KR101816109B1 - Apparatus for Growing SiC Single Crystal Ingot and Growing Method thereof - Google Patents

Abstract

The present invention relates to a method for manufacturing a silicon carbide (SiC) single crystal by reducing the temperature gradient of the inside of the single crystal ingot and the surface of the source when the surface of the single crystal ingot approaches the surface of the source, (SiC) single crystal ingot growing apparatus and method for growing the single crystal ingot, which is capable of increasing the growth length by maintaining the temperature gradient.
Wherein the silicon carbide single crystal ingot growing apparatus is a crucible in which a source made of silicon carbide (SiC) powder is filled in the lower part and a silicon carbide single crystal seed is mounted on the upper part to grow a silicon carbide single crystal ingot; A resistance heating heater provided on an outer periphery spaced apart from the crucible and heating the crucible with a characteristic that the lowering width of the temperature increases from a lower portion to a predetermined height or more; A heat insulating material surrounding the outer circumferential surface of the resistance heating heater; A vacuum chamber in which the crucible, the resistance heating heater, and the heat insulating material are incorporated and into which a carrier gas is injected; And a crucible moving system installed outside the vacuum chamber for moving the crucible upward and downward in conjunction with the growth of the silicon carbide single crystal ingot in the crucible, wherein, as the silicon carbide single crystal ingot grows, And the crucible is elevated to compensate for the temperature gradient decrease.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a silicon carbide single crystal ingot growth apparatus and a growth method thereof,

The present invention relates to a silicon carbide single crystal ingot growing apparatus, and more particularly, to a silicon carbide single crystal ingot growing apparatus wherein a temperature gradient of the inside of a silicon carbide (SiC) single crystal is reduced as a surface of a single crystal ingot approaches a surface of a source, (SiC) single crystal ingot growing apparatus and method for growing the same, which can increase the growth length by maintaining the temperature gradient by moving the crucible position inside the resistance heating heater.

Silicon carbide (SiC) is a semiconductor composed of a compound of carbon (C) and silicon (Si), and has physical and chemical properties excellent in thermal conductivity and heat resistance. .

The silicon carbide single crystal is a solidified material having a certain crystal structure in the process of solidifying silicon carbide after melting at a certain temperature.

Silicon carbide is a material exhibiting a polytype phenomenon having various lamination structures with the same composition. There are phases having different crystal structures over a range of 1000 to 2700 ° C or more, and more than 200 types of crystal polymorphism exist in all. However, large-sized single crystals can be grown in hexagonal (Hexagonal) mode, and the representative types required in the present industry are 4H and 6H types.

Ultra-high-purity SiC substrates are three times higher in thermal conductivity (~ 5.0W / cm) than silicon (Si) and 10 times larger in dielectric breakdown strength (~ 3MV / cm), making them energy efficient semiconductors operating at high temperatures and high voltages. It is possible to develop a component that operates normally at a high environmental temperature of ~ 500 ° C. Thus, the SiC semiconductor device can realize high performance and low power consumption of inverter devices, home power modules, automotive power semiconductor devices, and the like.

Especially, the power consumption is 100% theoretically compared with the conventional silicon (Si) power device, and it is expected that the application to silicon carbide power semiconductor will be further expanded.

Korean Patent Laid-Open Publication No. 10-2010-0089103 (Patent Document 1) discloses a manufacturing apparatus for producing an SiC single crystal ingot by sublimating and recrystallizing SiC powder as a raw material of SiC single crystal in a graphite crucible provided inside a double quartz tube However, this manufacturing apparatus is capable of manufacturing a single silicon carbide single crystal ingot in a single manufacturing process by heating a graphite crucible by heating a graphite crucible in a work coil installed on the periphery of a double quartz tube, .

In the manufacturing apparatus of Patent Document 1, the silicon carbide single crystal ingot is produced by the induction heating method. Even if the induced eddy current formed in the crucible is stabilized because the crucible serves as a heating element, The ratio of the energy absorbed by the crucible to the energy absorbed by the crucible is unavoidable and it is difficult to realize a stable temperature and it is difficult to actualize the actual balance of the calorie balance (the difference between the supplied heat quantity Qin and the removed heat quantity Qout) It is difficult to secure the stability of the calorie.

