Germanium crystal pulling growth equipment and method

Abstract

The invention provides germanium crystal pulling growth equipment and a germanium crystal pulling growth method. The germanium crystal pulling growth equipment comprises a furnace body, a crucible assembly and a heater, the crucible assembly comprises a first graphite crucible, the crucible assembly is arranged in the furnace body, and the first graphite crucible is used for containing melt formed by germanium ingots; the heater is used for heating the crucible assembly so that the germanium ingot in the first graphite crucible can form a melt. The crucible assembly further comprises a second graphite crucible, the first graphite crucible is fixed in the second graphite crucible, and the first graphite crucible and the second graphite crucible are separated from the first graphite crucible in the vertical direction and the circumferential direction to form a containing space; the germanium crystal pulling growth equipment further comprises a scum removing mechanism; and the scum removing mechanism is used for driving the scum of the melt in the first graphite crucible from the liquid level of the melt in the first graphite crucible to the accommodating space between the first graphite crucible and the second graphite crucible by utilizing airflow of non-oxidizing gas after the liquid level of the melt rises to the top end of the first graphite crucible before the lifting crystal grows.

Description

Technical Field

[0001] The present disclosure relates to the field of crystal growth, and more specifically to a germanium crystal pulling growth device and method. Background Art

[0002] In the process of germanium crystal growth, since a graphite crucible is used as a container, carbon powder is inevitably produced during the contact between germanium and the inner wall of graphite. Inert gas nitrogen is used as a protective gas, and a small amount of O 2 During the heating process of the melt, germanium reacts with oxygen to generate GeO 2 Since the pulling temperature of the chemical material is 940-1000℃, GeO 2 The melting point is 1080-1120℃, so after the melting is completed, carbon powder and GeO 2 As scum floating on the surface of germanium solution, the scum affects the crystallization and growth of crystals during the pulling process. Therefore, it is necessary to conduct further research and development on scum removal. Summary of the invention

[0003] In view of the problems existing in the background technology, an object of the present disclosure is to provide a germanium crystal pulling growth device and method, which can achieve effective separation of germanium melt and scum and removal of scum, so that the germanium crystal growth in the pulling process is not affected by the scum.

[0004] Another object of the present disclosure is to provide a germanium crystal pulling growth device and method, which can be applicable to the case where the amount of dross is large, and thus suitable for the growth of large-sized crystals.

[0005] Thus, a germanium crystal pulling and growing device includes a furnace body, a crucible assembly and a heater, wherein the crucible assembly includes a first graphite crucible, the crucible assembly is arranged in the furnace body, the first graphite crucible is used to hold a melt formed by a germanium ingot; the heater is used to heat the crucible assembly so that the germanium ingot in the first graphite crucible forms a melt. The crucible assembly also includes a second graphite crucible, the first graphite crucible is fixed in the second graphite crucible, the first graphite crucible and the second graphite crucible are spaced from the first graphite crucible in the vertical direction and the circumferential direction to form a receiving space; the germanium crystal pulling and growing device also includes a scum removal mechanism, which is used to drive the scum of the melt in the first graphite crucible from the liquid surface of the melt in the first graphite crucible to the receiving space between the first graphite crucible and the second graphite crucible by using a gas flow of non-oxidizing gas after the liquid level of the melt rises to the top of the first graphite crucible before the pulling crystal grows.

[0006] A method for growing germanium crystals by pulling and growing the above-mentioned germanium crystals by pulling and growing the above-mentioned device comprises the following steps: S1, loading the corroded polycrystalline germanium ingot into the first graphite crucible of the crucible assembly; S2, evacuating and passing nitrogen, repeating the process for multiple times, and maintaining the pressure at a specified vacuum; S3, passing non-oxidizing gas and exhausting the gas, so that the furnace body is kept at a normal pressure; S4, heating the heater, raising the temperature to 940-1000°C for melting, so that the germanium ingot in the first graphite crucible forms a melt and heats the slag mechanism; S5, after the melting is completed, , adjust the intake amount of non-oxidizing gas to make the furnace body slightly positive pressure; S6, the descumming mechanism is activated, and the melt is used to further preheat the descumming mechanism; S7, the descumming mechanism is activated again, so that the liquid level of the melt rises to the top of the first graphite crucible, and the descumming mechanism uses the airflow of non-oxidizing gas to drive the scum of the melt in the first graphite crucible from the liquid level of the melt in the first graphite crucible to the receiving space between the first graphite crucible and the second graphite crucible; S8, the descumming mechanism is activated again and returns to its original position, and then the pulling crystal growth is carried out.

[0007] The beneficial effects of the present disclosure are as follows.

