driving member; 320-a transmission assembly; 020-crucible.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, which are generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present application, as provided in the accompanying drawings, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In the description of the present application, it should be noted that, if the terms "upper," "lower," "inner," "outer," and the like indicate an azimuth or a positional relationship based on the azimuth or the positional relationship shown in the drawings, or the azimuth or the positional relationship in which the inventive product is conventionally put in use, it is merely for convenience of describing the present application and simplifying the description, and it is not indicated or implied that the apparatus or element referred to must have a specific azimuth, be configured and operated in a specific azimuth, and thus should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, if any, are used merely for distinguishing between descriptions and not for indicating or implying a relative importance.

It should be noted that, without conflict, features in embodiments of the present application may be combined with each other.

In the process of crystal growth, if the growth temperature gradient is unsuitable or the growth acceleration phenomenon occurs, the phenomenon of excessive inclusion, poor impurity removal and the like of the crystal easily occurs. However, the temperature gradient of the crystal growth cannot be well controlled by the prior descent method single crystal growth equipment in the related art, so that the purity requirement on raw materials is often high, too many impurities cannot be contained, and the cost is high. In the middle and later stages of the preparation, large-size single crystals tend to have a smaller gradient of crystals due to an increase in heat conduction of the crystals themselves, and even supercooling, thereby causing growth acceleration. Therefore, it is difficult to prepare high-quality large-sized single crystals by the existing apparatus and method. In addition, the headspace becomes larger gradually during the lowering of the crucible, and the convection of air becomes stronger, resulting in an insufficient temperature field. Since a stable temperature field is required for crystal growth, an unstable temperature field tends to cause deterioration of crystal growth quality, such as a wider impurity distribution region. In addition, as the furnace chamber space above the crucible becomes larger, the power of the apparatus required to maintain a proper temperature becomes higher, and thus the power consumption of the single crystal growth apparatus in the related art is also larger.

In order to improve at least one of the disadvantages in the related art, the embodiment of the application provides a single crystal growth apparatus, which forms a proper temperature field in a furnace chamber by additionally arranging a cooling ring and a steady flow plate in the furnace chamber, improves the stability of the flow field, thereby improving the crystal growth quality and providing good conditions for preparing large-size crystals.

FIG. 1 is a schematic diagram of a single crystal growth apparatus 010 in an embodiment of the present application; fig. 2 is a cross-sectional view of a single crystal growth apparatus 010 in an embodiment of the present application. As shown in fig. 1 and 2, the single crystal growth apparatus 010 provided in the embodiment of the present application includes a furnace body, a support assembly 200, a lift driving mechanism 300, a stabilizer plate 170, and a cooling ring 140. The furnace body forms a furnace chamber, and a heating component is arranged on the inner side of the furnace body; the support assembly 200 includes a stage 210 and a support shaft 220, the stage 210 is disposed in the furnace chamber for placing the crucible 020, one end of the support shaft 220 is connected to the bottom of the stage 210, and the other end extends out of the furnace chamber from the lower end of the furnace body. The lifting drive mechanism 300 is used to drive the furnace body and/or the support assembly 200 to lift the furnace body relative to the support assembly 200. The cooling ring 140 is located in the furnace chamber, a through hole is formed in the middle of the cooling ring 140 for the stage 210 and the support shaft 220 to pass through, a cooling channel for the flow of the cooling medium is formed inside the cooling ring 140, and the cooling ring 140 is communicated with the outside of the furnace body through a first pipeline and a second pipeline. The flow stabilizing plates 170 are disposed above the stage 210 in the furnace chamber at intervals, and can be lifted up and down along with the stage 210 relative to the furnace body.

In this embodiment, the furnace body includes an upper furnace body 110 and a lower furnace body 120, and the upper furnace body 110 and the lower furnace body 120 are axially communicated to form a furnace chamber together. The bottom end of the lower furnace body 120 forms an opening from which the lower end of the support shaft 220 protrudes. The upper and lower bodies 110 and 120 each include a heat insulating material therein so that the temperature inside the cavity can be maintained.