In addition, the PVC (Physical Vapor Transport), which is a major monocrystal growth method of silicon carbide (SiC) single crystal (ingot), is a method in which SiC powder of high purity is sublimated in a closed graphite crucible by induction heating, It is a method of attaching it on a single crystal and obtaining it as an ingot.

However, in the case of the induction heating method, the current density is simultaneously changed in accordance with the thickness change of the crucible after use, and the temperature distribution in the crucible changes. This makes it difficult to obtain growth reproducibility.

On the other hand, in the case of the resistance heating method, the crucible temperature can be raised by the radiant heat of the heating heater for resistance heating, and the crucible can be reused, and the reproducibility is easy due to the designed calorific value and the calorific value.

However, in the conventional resistance heating method, the inner temperature gradient decreases as the surface of the single crystal and the surface of the source approach each other as the growth of the SiC single crystal progresses. As a result, the growth rate of the ingot decreases .

In the resistance heating method, in order to continuously maintain the growth rate of the SiC single crystal, it is preferable that the temperature gradient (i.e., temperature deviation) between the surface of the source having the highest temperature and the seed surface having the lowest temperature is kept constant.

If the distance between the surface of the source and the seed (ingot) surface with the lowest temperature is reduced to reduce the temperature gradient (i.e., temperature deviation), the recrystallization rate of the sublimed silicon carbide (SiC) The growth rate is reduced.

In addition, when the temperature gradient (i.e., temperature deviation) is reduced, there is a problem that the possibility that the unrecrystallized source is deposited on the ingot surface elsewhere after the sublimation increases, and the growth efficiency decreases.

: Korean Patent Publication No. 10-2010-0089103

SUMMARY OF THE INVENTION The object of the present invention is to provide a method of manufacturing a silicon carbide (SiC) single crystal by growing the surface of a single crystal ingot and a surface of a source, (SiC) single crystal ingot growing apparatus capable of increasing the growth length by maintaining the temperature gradient by moving the crucible position inside the resistance heating heater while reducing the speed of the growth of the silicon carbide single crystal ingot.

Another object of the present invention is to provide a method of controlling the temperature of a crucible within a resistance heating heater by controlling the temperature distribution formed in the resistance heating heater by using a separate resistance heating heater, , The growth rate of the silicon carbide single crystal ingot can be maintained by preventing the decrease in the temperature gradient in the second half of the growth, and a method for growing the same.

An object of the present invention is to provide an apparatus for growing a silicon carbide single crystal ingot and a method of growing the silicon carbide single crystal ingot by which two or more silicon carbide single crystal ingots can be grown by operating the single apparatus.

In order to achieve the above-mentioned object, a silicon carbide single crystal ingot growing apparatus according to an embodiment of the present invention is characterized in that a source made of silicon carbide (SiC) powder is filled in the lower part, and a silicon carbide single crystal seed is mounted on the upper part A crucible in which a silicon carbide single crystal ingot is grown; A resistance heating heater provided on an outer periphery spaced apart from the crucible and heating the crucible with a characteristic that the lowering width of the temperature increases from a lower portion to a predetermined height or more; A heat insulating material surrounding the outer circumferential surface of the resistance heating heater; A vacuum chamber in which the crucible, the resistance heating heater, and the heat insulating material are incorporated and into which a carrier gas is injected; And a crucible moving system installed outside the vacuum chamber for moving the crucible upward and downward in conjunction with the growth of the silicon carbide single crystal ingot in the crucible, wherein, as the silicon carbide single crystal ingot grows, And the crucible is elevated to compensate for the temperature gradient decrease.

Wherein the crucible moving system comprises: a connection part having one end connected to an upper part of the crucible and the other end extended to the outside of the vacuum chamber; A lifting motor for providing a rotational force; And a vertical rotating shaft having one end connected to the other end of the connecting portion and the other end gear engaged with a motor rotating shaft of the elevating motor to move up and down according to the rotation of the elevating motor.

In addition, the connection part is made of a black seed rod, one end of the vertical rotation shaft is detachably connected to the other end of the connection part, and the vertical rotation axis of the connection part elevates the crucible to the set target position, The connecting portion and the vertical rotating shaft can be separated from each other.

Furthermore, the gear engagement between the vertical rotation axis and the motor rotation axis of the elevation motor can use rack-pinion coupling.

And the crucible movement section for moving the crucible is controlled such that when the temperature of the lower portion of the crucible is lowered by 10 占 폚, the temperature of the upper portion of the crucible moves to 15 Lt; 0 > C or more.

