KR102413658B1 - A Device for Single Crystal Ingot Growth and Its Growth Method - Google Patents

Abstract

The present invention relates to a single crystal ingot growth apparatus and a growth method. According to the present invention, there is provided a solution growth method, comprising: a process of creating a growth atmosphere for creating an atmosphere of monoatomic molecular gas at a growth pressure lower than atmospheric pressure; and a growth process of growing a single crystal ingot in an atmosphere of a monoatomic molecular gas created by a growth pressure in the process of creating a growth atmosphere.

Description

A Device for Single Crystal Ingot Growth and Its Growth Method}

The present invention relates to a single crystal ingot growing apparatus and a method for growing, and more particularly, to a single crystal ingot growing apparatus and method capable of growing a single crystal ingot in which the occurrence of defects due to craters or voids is suppressed.

A semiconductor single crystal such as silicon carbide is thermally and chemically very stable, has excellent mechanical strength, is strong against radiation, has a higher breakdown voltage and thermal conductivity than silicon single crystal, and has excellent properties.

Therefore, it is possible to realize high output, high frequency, withstand voltage, environmental resistance, etc. that cannot be realized with conventional semiconductor materials such as silicon single crystal and gallium arsenide single crystal. Expectations are increasing as next-generation semiconductor materials in a wide range such as high-capacity information communication device materials, vehicle-mounted high-temperature device materials, radiation-resistant device materials, and the like.

As a method of growing a single crystal ingot such as silicon carbide, there are a physical vapor deposition method, a high temperature chemical vapor deposition method, and a solution growth method. Among them, the solution growth method is a single crystal growth method that forms a high-purity, low-defect single crystal ingot using the thermal equilibrium state of the solution phase, and many studies are being conducted in this regard.

In order to grow a silicon carbide single crystal ingot by a solution process method, a silicon raw material is placed in a crucible, the silicon raw material is melted at a high temperature, and then a high temperature environment must be constantly maintained so that carbon can be dissolved. In this process, bubbles are generated due to various gas molecules dissolved into the molten silicon, and craters or void defects are generated inside the silicon carbide single crystal ingot due to the bubbles generated in this way.

Therefore, there has been a demand for a single crystal ingot growth technology capable of suppressing the occurrence of defects in the single crystal ingot due to the occurrence of such craters or voids.

Registered Patent No. 10-2163489

An object of the present invention is to solve the problems of the prior art as described above, and to provide a single crystal ingot growing apparatus and a method for growing a single crystal ingot in which the occurrence of defects due to craters or voids is suppressed.

A single crystal ingot growing apparatus according to an embodiment of the present invention for achieving the above object, a gas supply unit for providing a monoatomic molecular gas; a chamber unit provided with an internal space in which an atmosphere of the monoatomic molecular gas injected from the gas supply unit is created at a pressure lower than atmospheric pressure; a vacuum pump unit for exhausting the fluid from the inner space; an insulating housing portion disposed in the inner space and selectively communicating with the inner space to form a growth space in which a single crystal ingot is grown in the atmosphere of the monoatomic molecular gas formed at a growth pressure lower than atmospheric pressure; a crucible unit accommodating the raw material of the single crystal ingot and disposed in the growth space; a heating unit supplying heat to the crucible unit so that the raw material of the single crystal ingot is melted to generate a single crystal melt; And a seed for growing the single-crystal ingot from the single-crystal melt generated in the crucible part is mounted on the lower end, and a growth shaft part that can be moved upwardly or downwardly through an opening formed on the upper side of the heat-insulating housing part; It can also be used as a feature.

Here, the material of the heat insulating housing part may be a porous heat insulating felt (felt) as another feature.

Here, an opening/closing part connected to the growth shaft part and selectively interlocked, moving upward or downward while rotating along the growth shaft part to open or close the opening formed in the heat insulation housing part; and an opening/closing intermittent unit capable of selectively intermittently intermittent rotation of the opening/closing unit along the growth shaft unit.

Here, it may be further characterized by further comprising a; it is disposed in the space between the crucible part and the opening in the growth space, and has a through hole through which the growth axis can move upward or downward. .

Here, the opening and closing part may be made of a graphite material as another feature.

A single crystal ingot growth method according to an embodiment of the present invention for achieving the above object is a solution growth method, comprising: a growth atmosphere forming process of creating an atmosphere of monoatomic molecular gas at a growth pressure lower than atmospheric pressure; and a growth process of growing a single crystal ingot in the atmosphere of the monoatomic molecular gas created by the growth pressure in the process of creating the growth atmosphere; It may be characterized as one of including.

Here, the monoatomic molecule may be any one of helium, neon, argon, krypton, xenon, and radon as another feature.

Here, the growth pressure may be further characterized as a pressure of 300 Torr or less.

Here, it may further include a cooling process of cooling the single-crystal ingot grown in the growth process in the atmosphere of the monoatomic molecular gas formed at the growth pressure.

The process of creating a growth atmosphere may include: a preparation process of creating a vacuum state at a predetermined vacuum degree with respect to the growth space in the heat-insulating housing part in which the crucible part in which the raw material of the single crystal ingot is accommodated; and a pressure adjustment process of injecting the monoatomic molecular gas into the growth space in the heat insulating housing part where a vacuum is created in the preparation process to create an atmosphere of the monoatomic molecular gas with the growth pressure in the heat insulating housing part ; It may be characterized as another feature to include.

Here, the growth space and the inner space of the heat insulating housing disposed in the inner space of the chamber part selectively communicate with each other, and the monoatomic molecules are injected into the inner space and the growth space from a gas supply unit connected to the chamber part, Another feature may be that the vacuum pump unit communicating with the inner space exhausts the fluid on the inner space.

Here, in the pressure adjustment process, heat is supplied to the crucible part in the heat insulating housing part where the atmosphere of the monoatomic molecular gas is created with the growth pressure to melt the raw material of the single crystal ingot to produce a single crystal melt; a melting process; It may be further included as another feature.

Here, it may be further characterized in that the opening of the insulating housing part is selectively opened or closed while the heat is supplied to the crucible part.

Here, in the growing process, the single crystal ingot is grown by contacting the single crystal seed with the molten solution of the single crystal and moving the single crystal seed in one direction.

Here, while the single crystal ingot is grown, the pressure in the growth space may be maintained as the growth pressure as another feature.

According to the single crystal ingot growth apparatus and growth method according to an embodiment of the present invention, since the single crystal ingot is grown at a growth pressure lower than atmospheric pressure, the electrical characteristics of the grown single crystal ingot are different depending on the density of gas molecules dissolved into the single crystal melt. The generation of void defects is suppressed and the occurrence of void defects inside the ingot is suppressed, and the occurrence of crater defects appearing on the surface is also suppressed because it is dissolved into the melt and adsorbed to the surface of the seed crystal in the form of bubbles to prevent crystal growth. .

Accordingly, the occurrence rate of crater defects or void defects is significantly reduced to prevent deterioration of crystallinity in the grown single crystal ingot and improve single crystal ingot crystallinity. In addition, since the single crystal ingot is grown in an atmosphere of a monoatomic molecular gas lower than atmospheric pressure, the problem of changing the electrical characteristics of the single crystal ingot is also suppressed, unlike in the prior art, so that a high quality single crystal ingot can be grown.

