KR20130012695A - Apparatus for growing sapphire single crystal - Google Patents

Abstract

PURPOSE: An apparatus for growing sapphire single crystals is provided to remarkably reduce the process time for replacing seed crystals by omitting cooling and reheating. CONSTITUTION: A first chamber(101) accommodates a crucible receiving container(102), a crucible(103) and a heating portion(104). An inlet hole(111) passes through a first chamber. The crucible receiving container is positioned inside the first chamber. The crucible is positioned inside the crucible receiving container. The heating portion heats the crucible and produces molten alumina. A chamber blocking portion(107) is installed at the lower part of a second chamber to open and close the inlet hole.

Description

Sapphire single crystal growth device {APPARATUS FOR GROWING SAPPHIRE SINGLE CRYSTAL}

The present invention relates to a sapphire single crystal growth apparatus, and more particularly, to a sapphire single crystal growth apparatus capable of reducing the process time due to replacement of seed crystals.

Sapphire is a single crystal of alumina (Al2O3) having a hexagonal crystal structure. Sapphire single crystal is used as a substrate in the manufacture of light emitting diodes (LEDs). Examples of the sapphire single crystal manufacturing method include a czochralski method (hereinafter referred to as CZ method), a verneuil method, a kyropoulos method, an EFG method, and a heat exchanger method. Among them, the CZ method is very effective because the single crystal can be enlarged, the temperature gradient can be easily adjusted to produce a high quality single crystal, and the waste of raw materials can be prevented during the production of the C surface substrate. In addition, in recent years, the diameter of the substrate is increasing in order to increase the productivity and reduce the manufacturing cost during LED manufacturing, and in this tendency, sapphire crystal growth using the CZ method has many advantages.

1 is a diagram showing a sapphire single crystal growth apparatus 10 using the CZ method according to the prior art. As shown in FIG. 1, alumina is filled in the crucible 12 positioned inside the crucible accommodating container 11 made of a heat insulating material, and the high frequency coil 14 heats the crucible 12. The alumina is melted by the heat of the crucible 12 to form the alumina molten metal 13. The seed crystal 16 is connected to the lower end of the impression rod 15, and after contacting with the alumina molten metal 13, the sapphire single crystal 17 is grown by slowly pulling it while rotating. At this time, the convection phenomenon should be made in the alumina molten metal 13, and a CCD camera (not shown) is used to observe the convection phenomenon of the molten metal 13.

However, convective phenomena may not be properly observed due to the position, filter, zoom, etc. of the CCD camera. Due to this, the output of the high frequency coil 14 continues to increase, so that the internal temperature of the sapphire single crystal growth apparatus 10 also increases, and the seed crystal 16 melts to shorten or disappear completely from the lower end of the impression bar 15. Cases may occur. As a result, the growth of the sapphire single crystal 17 is not able to proceed, so that the new seed crystal 16 should be replaced and connected to the lower end of the impression bar 15. For this purpose, the high frequency coil 10 has its output value reaching zero and must be naturally cooled. The seed crystal 16 is then connected to the lower end of the impression rod 15. The high frequency coil 14 again heats the crucible 12 while increasing its output value. That is, in order to grow the sapphire single crystal by replacing the seed crystals, the output change of the high frequency coil which takes a considerable time must be made. Therefore, there is a problem in that the time taken to replace the seed crystals is considerably time-consuming. In addition, the crucible or crucible receiving vessel is repeatedly cooled or reheated and deformed, thereby reducing the life.

The present invention seeks to provide a sapphire single crystal growth apparatus which can facilitate the replacement of seed crystals installed in the seed crystal rods and thereby reduce the time accordingly.

In addition, the present invention is to provide a sapphire single crystal growth apparatus that can reduce the deformation of the crucible or crucible container due to repeated cooling and reheating and to extend the life of the crucible or crucible container.

The present invention provides a sapphire single crystal growth apparatus for growing a sapphire single crystal by raising the seed crystals after contacting the molten alumina, followed by raising the first chamber (an insertion hole is formed on an upper surface of the first chamber) in which alumina is melted. do); A second chamber installed above the first chamber so as to communicate with an insertion opening of the first chamber; A seed crystal rod descending into the first chamber through the second chamber or ascending from the first chamber (the seed crystal is installed at an end of the seed crystal rod); And a chamber blocking part installed at a lower end of the second chamber to open and close the insertion hole, and when the end of the seed crystal rod is raised to be positioned inside the second chamber to replace the seed crystal, The part discloses a sapphire single crystal growth apparatus characterized by closing the insertion hole.

In addition, the first chamber, the crucible receiving container located inside the first chamber; A crucible placed inside the crucible receiving container and containing the alumina; And a heating unit positioned to surround the crucible receiving container and melting the alumina to generate the alumina molten metal.

