JPS628145Y2 - - Google Patents

Description

[Detailed explanation of the invention] Recently, devices that heat the light from light sources such as halogen lamps and xenon lamps using reflective mirrors, i.e., radiation heating devices, have been developed to study crystal growth, melting of various materials, and physical properties at high temperatures. It has come to be widely used. For such purposes, it is often required to heat the object (sample) to a high temperature in an atmosphere of a special gas or high pressure.

Since radiation heating equipment uses light to heat,
The sample is placed in a chamber or container (atmosphere chamber) made of heat-resistant glass such as quartz, the desired atmospheric gas is introduced into the atmosphere chamber, and light is concentrated from outside the atmosphere chamber to heat it. will be held.

Since such an atmosphere chamber is made of glass, it is easily broken and can be destroyed due to operator carelessness or atmospheric pressure. If such destruction occurs, atmospheric gas in the atmosphere chamber, evaporated matter from the sample, glass fragments, etc. may be released to the outside, potentially posing a danger to the operator.

Recently, semiconductors with unique properties, ceramics,
Efforts are being made in various fields to discover or develop new materials such as metals, but in such cases, dangerous conditions such as the use of toxic atmospheric gases, evaporation of toxic vapors from samples, and high-pressure atmospheres are necessary. There are more and more demands. In such a case, the destruction of the glass atmosphere chamber as described above would expose the operator to an extremely dangerous situation, so there is a strong demand for improvements regarding the safety of the radiant heating equipment as described above. It has become like that.

The object of the present invention is to provide a highly safe apparatus that eliminates the danger to the operator due to the destruction of the glass atmosphere chamber in the above-mentioned radiation heating apparatus.

Figure 1 shows an example of a conventional radiation heating device.
This represents a device that focuses the light of a halogen lamp using a spheroidal mirror to heat and melt a sample, growing crystals using a floating zone method.

In FIG. 1, 1 represents a spheroidal mirror having a reflective surface on its inner surface, and 2 represents a removable portion of the spheroidal mirror 1. This spheroidal mirror 1 is 2
It has two focal points F ₁ and F _2. 3 is a halogen lamp (light source), which is placed above the focal point F ₁ . 4 represents a seed crystal, 5 represents a raw material rod, and 6 represents a melted part. Further, 7 represents a holding rod that holds the seed crystal 4, and 8 represents a holding rod that holds the material rod 5. Further, 9 is a quartz tube, 10 and 11 are holding cylinders for holding the quartz tube 9, and 12, 12', 13, 1
3', 14, and 14' each represent an O-ring. Furthermore, 15 represents an atmospheric gas inlet, 16 represents an atmospheric gas outlet, and 17 and 18 each represent a substrate.

The spheroidal mirror 1 has a hollow shape consisting of almost the entire surface of an ellipsoid of revolution in order to increase heating efficiency. Furthermore, a portion (two portions of 2) of the spheroidal mirror 1 can be removed in order to remove the quartz tube 9, lamp 3, etc.

In FIG. 1, the halogen lamp 3 is placed on one focal point F1 of the spheroidal mirror 1, so that its light is reflected by the spheroidal mirror ₁ and then passes through the quartz tube 9 to the other focal point _F2 . be concentrated. As a result, the joint between the seed crystal 4 and the raw material rod 5 is melted, and a fused portion 6 is formed. If this state is maintained and the holding rods 7 and 8 are slowly moved at the same speed, a new crystal will grow on the seed crystal 4.

As shown in FIG. 1, the quartz tube 9 is held by holding cylinders 10 and 11, and is provided so as not to come into contact with the spheroidal mirror 1 through an opening provided in the spheroidal mirror 1. In addition, the space surrounded by the inner surface of the quartz tube 9, the holding cylinders 10, 11, and the substrates 17, 18 includes O-rings 12, 12', 13, 13',
14 and 14' to form a sealed zero-air chamber. By introducing a desired atmospheric gas into the atmospheric chamber from the ambient gas inlet 15, the surroundings of the melting section 6 can be maintained in a desired atmosphere. If atmospheric gas circulation is required,
The atmospheric gas can also be discharged from the atmospheric gas outlet 16 at a desired speed.

As mentioned above, the quartz tube 9 constitutes an atmospheric chamber and at the same time serves to prevent vapor evaporated from the sample from adhering to the surface of the spheroidal mirror 1 and deteriorating its performance.

When growing crystals of substances with high vapor pressure at high temperatures, it is necessary to increase the pressure of the atmosphere to suppress evaporation.

Also, when growing crystals of certain substances, it must be done in an atmosphere of toxic gas.
(For example, GaAs crystal growth is performed in an atmosphere containing As gas.) Also, when crystal growth of certain substances is performed, toxic vapors evaporate from the sample (for example, in the case of GaAs, toxic vapors evaporate from the sample).
As evaporates. ).