In addition, the internal space of the chamber and the growth space of the insulated housing are separated from each other but are selectively communicated, and since the insulated housing is disposed inside the chamber and has a communicationable dual structure, it is possible to maintain a constant level of temperature gradient for a long time, and While a single crystal ingot is grown in a growth space, a low pressure state lower than atmospheric pressure can be continuously maintained, so the occurrence of defects due to craters or voids is suppressed and the crystal quality of the grown single crystal ingot is improved.

1 is a view schematically showing a cross section of a single crystal ingot growing apparatus according to an embodiment of the present invention.
2 is a perspective view schematically illustrating an embodiment of intermittent rotation of an opening and closing unit using an opening/closing interceptor in a single crystal ingot growing apparatus according to an embodiment of the present invention.
3 is a perspective view schematically illustrating an embodiment in which the opening and closing parts are independently rotated using the opening/closing interceptor in the single crystal ingot growing apparatus according to an embodiment of the present invention.
4 is a flowchart schematically illustrating a method for growing a single crystal ingot according to an embodiment of the present invention.
5 is a view schematically illustrating an optical image of a crater defect found on the surface of a single crystal ingot grown under different growth pressure conditions in a single crystal ingot growing method according to an embodiment of the present invention.
6 is a diagram schematically illustrating the diameter distribution of crater defects found in single crystal ingots grown under different growth pressure conditions in a single crystal ingot growing method according to an embodiment of the present invention.
7 is a view schematically showing an optical image of void defects appearing in a single crystal ingot grown at a growth pressure of 500 Torr in an atmosphere of monoatomic molecular gas.
8 is a view schematically showing an optical image of void defects appearing in a single crystal ingot grown at a growth pressure of 300 Torr in an atmosphere of monoatomic molecular gas.
9 is a graph schematically showing the diameter and density of pore defects according to the growth pressure of a monoatomic molecular gas atmosphere.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and the scope of the invention to those of ordinary skill in the art completely It is provided to inform you. In the description, the same reference numerals are assigned to the same components, and the drawings may be partially exaggerated in size to accurately describe the embodiments of the present invention, and the same reference numerals refer to the same elements in the drawings.

For convenience of explanation and understanding, a single crystal ingot growing apparatus according to an embodiment of the present invention will be first described, and then a single crystal ingot growing method according to an embodiment of the present invention will be described.

1 is a cross-sectional view showing a state in which an opening is opened or closed by an opening and closing unit in a single crystal ingot growing apparatus according to an embodiment of the present invention, and FIG. 1 (a) is a single crystal ingot growing apparatus according to an embodiment of the present invention. It is a cross-sectional view schematically showing a state in which the opening is opened, and FIG. 1 ( b ) is a cross-sectional view showing a state in which the opening is closed by the opening and closing part in the single crystal ingot growing apparatus according to an embodiment of the present invention.

1, the single crystal ingot growth apparatus according to an embodiment of the present invention is a gas supply unit for providing a monoatomic molecular gas; a chamber unit provided with an internal space in which an atmosphere of the monoatomic molecular gas injected from the gas supply unit is created at a pressure lower than atmospheric pressure; a vacuum pump unit for exhausting the fluid from the inner space; an insulating housing portion disposed in the inner space and selectively communicating with the inner space to form a growth space in which a single crystal ingot is grown in the atmosphere of the monoatomic molecular gas formed at a growth pressure lower than atmospheric pressure; a crucible unit accommodating the raw material of the single crystal ingot and disposed in the growth space; a heating unit supplying heat to the crucible unit so that the raw material of the single crystal ingot is melted to generate a single crystal melt; And a seed for growing the single-crystal ingot from the single-crystal melt generated in the crucible part is mounted at the lower end, and a growth shaft part that can be moved upwardly or downwardly through an opening formed on the upper side of the heat-insulating housing part; includes.

A gas supply unit (not shown) is connected to the chamber unit 10 , and supplies monoatomic molecular gas to the chamber unit 10 through the injection hole 23 to grow a single crystal ingot.

The vacuum pump unit is connected through the exhaust port 21 of the chamber unit 10 and communicates with the inner space of the chamber unit 10 to set a vacuum for the inner space. It is possible to maintain a predetermined level of pressure in the internal space of the chamber unit 10 by the gas supply unit and the vacuum pump unit.

The chamber unit 10 is provided with an internal space in which an atmosphere of a monoatomic molecular gas can be created at a pressure lower than atmospheric pressure. Here, the monoatomic molecule is preferably any one of helium, neon, argon, krypton, xenon, and radon.

The chamber unit 10 is provided with an injection port 23 through which the monoatomic molecular gas is injected so that the atmosphere of the monoatomic molecular gas can be maintained at a pressure lower than atmospheric pressure in the inner space, and the fluid from the internal space flows into the chamber unit 10 . An exhaust port 21 connected to the vacuum pump is provided so that it can be discharged to the outside.

In the inner space of the chamber part 10, a heat insulating housing part 200 to be described later is disposed.

The insulating housing unit 100 is disposed in the inner space of the chamber unit 10 to form a growth space for growing a single crystal ingot in an atmosphere of monoatomic molecular gas that is created at a growth pressure lower than atmospheric pressure.

The insulating housing unit 100 provides a growth space for growing a single crystal by a solution process, that is, a growth environment in which a single crystal can be grown in order to manufacture a single crystal ingot for a wafer such as silicon carbide, and a growth space in which a solution process is performed. have.

The insulating housing part 100 is made of a porous graphite felt material with excellent heat resistance so as to prevent the heat inside the insulating housing part 100 from leaking out and insulate it while the single crystal is growing. can be done

Since the insulating housing part 100 is made of a porous material, gas molecules can flow in and out according to the pressure difference between the inside and outside of the insulating housing part 100 . Accordingly, as the pressure in the chamber part 10 is kept constant, the pressure in the heat insulation housing part 100 may also be kept constant within an error range.

For reference, a modified or applied embodiment in which an output port (not shown) and an input port (not shown) are provided in the heat insulation housing unit 100 is sufficiently possible. The output port discharges the fluid in the growth space to the inner space according to the pressure difference between the inner space of the chamber part 10 and the growth space of the heat insulating housing part 100 . It is preferable that the output port allows the movement of the fluid only in one direction like a check valve, and when the pressure in the growth space is higher than the pressure in the inner space, the monoatomic molecular gas in the growth space or steam from the heated single crystal melt The back is discharged into the inner space of the chamber part (10). When the pressure in the growth space is lower than the pressure in the internal space, the fluid does not move through the output port.

The input port introduces the monoatomic molecular gas in the inner space into the growth space according to a pressure difference between the inner space of the chamber part 10 and the growth space of the insulating housing part 100 . It is preferable that the input port allows movement of the fluid in only one direction, such as a check valve, and when the internal space pressure of the chamber part 10 is higher than the pressure of the growth space of the insulating housing part 100, the unit in the internal space The magnetic molecular gas flows into the growth space of the heat insulating housing part 100 . When the pressure in the inner space is lower than the pressure in the growth space, the fluid does not move through the input port.

Accordingly, while injecting the monoatomic molecular gas through the inlet 23 provided in the chamber unit 10 and exhausting the fluid in the internal space of the chamber unit 10 through the exhaust port 21 connected to the vacuum pump, the chamber unit The pressure on the inner space in (10) can be maintained as a growth pressure, and an atmosphere of monoatomic molecular gas can be created in the inner space of the chamber part (10) by the growth pressure. In addition, by maintaining the pressure of the internal space in the chamber part 10 as the growth pressure, the internal space of the chamber part 10 and the growth space of the heat insulating housing part 100 may be maintained at the same growth pressure.

