CN218436025U - Single crystal furnace and growing device thereof - Google Patents
Single crystal furnace and growing device thereof Download PDFInfo
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- CN218436025U CN218436025U CN202222813178.0U CN202222813178U CN218436025U CN 218436025 U CN218436025 U CN 218436025U CN 202222813178 U CN202222813178 U CN 202222813178U CN 218436025 U CN218436025 U CN 218436025U
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Abstract
The utility model discloses a single crystal growing furnace and growing device thereof, this growing device are applied to carborundum single crystal, include: the crucible, the first crucible cover and the gas channel; the crucible is used for placing silicon carbide raw materials and is placed in the single crystal furnace to preheat the silicon carbide raw materials, and the crucible is provided with air holes; the first crucible cover is used for buckling with the crucible after the crucible is filled with the silicon carbide raw material and before the silicon carbide raw material is filled into the single crystal furnace; the gas channel is connected with the gas hole of the crucible and is used for introducing inert gas when the single crystal furnace preheats the hot silicon carbide raw material. Can carry out low temperature to the carborundum raw materials and burn in through this scheme and handle and let in inert gas in the carborundum raw materials to impurity discharge in the through air current drive carborundum raw materials under the condition of preheating, and then help realizing the purification of carborundum raw materials, thereby be favorable to making the impurity that the growth initial stage was transmitted to the growth face by the carborundum raw materials reduce.
Description
Technical Field
The utility model relates to a carborundum single crystal preparation technical field, in particular to single crystal growing furnace and growth device thereof.
Background
The currently common preparation method of the silicon carbide single crystal is a physical vapor deposition method (PVT method), and the main mechanism is that silicon carbide powder is decomposed and sublimated into mixed gas phase components of Si, C, siC, si2C, siC2 and the like in a high-temperature area, and the gas phase components are transmitted to a seed crystal growth interface in a low-temperature area and crystallized through the driving of a temperature field. In the process, if the silicon carbide powder or the impurities in the whole system are more, the crystal purity is low, and even the dislocation density is increased and the growth defects such as dense micropipes are generated.
In the preparation process of the silicon carbide powder, a stainless steel hammer or other metal equipment is generally used for crushing, then the pickling is carried out to remove impurity metals in the powder, but the metal impurities are difficult to be completely removed in the pickling process, the metal impurities can be mixed in the air flow when the silicon carbide crystal grows, and the melting point of the common metal impurities is lower than the growth temperature of the silicon carbide single crystal, so that the common metal impurities are easily brought to the growth surface of the seed crystal by the air flow in the initial growth stage, and the impurity content of the growth interface of the seed crystal is high.
SUMMERY OF THE UTILITY MODEL
In view of this, the utility model provides a single crystal growing furnace growth device can carry out the low temperature to the carborundum raw materials and preburn and handle and let in inert gas in the carborundum raw materials to impurity discharge in through the air current drive carborundum raw materials under the condition of preheating, and then help realizing the purification of carborundum raw materials, thereby be favorable to making the impurity that the initial stage of growth was transmitted to the growth face by the carborundum raw materials reduce.
In order to achieve the above object, the utility model provides a following technical scheme:
a growth device of a single crystal furnace is applied to a silicon carbide single crystal and comprises: the crucible, the first crucible cover and the gas channel;
the crucible is used for placing silicon carbide raw materials and is placed into a single crystal furnace to preheat the silicon carbide raw materials, and the crucible is provided with air holes;
the first crucible cover is used for buckling with the crucible after the silicon carbide raw material is put into the crucible and before the silicon carbide raw material is put into the single crystal furnace;
the gas channel is connected with the gas hole of the crucible and is used for introducing inert gas when the single crystal furnace preheats the silicon carbide raw material.
Preferably, the air holes are distributed at the bottom and/or the side wall of the crucible and are lower than the preset stacking height of the silicon carbide raw material in the crucible.
Preferably, the crucible is adapted to be loaded into a heating coil of the single crystal furnace such that a bottom of the first crucible cover is higher than a top of the heating coil.
Preferably, the first crucible cover comprises: a cylindrical crucible cover or a conical crucible cover.
Preferably, the first crucible cover is provided with a through hole.
