Germanium crystal pulling growth device and method

Abstract

The invention provides a germanium crystal pulling growth device and method. The germanium crystal pulling growth device comprises a furnace body, a graphite crucible and a heater, the graphite crucible is arranged in the furnace body, and the graphite crucible is used for containing melt formed by germanium ingots; the heater is used for heating the graphite crucible so that the germanium ingot in the graphite crucible can form melt. The part, close to the top, of the whole circumference of the inner circumferential wall of the graphite crucible is a downward arc surface which is concave outwards in the radial direction; the germanium crystal lifting growth device further comprises a scum removing mechanism; and the scum removing mechanism is used for driving the scum of the melt in the graphite crucible from the liquid level of the melt in the graphite crucible to the arc surface of the graphite crucible and adhering the scum to the arc surface of the graphite crucible by utilizing airflow of non-oxidizing gas after the liquid level of the melt rises to the bottom edge of the arc surface of the graphite crucible before the lifting crystal grows. Therefore, effective separation of the germanium melt and the dross and removal of the dross can be achieved, and germanium crystal growth in the pulling process is prevented from being affected by the dross.

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, carbon powder is inevitably produced during the contact between germanium and the inner wall of graphite due to the use of graphite crucible as a container; inert gas nitrogen is used as a protective gas, and burnt O2 will remain in the furnace. During the heating process of the melt, germanium will react with oxygen to generate GeO2. Since the pulling temperature of the material is 940-1000℃, and the melting point of GeO2 is 1080-1120℃, after the melting is completed, carbon powder and GeO2 float on the surface of the germanium solution as scum, which affects the crystallization and growth of the crystal 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 small, and thus suitable for small-sized crystal growth.

[0005] Thus, a germanium crystal pulling and growing device includes a furnace body, a graphite crucible and a heater, wherein the graphite crucible is arranged in the furnace body, and the graphite crucible is used to hold a melt formed by a germanium ingot; the heater is used to heat the graphite crucible so that the germanium ingot in the graphite crucible forms a melt. The inner peripheral wall of the graphite crucible has a portion close to the top of the entire circumference thereof which is a downwardly and radially outwardly concave arc surface; the germanium crystal pulling and growing device also includes a scum removal mechanism, which is used to raise the liquid level of the melt to the bottom edge of the arc surface of the graphite crucible before the pulling crystal grows, and then use a gas flow of non-oxidizing gas to drive the scum of the melt in the graphite crucible from the liquid level of the melt in the graphite crucible to the arc surface of the graphite crucible and adhere to the arc surface of the graphite crucible.

[0006] A method for growing germanium crystal by pulling and growing the germanium crystal adopts the above-mentioned germanium crystal pulling and growing device, and the method for growing germanium crystal by pulling and growing the germanium crystal comprises the following steps: S1, loading the corroded polycrystalline germanium ingot into a graphite crucible; 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 normal pressure; S4, heating the heater, raising the temperature to 940-1000°C for melting, so that the germanium ingot in the graphite crucible forms a melt and heats the slag mechanism; S5, after the melting is completed, adjusting the flow of non-oxidizing gas. The amount of gas is increased to make the furnace body slightly positively pressurized; S6, the descumming mechanism is actuated, and the melt is used to further preheat the descumming mechanism; S7, the descumming mechanism is actuated again, so that the liquid level of the melt rises to the bottom edge of the curved surface of the graphite crucible, and the descumming mechanism uses the gas flow of non-oxidizing gas to drive the scum of the melt in the graphite crucible from the liquid level of the melt in the graphite crucible to the curved surface of the graphite crucible and adhere to the curved surface of the graphite crucible; S8, the descumming mechanism is actuated again to return to its original position, and then the crystal is pulled for growth. During the crystal pulling process, the graphite crucible does not rotate.

[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 descumming mechanism makes the liquid surface of the melt rise to the bottom edge of the curved surface of the graphite crucible, so that the scum on the liquid surface of the melt reaches the starting bottom edge of the curved surface of the graphite crucible. When the descumming mechanism uses the airflow of the non-oxidizing gas to drive the scum of the melt in the graphite crucible from the liquid surface of the melt in the graphite crucible through the starting bottom edge of the curved surface to the curved surface of the graphite crucible, the heater is used to heat the graphite crucible. In order to form a melt from the germanium ingot in the graphite crucible, the temperature of the graphite crucible itself will be above the melting point of germanium (937.4°C). In this way, the germanium melt driven to the curved surface of the graphite crucible will flow back into the graphite crucible, and the remaining melt that no longer flows back into the graphite crucible will play a role in adhering scum and make the scum adhere to the curved surface of the graphite crucible. In this way, the melt and scum are effectively separated on the curved surface of the graphite crucible, and the scum is removed from the melt in the graphite crucible. Further, after the scum is removed, the germanium crystal is pulled and grown from the melt in the graphite crucible (the graphite crucible remains non-rotating during crystal growth), 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 device and method according to the present invention, since the curved surface is used to adhere to scum, the area of ​​the curved surface itself is originally small, and the use of the curved surface to remove scum is suitable for small-volume graphite crucibles, that is, the amount of germanium ingots contained in the graphite crucible is small, and is further suitable for the growth of small-sized (e.g., small equal diameter and short length) crystals. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1Schematic 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 2 It is a cutaway stereogram of a graphite crucible.