The crucible part 200 for accommodating the raw material for single crystal growth may be disposed in the growth space inside the insulating housing part 100, and the crucible part 200 has a seed (S) attached to the growth shaft part 300 to be described later. The raw material for single crystal growth may have an open top so that it can be supported in the single crystal melt (M) generated by melting.

The crucible part 200 accommodates the raw material of the single crystal ingot, and is disposed in the growth space of the heat insulating housing part 100 .

A crucible unit supporter 210 capable of supporting the crucible unit 200 may be disposed below the crucible unit 200 . The crucible unit support 210 may be rotated or lifted by a driving means (not shown) connected to the crucible unit support 210 .

In addition, a thermocouple temperature sensor (Thermocouple) is provided inside the crucible unit supporter 210 to measure the temperature around the lower portion of the single crystal melt M accommodated in the crucible unit 200, that is, around the bottom surface of the crucible unit 200. have.

The heating unit 400 supplies heat to the crucible unit so that the raw material of the single crystal ingot is melted to generate a single crystal melt.

The heating unit 400 may supply thermal energy to the crucible unit 200 to melt the raw material for single crystal growth accommodated in the crucible unit 200 to form a single crystal molten solution M, and is thermally insulated by the thermal energy of the heating unit 400 . The inside of the housing part 100 is a growth space in which the single crystal hollow is grown and may act as a hot zone.

As an embodiment of the heating unit 400 , a high-frequency induction coil for heating by supplying a high-frequency current to the crucible unit 200 may be used, but is not limited thereto. A heater that is a heat source for supplying thermal energy required for single crystal growth as radiant heat so that the raw material for single crystal growth can be melted may be used as the heating unit 400 .

In addition, the heating unit 400 may be disposed to surround the side surface of the insulating housing unit 100 from the outside of the insulating housing unit 100 , but in the inner space of the insulating housing unit 100 , the crucible unit 200 . Forms arranged around are also possible enough.

The growth shaft part 300 has a seed (S) for growing a single crystal ingot from the single crystal melt generated in the crucible part 200 is mounted on the lower end, and the opening 110 formed on the upper side of the heat insulating housing part 100 . ) can be moved upwards or downwards.

That is, the growth shaft part 300 may be inserted into the opening 110 formed on the upper side of the heat insulation housing part 100 and movably disposed, and at the lower end of the growth shaft part 300, a single crystal growth source, the seed (S). can be attached. In addition, the upper end of the growth shaft portion 300 may be connected to a first rotary motor 500 that provides power to move the growth shaft portion 300 upward or downward.

When the seed (S) attached to the lower end of the growth shaft part 300 by the downward movement of the growth shaft part 300 comes into contact with the single crystal melt M accommodated in the crucible part 200, a single crystal can be grown by a solution process.

Here, in the solution process, a raw material for single crystal growth is put into the crucible part 200, the crucible part 200 is heated and melted, and then the surface temperature of the single crystal melt (M) is measured, and the raw material for single crystal growth is melted above a certain level. If judged, it is a process of growing into a single crystal while slowly pulling up the seed (S) into contact with the surface of the single crystal melt (M).

Maintaining a constant temperature gradient by providing the same thermal environment to the single crystal melt (M) when a single crystal grows is one of the important factors in single crystal growth, so during the single crystal growth process, heat loss is blocked to ), it is desirable to maintain a constant internal temperature from the beginning to the end, and to equalize and stabilize the convection that affects the internal temperature change of the insulating housing 100 .

Since the growth of a single crystal can proceed from the surface of the single crystal melt (M) after the seed (S) is in contact with the surface of the single crystal melt (M), it is important to measure the exact surface temperature of the single crystal melt (M), and grow the single crystal It can be said that it is also important to directly observe the inside of the insulating housing part 100 in order to check whether the surface of the single crystal melt (M) and the seed (S) are in contact with each other. Therefore, since the opening 110 is provided on the upper side, that is, on the upper surface of the insulating housing part 100, the temperature sensor 800 disposed on the outside of the insulating housing part 100 is opened through the opening 110 through the single crystal molten solution ( It is also possible to measure the surface temperature of M).

Since the opening 110 is formed in the insulating housing part 100, it is possible to accurately measure the temperature of the surface of the single crystal melt (M) and observe the point where the single crystal melt (M) and the seed (S) come into contact. . When the opening 110 is formed, there is no problem in that particles generated during the single crystal growth process are deposited on the surface, unlike the see-through window, and the non-contact temperature sensor 800 opens the opening 110 from the outside of the insulating housing part 100 . ), it is possible to accurately measure the surface temperature of the single crystal melt (M).

And, during the single crystal growth process, the heat inside the heat insulating housing part 100 and the steam generated by vaporizing the single crystal melt (M) escapes to the outside of the heat insulating housing part 100 through the opening 110 of the insulating housing part 100 Heat loss may also occur.

Therefore, in the single crystal ingot growing apparatus according to the present invention, the opening 110 is selectively closed after the temperature measurement is finished to close the upper part of the hot zone, that is, the growth space so that the insulating housing part 100 can be sealed as much as possible. An opening/closing part 310 capable of selectively opening or closing 110 is provided.

The opening/closing part 310 is connected to the growth shaft part 300 and can be selectively interlocked, and moves upward or downward while rotating along the growth shaft part 300 to open or open the opening 110 formed in the heat insulation housing part 100 . to close

That is, the opening and closing part 310 may open or close the opening 110 by moving upward or downward while rotating in association with the growth shaft part 300 to be described later, and the growth shaft part 300 may move upward or downward. The opening 110 may be opened or closed while moving upward or downward like the growth shaft unit 300 by the first rotation motor 500 providing a driving force.

As mentioned above, the growth shaft part 300 moves upward or downward while rotating by the first rotation motor 500 connected to the growth shaft part 300 , and the opening/closing part 310 selectively interlocks with the growth shaft part 300 . It can be moved upward or downward while rotating together along the growth shaft portion 300 . The growth shaft portion 300 has a first screw thread formed on at least a portion of the outer circumferential surface of the growth shaft portion 300, and the opening/closing unit 310 may be connected to the growth shaft portion 300 through a second screw thread formed on the inner circumferential surface.

The first rotation motor 500 may provide a driving force for rotating the growth shaft portion 300 so that the growth shaft portion 300 moves upward or downward, and the growth shaft portion 300 connected to the first rotation motor 500 . ) may be rotated by receiving a driving force from the first rotation motor 500 .

The growth shaft unit 300 and the first rotation motor 500 are directly connected or indirectly connected through a power transmission unit (not shown) that transmits the driving force generated from the first rotation motor 500 to the growth shaft unit 300 . and can be rotated.

The growth shaft portion 300 may be provided with a first screw thread formed on at least a portion of the outer circumferential surface, and the growth shaft portion 300 has a heat-blocking member 320 having a screw thread corresponding to the first screw thread formed on the inner circumferential surface to be fixedly installed. have.

The heat blocking member 320 may have a shape in which the central portion is penetrated as shown in the drawings so that the growth shaft portion 300 can be fitted thereinto. In addition, a connecting member extending from one surface toward the wall of the chamber 10 may be formed so as to maintain a fixed state at the position inserted into the growth shaft 300 .