Preferably, the gas passage is provided with a gas regulating valve.
Preferably, the crucible is also used for taking out and reloading the silicon carbide raw material into the single crystal furnace for heating after preheating is completed so as to grow the silicon carbide single crystal;
the growth device of the single crystal furnace further comprises: a second crucible cover and a seed crystal;
the seed crystal is fixed at the bottom of the second crucible cover and used for replacing the first crucible cover to be buckled with the crucible before the crucible is reloaded into the single crystal furnace after preheating the silicon carbide raw material.
Preferably, the crucible is used for taking out and reloading the silicon carbide raw material into a heating coil of the single crystal furnace after preheating is finished, and the seed crystal is enabled to be flush with the top of the heating coil.
A single crystal furnace comprises a growing device, and the growing device is the single crystal furnace growing device.
According to the above technical scheme, the utility model provides a single crystal growing furnace growth device can carry out the low temperature to the carborundum raw materials and preburn and handle and let in inert gas in the carborundum raw materials to discharge through the impurity in the air current drive carborundum raw materials under the condition of preheating, and then help realizing the purification of carborundum raw materials, thereby be favorable to making the impurity that the initial stage of growth was transmitted to the growth face by the carborundum raw materials reduce.
The utility model also provides a single crystal growing furnace, owing to adopted foretell single crystal growing furnace growth device, consequently it also has corresponding beneficial effect, specifically can refer to the preceding explanation, no longer gives unnecessary details here.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic view of the overall structure of a growth apparatus of a single crystal growing furnace according to a first embodiment of the present invention;
FIG. 2 is a schematic view of the overall structure of a growing apparatus of a single crystal growing furnace according to a second embodiment of the present invention;
FIG. 3 is a schematic view of the overall structure of a growing apparatus of a single crystal growing furnace according to a third embodiment of the present invention;
FIG. 4 is a schematic view of the overall structure of a growing apparatus of a single crystal growing furnace according to a fourth embodiment of the present invention;
FIG. 5 is a schematic view of the overall structure of a growing apparatus of a single crystal growing furnace according to a fifth embodiment of the present invention;
FIG. 6 is a schematic view of the overall structure of a single crystal growing apparatus of the comparative example of the present invention;
FIG. 7 is a microscopic dislocation distribution view of an etched wafer of a growing crystal according to an embodiment of the present invention;
fig. 8 is a dislocation distribution under a microscope of an etched wafer of a grown crystal according to a comparative example of the present invention.
Wherein, 1 is cylindric crucible lid, 2 is the crucible, 3 is the carborundum raw materials, 4 is the heating coil, 5 is the gas passage, 6 is the gas regulating valve, 7 is cylindric trompil crucible lid, 8 is coniform crucible lid, 9 is the gas passage of side gas, 10 is the second crucible lid, 11 is the seed crystal, 12 is conventional crucible.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
The embodiment of the utility model provides a single crystal growing device of single crystal growing furnace is applied to the carborundum single crystal, as shown in figure 1, include: crucible 2, first crucible cover and gas channel 5;
the crucible 2 is used for placing the silicon carbide raw material 3 and is placed in a single crystal furnace to preheat the silicon carbide raw material 3, and the crucible 2 is provided with air holes;
the first crucible cover is used for buckling with the crucible 2 after the crucible 2 is filled with the silicon carbide raw material 3 and before being filled into the single crystal furnace;
the gas passage 5 is connected to the gas hole of the crucible 2 and is used for introducing an inert gas when the silicon carbide raw material 3 is preheated in the single crystal furnace.
The working principle of the growth device (pretreatment) of the single crystal furnace is as follows: firstly, enough silicon carbide raw material 3 (silicon carbide powder) is put in a crucible 2, then the crucible 2 is buckled with a first crucible cover, then an assembled growth device is put in a single crystal furnace for low-temperature pre-burning treatment to preheat the silicon carbide raw material 3, meanwhile, inert gas is introduced into the silicon carbide raw material 3 through a gas channel 5, in the preheating and ventilating process, on one hand, impurity gas generated by preheating the silicon carbide raw material 3 can be conveyed to the first crucible cover, crystallized or exhausted, on the other hand, fine impurity particles in the silicon carbide raw material 3 can be taken away due to the fact that the introduced inert gas is conveyed in the silicon carbide raw material 3, and the gas flow carrying the impurity particles is driven to move towards the first crucible cover, so that impurities in the silicon carbide raw material 3 can be removed. In other words, the scheme can play a role in purifying the silicon carbide raw material 3 through the pretreatment (preheating and ventilation) process.
