Compound single crystal growth furnace and single crystal growth method

Abstract

The invention relates to a compound single crystal growth furnace and a single crystal growth method, and relates to the technical field of single crystal growth, the growth furnace comprises a main growth furnace, an auxiliary annealing furnace, a growth table and a control device, a furnace cover is detachably arranged on the auxiliary annealing furnace, a communicating hole and a furnace hole are formed in the furnace cover, and the control device comprises a control mechanism used for controlling opening and closing of the communicating hole; the first temperature control mechanism is used for controlling the temperature of the growth main furnace; and the second temperature control mechanism is used for controlling the temperature of the annealing auxiliary furnace. The auxiliary annealing furnace is arranged on the main growth furnace, so that the space occupied by the auxiliary annealing furnace is reduced, the time spent on crystal cooling is greatly shortened, meanwhile, only one-time furnace disassembling, cleaning and other processes are needed in the process, the crystal growth efficiency is improved, and the crystal growth cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of single crystal growth, and in particular to a compound single crystal growth furnace and a single crystal growth method. Background Art

[0002] The existing crystal growth equipment, temperature field, that is, temperature field design is centered on crystal growth. Therefore, the temperature gradients at the top and bottom of the temperature field are generally large, and the temperature gradient in the middle is relatively small. Such a temperature gradient distribution is not conducive to crystal annealing, especially the process annealing of large-sized crystal blanks.

[0003] The crystal growth process generally requires furnace loading, crystal growth, cooling, and furnace dismantling. If the cooling process is carried out at a lower cooling rate, the thermal stress in the crystal can be reduced to a certain extent. However, due to the uneven distribution of the temperature field of the crystal growth furnace and the large temperature gradient between the upper and lower parts, the existing crystal growth equipment cannot meet the real process annealing requirements, the effect is poor, and the total time of the growth process is extended, which reduces the growth efficiency.

[0004] In order to achieve a good annealing effect, the commonly used method now is to use a separate annealing furnace for annealing, and put the grown crystals into the annealing furnace for process annealing. Although this method can achieve a relatively good annealing effect, it still has the following disadvantages: 1. Each annealing equipment needs to occupy an equipment position. Under the condition of limited growth area, the number of growth equipment must be compressed, which will reduce the growth efficiency; 2. After the crystal growth is completed, it needs to go through a relatively long cooling stage, especially when growing crystals that are prone to cracking. The cooling stage time is longer, and then the crystal is placed in a special annealing furnace for annealing. The annealing process requires the annealing equipment to be cleaned and loaded again, slowly heated, kept at a constant temperature, slowly cooled, and dismantled. Each process requires labor and time, which is time-consuming and labor-intensive, and the cost is high. Summary of the invention

[0005] In order to improve growth efficiency and reduce growth cost, the present application provides a compound single crystal growth furnace and a single crystal growth method.

[0006] In the first aspect, the present application provides a compound single crystal growth furnace, which adopts the following technical solution: A compound single crystal growth furnace, comprising a main growth furnace, an annealing auxiliary furnace, a growth platform, and a control device, wherein the annealing auxiliary furnace is detachably provided with a furnace cover for easy dismantling and cleaning and a connecting hole connected to the main growth furnace, the furnace cover is provided with a furnace hole for a seed crystal rod to pass through, the growth platform is arranged on the main growth furnace, the seed crystal rod is used to be connected with the crystal and then placed on the growth platform through the connecting hole for growth or moved to the annealing auxiliary furnace for annealing, and the control device comprises: A control mechanism, used for controlling the opening and closing of the communication hole; A first temperature control mechanism is used to control the temperature of the main growth furnace; The second temperature control mechanism is used to control the temperature of the annealing auxiliary furnace.

[0007] By adopting the above technical scheme, the crystal is installed on the seed rod, and the seed rod is slidably installed on the furnace cover so that the crystal is located in the annealing auxiliary furnace, and then the furnace cover is fixedly installed on the annealing auxiliary furnace, the seed rod is moved so that the crystal is placed on the growth table through the connecting hole, the control mechanism controls the connecting hole to be closed, the first temperature control mechanism controls the temperature of the main growth furnace, so that the crystal grows on the growth table, and the second temperature control mechanism controls the temperature of the annealing auxiliary furnace. After the crystal growth is completed, the control mechanism controls the connecting hole to open, the seed rod is moved so that the crystal is moved into the annealing auxiliary furnace, the connecting hole is closed, and the second temperature control mechanism continues to control the temperature of the annealing auxiliary furnace to realize the annealing treatment of the crystal. After the annealing is completed, the furnace cover is opened, the crystal is taken out, and the inside of the annealing auxiliary furnace is cleaned. At the same time, the inside of the main growth furnace can be cleaned through the connecting hole or after the annealing auxiliary furnace is removed. After the cleaning is completed, the next crystal growth is continued.

[0008] By arranging the annealing sub-furnace on the main growth furnace, the space occupied by the annealing sub-furnace is reduced, and the probability of compressing the number of equipment due to space problems is reduced. At the same time, the main growth furnace and the annealing sub-furnace are connected or closed through the connecting hole, which greatly reduces the time spent on crystal cooling, thereby greatly improving the growth efficiency of the crystal. The above process only requires one furnace dismantling and cleaning process, which reduces the growth cost of the crystal. In addition, during the temperature control process of the first temperature control mechanism and the second temperature control mechanism, heat can be radiated to the main growth furnace and the annealing sub-furnace at the same time, thereby further improving the heating rate and reducing heat loss, further reducing the growth cost of the crystal. The opening and closing of the connecting hole allows the annealing furnace body and the main growth furnace to be separated, reducing the probability of adverse effects caused by the movement of materials between the two, and further improving the growth quality of the crystal.