The heat-blocking member 320 is fastened to the chamber 10 through the connecting member and fixedly installed on the chamber 10 wall, so that the growth shaft 300 is the thread of the heat-blocking member 320 fixed to the chamber 10 . It is possible to move upwards or downwards while rotating in engagement with the .

That is, the growth shaft portion 300 and the heat-blocking member 320 are connected by threads formed on the outer and inner circumferential surfaces, respectively, and the heat-blocking member 320 maintains a state fixed by the wall of the chamber part 10 and Therefore, the growth shaft part 300 can be linearly moved upward or downward by the heat blocking member 320 while being rotated by the first rotation motor 500 .

As such, in the single crystal ingot growing apparatus according to an embodiment of the present invention, as an exemplary form, the heat-blocking member 320 is fixed to the chamber wall using a connecting member, but the growth shaft 300 is rotated and the train can move in a straight line. It is not particularly limited as long as it is a configuration capable of fixing the end member 320 .

As described above, the heat-blocking member 320 may serve to enable linear movement upward or downward while the growth shaft unit 300 rotates, but may also serve to protect the power transmission unit from heat at the same time.

When the heating unit 400 is provided between the heat insulation housing unit 100 and the chamber unit 10 as shown in FIG. 1 , it is provided between the growth shaft unit 300 and the first rotation motor 500 to provide the first It is preferable that the power transmission unit that transmits the rotational driving force generated by the rotary motor 500 is protected from the heat of the heating unit 400 .

To this end, the heat-blocking member 320 is positioned below the power transmission unit to not only serve to allow the growth shaft unit 300 to move in a straight line while rotating, but also to protect the power transmission unit from heat generated by the heating unit 400 . You may.

As such, as a configuration in which the growth shaft unit 300 can move in a straight line while rotating by the first rotation motor 500 , the fixed heat blocking member 320 may be used, but the present invention is not limited thereto. A form of rotating and moving the part 300 is also sufficiently possible.

The opening/closing part 310 is connected to the growth shaft part 300 through a second screw thread formed on the inner peripheral surface, and the opening/closing part 310 connected to the growth shaft part 300 is selectively interlocked with the growth shaft part 300 to connect the growth shaft part 300. It can move in a straight line in both directions while rotating.

When the opening 110 is opened as shown in FIG. 1( a ), the temperature of the single crystal melt M through the opening 110 opened from the outside of the insulating housing part 100 using the temperature sensor 800 . can be measured non-contact.

The temperature sensor 800 contacts the single crystal melt (M) in the crucible part 200 with the seed (S) attached to the bottom of the growth shaft part 300 to grow a single crystal in earnest before the process of single crystal melt (M). For measuring the surface temperature in a non-contact manner, a non-contact pyrometer may be used.

The opening 110 may have a wide width or diameter so that the temperature sensor 800 can sufficiently measure the temperature of the single crystal melt M from the outside, but the width or diameter of the opening 110 is not particularly limited and the temperature It is sufficient if the width or diameter of the opening 110 of a size that the sensor 800 can measure.

In order to measure the temperature, the single crystal melt (M) through the opening 110 formed in a form in which a non-contact temperature sensor 800 disposed outside the insulating housing part 100 penetrates the upper surface of the insulating housing part 100 . ) can accurately measure the surface temperature of

When the temperature sensed through the temperature sensor 800 is close to the melting temperature of the single crystal melt raw material, it may be determined that the single crystal melt raw material has been melted to a certain level or more.

In addition, a camera may be further provided on the outside of the insulated housing part 100 , and the camera transmits image information of the internal space of the insulated housing part 100 through the opening 110 open from the outside of the insulated housing part 100 . It is possible to observe the point where the surface of the seed (S) and the single crystal melt (M) comes into contact by photographing.

When it is determined that the raw material for single crystal growth is melted through the temperature sensor 800 , the growth shaft unit 300 is moved to bring the seed (S) attached to the bottom into contact with the surface of the single crystal melt (M), and then the single crystal growth process is performed. can

At this time, since the opening 110 opened for temperature measurement is still open, heat generated during the single crystal growth process and the gaseous material in which the single crystal melt (M) is sublimed escapes through the opening 110 to cause heat loss. And, there may be a problem that the temperature gradient of the single crystal melt (M) appears high or low at a specific point due to heat loss.

Accordingly, when the temperature measurement is completed using the opening/closing part 310 connected to the growth shaft part 300, the opening 110 is closed to proceed with the growth process of the single crystal ingot in a state in which the heat insulation housing part 100 is sealed.

The opening/closing part 310 is connected to the growth shaft part 300 through a second screw thread formed on the inner circumferential surface. As shown in Figure 1 (b), the growth shaft portion 300 is a first rotary motor 500 and a fixed heat blocking member 320 to support the seed (S), which is a source of single crystal ingot growth, in the molten solution. For example, when descending while rotating in a counterclockwise direction, the opening/closing unit 310 may also descend while rotating in a counterclockwise direction along the growth shaft portion 300 to close the opening 110 .

The opening and closing part 310 is formed with a diameter or width larger than the width of the opening 110 so that when the growth shaft part 300 descends while rotating, it descends while rotating along the growth shaft part 300 to block the opening 110 . can be

Since the width of the opening/closing part 310 is formed to be larger than the width of the opening 110 , when the growth shaft part 300 rotates and linearly moves in the downward direction, it is interlocked with the growth shaft part 300 and rotates along with the growth shaft part 300 in the downward direction. The opening/closing part 310 moving in a straight line does not descend while rotating due to the width of the opening 110 and maintains the closed state of the opening 110 . The opening/closing part 310 may be made of a graphite material.

When the opening 110 of the heat insulating housing part 100 is closed by the opening and closing part 310 that rotates and interlocks with the growth shaft part 300, the single crystal growth process can proceed in earnest. During the single crystal growth, the insulating housing part (100) In order to block the heat of the internal space from escaping to the outside, a plate-shaped insulating plate part 120 having a through hole through which the growth shaft part 300 can move may be disposed in the internal space.

The insulating plate part 120 is provided in the space between the crucible part 200 and the opening 110 in the growth space, and at least one or more may be arranged in plurality.

By arranging the plate-shaped insulating plate part 120 in the space between the crucible part 200 and the opening 110, the gaseous material sublimated with the heat of the crucible part 200 is further prevented from leaking to the outside while the single crystal is grown. can be effectively blocked. Therefore, it is possible to maintain the internal temperature gradient of the heat insulating housing part 100 as much as possible without fluctuation during the process.

In addition, since the growth of the single crystal ingot may be affected by convection in the growth space, the convection generated in the growth space inside the insulating housing part 100 can be an important factor in the process of pulling up the single crystal.

Therefore, by arranging the insulating plate part 120 in the space between the crucible part 200 and the insulating plate part 120 , the convection that affects the temperature change in the growth space inside the insulating housing part 100 is equalized and stabilized. It is possible to easily create or control an environment suitable for single crystal growth process conditions.