That is to say, the single crystal furnace growth device provided by the scheme can realize the purification of the silicon carbide raw material 3 before the crystal growth. The low-temperature presintering treatment is firstly carried out on the silicon carbide raw material 3 and the whole growth device, and inert gas is introduced into the silicon carbide raw material 3, so that the silicon carbide raw material 3 and impurities in a system are driven to be discharged through gas flow. From this it is not difficult to discover, through the single crystal growing furnace device of this scheme, can realize the preliminary treatment process of carborundum raw materials 3 presintering and ventilating, and then help improving the purity of carborundum raw materials 3. Of course, the purified silicon carbide feedstock 3 is reused to grow the crystal, thereby facilitating a reduction in the impurities transported from the silicon carbide feedstock to the growth surface during the initial stages of growth. In addition, the inert gas introduced into the gas channel 5 can be helium or argon, and the introduced gas flow is transmitted in the silicon carbide raw material 3, so that small particle impurities in the silicon carbide raw material 3 can be taken away.
In the scheme, as shown in fig. 1 or fig. 4, the air holes are distributed in the bottom and/or the side wall of the crucible 2, and are lower than the preset stacking height of the silicon carbide raw material 3 in the crucible 2, that is, lower than the preset material level of the silicon carbide raw material 3 in the crucible 2, so that the introduced inert gas can be transmitted in the silicon carbide raw material 3, fine impurity particles in the silicon carbide raw material 3 can be taken away, and the gas flow carrying the impurity particles is driven to move towards the first crucible cover at the upper part.
Specifically, as shown in FIGS. 1 to 4, the crucible 2 is used to be loaded into a heating coil 4 of a single crystal furnace, and the bottom of the first crucible cover is made higher than the top of the heating coil 4. Of course, the installation height of the crucible 2 in the single crystal furnace is adjustable. This scheme is so designed to make single crystal growing furnace induction heating coil's top be less than the bottom of first crucible cover, can make the temperature difference increase of first crucible cover and carborundum raw materials 3, thereby be favorable to carborundum raw materials 3 to preheat the impurity air current that produces and can cover transmission, crystallization or discharge to first crucible.
Preferably, as shown in fig. 1 and 3, the first crucible cover includes: the cylindrical crucible cover 1 or the conical crucible cover 8 has the characteristics of simple structure, easiness in manufacturing, convenience in buckling and the like. Of course, the first crucible cover of the scheme can also adopt other structures, and the details are not repeated here.
Further, the first crucible cover is provided with a through hole, so that the impurity airflow generated by preheating the silicon carbide raw material 3 is discharged through the through hole of the first crucible cover, and meanwhile, the airflow carrying the impurity particles of the silicon carbide raw material 3 is discharged through the through hole of the first crucible cover. Wherein the first crucible cover can be a cylindrical perforated crucible cover 7, as shown in fig. 4.
Still further, as shown in fig. 1, the gas channel 5 is provided with a gas regulating valve 6, so as to facilitate the regulation of the amount of the inert gas introduced, and of course, the gas channel can also be used for controlling the on-off of the gas channel 5.