[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 device 144 Gas receiving unit

[0020] D1 first horizontal direction 144a rigid tube

[0021] D2 second horizontal direction 144b flexible tube

[0022] D3 vertical direction 145 quartz round table

[0023] 11 Bottom surface of furnace body 145a

[0024] 111 wall 146 gas nozzle

[0025] 112 top cover 146a airway

[0026] 113 bottom cover 146b connecting rod

[0027] 12 Graphite crucible P gas channel

[0028] 121 arc 15 air inlet

[0029] 121a Bottom edge 16 air outlet

[0030] 13 heater 17 lifting rod

[0031] 14 scum removal mechanism 18 seed crystal

[0032] 141 mobile unit 19 seed crystal clamp

[0033] 141a vertical frame 20 lifting rod rotating mechanism 141b lifter 21 lifting rod lifting mechanism 141c horizontal slide rail 22 bracket

[0034] 141d First horizontal shifter 23 bracket rotation mechanism

[0035] 141e Second horizontal mover 24 bracket lifting mechanism

[0036] 141f mounting frame 25 observation window

[0037] 142 cylindrical rod 200 melt

[0038] 143 cylinder 300 scum DETAILED DESCRIPTION

[0039] 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.

[0040] [Germanium crystal pulling and growth device]

[0041] Reference Figures 1 to 8 According to the present disclosure, the germanium crystal pulling and growing device 100 includes a furnace body 11, a graphite crucible 12 and a heater 13. The graphite crucible 12 is arranged in the furnace body 11 and is used to hold a melt 200 formed by a germanium ingot. The heater 13 is used to heat the graphite crucible 12 so that the germanium ingot in the graphite crucible 12 forms a melt 200. The inner peripheral wall of the graphite crucible 12 has a portion close to the top thereof which is a downwardly and radially outwardly concave arc surface 121. The germanium crystal pulling and growing device 100 also includes a scum removal mechanism 14, which is used to raise the liquid level of the melt 200 to the bottom edge 121a of the curved surface 121 of the graphite crucible 12 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 graphite crucible 12 from the liquid level of the melt 200 in the graphite crucible 12 to the curved surface 121 of the graphite crucible 12 and adhere to the curved surface 121 of the graphite crucible 12.

[0042] In the germanium crystal pulling and growing device 100 according to the present disclosure, before the pulling and growing of the crystal, the descumming mechanism 14 makes the liquid level of the melt 200 rise to the bottom edge 121a of the curved surface 121 of the graphite crucible 12, so that the scum on the liquid level of the melt 200 reaches the starting bottom edge 121a of the curved surface 121 of the graphite crucible 12. When the descumming mechanism 14 uses the gas flow of the non-oxidizing gas to drive the scum 300 of the melt 200 in the graphite crucible 12 from the liquid level of the melt 200 in the graphite crucible 12 through the starting bottom edge 121a of the curved surface 121 to the curved surface 121 of the graphite crucible 12, the heater 13 is used to heat the graphite crucible. The graphite crucible 12 is formed into a melt 200 from the germanium ingot in the graphite crucible 12, so the temperature of the graphite crucible 12 itself will be above the melting point of germanium (937.4° C.). In this way, the germanium melt 200 driven onto the curved surface 121 of the graphite crucible 12 will flow back into the graphite crucible 12, and the remaining melt 200 that no longer flows back into the graphite crucible 12 will adhere to the scum 300, so that the scum 300 adheres to the curved surface 121 of the graphite crucible 12. In this way, the melt 200 and the scum 300 are effectively separated on the curved surface 121 of the graphite crucible 12, and the scum 300 is removed from the melt 200 in the graphite crucible 12. Furthermore, after the scum 300 is removed, the melt 200 in the graphite crucible 12 is pulled to grow germanium crystals (the graphite crucible 12 remains stationary during crystal growth), so that the growth of the germanium crystals during the pulling process is not affected by the scum.