The apparatus for growing a silicon carbide single crystal ingot according to the present invention comprises a plurality of the crucibles and is disposed between the plurality of crucibles and receives heat heated by the resistance heating heater and heats the plurality of crucibles And may further include a plurality of auxiliary heating heaters.

According to another aspect of the present invention, there is provided a method for growing a silicon carbide single crystal ingot comprising the steps of preparing a crucible having a source of silicon carbide powder filled in a lower portion of a crucible and a silicon carbide single crystal seed on a crucible ; Heating the crucible with a resistance heating heater to start the growth of the silicon carbide single crystal after the bottom of the crucible is aligned with the highest heating point of the resistance heating heater; And a step of growing a silicon carbide single crystal ingot by adsorbing the sublimated silicon carbide source on the surface of the silicon carbide single crystal seed, wherein the resistance heating heater has a characteristic in which the lowering width of the temperature increases from the lower side to a certain height, The crucible is moved upward until the temperature of the lower part of the crucible is lowered to a predetermined temperature so as to compensate for the decrease in the temperature gradient inside the crucible according to the growth of the silicon carbide single crystal ingot.

It is preferable that the start of movement of the crucible starts to move after 10 hours from the start of growth.

The temperature gradient between the source and the seed is preferably set in the range of 55 캜 to 75 캜.

As described above, as the surface of the single crystal ingot becomes closer to the surface of the source due to the growth of the SiC single crystal, the internal temperature gradient decreases, thereby causing a problem that the growth rate in the latter half of the growth decreases. And the temperature gradient is maintained by moving the position of the crucible inside the resistance heating heater to increase the growth length.

In addition, in the present invention, since the heating is progressed by using a separate resistance heating heater, the balance of the heat quantity can be realized as designed, and the temperature distribution formed in the resistance heating heater can be confirmed, and the crucible position inside the resistance heating heater can be controlled at a proper speed The growth rate can be maintained by preventing the decrease in the temperature gradient in the latter half of the growth.

Further, according to the present invention, two or more silicon carbide single crystal ingots can be grown by operating one apparatus, thereby reducing the damage of the heater and the refractory, thereby reducing unnecessary consumption and maximizing the improvement of the manufacturing efficiency .

In addition, the resistance heating method applied to the present invention has an advantage that the heating can be performed by using a separate resistance heating heater, so that the balance of the heat quantity can be realized as it is designed. The temperature distribution formed on the resistance heating heater is confirmed By changing the position of the crucible inside the resistance heating heater by using an appropriate speed, it is possible to prevent the decrease in the temperature gradient in the latter half of the growth and to maintain the growth rate.

According to the present invention, a plurality of crucibles are rotated to multi-grow a silicon carbide single crystal ingot, thereby uniformizing the temperature of the entire reaction atmosphere to keep the temperature gradient the same, The step of the silicon single crystal ingot can be minimized.

1 is a conceptual vertical sectional view for explaining a growth apparatus for a silicon carbide single crystal ingot according to a first embodiment of the present invention,
2 is a conceptual horizontal sectional view for explaining the crucible moving system of the apparatus for growing silicon carbide single crystal ingots according to the first embodiment of the present invention,
3 is a conceptual vertical sectional view for explaining a growth apparatus of a silicon carbide single crystal ingot according to a second embodiment of the present invention,
4 is a graph showing the temperature relationship inside the crucible according to the height of the resistance heating heater in the growth apparatus using the resistance heating type heater.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a conceptual vertical sectional view for explaining a growth apparatus for a silicon carbide single crystal ingot according to a first embodiment of the present invention. FIG. 2 is a schematic vertical sectional view for explaining a growth apparatus for a silicon carbide single crystal ingot according to the first embodiment of the present invention. Fig. 3 is a conceptual horizontal cross-sectional view for explaining the system.

Referring to FIGS. 1 and 2, a silicon carbide single crystal ingot growing apparatus according to a first embodiment of the present invention includes: a crucible 110 in which a silicon carbide single crystal ingot is grown; A resistance heating heater 200 installed on an outer circumference spaced apart from the crucible 110 to heat the crucible 110; And an insulator 300 surrounding the outer circumferential surface of the resistance heating heater 200.

The crucible 110 is made of, for example, graphite and has a closed structure. A source 112 made of high purity silicon carbide (SiC) powder is formed in the hollow portion 111 inside the crucible 110 And a silicon carbide (SiC) single crystal seed 113, which induces recrystallization after the silicon carbide (SiC) is sublimated, is mounted on the upper part.