2 is a perspective view schematically showing an embodiment of stopping the rotation of the opening/closing unit using the opening/closing interceptor in the single crystal ingot growing apparatus according to the embodiment of the present invention, FIG. 2(a) is the opening/closing unit according to the embodiment of the present invention; It is a perspective view schematically showing a state of linear movement upward or downward while rotating along the growth axis, and FIG. 2 (b) is an implementation of stopping the rotation of the opening and closing part using the opening and closing part in the single crystal ingot growing apparatus according to an embodiment of the present invention It is a perspective view schematically showing an example.

Referring to FIG. 2 , an interruption to selectively stop the rotation of the opening/closing unit 310 along the growth shaft unit 300 or rotating the opening/closing unit 310 independently from the growth axis unit 300 to determine the position of the opening/closing unit 310 It may further include an open/close control unit 600 that can be adjusted.

The opening/closing intercept unit 600 includes a rod shaft 620 that rotates or stops by receiving a driving force from a second rotation motor 630 connected to the other end; and a movable rod 610 connected to one end of the rod shaft 620 and interlocked with the rod shaft 620 to rotate or stop around the rod shaft 620, and the movable rod 610 has an uneven portion ( When connected to the concave-convex portion 311 by rotating toward 311), the moving rod 610 pushes the concave-convex portion 311 clockwise or counterclockwise to rotate the opening and closing portion 310 or with the concave-convex portion 311 and It is possible to stop the rotation of the opening/closing unit 310 by stopping at the connected position.

In addition, the opening and closing part 310 may be formed with uneven parts 311 spaced apart along the edge of the opening and closing part 310, and the uneven part 311 protrudes from the upper surface or side surface of the opening and closing member and is spaced apart. Alternatively, the holes formed to pass through the upper surface may be spaced apart along the edge. As shown in FIG. 3 , the concave-convex portion 311 of the present invention protrudes vertically from the upper surface of the opening and closing portion 310 and is illustrated as being spaced apart along the edge, but a shape that can be connected to a moving rod 610 to be described later it doesn't matter if

As shown in FIG. 2 , the opening/closing unit 600 is rotated along the growth axis unit 300 and the opening/closing unit 310 moving in a straight line in both directions is selectively linked to the growth axis unit 300 so that the opening/closing unit 310 is interlocked. rotation can be selectively stopped.

As described above, the opening/closing unit 310 is linked to the growth axis unit 300 and rotates along the growth axis unit 300 to move linearly in both directions. ), when it is necessary to measure or photograph the internal space through the opening 110 open from the outside, the opening and closing part 310 rotating along the growth axis 300 is fixed at a position spaced apart from the opening 110 by a predetermined distance. You should be able to maintain your status.

In the present invention, an opening/closing control unit 600 is provided to selectively stop the rotation of the opening/closing unit 310 . The rod shaft 620 may be rotated or stopped by receiving a driving force from the second rotation motor 630 connected to the other end, that is, the second driving system 630 , and one end by the rotation driving force of the second rotation motor 630 . By rotating the moving rod 610 connected to the concave-convex portion 311 to move the moving rod 610 to a position where it can be connected to the concave-convex portion 311 .

The moving rod 610 is connected to one end of the rod shaft 620, is interlocked with the rod shaft 620, and can rotate or stop along the rod shaft 620, and the second rotation motor 630 and the rod shaft ( When it is rotated by 620 and interconnected with the concavo-convex part 311 , it may stop at a position connected to the concave-convex part 311 to stop the rotation of the opening/closing part 310 as shown in FIG. 3( b ).

That is, the second rotation motor 630 and the rod shaft 620 may rotate the moving rod 610 toward the concave-convex portion 311 so that the moving rod 610 is in contact with the concave-convex portion 311 , and the moving rod When the 610 and the concave-convex part 311 are connected, the rotation of the moving rod 610 can be stopped to stop the opening and closing part 310 from rotating any more.

The opening/closing unit 310, which was rotationally moved along the growth shaft unit 300, rotates through the moving rod 610 stopped at a position connected to the concave-convex unit 311 by the second rotating motor 630 and the rod shaft 620. Since it can be stopped, the opening/closing unit 310 is selectively interlocked with the growth axis unit 300 to move linearly while rotating along the growth axis unit 300 .

3 is a perspective view schematically showing an embodiment in which the opening and closing parts are independently rotated using the opening/closing interceptor in the single crystal ingot growing apparatus according to an embodiment of the present invention, and FIG. 3(a) is a single crystal ingot according to an embodiment of the present invention. It is a perspective view schematically showing a state in which the concave-convex part of the opening and closing part and the moving rod are connected in the growth apparatus, and FIG. 3 (b) is the opening and closing part independent of the growth shaft part using the opening and closing part in the single crystal ingot growing apparatus according to the embodiment of the present invention. It is a perspective view schematically showing an embodiment of rotating with .

As described above, the single crystal growth may proceed downward by the seed (S) by gradually raising the seed (S) attached to the lower end of the growth shaft part (300) upwards of the single crystal molten solution (M). In order to raise the seed (S), the growth shaft part 300 is raised while rotating again by the first rotation motor 500 , and the opening and closing part 310 linked to the growth shaft part 300 also rotates along the growth shaft part 300 . The opening 110 is opened as shown in FIG. 4(a) while the opening and closing part 310 also rotates and rises according to the rotational rise of the growth shaft part 300 for raising the seed (S). When the opening 110 is opened during the single crystal growth process, since the steam generated by the vaporization of the single crystal molten solution M escapes to the outside of the insulating housing part 100 and heat loss may occur, in the present invention, the opening and closing intercept unit 600 ) to rotate the opening/closing unit 310 independently of the growth shaft unit 300 to adjust the position of the opening/closing unit 310 .

The description of connecting the moving rod 610 shown in FIG. 2 toward the concave-convex portion 311 to connect it with the concave-convex portion 311 will be omitted. As described above, when the moving rod 610 is rotated by the second rotating motor 630 and the rod shaft 620 and interconnected with the concave-convex portion 311, the moving rod 610 rotates the concave-convex portion 311 in a clockwise direction. Alternatively, the opening/closing unit 310 may be rotated independently of the growth shaft unit 300 by pushing it counterclockwise.

In the process of moving the seed (S) upward so that the single crystal ingot is grown, the second rotation motor 630 transmits the rotational driving force to the rod shaft 620 to continuously close the opening 110 to maintain the temperature gradient, The rod shaft 620 continuously rotates the moving rod 610 with the rotational driving force transmitted from the second rotation motor 630 to push the concave-convex part 311 formed in the opening and closing part 310 by the moving rod 610 .

When the moving rod 610 is rotated toward the concave-convex portion 311 by the second rotary motor 630 and the rod shaft 620 and is connected to the concave-convex portion 311 as shown in FIG. 3(a), the movement The rod 610 pushes the concave-convex part 311 in the opposite direction to the direction in which the growth shaft part 300 rotates without stopping the rotation, and the opening and closing part 310 having a second screw thread formed on the inner circumferential surface has the concave-convex part 311 . It is descended while rotating independently of the growth shaft portion along the first screw thread of the growth shaft portion 300 by the extruding moving rod 610 to close the opening 110 again as shown in FIG. 3(b). do.

Next, a single crystal ingot growth method according to an embodiment of the present invention will be described with further reference to FIG. 4 .

4 is a flowchart schematically illustrating a method for growing a single crystal ingot according to an embodiment of the present invention.

