JPH04292784A - Disc-shaped plasma image heater - Google Patents

Abstract

PURPOSE:To improve performance, i.e., increase in size of an opening diameter of a sample, uniformity of a temperature, easiness of maintenance, temperature stability of a disc-shaped plasma image heater. CONSTITUTION:A disc-shaped plasma lamp 2 sealed with metal element and gas in a light transmission spherical shell is disposed at a focus of an elliptical mirror 1, a cavity resonator 5 incorporating the lamp 2 and a magnetron 25 is provided, a wavelength is selected in a range from an ultraviolet light to a near infrared light, and a sample 8 is irradiated by the light to be heated. An atmosphere is regulated by a flowrate regulator 28 and a vacuum pump 29 while heating the sample 8, and the sample is moved while rotating to manufacture a crystal. A temperature of the sample 8 is measured to be grasped by a radiation thermometer 21 with a wavelength near 0.9 micron through a temperature observation window 22, while a heat power source is controlled by a control computer 23 to control oscillation of the magnetron 25, thereby controlling the temperature of the sample 8 to a desired value.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a disk-type plasma image heating device for an image furnace used for growing crystals of semiconductor materials, for example.

0002

[Prior Art] FIG. 19 shows, for example, Japanese Patent Application Laid-Open No. 63-22348.
FIG. 7 is a sectional view showing a conventional disk-type plasma image heating device disclosed in Publication No. 7. In the figure, 1 is an ellipsoidal mirror that has an ellipsoidal reflective surface inside, and 11 is the first mirror of the ellipsoidal mirror 1.
A light source such as a halogen or xenon lamp is installed at the focal point of the lamp and emits light 9; 12 is a power source connected via a wire 13 to supply power to the light source 11; 8 is an ellipsoidal mirror 1;
This is the sample placed at the second focus of the image.

Next, the operation will be explained. The light from the light source is focused on the sample by the ellipsoidal mirror 1 and heated, thereby dissolving the rod-shaped sample. As this dissolved part moves as the sample moves in the axial direction, the raw material dissolves into the solution in the dissolved part and crystals grow. Since the composition of this solution and the composition of the raw material are always in equilibrium, the composition of the crystal is maintained homogeneous. Therefore, it is attracting attention as the most suitable method for producing single crystals with a uniform dopant concentration.

0004

The conventional disk-type plasma image heating apparatus is constructed as described above, and is therefore still widely used as a single-crystal manufacturing apparatus. However, if a lamp with electrodes, such as a halogen lamp or a xenon lamp, is used as a light source, the wavelength of the light cannot be selected, so the light is absorbed only at the surface of the sample. In this state, the interface between the floating molten part and the raw material has an upwardly convex shape, and the solution flows downward. Therefore, the diameter of the single crystal could not be increased, and only crystals with a small opening diameter of about 1 cm could be produced.

On the other hand, as a method for increasing the diameter of a sample, a crystal pulling method using a crucible has been used, but it has been impossible to produce pure crystals due to contamination of the crucible. This is a problem especially when manufacturing large-diameter optical crystals, etc. Conventionally, crucibles have been used, but there are still problems such as impurities mixed in from the crucible and uneven crystal quality. Perfect optical crystals are not mass-produced. Perfecting crystals is a very important issue in applications such as laser rods, but there has been no method to manufacture crystals with large openings in place of the crucible method. Image heating devices using the floating molten zone method are expected, but since the crystal material is heated from the surface, it cannot be held, and crystals with large opening diameters have not been manufactured. Therefore, new manufacturing equipment was desired.

[0006] In addition, the lifespan of halogen lamps is very short, about 40 hours (for space applications; about 200 hours for terrestrial applications), so many spare halogen lamps are required, and this is difficult in the mass production of optical crystals. This was a fatal problem.