Here, the crucible 110, the resistance heating heater 200, and the heat insulating material 300 are embedded in the vacuum chamber 150 into which the carrier gas is injected. Ar and N ₂ may be used as the carrier gas used for growing silicon carbide single crystal.

When the crucible 110 is heated by the resistance heating heater 200, the source 112 of the crucible 110 is sublimated and then raised and adhered to the upper single crystal seed 113 to be recrystallized to form a silicon carbide single crystal ingot .

The apparatus for growing silicon carbide single crystal ingots according to the present invention employs a crucible moving system for elevating the crucible by interlocking the crucible with the growth time in order to prevent the decrease in the temperature gradient in the latter half of the growth.

Referring to FIG. 2, a crucible moving system according to the first embodiment includes a connecting portion 510, a lifting motor 400, and a vertical rotating shaft 500.

2, one end of a connection part 510 made of, for example, a black seed rod is connected to the upper part of the crucible 110, and the other end (upper end) of the connection part 510 is connected to the outside of the vacuum chamber 150 And is connected to the vertical rotating shaft 500. [

Between the connection part 510 and the vertical rotary shaft 500, a detachable coupling is provided to minimize heat loss. Accordingly, after the crucible is raised up to the set target position, the connection part 510 and the vertical rotation axis 500 separate the connection part 510 and the vertical rotation axis 500 to minimize heat loss.

The connection portion 510 connecting the crucible 110 and the vertical rotation axis 500 is formed of a black seed rod having excellent thermal conductivity in order to minimize the influence on the temperature gradient of the crucible 110. It is also possible to use another material having excellent thermal conductivity in addition to the black seed rod as the connecting portion 510.

The vertical rotation shaft 500 is supported on the support frame 420 so as to be vertically movable and is engaged with the motor rotation shaft 410 extending from the elevation motor 400 installed on the support frame 420 to rotate the vertical rotation shaft 500 And has a structure for lifting and lowering.

The gear coupling between the vertical rotation shaft 500 and the motor rotation shaft 410 may use, for example, a rack-pinion coupling. That is, when the pinion having the toothed wheel is applied to the tip of the motor rotation shaft 410 and the rack is applied to the vertical rotation shaft 500, the vertical rotation shaft 500 of the pinion structure and the crucible (110) can be performed.

In the first embodiment shown in FIG. 2, the rack-pinion gear combination is applied to the rotational force transmitting structure for elevating and lowering the crucible 110 by the lifting motor 400. However, the present invention is not limited to this, .

In addition, the apparatus for growing a silicon carbide single crystal ingot according to the first embodiment can employ a rotational force transmitting structure so as to simultaneously have a function of raising and lowering the crucible 110 by the elevating motor 400 and a function of rotating the crucible 110 have.

When the crucible has a function of rotating the crucible in the apparatus for growing a silicon carbide single crystal ingot according to the first embodiment, the temperature gradient is made even more uniform by making the overall reaction atmosphere temperature of the crucible uniform, and the sublimed raw material The steps of the silicon carbide single crystal ingot grown by adsorption can be minimized.

In this case, the rotation speed of the crucible can be varied from 1 to 100 cycles / hr, and the sublimation rate can be controlled by changing the speed according to the growth stage.

3, a plurality of crucibles 110 and 120 are installed inside the heat insulating material 300 and the resistance heating heater 200, as in the case of the silicon carbide single crystal ingot growing apparatus of the second embodiment shown in FIG. 3, Productivity can be increased.

3, the apparatus for growing silicon carbide single crystal ingots according to the second embodiment includes: a plurality of crucibles 110 and 120 in which silicon carbide single crystal ingots are respectively grown; A resistance heating heater 220 installed on an outer circumference spaced apart from the plurality of crucibles 110 and 120 to heat the plurality of crucibles 110 and 120; Auxiliary connections (531, 532) connected to the plurality of crucibles (110, 120) to rotate the plurality of crucibles (110, 120); And a heat insulating material 300 surrounding the outer circumferential surface of the resistance heating heater 200 and having through holes 311 and 312 through which the auxiliary connecting portions 531 and 532 pass.