[0009] Optionally, the control mechanism includes: Two baffles are arranged on the inner wall of the main growth furnace through relative sliding of stainless steel shafts and are used to close or open the connecting holes and are provided with avoidance holes for the crystal seed rods to pass through; The driving assembly is used to drive the two partitions to move closer to or away from each other.

[0010] By adopting the above technical solution, the driving component simultaneously drives the two partitions to move closer to or away from each other, thereby closing or opening the communicating hole.

[0011] Optionally, the connecting hole is located at the top of the main growth furnace, and the first temperature control mechanism includes: A bottom heater, disposed in the main growth furnace and used to heat the bottom of the main growth furnace; A heating assembly, arranged on two baffles and used for heating the top of the main growth furnace; A middle heater, which is arranged on the side wall of the main growth furnace and is located between the bottom heater and the heating assembly; A main heat-saturating tube is arranged on the bottom wall of the main growth furnace and extends upward to the connecting hole. The main heat-saturating tube is used for heat conduction and balances the heat in the main growth furnace. The first heat-insulating layer is arranged on the side wall and the inner bottom wall of the main growth furnace; The second thermal insulation layer is arranged on two partitions and cooperates with the first thermal insulation layer to achieve thermal insulation of the main growth furnace.

[0012] By adopting the above technical scheme, the bottom heater, the middle heater and the heating assembly are used to heat the bottom, the middle and the top of the main growth furnace respectively, and the main heat equalizing tube is used to conduct heat so that the heat can be evenly dispersed in the main growth furnace. At the same time, the first thermal insulation layer and the second thermal insulation layer cooperate to achieve thermal insulation of the main growth furnace, thereby reducing its heat loss, reducing the probability of uneven temperature field distribution in the main growth furnace, improving the growth quality and efficiency of the crystal, and reducing the growth cost of the crystal.

[0013] At the same time, the heating components are located at the two partitions, so that the heating components are located close to the growth platform, which makes it easier to control the temperature of the crystal placement, making the temperature control more accurate and more energy-saving, thereby further improving the growth quality and efficiency of the crystal and reducing the growth cost of the crystal.

[0014] Optionally, the main growth furnace and the auxiliary annealing furnace are both cylindrical structures and are coaxially arranged with the seed crystal rod, and the heating assembly includes: Heating plates are arranged on the two partitions and are evenly distributed radially around the periphery of the seed crystal rod; The electrode column is arranged on the heating plate and is used to energize the heating plate to achieve heating. When the two partitions are closed, the electrode column is energized for heating, and when the two partitions are away from each other, the electrode column is de-energized.

[0015] By adopting the above technical solution, when the two partitions are close to each other to close the connecting hole, the two partitions move to drive the electrode column to move, so that the electrode column energizes the heating plate to heat it, thereby achieving heating. After the heating is completed, the two partitions move away from each other, so that the electrode column is powered off and the heating is turned off, thereby improving the convenience of control. Moreover, when heating, the heating plate is brought close to the growth table, where the crystal is placed, thereby further accelerating the heating efficiency and saving heating energy consumption, improving the growth efficiency of the crystal, and reducing the growth cost of the crystal.

[0016] Optionally, the second temperature control mechanism includes: The third heat-insulating layer is arranged on the side wall of the furnace cover close to the inner side of the annealing auxiliary furnace and extends downward and abuts against the growth main furnace for heat insulation; A top baffle, which is arranged on the third insulation layer and located close to the furnace cover and is made of a heat-conducting material; Heater 1, disposed on the top baffle and located between the third insulation layer and the top baffle; A secondary heat soaking tube, which is arranged on the main growth furnace and extends upward to the top baffle, and is used for heat conduction and heat balance in the annealing secondary furnace; The second heater is located between the third heat-insulating layer and the auxiliary heat-saturating cylinder and cooperates with the first heater to achieve heating.

[0017] By adopting the above technical solution, the third insulation layer is used to insulate the annealing sub-furnace, and the top baffle is used to support and position heater one and can conduct the heat of heater one, so that the heat is conducted to the top of the annealing sub-furnace, heater two is started for heating, and the auxiliary heat-saturating cylinder conducts the heat into the annealing sub-furnace, so that the heat is evenly dispersed in the annealing sub-furnace, thereby reducing the probability of uneven temperature field distribution in the annealing sub-furnace, improving the annealing quality of the crystal, and also accelerating the heating efficiency, improving the growth quality and efficiency of the crystal, and reducing the growth cost of the crystal.

[0018] At the same time, after annealing is completed, the furnace cover can be opened to remove the third insulation layer, heater 1 and top baffle, so that only the auxiliary heat-saturating cylinder and heater 2 are left in the annealing auxiliary furnace, which makes it easier to clean the annealing auxiliary furnace and saves cleaning time. In addition, the third insulation layer can be covered on the lower surface of the furnace cover with the largest area, thereby further improving the insulation effect while meeting the requirements of furnace cover disassembly, thereby further improving the growth efficiency of the crystal and reducing the growth cost of the crystal.

[0019] Optionally, both the main growth furnace and the auxiliary annealing furnace are provided with ventilation components for achieving vacuuming and introducing gas, and the ventilation components include: The air inlet pipe and the air outlet pipe are arranged on the main growth furnace and are used for introducing gas and evacuating vacuum respectively.

[0020] By adopting the above technical scheme, the main growth furnace and the annealing auxiliary furnace are first evacuated simultaneously through the air outlet pipe, and the air inlet pipe is used to introduce the required gas. At the same time, after evacuation, the heating efficiency can be accelerated, and the adverse effects of air on crystal growth and annealing are reduced, thereby improving the growth quality and efficiency of the crystal. Moreover, only one device is needed to evacuate the main growth furnace and the annealing auxiliary furnace, thereby further reducing the growth cost of the crystal.