On the other hand, in the apparatus shown in FIG. 1, there is a portion of the quartz tube 9 exposed outside the spheroidal mirror 1, and the quartz tube 9 may be damaged due to operator carelessness. Furthermore, the quartz tube 9 may burst if it is heated to a high temperature under a pressure of about 30 atmospheres.

If the quartz tube 9 is destroyed when crystal growth is being performed using a toxic atmosphere as described above, or when crystal growth is being performed using a substance that evaporates toxic vapor, the toxic gas or vapor will evaporate. If it is released outside, the operator and others will be exposed to serious danger.

Furthermore, if the quartz tube 9 ruptures due to high pressure, its fragments will scatter and pose a hazard to the operator and the like.

As explained above, the conventional radiation heating apparatus shown in Fig. 1 is not suitable for crystal growth under normal conditions (safe ambient gas, sample with little evaporation, low pressure) due to safety concerns. Although this is not a problem, as mentioned above, there is a high risk of crystal growth in high pressure or toxic atmospheres, or crystal growth of substances that cause the evaporation of toxic vapors, and improvements are required. .

The object of the present invention is to provide a highly safe radiation heating device that eliminates the danger associated with destruction of the atmosphere chamber associated with the conventional radiation heating device as described above.

Figure 2 shows an embodiment of the present invention, and similarly to Figure 1, it shows the case where the present invention is applied to a crystal growth apparatus using a floating zone method using a radiation heating device using a halogen lamp as a light source. ing.

In FIG. 2, 21 denotes two foci F ₁ and
₂₂ is a removable part of the spheroidal mirror 21, 23 is a halogen lamp, 24 is a seed crystal, 25 is a raw material rod, 26 is a melting part, 27 is a seed crystal 24 holding rod for holding the
28 is a holding rod for holding the material rod 25; 29
is a quartz tube, 30 and 31 are quartz tube holding cylinders, 3
2, 32', 33, 34, 34' are O-rings, 35
is the atmosphere gas inlet, 36 is the atmosphere gas outlet, 37
represent the respective substrates.

The light from the halogen lamp 23 provided at one focal point is reflected by the reflecting mirrors 21 and 22 and concentrated at the other focal point _F2 through the quartz tube 29, melting the joint between the seed crystal 24 and the material rod 25, Melting part 2
6 is formed. If this state is maintained and the holding rods 27 and 28 are slowly moved downward at the same speed, a new crystal will grow on the seed crystal 24. In this respect, this embodiment also functions exactly the same as the conventional example shown in FIG.

In the embodiment of the invention shown in FIG. 2, the interior of the spheroidal mirror 21 is sealed by O-rings 33, 34, 34'. Although the socket of the halogen lamp 23 is not shown, it is sealed using an O-ring or a hermetic seal, and the cavity inside the spheroidal mirror 21 is completely sealed and isolated from the outside air. There is.

Further, the quartz tube 29 is installed inside the spheroidal mirror 21 as shown in the figure. Spheroidal mirror 21
The inside of the quartz tube 29 is sealed with O-rings 32, 32' with respect to the internal space of the quartz tube 29.
Circulation of atmosphere between the interior of the spheroidal mirror 9 and the interior of the spheroidal mirror 21 is prevented. Therefore, the vapor evaporated from the molten part 26 does not adhere to the inner surface of the spheroidal mirror 21 and reduce the reflectance.

The space formed between the inside of the quartz tube 29 and the inside of the holding cylinders 30 and 31 is filled with O-rings 32, 32',
34 and 34', forming a sealed atmosphere chamber. A desired atmospheric gas can be introduced into this atmospheric chamber from the atmospheric gas inlet 35. Further, when the atmospheric gas needs to be circulated, the atmospheric gas can be discharged from the atmospheric gas outlet 36 at a desired speed.

In the embodiment shown in FIG. 2, the quartz tube 29 is installed inside the sealed spheroidal mirror 21, so that the operator will not accidentally damage the quartz tube 29 during operation of the device. .

Furthermore, even if the quartz tube 29 breaks due to the pressure or high temperature of the atmospheric gas, its fragments, toxic atmospheric gas, toxic evaporated matter from the molten part, etc. will be released outside the sealed spheroidal mirror 21. never be done.

In this way, in the embodiment of the present invention, the atmosphere chamber using the quartz tube is provided inside the sealed spheroidal mirror, which eliminates the danger associated with the destruction of the quartz tube that existed with conventional devices. A highly safe radiant heating device has been realized in which radiation heating can be almost completely eliminated.

In the above explanation, a radiation heating device is shown as an example in which a light source is provided at one focal point of a single spheroidal mirror and the radiation heating device heats the other focal point by concentrating it. The same effect can be obtained in a heating device that includes two or more spheroidal mirrors and heats the light from a light source provided on the focal point of each spheroidal mirror.