[0043] In the germanium crystal pulling and growing device 100 according to the present disclosure, since the arc surface 121 is used to adhere the scum 300, the area of ​​the arc surface 121 itself is originally small, and the use of the arc surface 121 to remove the scum 300 is suitable for a small-volume graphite crucible 12, that is, the amount of germanium ingot contained in the graphite crucible 12 is small, and is further suitable for the growth of small-sized (e.g., small equal diameter and short length) crystals.

[0044] 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 mixture, preferably a gas containing hydrogen, such as hydrogen alone or a nitrogen-hydrogen mixture. 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.

[0045] 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.

[0046] Reference Figure 1 , Figure 2 , Figure 7 and Figure 8 The height of the arc surface 121 in the vertical direction D3 is determined according to the volume of the graphite crucible 12 (ie, the amount of the germanium ingot contained in the graphite crucible 12) and the amount of the scum 300 that may be generated).

[0047] 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.

[0048] 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 after being heated by the heater 13 and driven by the cylindrical rod 142 and the moving unit 141 to make the liquid level of the melt 200 rise to the bottom edge 121a of the arc surface 121 of the graphite crucible 12. 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 slag 300 around the quartz truncated cone 145 on the liquid surface of the melt 200 onto the arc surface 121 of the graphite crucible 12. 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 germanium melt 200 driven onto the arc surface 121 of the graphite crucible 12 to flow back into the graphite crucible 12, so that the germanium melt 200 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 with a small top and a large bottom. In addition to being inserted into the melt 200 to raise the liquid level of the melt 200 to the bottom edge 121a of the curved surface 121 of the graphite crucible 12, because the truncated cone with a small bottom and a large 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 obliquely downward along this generatrix, thereby generating a radially outward component force, thereby driving the scum 300 radially outward. The pressure of the pressurized gas is based on driving the scum 300 onto the curved surface 121 of the graphite crucible 12 without further leaving the curved surface 121 to the space outside the graphite crucible 12 of the furnace body 11.

[0049] 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 graphite crucible 12 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.

[0050] 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.

[0051] 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) for supplying 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 table 145 of the moving 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 in the circumferential direction around the top of the cylinder 143.

[0052] 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, and the walls of the gas channels 146a of adjacent circles are connected together by connecting rods 146b. Similarly, the cylinder 143 is connected to the walls of the gas channels 146a of adjacent circles by connecting rods 146b.

[0053] like Figure 6 As shown, in another example, the gas nozzle 146 has a multi-turn gas channel 146a spiraling from the inside to the outside around the quartz truncated cone 145, and the end of the wall of the innermost gas channel 146a is fixedly connected to the quartz truncated cone 145. The use of the multi-turn gas channel 146a spiraling from the inside to the outside can increase the circumferential separation and enhance the efficiency and effect of driving the scum 300 from the liquid surface of the melt 200 to the arc surface 121 of the graphite crucible 12.

[0054] 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.

[0055] 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 graphite crucible 12 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.

[0056] 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 graphite crucible 12 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 graphite crucible 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.

[0057] [Germanium crystal pulling growth method]

[0058] The germanium crystal pulling and growing method according to the present disclosure uses the aforementioned germanium crystal pulling and growing device 100 .

[0059] In one example, refer to Figure 1 , Figure 7 and Figure 8 According to the present disclosure, the germanium crystal pulling and growing method comprises the steps of:

[0060] S1, placing the etched polycrystalline germanium ingot into a graphite crucible 12;

[0061] S2, evacuate and pass nitrogen, repeat this process several times, and keep the pressure at the specified vacuum;

[0062] S3, passing non-oxidizing gas and exhausting gas to keep the furnace body 11 at normal pressure;

[0063] S4, the heater 13 is heated to 940-1000° C. to melt the germanium ingot in the graphite crucible 12 to form a melt 200 and heat the slag mechanism 14;

[0064] 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;

[0065] S6, the descumming mechanism 14 is activated, and the melt 200 is used to further preheat the descumming mechanism 14;

[0066] S7, the descum mechanism 14 operates again, so that the liquid level of the melt 200 rises to the bottom edge 121a of the curved surface 121 of the graphite crucible 12, and the descum mechanism 14 drives the scum 300 of the melt 200 in the graphite crucible 12 from the liquid level of the melt 200 in the graphite crucible 12 to the curved surface 121 of the graphite crucible 12 by the gas flow of the non-oxidizing gas and adheres to the curved surface 121 of the graphite crucible 12;

[0067] S8, the scum removal mechanism 14 moves back to its original position again, and then the crystal is pulled to grow. During the crystal pulling growth process, the graphite crucible 12 does not rotate.

[0068] 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.

[0069] In step S1 , for example, the polycrystalline germanium ingot has a purity of 6N.