In this embodiment, the heating assembly includes a first heating assembly 111 and a second heating assembly 121, and the first heating assembly 111 is disposed above the second heating assembly 121 at intervals. The first heating assembly 111 and the second heating assembly 121 each include a plurality of heating elements arranged at intervals in the circumferential direction, so that a uniform temperature field in the circumferential direction can be created. The heating elements included in the first heating element 111 and the second heating element 121 may be induction coils or resistance wires.

Alternatively, the cooling ring 140 is located between the first heating assembly 111 and the second heating assembly 121 in the vertical direction. The cooling ring may be annular with its central axis coinciding with the central axis of the cavity. Specifically, the cooling ring 140 is provided at the lower end of the first heating member 111, and the raw material in the crucible 020 is heated to a molten state by the first heating member 111, and crystallization is started when the raw material melt in the crucible 020 falls to the vicinity of the cooling ring 140. The first pipeline 141 can continuously provide the cooling ring 140 with the cooling medium, and the cooling medium absorbs the heat in the furnace chamber and then flows out of the furnace chamber through the second pipeline 142. By controlling the flow of the cooling medium, the temperature near the cooling ring 140 in the furnace chamber can be controlled, and a proper temperature field is constructed for crystallization. The refrigerant may be gas or liquid, for example, nitrogen, air, water or oil.

Optionally, the single crystal growing apparatus 010 further includes a cold source (not shown) connected to the first pipe so as to continuously supply the cooling medium into the cooling ring 140 through the first pipe. Optionally, the cold source and the cooling ring form a cooling loop through the first pipeline and the second pipeline. The cold source may be a device that provides cold water, such as a chiller. In one embodiment, the cooling loop is formed by the first pipeline 141, the cooling ring 140 and the second pipeline 142, the cooling loop cools water and pumps the cooled water to the cooling ring 140 through the first pipeline 141, the cooled water heats up after absorbing heat, and then returns to the cooling loop through the second pipeline 142, and the cooled water is pumped to the cooling ring 140 again after being cooled, so that the circulation of the refrigerant is formed. By adjusting the cooling power of the chiller and the circulation rate of the coolant, the efficiency of the cooling loop 140 to absorb heat can be adjusted, thereby adjusting the temperature field and thus the temperature gradient of the crystals.

In alternative embodiments, the cold source may be only connected to the first pipeline 141, and the refrigerant may be directly released through the second pipeline 142 after absorbing heat through the cooling ring 140, so that the cooling circuit may not be formed. The cold source may be a tap, which is communicated with only the first pipe 141, and the cooling intensity of the cooling ring 140 is adjusted by adjusting the opening degree of the tap.

In alternative embodiments, the cooling ring 140 may also be configured to be adjustable in position up and down, such as by a motor and associated gearing structure.

Further, a first heat preservation member 150 is disposed in the furnace body, and the first heat preservation member 150 is protruding on the inner wall of the furnace chamber and extends along the circumferential direction of the furnace chamber to form a ring shape. A through hole through which the stage 210 and the support shaft 220 pass is formed in the middle of the first heat insulating member 150, and the first heat insulating member 150 is located between the first heating assembly 111 and the second heating assembly 121 in the vertical direction. The central axis of the first heat insulating member 150 coincides with the central axis of the cavity. In the present embodiment, the first heat preservation member 150 is located at the upper end of the second heating element 121, and the cooling ring 140 is disposed above the first heat preservation member 150 at intervals.

It can be seen that the cooling ring 140 and the first heat retainer 150 divide the cavity into three general areas, and the area above the cooling ring 140 is a high temperature area, and the temperature is controlled by the first heating assembly 111. The region between the cooling ring 140 and the first heat retainer 150 is a transition region that is at a temperature lower than the high temperature region, and typically where the molten feedstock begins to crystallize after entering the region. Below the first thermal insulating member 150 is an annealing zone whose temperature is controlled by the second heating member 121 for annealing the crystal to relieve internal stress of the crystal. The transition zone and the annealing zone are relatively low in temperature compared to the high temperature zone.

Further, a second heat-insulating member 160 is disposed in the furnace body, the second heat-insulating member 160 is convexly disposed on the inner wall of the furnace chamber and extends along the circumferential direction of the furnace chamber to form a ring shape, a through hole for passing the stage 210 and the supporting shaft 220 is formed in the middle of the second heat-insulating member 160, and the second heat-insulating member 160 is disposed below the second heating assembly 121. The annealing zone is located between the first insulating member 150 and the second insulating member 160. Optionally, a second insulating member 160 is disposed at the opening of the lower furnace 120.