[0008] In the germanium crystal pulling and growing device and method according to the present disclosure, before the pulling and growing of the crystal, the liquid level of the melt is raised to the top of the first graphite crucible, so that the scum on the liquid level of the melt reaches the adjacent receiving space, and when the scum removal mechanism drives the scum of the melt in the first graphite crucible by the airflow of the non-oxidizing gas, the scum passes through the top of the liquid level of the melt in the first graphite crucible and enters the receiving space between the first graphite crucible and the second graphite crucible, so that the scum on the liquid level of the melt in the first graphite crucible is moved out of the first graphite crucible to the receiving space outside the first graphite crucible, and the melt and scum in the first graphite crucible are effectively separated, and the scum is removed from the melt in the first graphite crucible. Further, after the scum is removed, the germanium crystal is pulled and grown from the melt in the first graphite crucible, so that the growth of the germanium crystal in the pulling process is not affected by the scum.

[0009] In the germanium crystal pulling growth equipment and method according to the present disclosure, a structure in which the first graphite crucible and the second graphite crucible are fixed relative to each other is adopted, which can be suitable for the first graphite crucible with a large volume, that is, the situation where the amount of germanium ingots contained in the first graphite crucible is large (and the amount of scum generated is correspondingly large), and thus is suitable for the growth of crystals of large sizes (for example, large equal diameters and long lengths). BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic diagram of a germanium crystal pulling and growing device according to the present disclosure, wherein the descumming mechanism is in a non-working state.

[0011] Figure 2is a cutaway perspective view of the crucible assembly.

[0012] Figure 3 It is a bottom-up stereoscopic schematic diagram of a gas nozzle, a quartz truncated cone, a cylinder and a cylindrical rod, in which they are shown in perspective.

[0013] Figure 4 yes Figure 3 Schematic diagram of a cross section along the outlet of the airway.

[0014] Figure 5 yes Figure 3 A variation of .

[0015] Figure 6 yes Figure 4 A variation of .

[0016] Figure 7 It is a schematic diagram of a germanium crystal pulling and growing device according to the present disclosure, wherein the descumming mechanism is in operation.

[0017] Figure 8 It is a schematic diagram of a germanium crystal pulling and growing device according to the present disclosure, wherein the descumming mechanism is in a completed working state and the pulling rod enters a crystal growing state.

[0018] The description of the accompanying drawings is as follows.

[0019] 100 Germanium crystal pulling growth equipment 141f mounting frame

[0020] D1 first horizontal direction 142 cylindrical rod

[0021] D2 second horizontal direction 143 cylinder

[0022] D3 vertical direction 144 air connection unit

[0023] 11 furnace body 144a rigid tube

[0024] 111 surrounding wall 144b flexible tube

[0025] 112 top cover 145 quartz round table

[0026] 113 bottom surface of bottom cover 145a

[0027] 12 Crucible assembly 146 Gas nozzle

[0028] 121 first graphite crucible 146a gas channel 121a top 146b connecting rod 121b inclined surface P gas channel

[0029] 121c slope 15 air inlet

[0030] 122 second graphite crucible 16 gas outlet

[0031] 122a upper end 17 lifting rod

[0032] 123 support column 18 seed crystal

[0033] S storage space 19 seed crystal clip

[0034] 13 heater 20 lifting rod rotating mechanism

[0035] 14 scum removal mechanism 21 lifting rod lifting mechanism

[0036] 141 mobile unit 22 bracket

[0037] 141a Vertical frame 23 bracket rotation mechanism

[0038] 141b lifter 24 bracket lifting mechanism

[0039] 141c horizontal slide rail 25 observation window

[0040] 141d first horizontal shifter 200 melt

[0041] 141e Second horizontal shifter 300 scum DETAILED DESCRIPTION

[0042] The accompanying drawings show embodiments of the present disclosure, and it will be understood that the disclosed embodiments are merely examples of the present disclosure, and the present disclosure can be implemented in various forms. Therefore, the specific details disclosed herein should not be interpreted as limiting, but merely as the basis for the claims and as a representative basis for teaching ordinary technicians in the field to implement the present disclosure in various ways.

[0043] [Germanium crystal pulling and growth equipment]

[0044] Reference Figures 1 to 8According to the present disclosure, the germanium crystal pulling and growing device 100 includes a furnace body 11, a crucible assembly 12 and a heater 13. The crucible assembly 12 includes a first graphite crucible 121. The crucible assembly 12 is disposed in the furnace body 11. The first graphite crucible 121 is used to hold a melt 200 formed by a germanium ingot. The heater 13 is used to heat the crucible assembly 12 to form a melt 200 from the germanium ingot in the first graphite crucible 121. The crucible assembly 12 also includes a second graphite crucible 122. The first graphite crucible 121 is fixed in the second graphite crucible 122. The first graphite crucible 121 and the second graphite crucible 122 are spaced apart from the first graphite crucible 121 in the vertical direction D3 and the circumferential direction to form a receiving space S. The germanium crystal pulling and growing equipment 100 also includes a descumming mechanism 14, which is used to raise the liquid level of the melt 200 to the top 121a of the first graphite crucible 121 before pulling the crystal growth, and then use the gas flow of non-oxidizing gas to drive the scum 300 of the melt 200 in the first graphite crucible 121 from the liquid level of the melt 200 in the first graphite crucible 121 to the receiving space S between the first graphite crucible 121 and the second graphite crucible 122.