In the crucible moving system according to the second embodiment, one end of each of auxiliary connection portions 531 and 532, for example, a black seed rod is connected to upper portions of a plurality of crucibles 110 and 120, The other end (that is, the upper end) is connected to the horizontal connection portion 533. One end of the main connection part 510 is connected to the horizontal connection part 533 at the center and the other end is connected to the vertical rotation shaft 500 by extending to the outside of the vacuum chamber 150.

The connection portions 510, 531, 532, and 533 connecting the crucibles 110 and 120 and the vertical rotation shaft 500 are formed of a black seed rod having a good thermal conductivity in order to minimize the influence on the temperature gradient of the crucible 110.

The vertical rotation shaft 500 is supported on the support frame 420 so as to be vertically movable and is engaged with the motor rotation shaft 410 extending from the elevation motor 400 installed on the support frame 420 to rotate the vertical rotation shaft 500 And has a structure for lifting and lowering.

The gear connection between the vertical rotation shaft 500 and the motor rotation shaft 410 may be a rack-pinion coupling as in the first embodiment, and another gear connection may be used.

In the second embodiment, when the pinion having the toothed wheel is applied to the front end of the motor rotation shaft 410 and the rack is applied to the vertical rotation shaft 500, the vertical rotation axis 500 of the pinion structure And the connecting portions 510, 531, 532, and 533 and the crucibles 110 and 120 connected thereto can be lifted and lowered.

Furthermore, the apparatus for growing a silicon carbide single crystal ingot according to the second embodiment can simultaneously adopt a structure for rotating a plurality of crucibles 110 and 120 similarly to the first embodiment.

A worm 430 formed in a screw shape at the front end of the rotary motor 401 is coupled to a vertical rotation shaft 500 having a worm gear structure at the outer periphery at right angles to transmit the rotation force of the rotary motor 401, .

The rotational force of the vertical rotation shaft 500 can rotate the auxiliary connection parts 531 and 532 through the main connection part 510 and the horizontal connection part 533 by adopting appropriate gear connection.

Meanwhile, the second embodiment shown in FIG. 3 exemplifies the case where the crucibles 110 and 120 are two, but the present invention is not limited thereto. A plurality of crucibles 110 and 120 are disposed between the crucibles 110 and 120 so as to receive the heat heated by the resistance heating heater 200 installed on the outside and to heat the opposing surfaces of the crucibles 110 and 120, It is preferable to further include an auxiliary heating heater.

At this time, the region of the plurality of crucibles 110 and 120 opposed to the resistance heating heater 200 can continuously receive heat from the resistance heating heater 200. However, the region facing the plurality of crucibles 110 and 120 is the resistance heating heater The heat of the resistance heating heater 200 may not be sufficiently transmitted since the heater 200 is not directly opposed to the heater 200.

Therefore, in the second embodiment of the present invention, a plurality of auxiliary heating heaters are disposed in the area between the crucibles 110 and 120, and the heat heated by the resistance heating heater 200 is received by the plurality of auxiliary heating heaters, The plurality of crucibles 110 and 120 can be heated to a uniform temperature suitable for the growth of silicon carbide single crystal as a whole by heating the regions where the crucibles 110 and 120 face each other.

Here, the plurality of auxiliary heating heaters are not connected to the resistance heating heater 200, the resistance heating heater 200 is a graphite resistance heater, and a plurality of auxiliary heating heaters are connected to the power source or not connected to the power source And performs a function of a heater that heats the area between the crucibles 110 and 120 with heat received from the resistance heating heater 200 without heating itself. This auxiliary heating heater can be referred to as an auxiliary heating unit and can be realized as a separate black seed rod separated from the resistance heating heater 200.

In the present invention, it is necessary to construct a heater capable of heating two or more crucibles at a temperature of 2500 ° C or more in order to multi-grow a silicon carbide single crystal by providing two or more crucibles and a system capable of uniformly introducing carrier gas into each crucible Do.

Therefore, the multi-growth apparatus of the silicon carbide single crystal ingot of the present invention is capable of growing a silicon carbide single crystal ingot in each of a plurality of crucibles. The resistive heating heater can form a temperature gradient necessary for the growth of silicon carbide monocrystalline ingots, thereby increasing the productivity by about 25% when two 4-inch inches are grown and about 35% Can be increased.

Hereinafter, a method of growing a silicon carbide single crystal ingot according to the present invention will be described with reference to FIG.