The second chamber further includes a gas line extending from an outer circumferential surface of the second chamber and injecting an atmosphere gas into the second chamber.

In addition, the sapphire single crystal growth apparatus, characterized in that the crucible receiving container is made of a heat insulating material.

In addition, the heating unit discloses a sapphire single crystal growth apparatus, characterized in that the high frequency coil.

The sapphire single crystal growth apparatus according to the present invention includes a first chamber, a second chamber, a seed crystal rod and a chamber block. Here, the second chamber is installed on the upper part of the first chamber so as to communicate with the insertion hole of the first chamber through which the seed crystal rod passes, and the atmosphere gas is injected into the second chamber. In addition, when the chamber blocking part is installed at the lower end of the second chamber to close the insertion port, the second chamber is in an isolated state from the first chamber. Due to this, the seed crystals are located inside the second chamber in isolation from the first chamber and can be replaced after being cooled by the atmosphere gas.

Conventionally, the heating section had to be cooled and reheated over a significant time to replace seed crystals in a single chamber, but the cooling and reheating of the heated section, which would take a considerable time, can be omitted by the present invention. Thus, the sapphire single crystal growth apparatus according to the present invention has the effect of significantly reducing the time for replacing seed crystals.

 In addition, in the sapphire single crystal growth apparatus according to the present invention, the crucible or crucible receiving vessel, which is repeatedly cooled and reheated by the heating unit in the replacement of the seed crystals, is maintained under a constant temperature environment, thereby reducing deformation and life due to repeated cooling and reheating. Has the effect of preventing.

1 is a diagram showing a sapphire single crystal growth apparatus using the CZ method according to the prior art.
2 is a view showing a sapphire single crystal growth apparatus according to a preferred embodiment of the present invention.
FIG. 3 is a perspective view showing a chamber block of the second chamber of the sapphire single crystal growth apparatus shown in FIG. 2.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

2 is a view showing a sapphire single crystal growth apparatus 100 according to a preferred embodiment of the present invention, Figure 3 is a chamber blocking portion of the second chamber 105 of the sapphire single crystal growth apparatus 100 shown in FIG. It is a perspective view which shows 107. As shown in Figure 2 and 3, the sapphire single crystal growth apparatus 100 according to a preferred embodiment of the present invention is the first chamber 101, the crucible receiving container 102, the crucible 103, the heating unit 104 ), The second chamber 105, the seed crystal rod 106, and the chamber blocking portion 107, and the seed crystal 110 provided at the end of the seed crystal rod 106 in contact with the alumina molten metal, To grow the sapphire single crystal 120.

The first chamber 101 accommodates the crucible accommodating container 102, the crucible 103 and the heating part 104 to protect the crucible accommodating container 102, the crucible 103 and the heating part 104 from the external environment. In addition, the heat of the crucible accommodating container 102, the crucible 103, and the heating part 104 is blocked from being dissipated to the outside of the first chamber 101 to the outside.

In addition, an upper cover 101a is positioned on an upper surface of the first chamber 101, and the upper cover 101a is detachable from the first chamber 101 to function as a lid of the first chamber 101. .

In addition, the insertion hole 111 is formed in the upper cover 101a. The insertion hole 111 may communicate the inside and the outside of the first chamber 101, and the seed crystal rod 106 may be lowered and inserted into the first chamber 101 through the insertion hole 111.

The crucible receiving container 102 is located inside the first chamber 101 and is made of a heat insulating material.

The crucible 103 is located inside the crucible receiving container 102 and contains alumina. At this time, the alumina is in a solid state. In addition, the crucible 103 is made of iridium material, the size of the crucible 101 may be selected according to the size of the sapphire single crystal 120 to be manufactured.

In addition, the upper surface of the crucible 103 is in an open state and corresponds to the insertion opening 111 of the first chamber 101.

The heating unit 104 is positioned to surround the crucible accommodating container 102, and heats the crucible 103 to melt the alumina contained in the crucible 103, thereby producing molten alumina.

In addition, the output of the heating section 104 is adjustable and is produced as molten alumina molten in the solid state, and continues to increase until convection occurs in the alumina molten. It is preferable that the heating part 104 consists of a high frequency coil wound around the crucible accommodation container 102.

Meanwhile, in order to confirm the convection phenomenon of the alumina molten metal in the crucible 103, the first view port 113 is formed in the upper cover 101a of the first chamber 101. The current state of the alumina molten metal is confirmed through the first view port 113. When convection of the alumina molten metal occurs, an increase in output of the heating unit 104 may be stopped, and growth of the sapphire single crystal 120 using the seed crystal 110 may be performed. At this time, the inside of the first chamber 101 is too bright, so that the state of the alumina molten metal is difficult to check with the naked eye. Thus, an imaging device (not shown) such as a CCD camera photographs and provides the molten alumina through the first view port 113.