[0045] In the germanium crystal pulling and growing device 100 according to the present disclosure, before the pulling and growing of the crystal, the liquid level of the melt 200 is raised to the top 121a of the first graphite crucible 121, so that the scum on the liquid level of the melt 200 reaches the adjacent receiving space S. When the scum removal mechanism 14 drives the scum 300 of the melt 200 in the first graphite crucible 121 with the airflow of the non-oxidizing gas, the scum 300 passes through the liquid level of the melt 200 in the first graphite crucible 121. The top end 121a enters the receiving space S between the first graphite crucible 121 and the second graphite crucible 122, so that the scum 300 on the liquid surface of the melt 200 in the first graphite crucible 121 is moved out of the first graphite crucible 121 to the receiving space S outside the first graphite crucible 121, so that the melt 200 in the first graphite crucible 121 and the scum 300 are effectively separated, and the scum 300 is removed from the melt 200 in the first graphite crucible 121. Further, after the scum 300 is removed, the melt 200 in the first graphite crucible 121 is pulled to grow germanium crystals, so that the growth of germanium crystals in the pulling process is not affected by the scum.

[0046] In the germanium crystal pulling and growing device 100 according to the present disclosure, a structure in which the first graphite crucible 121 and the second graphite crucible 122 are fixed relative to each other is adopted, which can be suitable for the first graphite crucible 121 with a large volume, that is, the situation where the amount of germanium ingot contained in the first graphite crucible 121 is large (and the amount of slag 300 generated is correspondingly large), and thus suitable for the growth of large-sized crystals (e.g., large equal diameter and long length).

[0047] In the germanium crystal pulling and growing device 100 according to the present disclosure, a structure in which the first graphite crucible 121 and the second graphite crucible 122 are fixed relative to each other is adopted, so that the heat preservation effect and temperature stability of the melt 200 in the first graphite crucible 121 are enhanced, which is beneficial to reduce the defects of the pulled germanium single crystal.

[0048] In the germanium crystal pulling and growing apparatus 100 according to the present disclosure, the dross 300 contained in the containing space S together with a small amount of the melt 200 can be recovered and reused after the crystal is pulled and grown.

[0049] In the germanium crystal pulling growth device 100 according to the present disclosure, for example, the non-oxidizing gas is nitrogen, hydrogen or a nitrogen-hydrogen mixed gas, and preferably a gas containing hydrogen, such as hydrogen alone or a nitrogen-hydrogen mixed gas. The use of a hydrogen-containing gas is conducive to reducing the germanium oxide in the scum 300 to elemental germanium, and the hydrogen-containing gas is preferably hydrogen alone.

[0050] like Figure 1 , Figure 7 and Figure 8 As shown, the furnace body 11 has a surrounding wall 111, a top cover 112 and a bottom cover 113. For example, the surrounding wall 111, the top cover 112 and the bottom cover 113 are detachably assembled, so that the germanium ingot is easily loaded into the graphite crucible 12.

[0051] like Figure 1 , Figure 2 , Figure 7 and Figure 8 As shown, in one example, the top end 121a of the first graphite crucible 121 is lower than the upper end 122a of the second graphite crucible 122. In this way, the portion of the upper end 122a of the second graphite crucible 122 that exceeds the top end 121a of the first graphite crucible 121 can act as a stopper to prevent the scum 300 from splashing into the space outside the second graphite crucible 122 of the furnace body 11.

[0052] like Figure 1 , Figure 2 , Figure 7 and Figure 8 As shown, in one example, the portion of the entire circumference of the inner circumferential wall of the first graphite crucible 121 close to the top is an inclined surface 121b that is inclined inward from top to bottom. In this way, when the descum mechanism 14 causes the liquid level of the melt 200 to rise to the top 121a of the first graphite crucible 121, it is convenient to observe the rising condition of the liquid level of the melt 200.

[0053] like Figure 1 , Figure 2 , Figure 7 and Figure 8As shown, in one example, the portion of the entire circumference of the outer peripheral wall of the first graphite crucible 121 close to the top is a slope 121c that is inclined outward from top to bottom, and the slope 121c radially protrudes outward relative to the portion below the slope 121c of the outer peripheral wall of the first graphite crucible 121. The slope 121c is equivalent to forming an overhang at the top of the entire circumference of the outer peripheral wall of the first graphite crucible 121. When the scum 300 enters the receiving space S between the first graphite crucible 121 and the second graphite crucible 122 from the liquid level of the melt 200 in the first graphite crucible 121 through the top 121a, the scum 300 together with a small amount of the melt 200 will not contact and adhere to the portion below the slope 121c of the outer peripheral wall of the first graphite crucible 121.