Furthermore, in the case of halogen or xenon lamps, it is not possible to melt glass directly with light, and image heating is performed by placing the glass in a platinum wire mesh, so when glass is melted, platinum was causing the intrusion and deterioration of quality. This has been a major obstacle in the processing of materials such as infrared fibers, for example. That is, one factor that increases the loss of far-infrared fibers is impurities such as heavy ions mixed in the crucible and materials. This cannot be removed as long as a crucible is used.

Furthermore, since the light emitting area of the halogen lamp light source is small, about 5 mm, a small image is formed on the surface of the sample. For this reason, the temperature gradient becomes steeper and cracks appear in the sample, so it is necessary to adjust the heating area of the sample by widening or narrowing it. This adjustment was done by moving a part of the ellipsoidal mirror to blur its focus and by installing an after-heater. However, the installation of these mechanisms greatly impairs the operability of the furnace, complicates the configuration of the device, and impairs performance, posing a major problem.

Furthermore, since the conventional light source heats a narrow area, it is not possible to uniformly heat the sample in the circumferential direction. Therefore, a method of rotating the sample at a high speed of 100 rpm to make the temperature uniform is used. ing. However, applying such high-speed rotation to the sample inhibits the uniform growth of the crystal, and in microgravity experiments, artificial gravity is created, which causes air bubbles to get inside the crystal due to centrifugal force and never come out. A serious problem arises: At present, this problem has not yet been solved worldwide, and image reactors used in shuttle space experiments use a method that rotates the sample at high speed and heats it uniformly, so there is concern that the effects of microgravity may not be fully demonstrated. be done.

The present invention was made to solve the above-mentioned problems, and the light source is a disc-shaped plasma lamp of arbitrary shape, and by rotating the lamp, the incident distribution of light on the sample is adjusted. By making light incident around the entire circumference of the sample, it is possible to make the temperature gradient on the sample surface as steep as that of a halogen lamp, or conversely, to make the temperature distribution gentle by making the light beam spread over a wide range. In addition, it has a long life, can melt glass at a wavelength in the absorption band by selecting the heating wavelength, and makes it possible to increase the diameter of optical crystals.

[0011]

[Means for Solving the Problems] A disk-type plasma image heating device according to the present invention has an element sealed in a light-transmitting container such as quartz or transparent ceramics as a light source, and the element is heated by microwave (2.4 GHZ). A disk-shaped plasma lamp is used, which generates plasma in a container by heating with a microwave frequency (near microwave frequency band) and utilizes the emitted light. This disk-shaped plasma lamp is housed in a bowl-shaped cavity resonator formed by an ellipsoidal mirror and a radio wave shielding plate, and an ellipsoidal mirror is provided to focus the light emitted from the disk-shaped plasma lamp onto the sample. An ellipsoidal mirror is placed in the short axis direction at one focal point, and a part of the sample is heated and melted while the sample is moved in the short axis direction to grow crystals.

A disk-shaped plasma image heating device according to another invention includes an ellipsoid that is housed in a cup-shaped cylindrical cavity resonator of the disk-shaped plasma lamp described above, and that focuses the light emitted from the disk-shaped plasma lamp onto a sample. A mirror is provided, and a sample is placed in the short axis direction at one focal point of the ellipsoidal mirror, and a part of the sample is heated and melted while the sample is moved in the short axis direction to grow crystals.

[0013] In addition, a disk-type plasma image heating device according to another invention uses a light source that encloses an element in a translucent container such as quartz or translucent ceramic, and heats the element with microwaves (
A disk-shaped plasma lamp is used, which is heated in a microwave oven frequency band around 2.4 GHz to create plasma in a container and utilizes the emitted light. This disk-shaped plasma lamp is housed in a bowl-shaped cavity resonator formed by an ellipsoidal mirror and a radio wave shielding plate, and an ellipsoidal mirror is provided to focus the light emitted from the disk-shaped plasma lamp onto the sample. The ellipsoidal mirror is placed on the long axis including the focal point, and a part of the sample is heated and melted while the sample is moved in the long axis direction to grow crystals.