[0021] Optionally, the growth platform comprises: The crucible body is arranged on the main growth furnace through the vertical sliding of the crucible axis and is used for placing crystal growth; A lifting platform, arranged on the crucible shaft and used for driving the crucible shaft to move; A moving rod is arranged on the main growth furnace and is slidably arranged on the lifting platform; The tightening nut is threadedly connected to the moving rod and pressed against the lifting platform for positioning; The bellows is arranged on the lifting platform and the main growth furnace and sleeved on the crucible shaft and is used to seal the gap between the crucible shaft and the main growth furnace.

[0022] By adopting the above technical solution, the crystal is placed on the crucible body for growth, and the heating component is closest to the crystal. Therefore, the closer the distance between the heating component and the crystal, the faster the heating efficiency. However, in order for the crystal to grow, it is necessary to maintain a certain distance from the heating component. Therefore, the fastening nut is turned away from the lifting platform, and then the lifting platform drives the crucible body to move vertically, so as to adjust the crystal on the crucible body to maintain a suitable distance from the heating component. After the adjustment is completed, the fastening nut is turned to press against the lifting platform for positioning, so as to adjust the position of the crucible body as needed, so that the position of the crucible body is adapted to the growth of the crystal and the heating efficiency is the highest, thereby improving the quality and efficiency of crystal growth and reducing the cost of crystal growth.

[0023] The bellows can seal the gap between the crucible axis and the main growth furnace. Therefore, when there is leakage, hot air can enter the bellows. When the lifting platform moves up to drive the crucible body upward for crystal growth, the lifting platform also drives the bellows to contract, so that the hot air in the bellows enters the main growth furnace, thereby reducing the heat loss in the main growth furnace, improving the heating efficiency and reducing the heat loss, improving the crystal growth efficiency, and reducing the crystal production cost.

[0024] In a second aspect, the present application provides a single crystal growth method, which adopts the following technical solution: A single crystal growth method comprises the following steps: Furnace loading: connect the crystal to the seed crystal rod, and connect the furnace cover to the annealing auxiliary furnace; Crystal growth: the seed crystal rod moves so that the crystal is placed into the crucible through the connecting hole, the connecting hole is closed, and the first temperature control mechanism controls the temperature in the main growth furnace to achieve crystal growth; Crystal annealing: The second temperature control mechanism controls the temperature of the annealing auxiliary furnace, the connecting hole is opened, the crystal is moved to the annealing auxiliary furnace for annealing, and the connecting hole is closed; Furnace dismantling: Cool down the main growth furnace and the annealing auxiliary furnace to room temperature, open the furnace cover, take out the annealed crystal, open the connecting hole to the maximum limit, clean the annealing auxiliary furnace and the main growth furnace, and then prepare for the next growth.

[0025] By adopting the above technical scheme, the crystal is connected to the seed crystal rod, and the furnace cover is connected to the annealing auxiliary furnace. The seed crystal rod is moved so that the crystal is placed in the crucible through the connecting hole, and the connecting hole is closed. The first temperature control mechanism controls the temperature in the growth furnace body to achieve crystal growth. The second temperature control mechanism controls the temperature of the annealing auxiliary furnace. The connecting hole is opened, and the crystal is moved to the annealing auxiliary furnace for annealing. The connecting hole is closed, the furnace cover is opened, and the annealed crystal is taken out. The connecting hole is opened to the maximum limit, the annealing auxiliary furnace and the growth main furnace are cleaned, and then preparations are made for the next growth, thereby improving the growth quality and efficiency of the crystal and reducing the cost of crystal growth.

[0026] Optionally, the crystal growth comprises the following steps: Vacuuming: Vacuuming the main growth furnace and the annealing auxiliary furnace; Heating: The main growth furnace is heated to 200-300°C and kept at a constant temperature for 12-24 hours; Inflation: Inflate with argon and carbon tetrafluoride gas in sequence, with a volume ratio of 80:1; Melt: The main growth furnace is heated to 1400°C to melt the crystal; Seeding: Seeding begins after keeping the temperature constant for 12-24 hours. After seeding, the crystal grows automatically until the crystal growth is completed.

[0027] By adopting the above technical scheme, the main growth furnace and the annealing auxiliary furnace are first evacuated, the main growth furnace is heated to 200-300°C and then kept at a constant temperature for 12-24 hours, argon gas and carbon tetrafluoride gas are filled in turn, the main growth furnace is heated to 1400°C to melt the crystal, and after keeping the temperature for 12-24 hours, seeding is started. After seeding, the crystal grows automatically until the crystal growth is completed, thereby improving the growth quality and efficiency of the crystal.

[0028] Optionally, the crystal annealing comprises the following steps: Heating: The annealing auxiliary furnace is heated to 1200~1300℃; Transferring the crystal: First, open the two partitions to the maximum limit to open the connecting hole; In the second step, the seed crystal rod is moved upward to pull the crystal into the auxiliary annealing furnace, and the two partitions are moved closer to each other to the minimum limit to close the connecting hole; Gas filling: The growth main furnace is cooled down, and carbon tetrafluoride gas is filled into the annealing auxiliary furnace at the same time. The annealing auxiliary furnace is kept at a constant temperature for 12-24 hours; Cooling: The annealing auxiliary furnace is cooled to room temperature.

[0029] By adopting the above technical scheme, the annealing auxiliary furnace is heated to 1200~1300℃, the connecting hole is opened, the seed crystal rod is moved up to pull the crystal into the annealing auxiliary furnace, the connecting hole is closed, the growth main furnace is cooled down, and carbon tetrafluoride gas is filled into the annealing auxiliary furnace. The annealing auxiliary furnace is kept at a constant temperature for 12-24 hours, and the annealing auxiliary furnace is cooled down to room temperature to complete the annealing treatment of the crystal.