[0054] like Figure 1 , Figure 2 , Figure 7 and Figure 8 As shown, in one example, the crucible assembly 12 further includes a support column 123, which is fixed between the bottom wall of the first graphite crucible 121 and the bottom wall of the second graphite crucible 122. If the support column 123 is not used and the bottom wall of the first graphite crucible 121 is directly in contact with the bottom wall of the second graphite crucible 122, when the scum 300 and a small amount of melt 200 enter the receiving space S between the first graphite crucible 121 and the second graphite crucible 122, the first graphite crucible 121 will float due to lack of restraint, and the position of the first graphite crucible 121 relative to the second graphite crucible 122 is not fixed, which is not conducive to the removal of the scum 300. Of course, in order to facilitate disassembly and cleaning, the support column 123 and the bottom wall of the first graphite crucible 121 and the support column 123 and the bottom wall of the second graphite crucible 122 can be assembled in a disassembly manner, for example, by a threaded fitting structure. Similarly, the support column 123 is also made of graphite.

[0055] like Figure 1 , Figure 7 and Figure 8 As shown, the heater 13 is located outside the furnace body 11 and is arranged around the graphite crucible 12. For example, the heater 13 is a resistance heater.

[0056] Reference Figure 1 , Figure 7 and Figure 8In one example, the descumming mechanism 14 includes a moving unit 141, a cylindrical rod 142, a cylinder 143, a gas receiving unit 144, a quartz truncated cone 145 and a gas nozzle 146. The heater 13 is also used to heat at least the quartz truncated cone 145 and the gas nozzle 146. The moving unit 141 can achieve vertical lifting and horizontal translation. The top ends of the cylindrical rod 142 and the cylinder 143 are sealed and fixed to the moving unit 141, and the cylinder 143 surrounds the cylindrical rod 142. The inner circumference of the cylinder 143 is spaced apart from the outer circumference of the cylindrical rod 142 to form a gas channel P extending downward. The gas receiving unit 144 is connected to the gas channel P, and the gas receiving unit 144 is used to supply external pressurized gas (i.e., the aforementioned non-oxidizing gas) into the gas channel P. The quartz truncated cone 145 is a truncated cone with a small top and a large bottom and is made of quartz. The upper end of the quartz truncated cone 145 is fixed to the lower end of the cylindrical rod 142. The quartz truncated cone 145 is used to be inserted into the melt 200 driven by the cylindrical rod 142 and the moving unit 141 after being heated by the heater 13 so that the liquid level of the melt 200 rises to the top 121a of the first graphite crucible 121. The gas nozzle 146 is fixed around the quartz truncated cone 145 at the lower ends of the cylindrical rod 142 and the cylinder 143. The gas nozzle 146 is connected to the gas channel P. The gas nozzle 146 is higher than the bottom surface 145a of the quartz truncated cone 145. The gas nozzle 146 is used to transport the pressurized gas transported through the gas channel P to the liquid surface of the melt 200 so as to drive the scum 300 around the quartz truncated cone 145 on the liquid surface of the melt 200 through the top end 121a of the first graphite crucible 121 and into the receiving space S. In this example, the quartz truncated cone 145 is heated by the heater 13 to prevent the quartz truncated cone 145 from being too cold and causing germanium to solidify and adhere to the surface of the inserted portion of the quartz truncated cone 145 when inserted into the melt 200. The heater 13 heats the gas nozzle 146 to heat the pressurized gas passing through the gas nozzle 146, which is beneficial to maintaining the germanium at the liquid surface of the melt 200 at a liquid temperature, and is more beneficial for the scum 300 to be driven through the top 121a of the first graphite crucible 121 and enter the receiving space S, so that the melt 200 in the first graphite crucible 121 is separated from the scum 300 more effectively and thoroughly. In this example, the quartz truncated cone 145 is made of quartz material, and the quartz material will not generate new scum and impurities in the process of removing the scum 300. In this example, the quartz truncated cone 145 is a truncated cone that is small at the top and large at the bottom. In addition to being inserted into the melt 200 to raise the liquid level of the melt 200 to the top 121a of the first graphite crucible 121, because the truncated cone that is small at the bottom and large at the bottom is a rotating body structure, the generatrix of this rotating body structure is inclined radially outward from top to bottom, so that the pressurized gas discharged from the gas nozzle 146 is blown outward along this generatrix obliquely downward, thereby generating a radially outward component force, thereby driving the slag 300 radially outward.The pressure of the pressurized gas is such that the slag 300 is driven into the receiving space S without further leaving the receiving space S and entering the space outside the crucible assembly 12 of the furnace body 11 .