4 is a graph showing the temperature relationship inside the crucible according to the height of the resistance heating heater in the growth apparatus using the resistance heating type heater.

(Example 1) Setting of travel distance of crucible

The temperature distribution of the resistive heating heater 220 for the SiC single crystal, which was heated up to 2500 캜 by the resistance heating method, appeared as shown in Fig.

When the SiC single crystal ingot is grown in the state where the bottom of the crucible is matched to the highest heat generation section in the lower part of the resistance heating heater 220 in order to make the smooth source 112 and the temperature gradient large in the resistance heating type growth, And a growth length of about 15 mm was secured.

However, as the ingot grows, the distance between the source 112 and the ingot decreases, and the temperature gradient decreases.

In order to compensate for this, in the present invention, the position of the bottom of the crucible 110 is set to move according to the growth time of the ingot.

As shown in FIG. 4, the resistance heating heater employed in the silicon carbide single crystal ingot growing apparatus according to the present invention exhibits a characteristic in which the width of the falling temperature increases as the temperature exceeds a certain height.

That is, the characteristic of the resistance heating heater is that the position of the crucible 110 is moved to the upper portion of the resistance heating heater 220 so that the lower portion of the crucible 110, that is, the upper portion when the temperature of the source 112 is lowered by 10 캜 It can be seen that the temperature change width of the seed 113 is lowered to 15 DEG C or higher.

Therefore, when the crucible is raised when the SiC single crystal is grown, the interval between the seed 113, that is, the interval between the ingot and the source 112, in the second half of the growth is reduced, thereby compensating for the decrease in the temperature gradient.

However, in this case, the sublimation amount decreases as the temperature below the crucible 110, which determines the sublimation of the source 112, is lowered, It is difficult to expect.

In the present invention, the crucible movement interval is set to a period in which the temperature of the upper part is lowered to 15 ° C or more when the temperature of the lower part of the crucible 110 is lowered by 10 ° C.

(Embodiment 2) Setting of movement time

The growth rate of SiC before application of the crucible moving system according to the present invention was measured and the results are shown in Table 1 below. The growth was continued for a total of 50 hours and the growth interface was measured by injecting nitrogen at intervals of 10 hours.

Growth time (Hr) Ingot Growth Length (mm) Section Growth Length (mm) Growth rate (mm / Hr) 10 4 4.0 0.4 20 7.3 3.3 0.33 30 10.3 3.0 0.30 40 13 2.7 0.27 50 15 2.0 0.2

Referring to Table 1, the growth rate of SiC was measured while the crucible was fixed without applying a crucible moving system. As a result, as the growth time increased, the growth rate decreased. That is, when the growth time is 10 hours (Hr), the growth rate is 0.4 mm / Hr, but when the growth time is 50 Hr, the growth rate gradually decreases to 0.2 mm / Hr, which is 50% of the initial growth rate.

In addition, referring to Table 1, when the growth time is 10 hours (Hr), the growth rate is the highest at 0.4 mm / Hr. Therefore, it is preferable that the growth proceeds in a state where the crucible is fixed at the initial stage of growth, It is desirable to start moving up and down after 10 hours to maintain the initial growth rate.

(Example 3) Crucible Moving type growth

The crucible shift period is set to a period in which the temperature of the upper portion is lowered to 15 ° C or more when the temperature of the lower portion of the crucible 110 is lowered by 10 ° C and the start time of the crucible is moved after 10 hours And the growth rate of SiC was measured by carrying out the growth of SiC single crystal by the crucible moving method during the actual growth. The results are shown in Table 2 below.

At this time, the same amount of the source as in Example 2 was charged and 6H (0001) plane was used as a seed. The growth temperature was 2300 ~ 2500 ° C and the growth pressure was 10 Torr.

Referring to FIG. 4, the highest heating point in the lower portion of the heater is a point where the height of the heater is 2500 ° C., and the bottom of the crucible 110 is aligned with the highest heating point using a crucible moving system Lt; / RTI >

In this case, the temperature gradient between the bottom of the crucible 110, that is, the top of the crucible, that is, the seed 113, is set at 55 to 75 占 폚. If the temperature gradient between the source 112 and the seed 113 is set to 60 占 폚, the temperature of the seed 113 is set to 2440 占 폚 and the heater height of the seed 113 is set to 340 mm. Therefore, the distance between the source 112 and the seed 113 in the crucible 110 is set to 240 mm.