The second chamber 105 is installed on the upper portion of the first chamber 101 to communicate with the insertion hole 111 of the first chamber 101.

In general, even when the photographing apparatus is used to check the current state of the alumina molten metal, the state of the alumina molten metal, particularly convection, may not be properly observed depending on the position of the photographing apparatus, the filter, and the zoom. For this reason, even if a convection phenomenon occurs, the output of the heating part 104 may continue to increase. At this time, the internal temperature of the first chamber 101 increases, so that the seed crystal 110 becomes smaller or melts before the sapphire single crystal 120 is grown. At this time, the second chamber 105 is used to replace the seed crystal 110 installed at the end of the seed crystal rod 106.

In addition, the inner diameter of the second chamber 105 is preferably formed to a size such that the seed crystals 110 almost contact the inner wall of the second chamber 105. As a result, the seed crystal 110 may pass through the second chamber 105 without interference of the second chamber 105, and heat inside the first chamber 101 may be dissipated through the second chamber 105. May be limited.

In addition, a gas line 151 is formed on the outer circumferential surface of the second chamber 105. The gas line 151 injects the atmospheric gas into the second chamber 105. This atmospheric gas restricts heat inside the first chamber 104 from passing through the second chamber 105 and cools the seed crystal rod 106 located inside the second chamber 105.

In addition, a second view port 153 is formed on an outer circumferential surface of the second chamber 105. The inside of the second chamber 105 may be confirmed through the second view port 153. Due to this, it can be confirmed whether the seed crystal 110 installed at the end of the seed crystal rod 106 is located inside the second chamber 105 and is cooled and replaceable.

The seed crystal rod 106 passes through the second chamber 105 and descends into the first chamber 101 or rises from the first chamber 101. As the seed crystal 110 is installed at the end of the seed crystal rod 106, the seed crystal rod 106 descends to contact the seed crystal 110 with the alumina molten metal, and then rises to sapphire the seed crystal 110. It grows to single crystal 120. At this time, the seed crystal rod 106 is made of an iridium material like the crucible 103.

The chamber blocking unit 107 is installed at the lower end of the second chamber 105 to open and close the insertion opening 111. In general, the chamber blocking part 107 keeps the insertion hole 111 in an open state, and allows the seed crystal 110 to grow smoothly into the sapphire single crystal 120 by the lowering and raising of the seed crystal rod 106.

On the other hand, when seed crystals 110 become small or melt before they even grow into sapphire single crystals 120, they must be replaced. In this case, the end of the seed crystal rod 106 is positioned inside the second chamber 105 by using the second view port 153. Subsequently, the chamber blocking part 107 closes the insertion hole 111, thereby bringing the first chamber 101 and the second chamber 105 into an isolated state. As a result, the seed crystals 110 installed at the ends of the seed crystal rods 106 are not affected by the heat inside the first chamber 101 before being replaced by the atmosphere gas injected by the gas line 151. Cooling can be concentrated. Seed crystals 110 are replaced after being sufficiently cooled to a replaceable temperature in the second chamber. The chamber blocking part 107 opens the insertion hole 111 again, and the seed crystal 110 descends into the first chamber 101 by using the seed crystal rod 106 to grow the sapphire single crystal 120. Is used.

In addition, the chamber blocking unit 107 illustrated in FIG. 3 is illustrated as being rotated in a left and right direction about an axis at the bottom of the second chamber 105 to open and close the insertion hole 111, but is not limited thereto. The insertion hole 111 may be opened and closed in various ways, such as linearly moving with respect to the chamber 105 or being positioned on an inner wall of the second chamber 105 to rotate vertically about one axis.

In order to confirm the effect of the sapphire single crystal growth apparatus 100 according to the present invention, the seed crystals 110 are melted and then replaced and again grown in the state that can be grown into the sapphire single crystal 120 through the sapphire single crystal growth apparatus 100. The time required to reach was measured in Example 1, Example 2 and Comparative Example 1 below.

In Example 1, a sapphire single crystal growth apparatus including a second chamber 105 and a chamber blocking unit 107 was used, and no atmospheric gas was injected into the second chamber 105. In the state where the seed crystal 110 was melted inside the first chamber 101, the seed crystal rod 106 was raised, so that the seed crystal 110 was positioned inside the second chamber 105. At this time, the insertion hole 111 is closed by the chamber blocking part 107, and the seed crystal 110 is naturally cooled in the second chamber 105 without any action. The seed crystals 110 are replaced after reaching a replaceable temperature and lowered back into the first chamber 101 by the seed crystal rods 106 with the insertion opening 111 again opened by the chamber block 107. It became. Up to this point, the time spent in each step was measured.