[0057] Specifically, Figure 1 , Figure 7 and Figure 8 In one example, the mobile unit 141 includes a vertical frame 141a, a lifter 141b, a horizontal slide rail 141c, a first horizontal mover 141d, and a second horizontal mover 141e. The vertical frame 141a is fixed. The lifter 141b is slidably matched with the vertical frame 141a, and the lifter 141b can move up and down along the vertical frame 141a. One end of the horizontal slide rail 141c is fixedly connected to the lifter 141b, the horizontal slide rail 141c and the lifter 141b are fixed relative to each other, and the horizontal slide rail 141c extends in a horizontal plane. The first horizontal mover 141d is slidably matched with the horizontal slide rail 141c to reciprocate along the first horizontal direction D1. The second horizontal mover 141e is slidably matched with the first horizontal mover 141d to reciprocate along the second horizontal direction D2, and the second horizontal direction D2 is orthogonal to the first horizontal direction D1. The top ends of the cylindrical rod 142 and the cylinder 143 are sealed and fixed to the second horizontal mover 141e. Through the lifter 141b, the first horizontal mover 141d and the second horizontal mover 141e, the cylindrical rod 142 and the cylinder 143 as well as the quartz truncated cone 145 and the gas nozzle 146 can be translated in three dimensions, so that the quartz truncated cone 145 and the gas nozzle 146 can be moved and positioned to the desired position above the first graphite crucible 121 and the quartz truncated cone 145 can be inserted into the melt 200 to a desired depth. For example, the lifter 141b, the first horizontal mover 141d and the second horizontal mover 141e are cylinders.

[0058] Furthermore, if Figure 1 , Figure 7 and Figure 8 As shown, the mobile unit 141 further includes a mounting frame 141f. The mounting frame 141f is located inside the surrounding wall 111 and below the top cover 112. The upper side of the mounting frame 141f is fixed to the lower surface of the top cover 112, and the lower side of the mounting frame 141f is fixedly connected to the vertical frame 141a.

[0059] Specifically, Figure 1 , Figure 7 and Figure 8In one example, the gas receiving unit 144 includes a rigid tube 144a and a plurality of flexible tubes 144b. The upper end of the rigid tube 144a is used to connect to an external gas supply source (not shown) that supplies pressurized gas. The lower part of the rigid tube 144a is sealed and fixed to the top cover 112. One end of each flexible tube 144b is sealed and connected to the bottom end of the rigid tube 144a, and the other end of each flexible tube 144b is sealed and connected to the top of the cylinder 143, and then sealed and connected to the gas channel P. The length of each flexible tube 144b can be determined by the maximum stroke of the quartz truncated cone 145 of the mobile unit 141 when removing the scum 300. The flexible tube 144b can be a bellows. For example, a plurality of flexible tubes 144b are arranged at equal intervals along the circumferential direction around the top of the cylinder 143.

[0060] like Figure 3 and Figure 4 As shown, in one example, the gas nozzle 146 has multiple circles of gas channels 146a that are concentric, spaced from each other, and expand from top to bottom around the quartz truncated cone 145, the walls of adjacent circles of gas channels 146a are connected together by connecting rods 146b, and the cylinder 143 is connected to the walls of adjacent circles of gas channels 146a by connecting rods 146b.

[0061] like Figure 6 As shown, in another example, the gas nozzle 146 has a plurality of gas channels 146 a spiraling from the inside to the outside around the quartz truncated cone 145 , and the end of the wall of the innermost gas channel 146 a is fixedly connected to the quartz truncated cone 145 .

[0062] like Figure 3 As shown, the outlets of the multiple-circle air passages 146a are on the same horizontal plane, or as shown in Figure 5 As shown, the outlet of the air passage 146a of the inner ring is lower than the outlet of the air passage 146a of the adjacent outer ring. Figure 5 The structure makes the air passage 146a of the inner ring closer to the quartz truncated cone 145 under the same pressure, so that the force pushing the scum 300 radially outward from the quartz truncated cone 145 is the largest, thereby completely removing the scum 300 at the quartz truncated cone 145.

[0063] In addition, refer to Figure 1 , Figure 7 and Figure 8The germanium crystal pulling and growing device 100 also includes an air inlet 15, an air outlet 16, a lifting rod 17 and a seed crystal 18. The air inlet 15 is provided at the bottom cover 113, and the air inlet 15 is used to introduce a purge gas (such as nitrogen) into the furnace body 11 or selectively introduce a growth gas (such as nitrogen, hydrogen or a nitrogen-hydrogen mixture) during the process of pulling and growing the crystal. The air outlet 16 is provided at the top cover 112, and the air outlet 16 is used to exhaust gas to complete the purge or maintain the flow pressure in the furnace body 11 during the pulling process. The lifting rod 17 is provided at the furnace body 11 and can be raised and lowered and rotated. The seed crystal 18 is installed at the end of the lifting rod 17, and the seed crystal 18 is used to enter the melt 200 in the first graphite crucible 121 below the liquid surface as the lifting rod 17 descends during the process of pulling and growing the crystal, and to grow the crystal as the lifting rod 17 rises.