In the present embodiment, as shown in fig. 5, the crucible 2 is also used for taking out and reloading the silicon carbide raw material 3 into the single crystal furnace to heat after preheating is completed so as to grow the silicon carbide single crystal;
the single crystal growing furnace device further comprises: a second crucible cover 10 and a seed crystal 11;
the bottom of the second crucible cover 10 is fixed with a seed crystal 11 and is used for replacing the first crucible cover to be buckled with the crucible 2 before the crucible 2 is reloaded into the single crystal furnace after preheating the silicon carbide raw material 3. More specifically, after the silicon carbide raw material 3 is pretreated and purified, the growth device is moved out of the single crystal furnace, the first crucible cover is taken down, the second crucible cover 10 fixed with the seed crystal 11 is buckled with the crucible 2, the assembled growth device is reloaded into the single crystal furnace, and finally the operation is carried out according to the normal process of growing the silicon carbide single crystal. It is noted that the inert gas does not need to be introduced during the normal growth phase of the silicon carbide single crystal. Therefore, the impurity content in the silicon carbide single crystal can be reduced, and the dislocation density of the silicon carbide single crystal can be reduced. That is to say, the single crystal growing furnace that this scheme provided can regard as the preprocessing device of carborundum raw materials, can realize the preliminary treatment of carborundum raw materials earlier, and then help improving the purity of carborundum raw materials 3, can regard as carborundum single crystal growing device again, realizes the normal growth crystallization of purification back carborundum raw materials 3 from this next to be favorable to improving the purity of carborundum single crystal, reduce the production of carborundum single crystal defect.
Specifically, as shown in fig. 5, the crucible 2 is used to take out and re-load the silicon carbide raw material 3 into the heating coil 4 of the single crystal furnace after preheating is completed, and the seed crystal 11 is made flush with the top of the heating coil 4, so as to reduce the temperature difference between the silicon carbide raw material 3 and the surface of the seed crystal 11, reduce the crystal growth rate, and prevent the growth defect from being generated due to too fast crystal growth.
The embodiment of the utility model also provides a single crystal growing furnace, including growing device, growing device is as above single crystal growing furnace growing device. Due to the adoption of the single crystal furnace growth device, the device has corresponding beneficial effects, and specific reference can be made to the previous description, which is not repeated herein.
The present solution is further described below with reference to specific embodiments:
the open crucible is open at the bottom or side (i.e., gas hole) and is connected to a gas channel. And the silicon carbide raw material with a certain thickness is contained in the perforated crucible, and the special crucible cover (namely, the first crucible cover) can be buckled with the perforated crucible.
The special crucible cover can be cylindrical or conical, and the like, and does not need to be provided with holes or holes.
The gas channel in the crucible is arranged below the surface of the silicon carbide raw material, the introduced gas can be inert gases such as helium, argon and the like, and the introduced gas flow is transmitted in the raw material and can take away small particle impurities in the raw material.
When the silicon carbide raw material is pretreated, the uppermost end of the heating coil is lower than the special crucible cover, so that a larger temperature difference is formed between the raw material and the special crucible cover, and the transmission and crystallization of evaporated impurity airflow and particles in the raw material to the crucible are facilitated.
The purity of the silicon carbide raw material is improved through pretreatment of the silicon carbide raw material, the purified silicon carbide raw material is used for growing crystals, and impurities transmitted from the silicon carbide raw material to a growing surface in the initial growth stage are reduced.
When the pretreated silicon carbide formally grows crystals, the uppermost end of the heating coil can be flush with the seed crystals, so that the temperature difference between the raw material and the surface of the seed crystals is reduced, the growth speed of the crystals is reduced, and the growth defects caused by too fast growth of the crystals are prevented.
The heating coil can be an induction heating coil, and the highest heating temperature is lower than 1800 ℃ during raw material pretreatment, so that serious carbonization of the silicon carbide raw material due to overhigh temperature is avoided. When the silicon carbide crystal is formally grown, the maximum heating temperature can reach about 2300 ℃.
The embodiment is as follows:
in the embodiment, referring to fig. 2, 4 gas channels are arranged at the bottom of the perforated crucible and filled with sufficient silicon carbide raw material, the perforated crucible is buckled with the special crucible cover and then placed in a growth furnace chamber, the height difference between the highest end of the heating coil and the bottom of the special crucible in the vertical direction is ensured to be 20mm, the temperature is raised after the steps are completed, and meanwhile, 1500sccm argon gas is continuously introduced.
Wherein the temperature-raising procedure is as follows: the temperature is raised to 1800 ℃ in 1 hour, the temperature is kept for 3 hours, and a heating switch of the heating coil is closed.