In this embodiment, the aperture of the through hole of the second insulating member 160 is adjustable. Because the lower end of the through hole of the second heat insulating member 160 is communicated with the external environment, the temperature field of the annealing zone can be adjusted to a certain extent by adjusting the caliber of the second heat insulating member 160, thereby controlling the annealing process. The smaller caliber can reduce the convection of the external air and the air in the furnace, thereby being beneficial to improving the annealing temperature; the larger caliber can facilitate the taking out of the crucible 020.

Both the first insulating member 150 and the second insulating member 160 may be made of insulating bricks. The second insulating member 160 may be formed of a plurality of parts separately so as to realize an adjustable caliber. For example, the second thermal insulating member 160 is designed in a diaphragm-like multi-piece structure.

In the embodiment of the application, the furnace body is provided with a plurality of thermocouples for detecting the temperature in the furnace chamber.

Specifically, the several thermocouples include, from top to bottom, a high temperature monitoring thermocouple 131, a high temperature control thermocouple 132, a first crystallization monitoring thermocouple 133, a second crystallization monitoring thermocouple 134, an annealing monitoring thermocouple 135, and an annealing control thermocouple 136. In this embodiment, the high temperature control thermocouple 132 is disposed at the middle position of the high temperature region, and the set target temperature of the high temperature region is compared with the detected temperature of the high temperature control thermocouple 132, so as to control the first heating component 111 to regulate and control the temperature of the high temperature region; in other words, whether the high temperature region reaches the target temperature is determined according to the temperature fed back by the high temperature thermocouple 132. The first crystallization monitoring thermocouple 133 and the second crystallization monitoring thermocouple 134 are respectively disposed at upper and lower sides of the cooling ring 140 for monitoring the crystallization temperature condition because the melt starts to crystallize in the vicinity of the cooling ring 140. The second heating assembly 121 is controlled to regulate and control the temperature of the annealing zone by comparing the set target temperature of the annealing zone with the detected temperature of the annealing temperature control thermocouple 136; in other words, whether the annealing zone reaches the target temperature is determined based on the temperature fed back by the annealing temperature thermocouple 136. An annealing monitoring thermocouple 135 is provided at the lower side of the second heating assembly 121. The temperature of different positions of the whole furnace chamber is detected by each thermocouple, so that the temperature field of the furnace chamber can be effectively monitored.

In this embodiment, the lifting driving mechanism 300 is in transmission connection with the furnace body, and is used for driving the furnace body to lift relative to the supporting component 200. By driving the furnace to move, the crucible 020 on the stage 210 can be brought into a more stable state, thereby ensuring better crystallization. In alternative embodiments, the lifting drive mechanism 300 may be in driving connection with the support assembly 200, while the furnace body is stationary, and the crucible 020 is lifted relative to the furnace body by driving the support assembly 200 up and down.

Alternatively, the lifting drive mechanism 300 comprises a drive member 310 and a transmission assembly 320, the transmission assembly 320 drivingly connecting the drive member 310 to the furnace body. The driver 310 may be a motor, such as a stepper motor. The drive assembly 320 may include a screw-nut assembly to effect lifting of the furnace body.

Further, the single crystal growing apparatus 010 further comprises a rotation driving mechanism 230, and the rotation driving mechanism 230 is in transmission connection with the support shaft 220 for driving the support shaft 220 to rotate. The crucible 020 is driven to rotate by the bearing table before crystallization, so that the raw materials are fully melted, and impurities are more effectively distributed on the surface of the crystal.

In this embodiment, the stabilizer 170 can move up and down relative to the furnace body, and in the crystal growth process, it can be synchronized with the crucible 020 and lifted relative to the furnace body. Specifically, the movement range of the stabilizer plate 170 with respect to the furnace body is defined in a high temperature region, i.e., a region between the top of the furnace chamber and the cooling ring 140. The current stabilizer 170 moves with the crucible 020 during the crystal growth process, so that the headspace of the crucible 020 is not enlarged by the lowering of the crucible 020 relative to the furnace body before it reaches the cooling ring 140, and thus, there is no large air convection, which is advantageous for the stabilization of the temperature field near the crucible 020. Meanwhile, according to the law of conservation of energy, the heat required for maintaining the temperature field near the crucible 020 is relatively small (compared with the situation that the space above the crucible 020 is larger without the stabilizer 170) due to the heat insulation effect of the stabilizer 170, so that the energy consumption of the equipment is reduced.