[0064] In addition, refer to Figure 1 , Figure 7 and Figure 8 The germanium crystal pulling and growing device 100 also includes a seed crystal clamp 19, a lifting rod rotating mechanism 20, a lifting rod lifting mechanism 21, a bracket 22, a bracket rotating mechanism 23, a bracket lifting mechanism 24 and an observation window 25. The seed crystal clamp 19 is used to be detachably mounted on the end of the lifting rod 17 and to provide a seed crystal 18 for detachable installation. The lifting rod rotating mechanism 20 is connected to the top of the lifting rod 17, and the lifting rod rotating mechanism 20 is used to drive the lifting rod 17 to rotate. The lifting rod lifting mechanism 21 is connected to the lifting rod rotating mechanism 20, and the lifting rod lifting mechanism 21 is used to drive the lifting rod rotating mechanism 20 together with the lifting rod 17 to rise and fall. The bracket 22 is used to fix and support the second graphite crucible 122 from below. The bracket rotating mechanism 23 is connected to the bottom end of the bracket 22, and the bracket rotating mechanism 23 is used to drive the bracket 22 to rotate. The bracket lifting mechanism 24 is connected to the bracket rotating mechanism 23, and is used to drive the bracket rotating mechanism 23, the bracket 22 and the crucible assembly 12 to rise and fall together. The observation window 25 is provided on the top cover 112, and is used for the operator to observe the situation inside the furnace body 11 from the outside. For example, the lifting rod rotating mechanism 20 and the bracket rotating mechanism 23 are motors. For example, the lifting rod lifting mechanism 21 and the bracket lifting mechanism 24 are cylinders.

[0065] [Germanium crystal pulling growth method]

[0066] The germanium crystal pulling and growing method according to the present disclosure uses the aforementioned germanium crystal pulling and growing apparatus 100 .

[0067] In one example, refer to Figure 1 , Figure 7 and Figure 8 The method for growing germanium crystal by pulling includes the following steps:

[0068] S1, loading the etched polycrystalline germanium ingot into the first graphite crucible 121 of the crucible assembly 12;

[0069] S2, evacuate and pass nitrogen, repeat this process several times, and keep the pressure at the specified vacuum;

[0070] S3, passing non-oxidizing gas and exhausting gas to keep the furnace body 11 at normal pressure;

[0071] S4, the heater 13 is heated to 940-1000° C. to melt the germanium ingot in the first graphite crucible 121 to form a melt 200 and heat the slag mechanism 14;

[0072] S5, after the oxidizing process is completed, the intake amount of the non-oxidizing gas is adjusted to make the furnace body 11 slightly positively pressurized;

[0073] S6, the descumming mechanism 14 is activated, and the melt 200 is used to further preheat the descumming mechanism 14;

[0074] S7, the descum mechanism 14 operates again to raise the liquid level of the melt 200 to the top 121a of the first graphite crucible 121, and the descum mechanism 14 drives the scum 300 of the melt 200 in the first graphite crucible 121 from the liquid level of the melt 200 in the first graphite crucible 121 to the receiving space S between the first graphite crucible 121 and the second graphite crucible 122 by using the gas flow of the non-oxidizing gas;

[0075] S8, the scum removal mechanism 14 moves back to its original position, and then the crystal growth is carried out.

[0076] The characteristics, effects and operation of the aforementioned germanium crystal pulling and growing device 100 used in the germanium crystal pulling and growing method according to the present disclosure are described above and will not be repeated here.

[0077] In step S1 , for example, the polycrystalline germanium ingot has a purity of 6N.

[0078] In step S2, for example, the vacuum is set at 1×10 -3 Pa.

[0079] In step S3 , for example, the non-oxidizing gas is hydrogen.

[0080] In step S5, for example, the difference between the slightly positive pressure and the normal pressure is 0.5% of the normal pressure.

[0081] In step S6, the scum removal mechanism 14 is further preheated for 30-60 minutes using the melt 200. Specifically, the quartz truncated cone 145 is lowered to a certain height of 10-20 mm from the liquid surface of the melt 200, and the quartz truncated cone 145 and the gas nozzle 146 are further preheated for 30-60 minutes using the melt 200. The preheating in step S6 further prevents the quartz truncated cone 145 from being too cold and causing germanium to solidify and adhere to the surface of the insertion portion of the quartz truncated cone 145 when inserted into the melt 200, which is more conducive to the scum 300 being driven through the top 121a of the first graphite crucible 121 and entering the receiving space S, so that the melt 200 in the first graphite crucible 121 is separated from the scum 300 more effectively and thoroughly.