A disk-shaped plasma image heating device according to another invention includes an ellipsoid that is housed in the cup-shaped cylindrical cavity resonator of the disk-shaped plasma lamp described above, and focuses the light emitted from the disk-shaped plasma lamp onto a sample. A mirror is provided, and a sample is placed in the long axis direction at one focal point of the ellipsoidal mirror, and a part of the sample is heated and melted while the sample is moved in the long axis direction to grow crystals.

A disk-shaped plasma image heating device according to still another invention houses the disk-shaped plasma lamp described above in a bowl-shaped cavity resonator formed by an ellipsoidal mirror and a radio wave shielding plate, and generates a disk-shaped plasma image. An ellipsoidal mirror that focuses the light emitted from the lamp onto the sample, a motor that rotates the sample, and a moving device that moves the sample are heated and melted while moving the sample in the minor axis direction to grow crystals. However, the temperature of the sample is measured with a radiation thermometer and that information is used for temperature control. In addition, the sample is placed in the furnace tube and the atmosphere around the sample is controlled.

Furthermore, in the above case, the sample is placed on the long axis including the focal position of the ellipsoidal mirror, and a part of the sample is heated and melted while the sample is moved in the long axis direction. It moves and grows crystals.

A disk-type plasma image heating device according to still another invention is housed in a cup-shaped cylindrical cavity resonator of the disk-type plasma lamp described above, and an ellipse that focuses the light emitted from the disk-type plasma lamp onto a sample. Equipped with an ellipsoidal mirror, the sample is placed in the short axis direction at one focal point of the ellipsoidal mirror.
Crystals are grown by moving the sample in the minor axis direction while heating and melting a portion of the sample.The temperature of the sample is measured with a radiation thermometer and this information is used for temperature control. In addition, the sample is placed in the furnace tube and the atmosphere around the sample is controlled.

Still another invention is that in the above case, the sample is placed on the long axis including the focal position of the ellipsoidal mirror, and the sample is moved in the long axis direction while heating and melting a part of the sample. It moves and grows crystals.

[0019]

[Operation] Since the disc-shaped plasma lamp of this invention has a disc-shaped light source, the distribution of light at the second focal point can be made into a disc-shape, so that uniform heating can be achieved over the entire circumference of the sample, so high-speed rotation is not required. becomes. Also, by rotating the lamp 90 degrees, you can heat a wide area. Furthermore, since the emission wavelength of the lamp can be set from ultraviolet to infrared, it is possible to perform image heating in the absorption band of glass.

[0020]

[Example] Example 1. DESCRIPTION OF THE PREFERRED EMBODIMENTS A disk-type plasma image heating device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the configuration of a disk-shaped plasma image heating device according to an embodiment of the present invention, in which 1 is an ellipsoidal mirror, and 2 is a hollow ellipsoidal disk-shaped container made of glass or translucent ceramic. A disk-shaped plasma lamp that seals elements such as potassium inside and generates plasma light by microwave heating and emits light 9; 3 is a support made by processing highly thermally conductive ceramic into a rod shape; 4 is a disk-shaped 5 is a bowl-shaped cavity resonator formed by the end of the ellipsoidal mirror 1 and the radio wave shielding plate 4, and 6 is an ellipsoidal mirror. 1 is a waveguide attached to a hole drilled at the end of the waveguide 6; 7 is a high-frequency oscillator attached to the other end of the waveguide 6; 8 is a rod-shaped rod installed in the short axis direction at the second focal point of the ellipsoidal mirror 1; In the sample, 14 is a window opened at the contact point between the waveguide 6 and the ellipsoidal mirror 1. Reference numeral 15 denotes a rotating tool to which the supporter 3 is fixed and rotated at the end of the ellipsoidal mirror 1, and is made of a radio wave transparent material. This rotary tool changes the focused light distribution on the sample 8 by rotating the disc-shaped plasma lamp 2 to obtain an optimal distribution.