Thereafter, the growth was continued for a total of 50 hours, and the elevation of the crucible 110 started to move after the growth was continued for 10 hours, and the crucible 110 was moved for 40 hours until the temperature of the crucible 110 lowered by 10 [ The crucible 110 is gradually raised by using a moving system.

The temperature of the lower portion of the crucible 110 is 2490 ° C when the crucible 110 is raised until the temperature of the lower portion of the crucible 110 is lowered by 10 ° C over 40 hours, At this time, the heater height of the seed 113 is 420 mm (that is, 180 mm + 240 mm (distance between the source and the seed)) and the temperature of the seed 113 is 2417 ° C (see FIG.

Therefore, when the growth is completed for a total of 50 hours, the temperature difference (temperature gradient) between the lower part of the crucible 110 (that is, the source 112) and the seed 113 is 73 ° C., It is possible to prevent the temperature gradient from decreasing.

That is, when the temperature of the lower portion of the crucible 110 (that is, the source 112) is lowered by 10 占 폚, the temperature change width of the upper portion (that is, the seed 113) is lowered to 23 占 폚. Accordingly, in the present invention, when the SiC single crystal is grown, as the crucible 110 is transferred, the distance between the seed 113 and the source 112 is reduced in the second half of the growth, do.

After moving to the set target position, heat loss is minimized by separating the connecting part and the vertical axis of rotation. There was no change in the vacuum and temperature of the vacuum chamber during the growth.

Growth time (Hr) Ingot Growth Length (mm) Section Growth Length (mm) Growth rate (mm / Hr) 10 4 4.0 0.4 20 7.8 3.8 0.38 30 11.6 3.8 0.38 40 15.1 3.5 0.35 50 18.4 3.3 0.33

Referring to Table 2, the length of the SiC single crystal grown for 50 hours due to the growth of the crucible moving type was 18.4 mm, which was 23% longer than that of the crucible fixing type 15 mm. In contrast to the crucible fixing method, in which the growth rate is reduced by 50% from the growth rate to the latter half of growth, only a decrease of 17% was confirmed.

In Example 3, the same amount of raw material sublimation as in the crucible fixing method of Example 2 was shown, but the amount of raw material contributing to growth was increased. As a result, the growth length of the SiC single crystal seems to increase, and the additional effect of reducing the loss of the crucible due to the reduction of the SiC raw material deposited in other parts of the crucible was also confirmed.

In the third embodiment, the rising speed of the crucible is uniformly adjusted during the growth time of 40 hours after the start of the crucible so that the temperature of the lower part of the crucible 110 (that is, the source 112) It is also possible to adjust the speed to correspond to the growth rate of the ingot.

As described above, it was confirmed that the growth length of the SiC single crystal can be secured by using the crucible moving system during the SiC growth through the resistance vapor deposition (PVT).

In addition, it has been confirmed that the quality of the entire single crystal can be maintained constant by keeping the growth rate constant over the growth time. In order to increase the growth length under the existing growth conditions, the growth length of the SiC single crystal .

Further, in the present invention, a high-quality SiC growth method combining a crucible lifting method for maintaining a temperature gradient and a crucible rotation method for homogenizing a temperature distribution by employing a crucible moving system in a silicon carbide single crystal ingot growing apparatus is proposed.

In the case of the crucible rotation method, by rotating the crucible, the temperature of the entire reaction atmosphere can be made uniform, so that the temperature gradient can be kept the same and the step of the SiC ingot grown by uniformly adsorbing the sublimated raw material on the seed surface can be minimized.

Also, by the crucible lifting method using the crucible moving system, the temperature gradient is maintained through the change of the crucible position inside the heater, and the flat interface proceeds until the growth is completed, and the length of the ingot can be increased.

Further, by combining the crucible rotating method for rotating a plurality of crucibles and the crucible lifting / lowering method, it is possible to grow a large number of ingots for a longer time, and productivity can be improved.

Further, the present invention can grow two or more silicon carbide single crystal ingots by operating one device, thereby reducing the damage of the heater and the refractory, thereby reducing unnecessary consumption and maximizing the improvement of the manufacturing efficiency .

Further, since the heat generation is progressed by using the resistance heating heater of the resistance heating type, the present invention has an advantage that the balance of the heat quantity can be realized as designed. Based on these characteristics, it is advantageous to grow several silicon carbide monocrystalline ingots at the same time in one growth by installing two or more crucibles in case of changing the heater size.