Example 2 uses the sapphire single crystal growth apparatus including the second chamber 105 and the chamber blocking unit 107 as in Example 1, but unlike Example 1, the atmosphere gas is injected into the second chamber 105 I was. In the state where the seed crystal 110 was melted inside the first chamber 101, the seed crystal rod 106 was raised, so that the seed crystal 110 was positioned inside the second chamber 105. At this time, the insertion hole 111 is closed by the chamber blocking part 107, and the seed crystal 110 is cooled by the atmosphere gas injected into the second chamber 105. The seed crystals 110 are replaced after reaching a replaceable temperature and lowered back into the first chamber 101 by the seed crystal rods 106 with the insertion opening 111 again opened by the chamber block 107. It became. Up to this point, the time spent in each step was measured.

In Comparative Example 1, a sapphire single crystal growth apparatus that did not include the second chamber 105 and the chamber blocking unit 107 was used. As a result, a cool down step is performed in which the output value of the heating unit 104 reaches zero as in the related art, and the seed crystal 110 melted inside the first chamber 101 is transferred to the first chamber 101. Located outside of), it was naturally cooled without any action. After the seed crystal 110 reaches a replaceable temperature, a temperature raising step is performed in which the output value of the heating unit 104 is increased again so that convection of the alumina molten metal can occur again. Lowered into chamber 101. Up to this point, the time spent in each step was measured.

Results according to the experiment are shown in Table 1. Table 1 shows the time taken for each step made for the replacement of the seed crystals (110).

Example 1 Example 2 Comparative Example 1 Cool down 0 0 20 Atmosphere gas injection 0 One 0 Seed Crystal Natural Cooling 5 0 24 Seed crystal replacement One One One Purge 0.5 0.5 1.5 Elevated temperature 0 0 15 Sum 6.5 2.5 60.5

Referring to Table 1, the sapphire single crystal growth apparatus 100 according to the present embodiment includes a second chamber 105 and a chamber blocking unit 107, and thus the cooling time and the temperature raising step are omitted, and the time for cooling the seed crystals is shown. Was found to be significantly reduced. In addition, by injecting the atmospheric gas into the second chamber 105, it was confirmed that the cooling time of the seed crystals was further reduced. Therefore, the sapphire single crystal growth apparatus according to the present invention omits the step of adjusting the output of the heating section by using the second chamber for replacing seed crystals, and in the second chamber isolated from the first chamber by the chamber blocking unit. The atmosphere gas is injected to quickly cool the seed crystals so that they can be replaced. For this reason, the time according to the replacement of the seed crystal 110 can be remarkably reduced, and the productivity of the sapphire single crystal can also be prevented from being lowered. In addition, the crucible or crucible receiving container is omitted by repeated cooling and reheating by the heating portion, the deformation caused by the cooling and reheating is reduced, thereby reducing the life can be prevented.

While the present invention has been described in connection with certain exemplary embodiments, it will be understood by those skilled in the art that various changes may be made without departing from the scope of the present invention.

100: sapphire single crystal growth device
101: first chamber 102: crucible receiving container
103: crucible 104: heating portion
105: second chamber 106: seed crystal rod
107: chamber block 110: seed determination
151: gas line

Claims (5)

In the sapphire single crystal growth apparatus for growing a sapphire single crystal by raising the seed crystals after contacting the alumina molten metal,
A first chamber for receiving alumina and melting the alumina (insertion openings are formed on an upper surface of the first chamber);
A second chamber installed above the first chamber so as to communicate with an insertion opening of the first chamber;
A seed crystal rod descending into the first chamber through the second chamber or ascending from the first chamber (the seed crystal is installed at an end of the seed crystal rod); And
Is installed at the bottom of the second chamber, including a chamber blocking unit for opening and closing the insertion hole,
And the chamber blocking part closes the insertion hole when an end of the seed crystal rod is raised and positioned inside the second chamber to replace the seed crystal.
The method of claim 1, wherein the first chamber,
A crucible receiving container located inside the first chamber;
A crucible placed inside the crucible receiving container and containing the alumina; And
Sapphire single crystal growth apparatus is positioned to surround the crucible receiving container, and comprising a heating unit for melting the alumina to produce the alumina molten metal.
The method of claim 1, wherein the second chamber,
And a gas line extending from an outer circumferential surface of the second chamber and injecting an atmosphere gas into the inside of the second chamber.
The method of claim 2,
The sapphire single crystal growth apparatus, characterized in that the crucible receiving container is made of a heat insulating material.
The method of claim 2,
Sapphire single crystal growth apparatus, characterized in that the heating unit is a high frequency coil.

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