FIG. 2 is a diagram illustrating the configuration of the vicinity of the disk-shaped plasma lamp 2. As shown in FIG. In the figure, cavity resonator 5
Microwave power of 1KW to 5KW at a high frequency such as 2 GHz is transmitted from the high frequency oscillator 7 to the waveguide 6 and the rotating tool 15.
Applied via. The disk-shaped plasma lamp 2 housed in the cavity resonator 5 generates plasma light and emits a powerful light of about 3 KW. This light is reflected on the inner surface of the ellipsoidal mirror 1 and
The light is focused on the sample 8 at the focal point. Here, sample 8 becomes highly heated and melts. When sample 8 is slowly rotated and pulled up, crystals grow. In this case, the temperature distribution on the side surface of the sample 8 is such that the light circulates around the entire circumference, as shown in FIG. 3, and uniform heating is possible. Therefore, it is not necessary to rotate at a high speed as in the conventional method, but to rotate at a low speed to create a solid solution layer interface between solid and liquid, and to perform crystal growth at a low rotation speed that can create a clean laminar flow at the solid solution layer interface. Can be done.

FIG. 4 shows the results of a heating experiment of a sample 8 (aluminum in this case) using a disk-shaped plasma lamp 2 using a single elliptical disk-type plasma image heating device, with time plotted vertically on the horizontal axis. The temperature is shown on the axis. The disk-shaped plasma lamp 2 used in the experiment emits light at a near-infrared wavelength of 0.76 microns. As can be seen from this figure, the aluminum sample 8 reached 660 degrees and melted in about 2 minutes. At this time, the input power of the disc-shaped plasma lamp 2 is approximately 300W.

Furthermore, FIG. 5 shows the maximum temperature reached in the case of tungsten sample 8 determined by analysis. In this case, calculations are made for three types of lamp shapes: 10, 20, and 30 mm. In this way, it exhibits superior heating performance compared to furnaces using xenon lamps currently on the market. This is because the emission spectrum of the disk-shaped plasma lamp 2 can be concentrated in the wavelength where the sample 8 has the highest absorbance, for example in the near-infrared region, so it is possible to obtain extremely high heating efficiency compared to xenon lamps, etc. It's for a reason.

FIG. 6 is a diagram showing the result of actually measuring the emission spectrum of the disc-shaped plasma lamp 2. In this case, the disc-shaped plasma lamp 2 is filled with potassium so as to emit light of 0.76 microns. A sharp luminescence can be seen near this area. Using this kind of wavelength selectivity, sample 8
Since the light enters the inside of the sample 8, heat is generated from inside, and the solid solution layer interface between the melted portion and the solid portion of the sample 8 becomes a flat or concave surface, thereby preventing leakage of the melt. Therefore, it is possible to process a sample 8 having a larger diameter than in the conventional method using the floating zone method.

FIG. 7 is a diagram showing the shape of the solid solution layer interface 17 between the molten part 16 and the solid of the sample 8, and this case shows the case of irradiation with a halogen lamp or a xenon lamp. The light is incident only on the surface of the sample 8, heats the surface, and gradually diffuses and spreads inside. It is melted to a thickness approximately close to the radius of sample 8, and the solid solution layer boundary surface 17 is formed as shown in the figure.
becomes mountain-shaped, and the molten portion 16 has a shape that tends to drip downward.

FIG. 8 is a diagram similarly showing the shape of the solid solution layer interface 17 between the molten part 16 and the solid of the sample 8, and in this case shows the case of irradiation with the disk-shaped plasma lamp 2. Since the light penetrates into the inside of the sample 8, it is diffused and spread inside. Since the temperature gradient inside the sample 8 is almost eliminated, the solid solution layer boundary surface 17 is horizontal or bowl-shaped as shown in the figure, and the molten part 16 has a shape that prevents it from dripping downward. Therefore, even if the diameter of the sample 8 increases, the molten part 16 will not drip down, making it possible to grow large crystals using the floating zone method.