And taking down the special crucible cover after the system is cooled, and structurally referring to fig. 5, buckling the perforated crucible and a conventional crucible cover (namely a second crucible cover) fixed with the seed crystal 11, placing the crucible in a growth furnace chamber, keeping a gas passage switch completely closed, keeping the height difference between the highest end of the heating coil and the seed crystal in the vertical direction to be 0, and starting to operate according to a normal silicon carbide single crystal growth flow after the steps are completed. The dislocation distribution of the etched wafer of the grown crystal under the microscope is shown in figure 7, with less ted.
Comparative example:
referring to fig. 6, a conventional crucible is filled with a sufficient amount of silicon carbide raw material, and is placed in a growth furnace chamber after being fastened with a conventional crucible cover on which a seed crystal 11 is fixed, the height difference between the highest end of a heating coil and the seed crystal in the vertical direction is 0, and the operation is started according to the normal silicon carbide single crystal growth flow after the steps are completed. The dislocation distribution of the etched wafer of the grown crystal under the microscope is shown in fig. 8, ted is high, and a small amount of TSD is present.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (9)
1. A single crystal growing apparatus is applied to a silicon carbide single crystal, and is characterized by comprising: a crucible (2), a first crucible cover and a gas channel (5);
the crucible (2) is used for placing a silicon carbide raw material (3) and is placed in a single crystal furnace to preheat the silicon carbide raw material (3), and the crucible (2) is provided with air holes;
the first crucible cover is used for buckling with the crucible (2) before the crucible (2) is placed into the single crystal furnace after the silicon carbide raw material (3) is placed into the crucible (2);
the gas channel (5) is connected with the gas hole of the crucible (2) and is used for introducing inert gas when the single crystal furnace preheats the silicon carbide raw material (3).
2. The growth device of the single crystal furnace according to claim 1, characterized in that the air holes are distributed on the bottom and/or the side wall of the crucible (2) and are lower than the preset stacking height of the silicon carbide raw material (3) in the crucible (2).
3. The growing apparatus of the single crystal furnace according to claim 1, wherein the crucible (2) is adapted to be loaded into a heating coil (4) of the single crystal furnace such that a bottom of the first crucible cover is higher than a top of the heating coil (4).
4. The single crystal furnace growth apparatus of claim 1, wherein the first crucible cover comprises: a cylindrical crucible cover (1) or a conical crucible cover (8).
5. The growing apparatus of the single crystal furnace as claimed in claim 1, wherein the first crucible cover is opened with a through hole.
6. The growth apparatus of a single crystal furnace according to claim 1, wherein the gas channel (5) is provided with a gas regulating valve (6).
7. The growing apparatus of the single crystal furnace according to claim 1, wherein the crucible (2) is further adapted to be taken out and re-charged into the single crystal furnace to be heated after preheating the silicon carbide raw material (3) is completed to grow the silicon carbide single crystal;
the growth device of the single crystal furnace further comprises: a second crucible cover (10) and a seed crystal (11);
the seed crystal (11) is fixed at the bottom of the second crucible cover (10) and is used for replacing the first crucible cover to be buckled with the crucible (2) before the crucible (2) is reloaded into the single crystal furnace after preheating the silicon carbide raw material (3).
8. The single crystal furnace growth apparatus according to claim 7, wherein the crucible (2) is adapted to be taken out and reloaded into a heating coil (4) of the single crystal furnace after preheating the silicon carbide raw material (3) is completed, and the seed crystal (11) is made flush with the top of the heating coil (4).
9. A single crystal furnace comprising a growing apparatus, wherein the growing apparatus is a single crystal furnace growing apparatus according to any one of claims 1 to 8.
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| CN202222813178.0U CN218436025U (en) | 2022-10-25 | 2022-10-25 | Single crystal furnace and growing device thereof |
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| CN202222813178.0U CN218436025U (en) | 2022-10-25 | 2022-10-25 | Single crystal furnace and growing device thereof |
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Assignee: Shenzhen Reinvested Tianke Semiconductor Co.,Ltd. Assignor: TANKEBLUE SEMICONDUCTOR Co.,Ltd. Contract record no.: X2023990000672 Denomination of utility model: A Single Crystal Furnace and Its Growth Device Granted publication date: 20230203 License type: Common License Record date: 20230725 |
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