[0082] In step S7, for example, the scum removal mechanism 14 is activated again, and the quartz round table 145 is inserted into the liquid surface, as shown in FIG. Figure 7 As shown, the liquid level of the melt 200 rises to the top 121 a of the first graphite crucible 121 .

[0083] In step S7, for example, when the crystal is pulled to grow, the seed crystal 18 is driven by the pulling rod 17 to descend below the liquid surface of the melt 200 in the graphite crucible 12 and grows as the pulling rod 17 rises. Figure 8 The crystal growth process includes, for example, seeding, necking, shouldering, equalizing, finishing, cooling, etc. During the crystal growth process, the crucible assembly 12 can be rotated under the drive of the bracket rotating mechanism 23 .

[0084] The above detailed description is used to describe multiple exemplary embodiments, but this document is not intended to be limited to the explicitly disclosed combinations. Therefore, unless otherwise stated, the various features disclosed herein can be combined together to form multiple additional combinations that are not shown for the sake of simplicity.

Claims

1. A germanium crystal pulling and growing device, comprising a furnace body (11), a crucible assembly (12) and a heater (13), wherein the crucible assembly (12) comprises a first graphite crucible (121), the crucible assembly (12) is arranged in the furnace body (11), and the first graphite crucible (121) is used to hold a melt (200) formed by a germanium ingot; The heater (13) is used to heat the crucible assembly (12) so that the germanium ingot in the first graphite crucible (121) forms a melt (200); It is characterized in that The crucible assembly (12) further comprises a second graphite crucible (122), the first graphite crucible (121) being fixed in the second graphite crucible (122), the first graphite crucible (121) and the second graphite crucible (122) being spaced apart from the first graphite crucible (121) in a vertical direction (D3) and a circumferential direction to form a receiving space (S); The germanium crystal pulling and growing device (100) further comprises a scum removal mechanism (14), which is used to raise the liquid level of the melt (200) to the top (121a) of the first graphite crucible (121) before pulling the crystal for growth, and then use a gas flow of non-oxidizing gas to drive the scum (300) of the melt (200) in the first graphite crucible (121) from the liquid level of the melt (200) in the first graphite crucible (121) into a receiving space (S) between the first graphite crucible (121) and the second graphite crucible (122).

2. The germanium crystal pulling and growing device according to claim 1, characterized in that: The top end (121a) of the first graphite crucible (121) is lower than the upper end (122a) of the second graphite crucible (122); and / or The portion of the inner circumference of the first graphite crucible (121) close to the top is a slope (121b) that slopes inward from top to bottom; and / or The portion of the entire circumference of the outer peripheral wall of the first graphite crucible (121) close to the top is a slope surface (121c) that tilts outward from top to bottom, and the slope surface (121c) protrudes radially outward relative to the portion below the slope surface (121c) of the outer peripheral wall of the first graphite crucible (121); and / or The crucible assembly (12) further comprises a support column (123), wherein the support column (123) is fixed between the bottom wall of the first graphite crucible (121) and the bottom wall of the second graphite crucible (122).

3. The germanium crystal pulling and growing device according to claim 1, characterized in that: The heater (13) is located outside the furnace body (11) and is arranged around the crucible assembly (12); and / or The heater (13) is a resistance heater.

4. The germanium crystal pulling and growing device according to claim 1, characterized in that: The scum removal mechanism (14) comprises a moving unit (141), a cylindrical rod (142), a cylinder (143), an air receiving unit (144), a quartz truncated cone (145) and an air nozzle (146); The heater (13) is also used to heat at least the quartz truncated table (145) and the gas nozzle (146); The moving unit (141) can realize vertical lifting and horizontal translation; The top ends of the cylindrical rod (142) and the cylinder (143) are sealed and fixed to the moving unit (141), the cylinder (143) surrounds the cylindrical rod (142), and the inner circumference of the cylinder (143) is spaced apart from the outer circumference of the cylindrical rod (142) to form a gas passage (P) extending downward; The gas receiving unit (144) is connected to the gas channel (P), and the gas receiving unit (144) is used to supply external pressurized gas into the gas channel (P); The quartz truncated cone (145) is a truncated cone with a small top and a large bottom and is made of quartz. The upper end of the quartz truncated cone (145) is fixed to the lower end of the cylindrical rod (142). The quartz truncated cone (145) is used to be inserted into the melt (200) after being heated by the heater (13) and driven by the cylindrical rod (142) and the moving unit (141) so that the liquid level of the melt (200) rises to the top end (121a) of the first graphite crucible (121); A gas nozzle (146) surrounds the quartz truncated cone (145) and is fixed to the lower ends of the cylindrical rod (142) and the cylinder (143). The gas nozzle (146) is connected to the gas channel (P). The gas nozzle (146) is higher than the bottom surface (145a) of the quartz truncated cone (145). The gas nozzle (146) is used to transport the pressurized gas transported through the gas channel (P) to the liquid surface of the melt (200) so as to drive the scum (300) surrounding the quartz truncated cone (145) on the liquid surface of the melt (200) through the top end (121a) of the first graphite crucible (121) and into the receiving space (S).