The apparatus for growing a silicon carbide single crystal ingot according to the present invention is characterized in that the temperature of the reaction atmosphere is made uniform by rotating the crucible so that the temperature gradient is maintained at the same temperature and the sublimed raw material is uniformly adsorbed on the seed surface, The steps of the single crystal ingot can be minimized.

In addition, if a plurality of crucibles are integrally rotated, even local temperature variations within the heater are eliminated, which enables multi-growth of a more stable silicon carbide single crystal ingot.

In the apparatuses of the first and second embodiments of the present invention, the heater may be implemented in various forms, and a circular heater, a square heater, a double-sided heater, or the like may be used.

INDUSTRIAL APPLICABILITY According to the present invention, a high-quality silicon carbide single crystal having few dislocation defects can be obtained with high reproducibility. In particular, the larger the ingot of a large diameter, the greater the effect. By using a substrate cut from the SiC single crystal and an epitaxial wafer, it is possible to manufacture a high-frequency, high-breakdown-voltage electronic device having excellent electrical characteristics and a blue light emitting device having excellent optical characteristics.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limited to the embodiments set forth herein. Various changes and modifications may be made by those skilled in the art.

According to the present invention, by employing a crucible moving system that elevates and lowers a crucible in conjunction with a crucible in a growing apparatus for a silicon carbide single crystal ingot, it is possible to prevent the decrease in the temperature gradient in the latter half of the growth, The present invention is applied to a growth apparatus for a silicon carbide single crystal ingot capable of maintaining a high speed.

110, 120: crucible 111, 121:
112, 122: source 113, 123: single crystal seed
150: vacuum chamber 200, 220: resistance heating heater
311,312; Through hole 400: lift motor
401: rotation motor 410: motor rotation axis
420: Support frame 430: Worm
300: Insulation material 500: Vertical rotary shaft
510: main connection part 531,532: auxiliary connection part
533: Horizontal connection

Claims (10)

A crucible in which a source made of silicon carbide (SiC) powder is filled in the lower part and a silicon carbide single crystal seed is mounted on the upper part to grow a silicon carbide single crystal ingot;
A resistance heating heater provided on an outer periphery spaced apart from the crucible and heating the crucible with a characteristic that the lowering width of the temperature increases from a lower portion to a predetermined height or more;
A heat insulating material surrounding the outer circumferential surface of the resistance heating heater;
A vacuum chamber in which the crucible, the resistance heating heater, and the heat insulating material are incorporated and into which a carrier gas is injected; And
And a crucible moving system installed outside the vacuum chamber for moving the crucible in conjunction with the growth of the silicon carbide single crystal ingot in the crucible,
The crucible moving system
A connection part having one end connected to the upper part of the crucible and the other end extended to the outside of the vacuum chamber;
A lifting motor for providing a rotational force; And
A vertical rotation shaft having one end connected to the other end of the connection portion and the other end being gear-engaged with a motor rotation shaft of the elevation motor and moving up and down according to the rotation of the elevation motor; / RTI >
Wherein the crucible is raised so as to compensate for a decrease in the temperature gradient inside the crucible in accordance with the growth of the silicon carbide single crystal ingot. delete The method according to claim 1,
Wherein the connection portion is formed of a black seed rod, the vertical rotation shaft is detachably connected to the other end of the connection portion,
Wherein the connection portion and the vertical rotation axis are separated from each other so as to minimize the heat loss inside the crucible after the crucible is raised to the set target position. The method according to claim 1,
Wherein the gear connection between the vertical rotation shaft and the motor rotation shaft of the elevation motor uses rack-pinion coupling. The method according to claim 1,
Further comprising rotating means coupled to the crucible moving system for rotating the crucible. The method according to claim 1,
And the growth of the silicon carbide single crystal is started with the bottom of the crucible coinciding with the highest heat generating point of the resistance heating heater. The method according to claim 1,
Wherein the crucible shifting period for moving the crucible is set to a period in which the temperature of the upper portion is lowered to 15 ° C or more when the temperature of the lower portion of the crucible is lowered by 10 ° C. The method according to claim 1,
The crucibles are formed of a plurality of crucibles,
Further comprising a plurality of auxiliary heaters disposed between the plurality of crucibles to receive the heat heated by the resistance heating heater and to heat the plurality of crucibles with the received heat. Device. delete delete

Images