Figure 3 shows an example of a radiation heating device that combines multiple spheroidal mirrors as described above, and a heating device with two spheroidal mirrors facing each other is applied to crystal growth using the floating zone method. Indicates the case where

In FIG. 3, 41 and 42 are spheroidal mirrors, 43 and 44 are halogen lamps, 45 is a seed crystal, 46 is a material rod, 47 is a melting part, and 48 and 49 are for a seed crystal 45 and a material rod 46, respectively. holding rod, 50 is a quartz tube, 51 and 52 are quartz tubes 50
The holding cylinder, 53, 53', 54, 55, 55' is O
Ring 56 represents an atmospheric gas inlet, 57 represents an atmospheric gas outlet, and 58 represents a substrate.

Two spheroidal mirrors 41 and 42 having two foci F ₁ and F ₂ and F ₁ ′ and F ₂ ′ are provided facing each other so that F ₂ and F ₂ ′ coincide, and F ₁ and two halogen lamps 43 and 4 provided on F ₁ '
By concentrating the light of 4 on F ₂ and F ₂ ', the sample is heated and melted, and crystals can be grown in a floating zone method.

Inside the spheroidal mirrors 41 and 42 is an O-ring 5.
3, 53', 54, 55, 55' and are sealed. Although the sockets of the halogen lamps 43 and 44 are not shown,
It is sealed with an O-ring or hermetic seal.

The quartz tube 50 is thus placed inside the sealed spheroidal mirrors 41 and 42. Furthermore, O-rings 53 and 53' seal the quartz tube 50 so that atmospheric gas does not enter the spheroidal mirrors 41 and 42.

Therefore, it is possible to prevent the vapor evaporated from the melting part 47 from adhering to the reflecting surfaces of the spheroidal mirrors 41 and 42 and reducing the reflection efficiency.

In addition, since the quartz tube 50 is not exposed to the outside, an operator may accidentally open the quartz tube 50 while operating the device.
An accident that would destroy the equipment cannot occur.

Furthermore, even if the quartz tube 50 ruptures due to atmospheric pressure or high temperature, fragments of the quartz tube, toxic atmospheric gas, toxic vapors, etc. will not leak outside, completely eliminating danger to operators and others. can be removed.

Although the above explanation shows the case where a halogen lamp is used as the light source, it is clear that the effects of the present invention can be obtained in exactly the same way even when any lamp such as a xenon lamp or mercury lamp is used as the light source. .

Further, in the embodiments shown in FIGS. 2 and 3, the atmosphere chamber is made of a quartz tube, but any transparent heat-resistant glass such as Pyrex glass may be used instead of the quartz tube. It is clear that the same effects of the present invention can be obtained even if the glass is made of transparent heat-resistant glass.

In addition, in the embodiment, the case where the holding rods 7 and 8, 27 and 28, or 48 and 49 are manually moved slowly downward has been described, but the spheroidal mirror 1 or 21 or 51
It is also possible to perform crystal growth by moving the crystals and 52, and even in such a case, the effects of the present invention are exhibited without any difference.

Furthermore, although the above explanation deals with the case where the radiation heating device is applied to crystal growth using the floating zone method, crystal growth using other methods (e.g. epitaxial growth), sample dissolution,
It is clear that the effects of the present invention can be obtained in exactly the same way even when applied to heating a sample.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing a conventional radiation heating device, in which 1 is a spheroidal mirror, 3 is a halogen lamp, 4 is a seed crystal, 5 is a raw material rod, 6 is a melting part, 6 is a quartz tube, 1
2, 12', 13, 13', 14, and 14' are O-rings, 15 is an atmospheric gas inlet, and 16 is an atmospheric gas outlet. FIG. 2 is a sectional view showing an embodiment of the present invention.
1 is a spheroidal mirror, 23 is a halogen lamp, 24
25 is a seed crystal, 25 is a raw material rod, 26 is a melting part, 29 is a quartz tube, 32, 32', 33, 34, 34' are O-rings, 35 is an atmospheric gas inlet, and 36 is an atmospheric gas outlet. FIG. 3 is a sectional view showing another embodiment of the present invention, in which 41 and 42 are spheroidal mirrors, 43 and 44 are halogen lamps, 45 is a seed crystal, 46 is a material rod,
50 is a quartz tube, 53, 53', 54, 55, 5
5' represents an O-ring, 56 an atmospheric gas inlet, and 57 an atmospheric gas outlet.

Claims (1)

[Scope of utility model registration request] A light source is provided at one focal point of one or more spheroidal mirrors, and the light is concentrated at the other focal point,
In a radiation heating device for heating an object disposed inside an atmosphere chamber made of heat-resistant glass, the spheroidal mirror has a sealed structure that seals the inside of the mirror, and the sealed structure A radiation heating device characterized in that the atmosphere chamber is constructed of heat-resistant glass inside and is sealed with the spheroidal mirror including the heat-resistant glass itself.