[0030] In summary, the present application includes at least one of the following beneficial technical effects: 1. By setting the annealing auxiliary furnace on the main growth furnace, the space occupied by the annealing auxiliary furnace is reduced, the probability of compressing the number of equipment due to space problems is reduced, and the growth efficiency of the crystal is improved.

[0031] 2. The main growth furnace and the annealing auxiliary furnace are connected or closed through the connecting hole, which greatly reduces the time spent on crystal cooling. At the same time, the above process only requires one furnace dismantling and cleaning process, which reduces the crystal growth cost. At the same time, the connecting hole is opened and closed, so that the annealing furnace body and the main growth furnace can be separated, reducing the probability of adverse effects caused by material movement between the two, and further improving the growth quality of the crystal. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a plan view of a growth furnace; Figure 2 yes Figure 1 Enlarged view of part A in the middle; Figure 3 It is a schematic diagram of the structure of the partition and heating components in the growth furnace.

[0033] Figure numerals: 1. growth main furnace; 11. cover; 12. mounting hole; 2. annealing auxiliary furnace; 21. connecting hole; 22. furnace cover; 23. furnace hole; 24. seed crystal rod; 3. growth platform; 31. crucible body; 32. lifting platform; 33. moving rod; 34. fastening nut; 35. bellows; 36. crucible shaft; 4. control device; 41. control mechanism; 42. partition; 421. upper plate body; 422. lower plate body; 43. stainless steel shaft; 44. avoidance hole; 5. first temperature control mechanism; 51. Bottom heater; 52, middle heater; 53, main heat-averaging tube; 54, first insulation layer; 541, horizontal section; 542, vertical section; 55, second insulation layer; 6, heating assembly; 61, heating plate; 62, electrode column; 7, second temperature control mechanism; 71, third insulation layer; 711, horizontal part; 712, vertical part; 72, top baffle; 73, heater one; 74, auxiliary heat-averaging tube; 75, heater two; 76, passage hole; 8, ventilation assembly; 81, air inlet pipe; 82, air outlet pipe. DETAILED DESCRIPTION

[0034] The following is combined with Figure 1-3 This application is described in further detail.

[0035] The embodiment of the present application discloses a compound single crystal growth furnace.

[0036] Reference Figure 1 and Figure 2The compound single crystal growth furnace comprises a main growth furnace 1, an annealing auxiliary furnace 2, a growth platform 3 and a control device 4. The main growth furnace 1 and the annealing auxiliary furnace 2 are both cylindrical structures and are coaxially arranged. The top of the main growth furnace 1 is open and a cover 11 is detachably installed. The cover 11 is coaxially arranged with the main growth furnace 1 and a mounting hole 12 is coaxially opened. The bottom of the annealing auxiliary furnace 2 is integrally arranged on the upper surface of the cover 11 and is opened with a connecting hole 21. The diameter of the connecting hole 21 is larger than the mounting hole 12 and the two are coaxially arranged. The top of the annealing auxiliary furnace 2 is in an open state and a furnace cover 22 is detachably installed. After removing the furnace cover 22, the annealing auxiliary furnace 2 can be cleaned; the growth table 3 is arranged on the growth main furnace 1, and the control device 4 is used to control the opening or closing of the connecting hole 21; a furnace hole 23 with a diameter smaller than the diameter of the mounting hole 12 is coaxially opened on the furnace cover 22, and the diameter of the furnace hole 23 is equal to or larger than the diameter of the seed crystal rod 24 and is for the seed crystal rod 24 to pass through, and the bottom end of the seed crystal rod 24 is used to clamp the crystal; when the connecting hole 21 is opened, the seed crystal rod 24 drives the crystal to pass through the connecting hole 21 and is placed on the growth table 3 for crystal growth. After the growth is completed, the seed crystal rod 24 drives the crystal to move to the annealing auxiliary furnace 2 for annealing.

[0037] The control device 4 includes a control mechanism 41, a first temperature control mechanism 5 and a second temperature control mechanism 7. The control mechanism 41 is used to control the opening and closing of the connecting hole 21. The control mechanism 41 includes two partitions 42 and a driving assembly. The two partitions 42 are mirror-imaged about the axis of the main growth furnace 1. The two partitions 42 are relatively slidably arranged on the inner wall of the main growth furnace 1 through a stainless steel shaft 43, and the two partitions 42 are located near the cover 11. The stainless steel shaft 43 is fixedly installed on the side walls on the opposite sides of the two partitions 42, and the stainless steel shaft 43 is in a horizontal state and horizontally slidably penetrates the inner wall of the main growth furnace 1. The stainless steel shaft 43 extends to the outside of the main growth furnace 1. The two stainless steel shafts 43 move closer to or farther from each other to drive the two partitions 42 closer to or farther from each other; the driving assembly can be an electric push rod, a motor screw structure, etc., so as to drive the two partitions 42 closer to or farther from each other. The driving assembly is a prior art, so it will not be repeated here.

[0038] Reference Figure 1-3 A semicircular avoidance hole 44 is opened on the side wall on the opposite side of the two partitions 42. When the two partitions 42 are pressed together to block the connecting hole 21, the avoidance hole 44 is for the seed crystal rod 24 to pass through. The diameter of the avoidance hole 44 is greater than or equal to the diameter of the seed crystal rod 24; each partition 42 is spliced ​​by an upper plate body 421 and a lower plate body 422 stacked vertically, and the lower plate body 422 is located below the upper plate body 421.

[0039] The first temperature control mechanism 5 is used to control the temperature inside the main growth furnace 1. The first temperature control mechanism 5 includes a bottom heater 51, a heating assembly 6, a middle heater 52, a main heat-matching tube 53, a first insulation layer 54 and a second insulation layer 55. The bottom heater 51 is annular and is coaxially arranged with the main growth furnace 1. The bottom heater 51 is fixedly mounted on the inner wall of the main growth furnace 1 and is located close to the bottom of the main growth furnace 1. The bottom heater 51 is used to heat the bottom of the main growth furnace 1.