As shown in FIG. 4 , the single crystal ingot growth method according to an embodiment of the present invention is a solution growth method, comprising: a growth atmosphere creating process ( S100 ) of creating an atmosphere of monoatomic molecular gas at a growth pressure lower than atmospheric pressure; and a growth process (S200) of growing a single crystal ingot in the atmosphere of the monoatomic molecular gas created by the growth pressure in the process of creating a growth atmosphere (S100); includes

In the process of creating a growth atmosphere ( S100 ), a molten solution of a single crystal is prepared in an atmosphere of a monoatomic molecular gas formed at a growth pressure lower than atmospheric pressure. Here, the monoatomic molecule is preferably any one of helium, neon, argon, krypton, xenon, and radon. And the growth pressure is preferably a pressure lower than atmospheric pressure, and more preferably a pressure of 300 Torr or less or a pressure between 0.01 Torr and 300 Torr.

With such a growth pressure, an atmosphere of monoatomic molecular gas is created and heat is supplied to the raw material of the single crystal melt so that the single crystal ingot can be formed.

Next, in the growth process (S200), which is a process after the growth atmosphere creation process (S100), a single crystal ingot is grown from the single crystal melt prepared in the growth atmosphere creation process (S100) in an atmosphere of a monoatomic molecular gas formed by a growth pressure. makes it

The single crystal seed is brought into contact with the single crystal melt and the single crystal seed is moved upward so that the single crystal ingot is grown. Here, the growth of the single-crystal ingot proceeds in an atmosphere of monoatomic molecular gas created by a growth pressure.

When a single crystal ingot is grown in this growth process ( S200 ), it may lead to a cooling process ( S300 ) for cooling the single crystal ingot in a high temperature state. In the cooling process (S300), the ingot of the single crystal grown in the growth process (S200) is cooled in an atmosphere of monoatomic molecular gas formed at a growth pressure.

As such, the single crystal ingot grown through the growth atmosphere creation process (S100) and the growth process (S200) is in a hot state, so when the single crystal ingot is cooled in the atmosphere of the monoatomic molecular gas created by the growth pressure in the cooling process (S300), It is possible to obtain a single crystal ingot in which the ratio of pore defects having a diameter of 200 μm or more among the total pore defects generated in the single crystal ingot is grown to less than 1%.

In addition, it is preferable that the growth pressure is consistently maintained while the single crystal ingot is grown while going through the growth atmosphere creation process ( S100 ), the growth process ( S200 ), and the cooling process ( S300 ).

As described above, the single crystal ingot growth method according to an embodiment of the present invention is a more specific aspect, and as follows, the single crystal ingot growth method using the single crystal ingot growing apparatus as described above will be described for better understanding of the present invention. Could be more helpful.

The aforementioned growth atmosphere creation process (S100) includes a preparation process (S110) and a pressure adjustment process (S120), and may further include a melting process. And the preparation process (S110), the pressure adjustment process (S120), and the melting process may be performed using the single crystal ingot growing apparatus according to the embodiment of the present invention described above.

1 to 4, in the preparation process (S110), the crucible part 200 in which the raw material of the single crystal molten liquid M is accommodated is placed in a vacuum state at a predetermined vacuum degree with respect to the growth space in the insulating housing part 100 creates a Specifically, the raw material of the melt (M) of the single crystal is accommodated in the crucible part. And the crucible part 200 in which the raw material of the single crystal molten solution M is accommodated is disposed on the upper end of the crucible part supporter 210 provided inside the heat insulating housing part 100 . Here, the opening 110 at the upper side of the heat insulating housing part 100 is in an open state to communicate with the internal space of the chamber part 10 .

Then, the gas in the internal space of the chamber part 10 is exhausted through the exhaust port 21 provided in the chamber part 10 to form a vacuum state with a predetermined pressure in the internal space of the chamber part 10 . The growth space inside the heat insulating housing part 100 together with the internal space of the chamber part 10 is also in a vacuum state at the same level.

Subsequent to the preparation process (S110), in the pressure adjustment process (S120), monoatomic molecular gas is injected into the growth space in the insulating housing unit 100 in which the vacuum state has been created in the preparation process (S110) in the insulating housing unit 100 . At the growth pressure, an atmosphere of monoatomic molecular gas is created. Here, as mentioned above, the monoatomic molecule is preferably any one of helium, neon, argon, krypton, xenon, and radon.

The chamber part 10 while injecting the monoatomic molecular gas through the inlet 23 provided in the chamber part 10 and exhausting the fluid in the internal space of the chamber part 10 through the exhaust port 21 connected to the vacuum pump ) so that the pressure on the inner space becomes the growth pressure. Accordingly, an atmosphere of monoatomic molecular gas is created in the inner space of the chamber unit 10 by the growth pressure. In addition, by adjusting the pressure of the internal space in the chamber part 10, the internal space of the chamber part 10 and the growth space of the heat insulating housing part 100 can be maintained at the same growth pressure.

Since the opening of the heat insulating housing part 100 is opened, the growth space inside the heat insulating housing part 100 also creates an atmosphere of monoatomic molecular gas by the growth pressure.

Here, as mentioned above, the growth pressure is preferably a pressure lower than atmospheric pressure as an atmosphere of a monoatomic gas, and more preferably a pressure of 300 Torr or less or a pressure between 0.01 torr and 300 Torr.

When the pressure on the growth space of the insulating housing part 100 is adjusted to the growth pressure and maintained stably, it may lead to a melting process.

Then, in the melting process, heat is supplied to the crucible part 200 in the insulating housing part 100 where the atmosphere of monoatomic molecular gas is created by the growth pressure in the pressure adjustment process (S120) to supply the raw material of the single crystal melt (M). It melts to produce a single crystal molten solution (M).

Here, when heat is supplied to the crucible unit 200 through the operation of the heating unit 400, heat is supplied to the crucible unit 200 in a state in which the opening 110 of the insulating housing unit 100 is closed. You can also create a melt (M). Alternatively, it is also possible to supply heat to the crucible unit 200 through the operation of the heating unit 400 in a state in which the opening 110 of the insulating housing unit 100 is opened to generate a single crystal molten solution M. . That is, the opening 110 of the insulating housing part 100 may be selectively closed or open as needed while heat is supplied to generate the single crystal molten liquid M.

When the single crystal melt (M) is generated in the crucible part 200 in the melting process, it leads to a growth process (S200).

As mentioned above, in the growth process ( S200 ), a single crystal ingot is grown from the single crystal melt (M) prepared in the growth atmosphere creation process ( 100 ) in an atmosphere of a monoatomic molecular gas created by a growth pressure.

In order to grow a single crystal ingot from a single crystal melt, if the opening 110 of the insulating housing part 100 is open, the single crystal seed S is contacted with the single crystal melt M before the opening 110 is closed. give. And the single crystal seed (S) provided at the lower end of the growth shaft part (300) is brought into contact with the single crystal molten solution (M) provided inside the crucible part (200).

A single crystal ingot is grown from the single crystal melt (M) by bringing the single crystal seed (S) into contact with the single crystal melt (M) and moving the single crystal seed (S) in one direction, that is, upward. While the single crystal ingot is grown from the melt M of the single crystal, the heating unit 400 supplies heat to the crucible unit 200 and maintains a constant temperature during the growth.

At this time, the growth space is an atmosphere of monoatomic molecular gas formed by a growth pressure, and the growth pressure is the same as described above.