5. The germanium crystal pulling and growing device according to claim 4, characterized in that: The moving unit (141) includes a vertical frame (141a), a lifter (141b), a horizontal slide rail (141c), a first horizontal mover (141d) and a second horizontal mover (141e); The vertical frame (141a) is fixed; The lifter (141b) is slidably matched with the vertical frame (141a), and the lifter (141b) can move up and down along the vertical frame (141a); One end of the horizontal slide rail (141c) is fixedly connected to the lifter (141b), the horizontal slide rail (141c) and the lifter (141b) are fixed relative to each other, and the horizontal slide rail (141c) extends in a horizontal plane; The first horizontal mover (141d) is slidably matched with the horizontal slide rail (141c) to reciprocate and translate along the first horizontal direction (D1); The second horizontal mover (141e) is slidably matched with the first horizontal mover (141d) to reciprocate along a second horizontal direction (D2), and the second horizontal direction (D2) is orthogonal to the first horizontal direction (D1); The top ends of the cylindrical rod (142) and the cylinder (143) are sealed and fixed to the second horizontal mover (141e).

6. The germanium crystal pulling and growing device according to claim 5, characterized in that: The furnace body (11) comprises a surrounding wall (111) and a top cover (112); The mobile unit (141) further includes a mounting frame (141f); The mounting frame (141f) is located inside the surrounding wall (111) and below the top cover (112); the upper side of the mounting frame (141f) is fixed to the lower surface of the top cover (112); and the lower side of the mounting frame (141f) is fixedly connected to the vertical frame (141a).

7. The germanium crystal pulling and growing device according to claim 4, characterized in that: The furnace body (11) has a top cover (112); The air receiving unit (144) includes a rigid tube (144a) and a plurality of flexible tubes (144b); The upper end of the rigid tube (144a) is used to connect to an external gas supply source for supplying pressurized gas; The lower portion of the rigid tube (144a) is sealed and fixed to the top cover (112); One end of each flexible tube (144b) is sealed and connected to the bottom end of the rigid tube (144a), and the other end of each flexible tube (144b) is sealed and connected to the top of the cylinder (143), and further sealed and connected to the gas channel (P).

8. The germanium crystal pulling and growing device according to claim 7, characterized in that: A plurality of flexible tubes (144b) are arranged at equal intervals in the circumferential direction around the top of the cylinder (143).

9. The germanium crystal pulling and growing device according to claim 4, characterized in that: The gas nozzle (146) has multiple circles of gas passages (146a) that are concentric, spaced from each other, and expand from top to bottom around the quartz truncated cone (145), the walls of adjacent circles of gas passages (146a) are connected together by connecting rods (146b), and the cylinder (143) and the walls of adjacent circles of gas passages (146a) are connected together by connecting rods (146b); and / or The air nozzle (146) has a plurality of spiral air passages (146a) surrounding the quartz truncated cone (145) from the inside to the outside, and the end of the wall of the innermost air passage (146a) is fixedly connected to the quartz truncated cone (145); and / or The outlets of the multiple rings of air passages (146a) are on the same horizontal plane, or the outlet of the inner ring of air passages (146a) is lower than the outlet of the adjacent outer ring of air passages (146a).

10. A method for growing germanium crystal by pulling, characterized in that: Using the germanium crystal pulling and growing device (100) according to any one of claims 1 to 9, a germanium crystal pulling and growing method comprises the steps of: S1, placing the etched polycrystalline germanium ingot into a first graphite crucible (121) of a crucible assembly (12); S2, evacuate and pass nitrogen, repeat this process several times, and keep the pressure at the specified vacuum; S3, passing non-oxidizing gas and exhausting the gas to maintain the furnace body (11) at normal pressure; S4, heating the heater (13) to 940-1000°C to melt the material, so that the germanium ingot in the first graphite crucible (121) forms a melt (200) and heats the slag mechanism (14); S5, after the material is oxidized, the intake amount of the non-oxidizing gas is adjusted to make the furnace body (11) slightly positively pressurized; S6, the descumming mechanism (14) is activated, and the melt (200) is used to further preheat the descumming mechanism (14); S7, the descumming mechanism (14) operates again, so that the liquid level of the melt (200) rises to the top (121a) of the first graphite crucible (121), and the descumming mechanism (14) uses the gas flow of the non-oxidizing gas to drive the scum (300) of the melt (200) in the first graphite crucible (121) from the liquid level of the melt (200) in the first graphite crucible (121) into the receiving space (S) between the first graphite crucible (121) and the second graphite crucible (122); S8, the scum removal mechanism (14) moves back to its original position, and then the crystal growth is carried out.

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