[0040] The heating assembly 6 is arranged on two partitions 42 and is used to heat the top of the growth main furnace 1. The heating assembly 6 includes a heating plate 61 and an electrode column 62. A plurality of heating plates 61 are provided and are respectively fixedly installed on the two partitions 42. The plurality of heating plates 61 are arranged in a circular array around the axis of the growth main furnace 1, that is, the plurality of heating plates 61 are evenly distributed radially. The heating plates 61 are fixedly installed on the upper surface of the lower plate body 422. The heating plates 61 are heated and the heat is conducted to the growth main furnace 1 through the lower plate body 422, so as to heat the top of the growth main furnace 1.

[0041] Two electrode columns 62 are provided and are located on the inner sides of the two partitions 42. The electrode columns 62 are electrically connected to the multiple heating plates 61, and the electrode columns 62 pass through the stainless steel shaft 43. When the two partitions 42 abut against each other to close the connecting hole 21, the electrode columns 62 are energized to achieve electrical heating of the heating plates 61. When the two partitions 42 move away from each other to open the connecting hole 21, the electrode columns 62 cut off the power to the heating plates 61 and turn off the heating.

[0042] The middle heater 52 is fixedly installed on the inner wall of the main growth furnace 1, and the middle heater 52 is distributed in a ring shape and the bottom end extends to the bottom heater 51 and the top end extends to the bottom of the partition 42. The middle heater 52 is used to heat the middle of the main growth furnace 1, so the heating component 6, the middle heater 52 and the bottom heater 51 cooperate to achieve heating inside the main growth furnace 1; the main heat equalizing tube 53 is coaxially fixedly installed on the inner wall of the main growth furnace 1, and the bottom end of the main heat equalizing tube 53 extends downward to the bottom of the bottom heater 51 and the top end extends upward to the top of the middle heater 52 and close to the partition 42. The main heat equalizing tube 53 is made of heat-conducting material, and the material can be copper, etc. The main heat equalizing tube 53 is used for heat conduction and makes the heat distribution inside the main growth furnace 1 uniform, reducing the probability of uneven temperature field distribution in the main growth furnace 1.

[0043] The first insulation layer 54 includes a horizontal section 541 and a vertical section 542. The horizontal section 541 is fixedly mounted on the inner bottom wall of the main growth furnace 1. The vertical section 542 is coaxially and integrally arranged on the outer side wall of the horizontal section 541 and vertically extends upward to near the partition 42. The top of the vertical section 542 extends above the main heat-absorbing tube 53. The middle heater 52 is located inside the vertical section 542. The main heat-absorbing tube 53 is located inside the middle heater 52. Two second insulation layers 55 are provided and are respectively located on two partitions 42. The second insulation layer 55 is fixedly mounted on the upper plate body 421. The second insulation layer 55 and the first insulation layer 54 are both made of insulation materials and cooperate to insulate the main growth furnace 1.

[0044] The second temperature control mechanism 7 is used to control the temperature in the annealing auxiliary furnace 2. The second temperature control mechanism 7 includes a third insulation layer 71, a top baffle 72, a heater 1 73, an auxiliary heat-matching cylinder 74 and a heater 2 75. The third insulation layer 71 includes a horizontal portion 711 and a vertical portion 712. The horizontal portion 711 is fixedly mounted on the lower surface of the furnace cover 22, and a through hole 76 is formed on the horizontal portion 711 for the seed rod 24 to pass through; the vertical portion 712 is integrally arranged on the outer side wall of the horizontal portion 711, and the vertical portion 712 is vertically downward and abuts against the upper surface of the cover 11 for positioning.

[0045] The top baffle 72 is located on the side close to the furnace cover 22, and the top baffle 72 is annular and coaxially arranged with the annealing sub-furnace 2. The top baffle 72 is fixedly mounted on the vertical portion 712 and is located on the side close to the horizontal portion 711. The top baffle 72 is also formed with a through hole 76 for the seed crystal rod 24 to pass through and is made of heat-conducting material, which may be copper. The heater 1 73 is fixedly mounted on the upper surface of the top baffle 72. The heater 1 73 is heated, and the heat is conducted to the annealing sub-furnace 2 through the top baffle 72, so as to heat the top of the annealing sub-furnace 2.

[0046] The auxiliary heat equalizing tube 74 is fixedly installed on the upper surface of the cover 11, and the auxiliary heat equalizing tube 74 is coaxially arranged with the annealing auxiliary furnace 2, and the seed rod 24 passes through the inner side of the auxiliary heat equalizing tube 74; the second heater 75 is fixedly installed on the side wall of the annealing auxiliary furnace 2, and the second heater 75 is located between the vertical portion 712 and the auxiliary heat equalizing tube 74, the second heater 75 and the first heater 73 cooperate to heat the annealing auxiliary furnace 2, the auxiliary heat equalizing tube 74 is made of heat-conducting material, and the material can be copper, etc. The auxiliary heat equalizing tube 74 is used for heat conduction and makes the heat distribution inside the annealing auxiliary furnace 2 uniform, thereby reducing the probability of uneven temperature field distribution inside the annealing auxiliary furnace 2.

[0047] The furnace cover 22 is opened, the seed crystal rod 24 is passed through the top baffle 72, the heater 1 73, the horizontal part 711 and the furnace cover 22, and then the crystal is connected to the seed crystal rod 24, the furnace cover 22 is fixedly installed on the annealing auxiliary furnace 2, the connecting hole 21 is opened, the seed crystal rod 24 moves to drive the crystal to move down into the growth main furnace 1, and the crystal is placed on the growth table 3. The two partitions 42 move to close the connecting hole 21, the bottom heater 51, the middle heater 52 and the heating plate 61 are started at the same time for heating, and the first insulation layer 54 and the second insulation layer 55 are insulated and kept warm, so as to heat and melt the crystal to achieve growth; at the same time, the heater 1 73 and the heater 2 75 are started to heat the annealing auxiliary furnace 2. After the crystal growth is completed, the heating in the growth main furnace 1 stops, the connecting hole 21 is opened, the seed crystal rod 24 moves to drive the crystal to move into the annealing auxiliary furnace 2, the connecting hole 21 is closed, and the heater 1 73 and the heater 2 75 are started to control the temperature in the annealing auxiliary furnace 2, so as to achieve annealing of the crystal.