Since the material of the insulating housing part 100 is insulating felt made of graphite material having thermal insulation and porosity, the monoatomic molecular gas can pass through the fine porosity of the insulating felt and move to the inner space of the chamber part 10, so the insulating housing The pressure in the growth space of the part 100 may be maintained as the growth pressure.

That is, the monoatomic molecular gas is injected through the inlet 23 provided in the chamber unit 10 , and the fluid in the internal space of the chamber unit 10 is exhausted through the exhaust port 21 connected to the vacuum pump while exhausting the chamber unit. (10) Maintain the pressure on the inner space as the growth pressure. Accordingly, an atmosphere of monoatomic molecular gas is created in the inner space of the chamber unit 10 by the growth pressure. In addition, by maintaining the pressure of the internal space in the chamber part 10 as the growth pressure, the internal space of the chamber part 10 and the growth space of the heat insulating housing part 100 may be maintained at the same growth pressure.

In this way, the inner space and the growth space can be maintained at the same growth pressure.

For reference, the pressure in the growth space of the heat insulating housing part 100 can be maintained as the growth pressure by the internal space of the chamber part 10 and the porous graphite felt maintained at the growth pressure as described above, but as mentioned above, When the input port and the output port are provided in the insulated housing unit 100 , the pressure in the insulated housing unit 100 may be maintained by using the input port and the output port as well.

During the growth of the single crystal ingot, the pressure rise due to the high temperature is suppressed so that the growth space can be maintained at the growth pressure of the monoatomic molecular gas. fluid flows in and out.

When the pressure in the internal space of the chamber part 10 is higher than the pressure in the growth space of the heat insulating housing part 100 , the monoatomic molecular gas in the internal space flows into the growth space of the heat insulating housing part 100 . When the pressure in the inner space is lower than the pressure in the growth space, the fluid does not move through the input port.

The output port is a port through which the fluid can move only in one direction like a check valve. When the pressure in the growth space is higher than the pressure in the internal space of the chamber part 10, the fluid in the growth space is discharged to the internal space through the output port. When the pressure in the growth space is lower than the pressure in the internal space, the fluid does not move through the output port.

Accordingly, by adjusting the pressure of the internal space in the chamber part 10 , the internal space of the chamber part 10 and the growth space of the heat insulating housing part 100 may be maintained at the same growth pressure.

In addition, while the single crystal ingot is grown in the growth process ( S200 ), the growth temperature is kept constant.

When the single crystal ingot is grown through this growth process (S200), it may lead to a cooling process (S300).

As mentioned above, the cooling process (S300) is a process of cooling the ingot of the single crystal grown in the growth process (S200) in an atmosphere of monoatomic molecular gas created by a growth pressure.

In the cooling process (S300), heating by the heating unit 400 is stopped, and the grown single crystal ingot in a high temperature state is cooled. The growth space is also cooled. When the growth space is cooled, the pressure on the growth space may also be reduced. That is, as the single crystal ingot is cooled and the growth space is also cooled, it can be reduced to a pressure lower than the growth pressure. Here, while the single crystal ingot is cooled, the monoatomic molecular gas on the inner space flows into the growth space through the heat insulating housing unit 100 so that the pressure in the growth space can be maintained at the growth pressure without being lower than the growth pressure. When there is an input port, the monoatomic molecular gas may be introduced into the growth space through the input port. That is, when the pressure in the growth space is lower than the growth pressure, which is the pressure in the inner space, the monoatomic molecular gas in the inner space flows into the growth space due to the pressure difference between the growth space and the inner space, so the pressure difference between the growth space and the inner space is resolved

As such, if the material of the insulating housing part 100 is porous insulating felt, the monoatomic molecular gas in the internal space passes through the insulating housing part 100 and moves to the growth space according to the pressure difference between the growth space and the internal space. Therefore, the growth pressure can be maintained as the same pressure level in the growth space and the inner space.

Therefore, the pressure in the growth space maintains the growth pressure, and the single crystal ingot in a high temperature state is cooled in the atmosphere of the growth pressure of the monoatomic molecular gas.

While the single crystal ingot is being cooled, the opening 110 of the insulating housing part 100 may be selectively opened or closed as needed. At the initial stage of cooling for the single crystal ingot, the opening 110 is maintained in a closed state in order to maintain the stability of convection in the growth space of the insulating housing part 100, and when a certain time elapses, the temperature of the single crystal ingot is lowered to a certain level By opening the opening 110 of the insulating housing part 100, the cooling of the single crystal ingot may be performed more rapidly.

When the single crystal ingot in a high temperature state is sufficiently cooled to be withdrawn to the outside, the opening 110 of the heat insulating housing part 100 is opened to extract the single crystal ingot from the inside of the heat insulating housing part 100 .

As described above, the single crystal ingot grown by the single crystal ingot growing apparatus and growth method according to the embodiment of the present invention is grown in the atmosphere of a monoatomic molecule gas, so that it affects the electrical properties of the single crystal ingot compared to the polyatomic molecule gas. is suppressed In addition, since the single crystal ingot is grown at a growth pressure lower than atmospheric pressure, the generation of bubbles on the surface of the single crystal melt is suppressed, and gas molecules are suppressed from being dissolved into the melt. Therefore, the occurrence of crater defects or void defects during growth of the single crystal ingot is suppressed.

As described above, according to the present invention, a single crystal ingot in which the ratio of pore defects having a diameter of 200 μm or more among the total pore defects generated in the grown single crystal ingot is suppressed to less than 1% can be obtained, and it is helpful in improving the crystal quality of the single crystal ingot .

5 is a view schematically showing an optical image of a crater defect found on the surface of a silicon carbide single crystal ingot grown under different growth pressure conditions according to a single crystal ingot growth method according to an embodiment of the present invention, FIG. 6 is each It is a diagram schematically showing the diameter distribution of crater defects found in silicon carbide single crystal ingots grown under different growth pressure conditions.

As referenced in Fig. 5(a), the diameter of the crater in which the single crystal grown at the growth pressure of 715 torr in the atmosphere of monoatomic molecular gas appeared in the ingot was 2.1 mm, and as referenced in Fig. 5(b), the single crystal A single crystal grown at a growth pressure of 500 torr in an atmosphere of magnetic molecular gas had a crater diameter of 1.6 mm in the ingot, and as shown in FIG. The diameter of the crater in which the obtained single crystal appeared in the ingot was 0.64 mm.

As can be seen from the image shown in FIG. 5 like this, as the pressure on the growth space in which the single crystal ingot is grown is lowered, the diameter of the crater is reduced.

And, as can be seen from FIG. 6, as the pressure in the growth space decreases, the diameter of the crater defect decreases, and it can be seen that the distribution range of the diameter of the crater defect becomes relatively narrow, especially when the growth pressure is 300 Torr or less It can be seen that the crater diameter is concentrated in the size of 0.7 mm or less, and the number of crater defects is also reduced, so that the density of crater defects is reduced.

Among the defects caused by bubbles, crater defects can be observed with the naked eye, but void defects can be observed with an optical microscope after surface processing.

7 is a view schematically showing an optical image of void defects appearing in a silicon carbide single crystal ingot grown at a growth pressure of 500 Torr in an atmosphere of monoatomic molecular gas, and FIG. 8 is a growth pressure of 300 Torr in an atmosphere of monoatomic molecular gas. It is a view schematically showing an optical image of pore defects appearing in a grown silicon carbide single crystal ingot, and FIG. 9 is a graph showing the diameter and density of pore defects according to the growth pressure of a monoatomic molecular gas atmosphere.