Example 2. Next, another embodiment of the invention is shown in FIG. Further, the structure around the disk-shaped plasma lamp 2 is shown in FIG. In the figure, reference numeral 10 refers to a cavity resonator 5 which is formed by bringing the open side peripheral edge of a cup-shaped radio wave shield into contact with the first focus side of the ellipsoidal mirror 1, and a disk-shaped plasma lamp 2 is placed inside the cavity resonator 5, which emits light. let In this case, the optimum light emission conditions of the lamp can be maintained regardless of the shape of the ellipsoidal mirror 1.

Example 3. Another embodiment of the invention is shown in FIG. In the figure, 1 is an ellipsoidal mirror, 2 is a hollow ellipsoid made of glass or translucent ceramic, and elements such as potassium are sealed inside the container, which generates plasma light by microwave heating and emits light 9. 3 is a support made by processing highly thermally conductive ceramic into a rod shape; 4 is a radio wave shielding plate attached with the periphery of the disk in contact with the inside of the ellipsoidal mirror 1; 5 is a A microwave cavity resonator is formed by the end of the ellipsoidal mirror 1 and the radio wave shielding plate 4, 6 is a waveguide attached to a hole made in the end of the ellipsoidal mirror 1, and 7 is a waveguide. A high-frequency transmitter is attached to the other end of 6, 8 is a rod-shaped sample placed on the long axis at the second focus of ellipsoidal mirror 1, and 14 is opened at the contact point of waveguide 6 and ellipsoidal mirror 1. It's a window. Reference numeral 15 denotes a rotating tool to which the supporter 3 is fixed and rotated at the end of the ellipsoidal mirror 1, and is made of a radio wave transparent material. This rotary tool 15 changes the focused distribution on the sample 8 by rotating the disc-shaped plasma lamp 2 to obtain an optimal distribution.

Example 4. Next, another embodiment of the invention is shown in FIG. Further, the distribution of light condensed on the sample 8 is shown in FIG. In the figure, reference numeral 10 refers to a cavity resonator 5 which is formed by bringing the open side peripheral edge of a cup-shaped radio wave shield into contact with the first focus side of the ellipsoidal mirror 1, and a disk-shaped plasma lamp 2 is placed inside the cavity resonator 5, which emits light. let In this case, the optimum light emission conditions of the lamp can be maintained regardless of the shape of the ellipsoidal mirror 1. Figure 13
The light is all focused on the molten part 16 of the sample 8 and uniformly irradiated around it. Therefore, since the light collection efficiency is greatly improved, efficient heating can be achieved.

Example 5. Another embodiment of the invention is shown in FIG. In the figure, 1 is an ellipsoidal mirror, 2 is a hollow ellipsoid made of glass or translucent ceramic, and elements such as potassium are sealed inside the container, which generates plasma light by microwave heating and emits light 9. 3 is a support made by processing highly thermally conductive ceramic into a rod shape; 4 is a radio wave shielding plate attached with the periphery of the disk in contact with the inside of the ellipsoidal mirror 1; 5 is a A microwave cavity resonator is formed by the end of the ellipsoidal mirror 1 and the radio wave shielding plate 4, 6 is a waveguide attached to a hole made in the end of the ellipsoidal mirror 1, and 8 is an ellipsoidal mirror. 1 is a rod-shaped sample placed on the short axis at the second focal point of 1, 18 is a furnace tube made of a cylindrical quartz tube that houses the sample 8, and 19 is a furnace tube for rotating the sample attached above and below the furnace core tube 18. A motor, 20 is a moving device for moving the sample 8, 21 is a radiation thermometer that measures the temperature of the sample 8 through a temperature observation window 22, and the sample 8 is observed through a hole made in the ellipsoidal mirror 1. 23 is a control computer connected to the radiation thermometer 21 and the heating power source, 25 is the heating power source 24
A magnetron, which is powered by a magnetron and emits high-frequency waves,
26 is a gas cylinder for storing gas, 27 is a valve, 28
is a flow rate regulator, and 29 is a vacuum pump. 26 to 29
The atmosphere control device 32 is composed of these elements.