[0048] Reference Figure 1-2 Both the main growth furnace 1 and the annealing auxiliary furnace 2 are provided with ventilation components 8 for achieving vacuuming and gas introduction. The two ventilation components 8 have the same structure. The ventilation component 8 located on the main growth furnace 1 is taken as an example for explanation below. The ventilation component 8 includes an air inlet pipe 81 and an air outlet pipe 82. The air inlet pipe 81 is fixedly installed on the outer wall of the main growth furnace 1 and is located near the top of the main growth furnace 1; the air outlet pipe 82 is fixedly installed at the bottom of the main growth furnace 1, and the air outlet pipe 82 and the air inlet pipe 81 are both connected with the main growth furnace 1. The air inlet pipe 81 is used to input gas into the main growth furnace 1, and the air outlet pipe 82 is used to output the gas in the main growth furnace 1. The air outlet pipe 82 can also be connected to a vacuum pump to extract the gas in the main growth furnace 1 to achieve vacuuming.

[0049] When the crystal is moved into the main growth furnace 1, the two ventilation components 8 are started at the same time, so that the gas in the main growth furnace 1 and the annealing auxiliary furnace 2 is extracted, and then the main growth furnace 1 is heated to make the crystal grow. Vacuum heating improves the heating efficiency and reduces the adverse effects of impurities in the air on crystal growth and subsequent annealing. At the same time, when gas needs to be introduced, it is input through the air inlet pipe 81, which makes crystal growth and annealing more convenient and improves the growth efficiency of the crystal.

[0050] The growth table 3 includes a crucible body 31, a lifting platform 32, a moving rod 33, a fastening nut 34 and a bellows 35. The crucible body 31 is coaxially arranged with the main growth furnace 1 and a crucible shaft 36 is coaxially fixedly installed at the bottom. The crucible shaft 36 is coaxially slidably installed on the bottom of the main growth furnace 1, and a circular hole for the crucible shaft 36 to pass through is formed on the horizontal section 541; the top end of the crucible shaft 36 passes through the bottom heater 51 and extends to the top of the bottom heater 51. The crucible body 31 is for crystal placement for growth. The bottom end of the crucible shaft 36 extends to the bottom of the main growth furnace 1, and the crucible body 31 is located on the inner side of the main heat equalizing cylinder 53; the lifting platform 32 is fixedly installed at the bottom of the crucible shaft 36. The lifting platform 32 is used to drive the crucible shaft 36 and the crucible body 31 to move vertically. The driving force of the lifting platform 32 comes from an electric push rod, a cylinder, etc. This structure adopts the existing technical structure, so it will not be repeated.

[0051] The moving rod 33 is fixedly installed below the main growth furnace 1 and slides vertically downward to pass through the lifting platform 32, and a plurality of moving rods 33 are arranged at intervals; a plurality of fastening nuts 34 are arranged at intervals and correspond to the plurality of moving rods 33 one by one, the fastening nuts 34 are threadedly connected to the moving rod 33, and the fastening nuts 34 are pressed against the upper surface of the lifting platform 32 for positioning; when the lifting platform 32 needs to be lifted or lowered, the fastening nuts 34 are turned away from the lifting platform 32, and the lifting platform 32 moves. After the movement is completed, the fastening nuts 34 are turned to press against the lifting platform 32 for positioning, thereby realizing the positioning of the lifting platform 32.

[0052] The two ends of the bellows 35 are fixedly connected to the lower surface of the main growth furnace 1 and the upper surface of the lifting platform 32 respectively. The bellows 35 is sleeved on the crucible shaft 36 to protect the crucible shaft 36 and seal the gap between the crucible shaft 36 and the main growth furnace 1; when heat dissipates through the gap between the crucible shaft 36 and the main growth furnace 1, it can also stay in the bellows 35. When the lifting platform 32 moves up, it can drive the bellows 35 to squeeze the heat inside itself back into the main growth furnace 1.

[0053] After annealing is completed, wait for the annealing sub-furnace 2 and the growth main furnace 1 to cool down to room temperature, remove the furnace cover 22 to take out the crystal, and when the furnace cover 22 is removed, remove the third insulation layer 71, the top baffle 72 and the heater 73 at the same time, so as to facilitate cleaning the inside of the annealing sub-furnace 2. The lifting platform 32 moves downward to drive the crucible body 31 to move downward, remove the cover 11 and take out the annealing sub-furnace 2, and then the inside of the growth main furnace 1 can be cleaned, so as to facilitate subsequent crystal growth; fix the cover 11 on the growth main furnace 1, and then continue the crystal growth.