Alternatively, the outer peripheral side of the stabilizer 170 is slidably connected to the inner wall of the furnace body, so that the stabilizer 170 can be lifted up and down relative to the furnace body. For example, the outer periphery of the stabilizer 170 is provided with a sliding block, the inner wall of the furnace body is provided with a sliding groove, the lower surface of the stabilizer 170 is abutted to the top of the crucible 020, and the stabilizer 170 can be lifted along with the crucible 020. Alternatively, the stabilizer 170 may be circular, and maintain a gap with the inner wall of the furnace. In alternative embodiments, the stabilizer 170 may be in driving connection with a driving assembly, and the driving assembly drives the stabilizer 170 to lift relative to the furnace body.

The application method of the single crystal growth apparatus 010 provided by the embodiment of the application is as follows:

first, a seed crystal is placed in the bottom of a crucible 020, then a raw material is charged into the crucible 020, a lid plate is covered, and the crucible 020 is placed on a stage 210. The high temperature region is raised to a target temperature by the first heating assembly 111 according to the normal growth temperature of the crystal, so that the raw material is completely melted. In the early stage of crystal growth, the rotation driving mechanism 230 may be controlled to control the rotation speed of the crucible 020 to 0 to 30rpm, so that the raw material is sufficiently melted. When the crystal starts to grow, the rotation is stopped, and the crucible 020 is kept stable.

After the raw materials are sufficiently melted, the lifting driving mechanism 300 is controlled to drive the furnace body to move upwards slowly according to the set growth rate, at this time, the crucible 020 slowly descends relative to the furnace body, and the cooling ring 140 is continuously filled with the cooling medium. When the temperature field has proper temperature gradient, the top of the seed crystal and the melt slowly pass through the solid-liquid interface for inoculation by moving the furnace body upwards. By moving the furnace up, its melt is passed through cooling ring 140. In the process, the flow stabilizing plate 170 simultaneously descends along with the crucible 020, so that the rapid heat dissipation caused by the upward movement of the furnace body can be prevented, and the fluctuation of a temperature field caused by the rising of equipment power and the increase of the convection space of the furnace chamber can be prevented. The crystallization temperature can be monitored by the first crystallization monitor thermocouple 133 and the second crystallization monitor thermocouple 134, and a proper crystallization temperature gradient can be always formed by controlling the flow rate of the cooling medium of the cooling ring 140. The cooling ring 140 may also be suitably adjusted up and down as needed for the length of crystal growth.

When crucible 020 is brought below first insulating member 150, the crystal enters the annealing zone. Whether the temperature of the annealing zone is suitable for crystal annealing can be monitored by the annealing monitoring thermocouple 135, and the annealing temperature can be adjusted by the annealing control thermocouple 136 and the second heating member 121.

The second insulating member 160 can adjust the caliber according to the annealing temperature. Optionally, in the initial stage of lowering the crucible 020, the distance from the inner edge of the through hole of the second insulating member 160 to the support shaft 220 is smaller than 10mm, and after the annealing temperature reaches the set temperature, the distance from the inner edge of the through hole of the second insulating member 160 to the support shaft 220 is controlled to be 10-30 mm, and specifically, the distance can be adjusted according to the difference between the actual temperature and the annealing temperature.

Alternatively, the single crystal growth apparatus 010 of the present application may be made into an array type multi-station for mass production according to production requirements.