As can be seen by comparing the optical image shown in FIG. 7 and the optical image shown in FIG. 8, the number of pore defects per unit area under a growth pressure of 300 Torr was significantly lower than the number of pore defects per unit area under a growth pressure of 500 Torr. Able to know.

In addition, as confirmed in FIG. 9 showing the number of pore defects observed with an optical microscope classified according to size, the pore defect density was reduced to about 40% when the growth pressure of 300 Torr was compared to the growth pressure of 500 Torr. Therefore, in the same way that crater defects are affected by the growth pressure, which is the internal pressure of the adiabatic housing, the average diameter of the pore defects decreases as the growth pressure decreases, and the defect density of the pores decreases as the number of generated void defects decreases. it can be seen that

When bubbles with a diameter of more than 200 μm are adsorbed on the growth surface of the single crystal ingot and develop into void defects, the growth pattern of the single crystal ingot is affected, and as a result, it grows as a negative crystal defect having a hexagonal crystallographic shape. It is important to control the size of the void defect not to exceed 200 μm because it acts as a factor for local growth of polycrystal on this defect.

Therefore, according to the single crystal ingot growing apparatus and the single crystal ingot growth method according to the present invention, when the single crystal ingot is grown under a growth pressure of 300 Torr or less or a pressure between 0.01 torr and 300 Torr in a monoatomic gas atmosphere, the grown single crystal ingot Since the occurrence rate of pore defects having a diameter of 200 μm or more among the pore defects generated in .

As described above, according to the single crystal ingot growth apparatus and growth method according to the embodiment of the present invention, since generation of defects due to craters or voids is suppressed, there is an advantage in that the crystal quality of the grown single crystal ingot is improved.

Although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the above-described embodiments, and common knowledge in the field to which the present invention pertains without departing from the gist of the present invention as claimed in the claims Those having a will understand that various modifications and equivalent other embodiments are possible therefrom. Accordingly, the technical protection scope of the present invention should be defined by the following claims.

10: chamber part 100: insulation housing part
110: opening 120: insulating plate portion
200: crucible part 210: crucible part supporter
300: growth shaft part 310: opening and closing part
311: uneven portion 320: heat blocking member
400: heating unit 500: first rotation motor
600: opening/closing control unit 610: moving rod
620: rod shaft 630: second rotation motor
S: Seed M: Single crystal melt

Claims (16)

a gas supply unit providing a monoatomic molecular gas;
a chamber unit provided with an internal space in which an atmosphere of the monoatomic molecular gas injected from the gas supply unit is created at a pressure lower than atmospheric pressure;
a vacuum pump unit for exhausting the fluid from the inner space;
an insulating housing portion disposed in the inner space and communicating with the inner space to form a growth space in which a single crystal ingot is grown in the atmosphere of the monoatomic molecular gas formed at a growth pressure lower than atmospheric pressure;
a crucible unit accommodating the raw material of the single crystal ingot and disposed in the growth space;
a heating part for supplying heat to the crucible part so that the raw material of the single crystal ingot is melted to generate a single crystal molten solution; and
A seed for growing the single-crystal ingot from the single-crystal melt generated in the crucible part is mounted on the lower end, and a growth shaft part that can be moved upward or downward through an opening formed on the upper side of the heat-insulating housing part; includes;
The insulated housing part is made of a porous material, or an input port allowing movement of the monoatomic molecular gas to the growth space in the insulated housing part is provided,
In the growth space and the inner space, the monoatomic molecular gas in the inner space moves to the growth space through the pores or the input port of the heat insulating housing part according to a pressure difference between the growth space and the single crystal maintained at the same growth pressure. Ingot growing device.
delete The method of claim 1,
an opening/closing part connected to the growth shaft part and selectively interlocked, and moving upward or downward while rotating along the growth shaft part to open or close the opening formed in the heat insulation housing part; and
The single crystal ingot growing apparatus further comprising; an opening and closing intermittent unit capable of selectively intermitting rotation of the opening and closing unit along the growth shaft.
4. The method of claim 3,
The single crystal ingot growing apparatus further comprising a; disposed in the space between the crucible part and the opening in the growth space, the heat insulating plate part having a through hole through which the growth axis can be moved upward or downward.
4. The method of claim 3,
The opening and closing part is a single crystal ingot growing device made of a graphite material.
A solution growth method comprising:
An input made of a porous material or allowing movement of the monoatomic molecular gas into the interior space by injecting the monoatomic molecular gas from the gas supply part into the internal space of the chamber part while the vacuum pump part exhausts the fluid in the internal space of the chamber part a growth atmosphere creation process of creating an atmosphere of the monoatomic molecular gas at a growth pressure lower than atmospheric pressure in a growth space in a heat insulating housing unit provided with a port; and
a growth process of growing a single crystal ingot in the atmosphere of the monoatomic molecular gas created by the growth pressure in the process of creating the growth atmosphere; and
The monoatomic molecular gas injected into the inner space of the chamber part according to a pressure difference between the growth space in the insulated housing part and the internal space of the chamber part is insulated through the pores or the input port of the insulated housing part. A method of growing a single crystal ingot by moving to the growth space in the housing and maintaining the same with the growth pressure.
7. The method of claim 6,
The monoatomic molecule is a single crystal ingot growth method of any one of helium, neon, argon, krypton, xenon, and radon.
7. The method of claim 6,
The growth pressure is a single crystal ingot growth method of a pressure of 300 Torr or less.
7. The method of claim 6,
A method of growing a single crystal ingot further comprising a cooling process of cooling the single crystal ingot grown in the growth process in the atmosphere of the monoatomic molecular gas at the growth pressure.
7. The method of claim 6,
The process of creating a growth atmosphere is
a preparation process of creating a vacuum state at a predetermined vacuum degree with respect to the growth space in the heat insulating housing part in which the crucible part in which the raw material of the single crystal ingot is accommodated; and
In the preparation process, the monoatomic molecular gas is introduced into the growth space in the heat insulating housing part in which a vacuum state is created, and the pressure of creating an atmosphere of the monoatomic molecular gas by the growth pressure in the growth space in the heat insulating housing part Adjustment process; single crystal ingot growth method comprising.
delete 11. The method of claim 10,
In the pressure adjustment process, heat is supplied to the crucible part disposed in the growth space in the heat insulating housing part where the atmosphere of the monoatomic molecular gas is created by the growth pressure to melt the raw material of the single crystal ingot to produce a single crystal melt A single crystal ingot growth method further comprising a melting process.
13. The method of claim 12,
A single crystal ingot growing method in which an opening of the insulating housing part is selectively opened or closed while heat is supplied to the crucible part.
13. The method of claim 12,
In the growth process, the single crystal ingot is
A single crystal ingot growing method, characterized in that the single crystal is grown by contacting a seed of the single crystal with the melt of the single crystal and moving the seed of the single crystal in one direction.
15. The method of claim 14,
While the single crystal ingot is grown, the pressure in the growth space in the heat insulating housing is maintained at the growth pressure.
16. A single crystal ingot grown by the single crystal ingot growing method according to any one of claims 6 to 10 and 12 to 15, comprising:
A single crystal ingot in which the ratio of pore defects having a diameter of 200 μm or more among the pore defects generated in the single crystal ingot is less than 1%.

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