[0054] The working principle of the embodiment of the present application is as follows: The crystal is connected to the seed crystal rod 24, the furnace cover 22 is fixedly installed on the annealing auxiliary furnace 2, the connecting hole 21 is opened, and the lifting platform 32 drives the crucible body 31 to move upward, the seed crystal rod 24 moves and drives the crystal to be placed on the crucible body 31, the connecting hole 21 is closed, the bottom heater 51, the middle heater 52 and the heating plate 61 are started to heat the crystal, so as to achieve crystal melting growth, the heater 1 73 and the heater 2 75 are heated, and after the crystal growth is completed, the connecting hole 21 is opened, and the seed crystal rod 24 moves and drives the crystal to move into the annealing auxiliary furnace 2, The connecting hole 21 is closed, and the heater 1 73 and the heater 2 75 continue to control the temperature in the annealing auxiliary furnace 2 to anneal the crystal. After the annealing is completed, wait for the growth main furnace 1 and the annealing auxiliary furnace 2 to cool down to room temperature, remove the furnace cover 22 and take out the crystal, then clean the annealing auxiliary furnace 2, and at the same time remove the cover 11 to clean the growth main furnace 1, fix the cover 11 to the growth main furnace 1, and finally continue to install the crystal for growth, thereby improving the growth efficiency and quality of the crystal and reducing the production cost of the crystal.

[0055] The embodiment of the present application discloses a single crystal growth method.

[0056] Reference Figure 1-3 , a single crystal growth method, comprising the following steps: Furnace loading: connect the crystal to the seed crystal rod 24, and connect the furnace cover 22 to the annealing auxiliary furnace 2; Crystal growth: the seed crystal rod 24 moves so that the crystal is placed in the crucible body 31 through the connecting hole 21, the connecting hole 21 is closed, and the first temperature control mechanism 5 controls the temperature in the main growth furnace 1 to achieve crystal growth; Crystal annealing: the second temperature control mechanism 7 controls the temperature of the annealing auxiliary furnace 2, the connecting hole 21 is opened, the seed crystal rod 24 moves so that the crystal is moved into the annealing auxiliary furnace 2 for annealing, and the connecting hole 21 is closed; Furnace dismantling: cool the main growth furnace 1 and the annealing auxiliary furnace 2 to room temperature, open the furnace cover 22, take out the annealed crystal, open the connecting hole 21 to the maximum limit, clean the annealing auxiliary furnace 2, remove the cover 11, clean the main growth furnace 1, and then prepare for the next crystal growth.

[0057] Crystal growth includes the following steps: Vacuuming: vacuuming the growth main furnace 1 and the annealing auxiliary furnace 2; Heating: The main growth furnace 1 is heated to 200-300°C and then kept at a constant temperature for 12-24 hours; Inflation: Inflate with argon and carbon tetrafluoride gas in sequence, with a volume ratio of 80:1; Melt: The temperature of the growth main furnace 1 is raised to 1400°C to melt the crystal; Seeding: Seeding begins after keeping the temperature constant for 12-24 hours. After seeding, the crystal grows automatically until the crystal growth is completed.

[0058] Crystal annealing includes the following steps: Heating: Annealing auxiliary furnace 2 is heated to 1200~1300℃; Transferring the crystal: First, opening the two partitions 42 to the maximum limit to open the communicating hole 21; In the second step, the seed crystal rod 24 is moved upward to pull the crystal into the annealing auxiliary furnace 2, and the two partitions 42 are moved closer to each other to close the connecting hole 21; Gas filling: The growth main furnace 1 is cooled down, and carbon tetrafluoride gas is filled into the annealing auxiliary furnace 2 at the same time. The annealing auxiliary furnace 2 is kept at a constant temperature for 12-24 hours; Cooling: The annealing auxiliary furnace 2 is cooled to room temperature.

[0059] The working principle of the embodiment of the present application is as follows: The crystal is connected to the seed rod 24, and the furnace cover 22 is connected to the annealing auxiliary furnace 2. The seed rod 24 moves so that the crystal is placed in the crucible body 31 through the connecting hole 21. The control mechanism 41 closes the connecting hole 21. The first temperature control mechanism 5 controls the temperature in the growth main furnace 1 to achieve crystal growth; the second temperature control mechanism 7 controls the temperature of the annealing auxiliary furnace 2, the connecting hole 21 is opened, the crystal is moved to the annealing auxiliary furnace 2 for annealing treatment, and the connecting hole 21 is closed; the furnace cover 22 is opened, the annealed crystal is taken out, the connecting hole 21 is opened to the maximum limit, the annealing auxiliary furnace 2 is cleaned, the cover 11 is removed, the growth main furnace 1 is cleaned, and then preparations are made for the next crystal growth.

[0060] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A compound single crystal growth furnace, characterized in that: The invention comprises a main growth furnace (1), an annealing auxiliary furnace (2), a growth platform (3), and a control device (4); the annealing auxiliary furnace (2) is detachably provided with a furnace cover (22) for easy dismantling and cleaning and a connecting hole (21) connected to the main growth furnace (1); the furnace cover (22) is provided with a furnace hole (23) for allowing a seed crystal rod (24) to pass through; the growth platform (3) is arranged on the main growth furnace (1); the seed crystal rod (24) is used to be connected to a crystal and then placed on the growth platform (3) through the connecting hole (21) for growth or moved to the annealing auxiliary furnace (2) for annealing; and the control device (4) comprises: A control mechanism (41) for controlling the opening and closing of the communication hole (21); A first temperature control mechanism (5) for controlling the temperature of the main growth furnace (1); A second temperature control mechanism (7) is used to control the temperature of the auxiliary annealing furnace (2); The control mechanism (41) comprises: Two partitions (42) are arranged on the inner wall of the main growth furnace (1) through a stainless steel shaft (43) for relative sliding movement and are used to close or open the connecting hole (21) and are provided with a avoidance hole (44) for the crystal seed rod (24) to pass through; The driving assembly is used to drive the two partitions (42) to move closer to or farther from each other.