The single crystal growth apparatus 010 provided in the embodiment of the present application can well satisfy the temperature gradient required by various crystals by adjusting the heat taken away by the cooling ring 140, so that crystals with better quality can be prepared. By adjusting the cooling ring 140, the temperature gradient required for each stage of early, middle and late crystal growth can be effectively adjusted, and impurity removal can be effectively performed, so that large-sized crystals can be prepared. Due to the flow stabilizing plate 170 arranged in the furnace chamber, the temperature field can be stabilized in the growth process of the large-size crystal, particularly in the middle and later stages, and the stable temperature field is provided for the crystal growth, so that the large-size crystal can be prepared. The steady flow plate 170 can provide a stable temperature field for crystal preparation, so that the impurity removal is facilitated, and the crystal quality is improved. In the process of melting the raw materials, the supporting shaft 220 is effectively rotated by the rotating mechanism, so that the raw materials can be sufficiently melted in the process of preparing the crystal, impurities can be more effectively distributed on the surface of the crystal, and in the process of growing, the impurities can be more effectively discharged to the top of the crystal due to the stable temperature field provided by the current stabilizer 170. By arranging the flow stabilizing plate 170, the problem of overhigh energy consumption of the crystal in the middle and later stages of preparation can be effectively reduced.

The efficacy of the cooling ring 140 and the flow stabilizer 170 in the single crystal growth apparatus 010 of the embodiment of the present application is explained below by two test examples.

1. To prepare CNGS (Ca ₃ NbGa ₃ Si ₂ O ₁₄ ) Crystals are examples. The crucible 020 has a length of 300mm, the furnace chamber has a height of 400mm, the crystal growth length is 180mm, and the growth temperature is 1330 ℃ (namely, the high temperature control thermocouple 132 sets the temperature control temperature to 1387 ℃ so that the inoculation temperature is higher than the melting point by 50 ℃).

The data measured without the cooling ring 140 (replaced by insulating bricks) and the stabilizer 170 are as follows:

in the crystallization stage, the temperature measured by the high-temperature monitoring thermocouple 131 is 1487 ℃, the temperature measured by the first crystallization monitoring thermocouple 133 is 1380 ℃, the temperature measured by the second crystallization monitoring thermocouple 134 is 1243 ℃, and the power is 2.46KW.

When the crystal grows to 80mm, the temperature measured by the high-temperature monitoring thermocouple 131 is 1492 ℃, the temperature of the first crystallization monitoring thermocouple 133 is 1367 ℃, the temperature of the second crystallization monitoring thermocouple 134 is 1252 ℃, and the power is 2.67KW. The crystal has no abnormal condition in the macroscopic sense, is crystal clear, and has no light path when the interior of the crystal is observed by laser, so that the crystal has better impurity removing effect.

When the crystal grows to 130mm, the temperature measured by the high-temperature monitoring thermocouple 131 is 1513 ℃, the temperature of the first crystallization monitoring thermocouple 133 is 1356 ℃, the temperature of the second crystallization monitoring thermocouple 134 is 1263 ℃, and the power is 3.12KW. The interior of the crystal was observed with a laser, and the crystal appeared to be tiny bubbles starting from 116mm, but was substantially distributed on the outer surface.

When the crystal grows to 180mm, the temperature measured by the high-temperature monitoring thermocouple 131 is 1532 ℃, the temperature of the first crystallization monitoring thermocouple 133 is 1338 ℃, the temperature of the second crystallization monitoring thermocouple 134 is 1275 ℃, and the power is 3.98KW. The inside of the crystal is observed by laser, the crystal is wrapped from 142mm, the impurities are gradually wrapped towards the center, and bubbles and internal impurities on the outer surface of the crystal are obvious.

Fig. 3 is a case of a CNGS crystal grown without the cooling ring 140 and the stabilizer plate 170. As shown in fig. 3, impurities were found to be more pronounced from the top of the crystal (square region in fig. 3).

The data measured after the cooling ring 140 and the stabilizer plate 170 are set as follows:

in the crystallization stage, the temperature measured by the high-temperature monitoring thermocouple 131 is 1483 ℃, the temperature of the first crystallization monitoring thermocouple 133 is 1376 ℃, the temperature of the second crystallization monitoring thermocouple 134 is 1196 ℃, and the power is 2.31KW.

When the crystal grows to 80mm, the temperature measured by the high-temperature monitoring thermocouple 131 is 1485 ℃, the temperature of the first crystallization monitoring thermocouple 133 is 1373 ℃, the temperature of the second crystallization monitoring thermocouple 134 is 1193 ℃, and the power is 2.38KW. The interior of the crystal is observed by laser, no light path exists, and the crystal has better impurity removing effect, and has no difference from the crystal without a cooling ring and a current stabilizer.