[0070] In step S2, for example, the vacuum is set at 1×10 -3 Pa.

[0071] In step S3 , for example, the non-oxidizing gas is hydrogen.

[0072] In step S5, for example, the difference between the slightly positive pressure and the normal pressure is 0.5% of the normal pressure.

[0073] In step S6, the scum removal mechanism 14 is further preheated for 30-60 minutes by the melt 200. Specifically, the quartz truncated cone 145 is lowered to a certain height of 10-20 mm from the liquid level of the melt 200, and the quartz truncated cone 145 and the gas nozzle 146 are further preheated for 30-60 minutes by 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 inserted portion of the quartz truncated cone 145 when inserted into the melt 200, which is conducive to the germanium melt 200 driven onto the arc surface 121 of the graphite crucible 12 to flow back into the graphite crucible 12, so that the germanium melt 200 is separated from the scum 300 more effectively and thoroughly.

[0074] 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 bottom edge 121 a of the arc surface 121 of the graphite crucible 12 .

[0075] 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 diameters, finishing, and cooling.

[0076] 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 graphite crucible (12) and a heater (13), wherein the graphite crucible (12) is arranged in the furnace body (11), and the graphite crucible (12) is used to contain a melt (200) formed by a germanium ingot; The heater (13) is used to heat the graphite crucible (12) so that the germanium ingot in the graphite crucible (12) forms a melt (200); It is characterized in that The portion of the inner peripheral wall of the graphite crucible (12) close to the top of the entire circumference is a curved surface (121) that is concave downward and radially outward; 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 bottom edge (121a) of the curved surface (121) of the graphite crucible (12) 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 graphite crucible (12) from the liquid level of the melt (200) in the graphite crucible (12) to the curved surface (121) of the graphite crucible (12) and adhere to the curved surface (121) of the graphite crucible (12).

2. 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 graphite crucible (12); and / or The heater (13) is a resistance heater.

3. 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 bottom edge (121a) of the arc surface (121) of the graphite crucible (12); 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) onto the arc surface (121) of the graphite crucible (12).

4. The germanium crystal pulling and growing device according to claim 3, 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).

5. The germanium crystal pulling and growing device according to claim 3, 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).

6. The germanium crystal pulling and growing device according to claim 3, 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).

7. The germanium crystal pulling and growing device according to claim 3, 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).

8. The germanium crystal pulling and growing device according to claim 1, characterized in that: The furnace body (11) comprises a surrounding wall (111), a top cover (112) and a bottom cover (113); The germanium crystal pulling and growing device (100) also includes an air inlet (15), an air outlet (16), a pulling rod (17) and a seed crystal (18); The air inlet (15) is arranged on the bottom cover (113), and the air inlet (15) is used to introduce purge gas into the furnace body (11) or selectively introduce growth gas during the process of pulling and growing crystals; An air outlet (16) is provided on the top cover (112), and the air outlet (16) is used to exhaust gas to complete cleaning or maintain the flow pressure in the furnace body (11) during the pulling process; The lifting rod (17) is arranged on the furnace body (11) and can be lifted and rotated; The seed crystal (18) is installed at the end of the lifting rod (17). The seed crystal (18) is used to enter the melt (200) in the graphite crucible (12) 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.

9. The germanium crystal pulling and growing device according to claim 8, characterized in that: The germanium crystal pulling and growing device (100) also includes a seed crystal clamp (19), a pulling rod rotating mechanism (20), a pulling 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 detachable mounting for the seed crystal (18); The lifting rod rotating mechanism (20) is connected to the top end 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) and the lifting rod (17) to rise and fall; The bracket (22) is used to fix and support the graphite crucible (12) 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 the bracket lifting mechanism (24) is used to drive the bracket rotating mechanism (23), the bracket (22) and the graphite crucible (12) to rise and fall together; An observation window (25) is arranged on the top cover (112), and the observation window (25) is used for an operator to observe the situation inside the furnace body (11) from the outside.

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 graphite crucible (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 graphite crucible (12) 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 scum removal mechanism (14) operates again, so that the liquid level of the melt (200) rises to the bottom edge (121a) of the curved surface (121) of the graphite crucible (12), and the scum removal mechanism (14) uses the gas flow of the non-oxidizing gas to drive the scum (300) of the melt (200) in the graphite crucible (12) from the liquid level of the melt (200) in the graphite crucible (12) to the curved surface (121) of the graphite crucible (12) and adhere to the curved surface (121) of the graphite crucible (12); S8, the scum removal mechanism (14) moves back to its original position again, and then the crystal is pulled to grow. During the crystal pulling growth process, the graphite crucible (12) does not rotate.

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