2. A compound single crystal growth furnace according to claim 1, characterized in that: The communicating hole (21) is located at the top of the main growth furnace (1), and the first temperature control mechanism (5) comprises: A bottom heater (51), arranged in the main growth furnace (1) and used to heat the bottom of the main growth furnace (1); A heating assembly (6) disposed on two partitions (42) and used to heat the top of the main growth furnace (1); A middle heater (52) is arranged on the side wall of the main growth furnace (1) and is located between the bottom heater (51) and the heating assembly (6); A main heat-averaging tube (53) is arranged on the inner bottom wall of the main growth furnace (1) and extends upward to the connecting hole (21); the main heat-averaging tube (53) is used for conducting heat and balancing the heat in the main growth furnace (1); A first heat-insulating layer (54) is arranged on the side walls and inner bottom wall of the main growth furnace (1); The second thermal insulation layer (55) is arranged on the two partitions (42) and cooperates with the first thermal insulation layer (54) to achieve thermal insulation of the main growth furnace (1).

3. A compound single crystal growth furnace according to claim 2, characterized in that: The main growth furnace (1) and the auxiliary annealing furnace (2) are both cylindrical structures and are coaxially arranged with the seed crystal rod (24). The heating component (6) comprises: Heating plates (61) are arranged on the two partitions (42) and are evenly distributed radially around the periphery of the seed crystal rod (24); The electrode column (62) is arranged on the heating plate (61) and is used to energize the heating plate (61) to achieve heating. When the two partitions (42) are closed, the electrode column (62) is energized to achieve heating. When the two partitions (42) are away from each other, the electrode column (62) is de-energized.

4. A compound single crystal growth furnace according to claim 3, characterized in that: The second temperature control mechanism (7) comprises: A third heat-insulating layer (71) is arranged on a side wall of the furnace cover (22) close to the inside of the auxiliary annealing furnace (2) and extends downward and abuts against the main growth furnace (1) for heat insulation; A top baffle (72) is disposed on the third heat-insulating layer (71) and is located on a side close to the furnace cover (22) and is made of a heat-conducting material; Heater 1 (73), disposed on the top baffle (72) and located between the third thermal insulation layer (71) and the top baffle (72); A secondary heat-saturating cylinder (74) is arranged on the main growth furnace (1) and extends upward to the top baffle (72), the secondary heat-saturating cylinder (74) being used for conducting heat and balancing the heat in the secondary annealing furnace (2); Heater 2 (75) is located between the third thermal insulation layer (71) and the auxiliary heat equalizing cylinder (74) and cooperates with heater 1 (73) to achieve heating.

5. The compound single crystal growth furnace according to claim 1, characterized in that: The main growth furnace (1) and the auxiliary annealing furnace (2) are both provided with a ventilation assembly (8) for achieving vacuum extraction and gas introduction, and the ventilation assembly (8) comprises: The air inlet pipe (81) and the air outlet pipe (82) are arranged on the main growth furnace (1) and are used for introducing gas and evacuating vacuum respectively.

6. The compound single crystal growth furnace according to claim 1, characterized in that: The growth platform (3) comprises: A crucible body (31) is arranged on the main growth furnace (1) by means of a crucible shaft (36) for vertical sliding movement and is used for placing crystal growth; A lifting platform (32) is arranged on the crucible shaft (36) and is used to drive the crucible shaft (36) to move; A moving rod (33) is arranged on the main growth furnace (1) and is slidably arranged on the lifting platform (32); A fastening nut (34) is threadedly connected to the moving rod (33) and pressed against the lifting platform (32) for positioning; The bellows (35) is arranged on the lifting platform (32) and the main growth furnace (1) and is sleeved on the crucible shaft (36) and is used to seal the gap between the crucible shaft (36) and the main growth furnace (1).

7. A single crystal growth method using the growth furnace according to any one of claims 1 to 6, characterized in that: The following steps are involved: Furnace loading: connecting the crystal to the seed crystal rod (24), and connecting the furnace cover (22) to the annealing auxiliary furnace (2); Crystal growth: the seed crystal rod (24) moves so that the crystal is placed into the crucible body (31) through the connecting hole (21), the connecting hole (21) is closed, and the first temperature control mechanism (5) controls the temperature in the main growth furnace (1), thereby achieving crystal growth; Crystal annealing: the second temperature control mechanism (7) controls the temperature of the annealing auxiliary furnace (2), the connecting hole (21) is opened, the crystal is moved into the annealing auxiliary furnace (2) for annealing, and the connecting hole (21) is closed; Furnace dismantling: The growth main furnace (1) and the annealing auxiliary furnace (2) are cooled to room temperature, the furnace cover (22) is opened, the annealed crystal is taken out, the connecting hole (21) is opened to the maximum limit, the annealing auxiliary furnace (2) and the growth main furnace (1) are cleaned, and then preparations are made for the next growth.

8. A single crystal growth method according to claim 7, characterized in that: The crystal growth The following steps are involved: Vacuuming: evacuating the main growth furnace (1) and the auxiliary annealing furnace (2); Heating: The main growth furnace (1) is heated to 200-300°C and then kept at a constant temperature for 12-24 hours; Inflation: Inflate with argon and carbon tetrafluoride gas in sequence, with a volume ratio of 80:1; Melt: The main growth furnace (1) is heated to 1400°C to melt the crystal; Seeding: Seeding begins after keeping the temperature constant for 12-24 hours. After seeding, the crystal grows automatically until the crystal growth is completed.

9. A single crystal growth method according to claim 7, characterized in that: The crystal annealing comprises the following steps: Heating: The annealing auxiliary furnace (2) is heated to 1200-1300°C; Transferring the crystal: First, opening the two partitions (42) to the maximum limit to open the communicating hole (21); In the second step, the seed crystal rod (24) is moved upward to pull the crystal into the annealing auxiliary furnace (2), and the two partitions (42) are moved closer to each other to a minimum limit position to close the connecting hole (21); Gas filling: The growth main furnace (1) is cooled down, and at the same time, carbon tetrafluoride gas is filled into the annealing auxiliary furnace (2). The annealing auxiliary furnace (2) is kept at a constant temperature for 12-24 hours; Cooling: The annealing auxiliary furnace (2) is cooled to room temperature.

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