When the crystal grows to 130mm, the temperature measured by the high-temperature monitoring thermocouple 131 is 1489 ℃, the temperature of the first crystallization monitoring thermocouple 133 is 1367 ℃, the temperature of the second crystallization monitoring thermocouple 134 is 1187 ℃, and the power is 2.52KW. The interior of the crystal was observed with a laser, and the crystal was likewise free from impurities.

When the crystal grows to 180mm, the temperature measured by the high-temperature monitoring thermocouple 131 is 1492 ℃, the temperature of the first crystallization monitoring thermocouple 133 is 1362 ℃, the temperature of the second crystallization monitoring thermocouple 134 is 1183 ℃, and the power is 2.78KW. When the laser is used for observation, bubbles and impurities begin to appear at the position above 173mm, and no impurities, bubbles and the like are found in the crystal at the position below 173mm, which indicates that the overall growth quality of the crystal is relatively good and the impurity removing effect is obvious.

Fig. 4 is a diagram showing the case of CNGS crystals grown by the single crystal growth apparatus 010 according to the embodiment of the present application. As shown in fig. 4, the crystals were partially contaminated at 173mm or more (the square and circular frame inner regions in fig. 4).

From the comparison of the above data, without the cooling ring 140 and the stabilizer 170, the power increases as the length of the crystal growth increases, and the energy consumption increases. Meanwhile, the space of the high temperature area is larger and larger, heat is continuously dissipated upwards, space convection is enhanced, and the temperature measured in the high temperature area is dynamic, so that the temperature is relatively high. During the process of growing crystals, the first crystallization monitoring thermocouple 133 increases heat conduction and gradually decreases the temperature as the growth length of the crystals increases. Meanwhile, the second crystallization monitoring thermocouple 134 gradually increases the temperature of the region where the crystals are crystallized due to the diffusion of latent heat of the crystals, which eventually results in a smaller gradient and poor impurity removal capability.

In contrast, after the cooling ring 140 and the flow stabilizer 170 are arranged, the power is relatively higher than that of the cooling ring which is not arranged at the material melting stage because the cooling ring 140 takes away a part of heat, but the power relatively tends to be stable after the crystal slowly starts to grow, and the fluctuation is smaller. The convection of the furnace chamber in the high temperature area is reduced under the action of the flow stabilizing plate 170, so that the temperature measured by the thermocouple has relatively small fluctuation. Meanwhile, the first crystallization monitoring thermocouple 133 and the second crystallization monitoring thermocouple 134 have relatively low early temperature but relatively low late fluctuation due to the cooling ring 140. In terms of gradient, although the gradient fluctuates in the latter stage of crystal production after the cooling ring 140 and the flow stabilizer 170 are provided, the fluctuation is small and acceptable in comparison with the former. This effective control of the gradient of the crystal growth process toward steady state is a critical factor in the preparation of large size crystals.

2. To prepareTeO ₂ Crystals are examples. The crucible 020 has a length of 300mm, a furnace chamber has a height of 400mm, a crystal growth length of 180mm, and a growth temperature 733 ℃ (Gao Wenkong thermocouple 132 is provided with a temperature control temperature of 780 ℃).

The data measured without the cooling ring 140 (replaced by insulating bricks) and the stabilizer 170 are as follows:

in the crystallization stage, the temperature measured by the high-temperature monitoring thermocouple 131 is 865 ℃, the temperature of the first crystallization monitoring thermocouple 133 is 772 ℃, the temperature of the second crystallization monitoring thermocouple 134 is 618 ℃, and the power is 1.92KW.

When the crystal grows to 80mm, the temperature measured by the high-temperature monitoring thermocouple 131 is 876 ℃, the temperature of the first crystallization monitoring thermocouple 133 is 765 ℃, the temperature of the second crystallization monitoring thermocouple 134 is 624 ℃, and the power is 2.13KW. The crystal was observed with a laser, and no impurities, bubbles, and the like were found.

When the crystal grows to 130mm, the temperature measured by the high-temperature monitoring thermocouple 131 is 891 ℃, the temperature of the first crystallization monitoring thermocouple 133 is 753 ℃, the temperature of the second crystallization monitoring thermocouple 134 is 633 ℃, and the power is 2.36KW. The crystal was observed with a laser, and the crystal had fine bubbles starting from 123mm, which were formed on the crystal surface.

When the crystal grows to 180mm, the temperature measured by the high-temperature monitoring thermocouple 131 is 904 ℃, the temperature of the first crystallization monitoring thermocouple 133 is 741 ℃, the temperature of the second crystallization monitoring thermocouple 134 is 645 ℃, and the power is 2.84KW. The inside of the crystal was observed with a laser, a weak optical path was gradually developed from 156mm, bubbles on the outer surface and impurities in the inside were developed from 159mm, and the impurities were concentrated and distributed within a range of 10mm below the top of the crystal.

FIG. 5 shows a TeO grown without the cooling ring 140 and the stabilizer plate 170 ₂ Crystalline case. As shown in fig. 5, the crystals began to slowly appear as impurities at and above 159mm (the area within the box in fig. 5).

The data measured after the cooling ring 140 and the stabilizer plate 170 are set as follows:

in the crystallization stage, the temperature measured by the high-temperature monitoring thermocouple 131 is 863 ℃, the temperature of the first crystallization monitoring thermocouple 133 is 776 ℃, the temperature of the second crystallization monitoring thermocouple 134 is 626 ℃, and the power is 1.81KW.

When the crystal grows to 80mm, the temperature measured by the high-temperature monitoring thermocouple 131 is 865 ℃, the temperature of the first crystallization monitoring thermocouple 133 is 774 ℃, the temperature of the second crystallization monitoring thermocouple 134 is 624 ℃, and the power is 1.89KW. The crystal was observed with a laser, and no impurities, bubbles, and the like were found.

When the crystal grows to 130mm, the temperature measured by the high-temperature monitoring thermocouple 131 is 867 ℃, the temperature of the first crystallization monitoring thermocouple 133 is 772 ℃, the temperature of the second crystallization monitoring thermocouple 134 is 622 ℃, and the power is 2.11KW. The inside of the crystal was observed with a laser, and no impurity was found.

When the crystal grows to 180mm, the temperature measured by the high-temperature monitoring thermocouple 131 is 871 ℃, the temperature of the first crystallization monitoring thermocouple 133 is 771 ℃, the temperature of the second crystallization monitoring thermocouple 134 is 621 ℃, and the power is 2.35KW. The inside of the crystal was observed with a laser, and the crystal was gradually seen as a weak optical path from 173mm, and was found to be a bubble after single line cutting of the crystal. The crystals appear a lot of impurities from 175mm to the top of the crystals.

FIG. 6 is a TeO grown by the single crystal growth apparatus 010 of the embodiment of the present application ₂ Crystalline case. As shown in fig. 6, the crystal starts to appear as an impurity at 175mm and above (the area within the box in fig. 6).

As can be seen from the comparison of the above data, the single crystal growth apparatus provided in the examples of the present application prepares TeO ₂ The effect of the crystals is also evident, only because the required temperature is relatively low, and is less pronounced in energy saving compared to high temperature crystals. But is as critical and important for the impurity removal and other effects of preparing large-size crystals.

As can be seen from the above two test examples, in the case of using the method of placing the insulating brick instead of the cooling ring 140 and not providing the flow stabilizer 170, the crystal is not changed much in the initial stage of growth, but as the crystal grows to about 140mm, the impurity removing capability of the crystal is poorer and poorer, and under the influence of factors such as heat conduction of the crystal, impurities on the surface of the crystal are more and more, so that the size of the prepared crystal is limited, and the large-size crystal with better quality cannot be prepared. In the case of using the cooling ring 140, the temperature gradient required by the crystal variety can be effectively adjusted by the cooling ring 140, so that the required temperature gradient can be achieved at the early, middle and later stages of crystal growth, thereby being beneficial to preparing single crystals with large size and good quality. And as the crystal grows to 80mm, the fluidity due to air convection becomes stronger and stronger due to the larger and larger cavity space, and the temperature measured by the high temperature monitoring thermocouple 131 also gradually rises. Since the Gao Wenkong thermocouple 132 temperature setting is constant, the device needs to provide higher power to maintain this temperature balance according to the law of conservation of energy, so the energy consumption increases gradually in the late growth stage. In the case where the flow stabilizer 170 is placed, the furnace chamber high temperature monitoring thermocouple 131 is not changed much in temperature at the initial stage of crystal growth because the head space is not large. It can be found from the data that although the temperature of the high temperature monitoring thermocouple 131 increases somewhat in the three stages of crystal growth to 80mm, 130mm and 180mm, the temperature measured by the high temperature monitoring thermocouple 131 changes less than that measured by the temperature monitoring thermocouple 131 without the flow stabilizer 170 because the flow stabilizer 170 is arranged at the top of the crucible 020 and the air fluidity at the top of the furnace chamber is relatively poor. Meanwhile, the power change condition of the power meter of the control equipment can be compared, and the power is lower than that of the power meter without the current stabilizer 170 when the current stabilizer 170 is added and the crystal grows to the middle and later stages.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions easily conceivable by those skilled in the art within the technical scope of the present application should be covered in the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (10)

1. A single crystal growing apparatus, comprising:

the furnace comprises a furnace body, wherein the furnace body forms a furnace chamber, and a heating assembly is arranged on the inner side of the furnace body;

the support assembly comprises an objective table and a support shaft, the objective table is positioned in the furnace chamber and used for placing a crucible, one end of the support shaft is connected to the bottom of the objective table, and the other end of the support shaft extends out of the furnace chamber from the lower end of the furnace body;

the lifting driving mechanism is used for driving the furnace body and/or the supporting component so as to enable the furnace body to lift relative to the supporting component;

the current stabilizing plates are positioned in the furnace chamber and are arranged above the objective table at intervals, and can lift relative to the furnace body along with the objective table;

the cooling ring is arranged in the furnace chamber, a through hole is formed in the middle of the cooling ring and used for the objective table to pass through with the supporting shaft, a cooling channel for cooling medium to flow is formed inside the cooling ring, and the cooling ring is communicated with the outside of the furnace body through a first pipeline and a second pipeline.

2. The single crystal growing apparatus of claim 1, comprising a cold source connected to the first conduit.

3. The single crystal growing apparatus of claim 2, wherein the cold source is circulated with the cooling loop through the first pipe, the second pipe, and the cooling ring.

4. The single crystal growing apparatus of claim 3, wherein the cooling medium is water and the cold source comprises a chiller.

5. The single crystal growth apparatus of claim 1, wherein the heating assembly comprises a first heating assembly and a second heating assembly, the first heating assembly being disposed above the second heating assembly at intervals, the cooling ring being disposed between the first heating assembly and the second heating assembly.

6. The apparatus according to claim 5, wherein a first heat-retaining member is provided in the furnace body, the first heat-retaining member is provided protruding from an inner wall of the furnace chamber and extends in a circumferential direction of the furnace chamber to form a ring shape, a through hole through which the stage and the support shaft pass is formed in a middle portion of the first heat-retaining member, the first heat-retaining member is located between the first heating assembly and the second heating assembly in a vertical direction, the cooling ring is located at a lower end of the first heating assembly, the first heat-retaining member is located at an upper end of the second heating assembly, and the cooling ring is provided above the first heat-retaining member at an interval.

7. The apparatus according to claim 6, wherein a second heat-insulating member is provided in the furnace body, the second heat-insulating member being provided protruding from an inner wall of the furnace chamber and extending in a circumferential direction of the furnace chamber to form a ring shape, a through hole through which the stage and the supporting shaft pass being formed in a middle portion of the second heat-insulating member, the second heat-insulating member being provided below the second heating assembly.

8. The single crystal growing apparatus of claim 7, wherein the aperture of the through hole of the second thermal insulating member is adjustable.

9. The single crystal growing apparatus of claim 1, wherein an outer peripheral side of the stabilizer plate is slidably connected to an inner wall of the furnace body so that the stabilizer plate can be lifted up and down relative to the furnace body.

10. The single crystal growing apparatus of claim 1 further comprising a rotary drive mechanism drivingly connected to the support shaft for driving the support shaft in rotation.