With this structure, while heating the sample 8, the atmosphere is controlled by the flow rate regulator 28 or the vacuum pump 29.
The crystals are manufactured by moving the crystals while rotating them with the motor 19. Further, the temperature of the sample 8 is measured with a radiation thermometer 21 via a temperature observation window 22 at a wavelength around 0.9 microns to grasp the temperature, and the heating power source is controlled by a control computer 23 to control the transmission of the magnetron 25. Control the temperature of sample 8 to a desired value. At this time, the change in emissivity on the surface of the sample 8, which is a cause of error in temperature measurement, can be corrected by using a simple emissivity monitor.

Example 6. Next, another embodiment of the invention is shown in FIG. In the figure, reference numeral 10 refers to a cavity resonator 5 which is formed by bringing the open side peripheral edge of a cup-shaped radio wave shield 10 into contact with the first focus side of the ellipsoidal mirror 1, and placing a disc-shaped plasma lamp 2 inside the cavity resonator 5. Make it emit light. In this case, the optimum light emission conditions of the lamp can be maintained regardless of the shape of the ellipsoidal mirror 1.

Example 7. Another embodiment of the invention is shown in FIG. In the figure, 1 is an ellipsoidal mirror, 2 is a hollow ellipsoid made of glass or translucent ceramic, and elements such as potassium are sealed inside the container, which generates plasma light by microwave heating and emits light 9. 3 is a support made by processing highly thermally conductive ceramic into a rod shape; 4 is a radio wave shielding plate attached with the periphery of the disk in contact with the inside of the ellipsoidal mirror 1; 5 is a A microwave cavity resonator is formed by the end of the ellipsoidal mirror 1 and the radio wave shielding plate 4, 6 is a waveguide attached to a hole made in the end of the ellipsoidal mirror 1, and 8 is an ellipsoidal mirror. A rod-shaped sample is placed on the long axis at the second focal point of 1, and 14 is a window opened at the contact point of the waveguide 6 and the ellipsoidal mirror 1. 18 is a furnace tube made of a cylindrical quartz tube that houses the sample 8, 19 is a motor for rotating the sample 8 attached to the end of the furnace core tube 18, and 20 is the sample 8
A moving device 21 is a radiation thermometer that measures the temperature of the sample 8 through a temperature observation window 22, and the sample 8 is observed through a hole made in the ellipsoidal mirror 1. 23 is a control computer connected to the radiation thermometer 21 and the heating power source; 25 is a magnetron that is supplied with power from the heating power source 24 and emits high frequency waves; 26 is a gas cylinder for storing gas; 27 is a valve; and 28 is a flow rate regulator. , 26 to 29 constitute the atmosphere control device 32.

With this structure, crystals are produced by heating the sample 8 while adjusting the atmosphere with the flow rate regulator 28 and moving it while being rotated by the motor 19. In addition, the radiation thermometer 21 measures the temperature of the sample 8 at a wavelength around 0.9 microns to determine the temperature, and the heating power source is controlled by the control computer 23 to control the transmission of the magnetron 25 to determine the temperature of the sample 8. control to the value of At this time, the change in emissivity on the surface of the sample 8, which is a cause of error in temperature measurement, can be corrected by using a simple emissivity monitor.

Example 8. Next, another embodiment of the invention is shown in FIG. In the figure, reference numeral 10 refers to a cavity resonator 5 which is formed by bringing the open side peripheral edge of a cup-shaped radio wave shield into contact with the first focus side of the ellipsoidal mirror 1, and a disk-shaped plasma lamp 2 is placed inside the cavity resonator 5, which emits light. let In this case, the optimum light emission conditions of the lamp can be maintained regardless of the shape of the ellipsoidal mirror 1. All of the light is focused on the molten part 16 of the sample 8 and uniformly irradiated around it. Therefore, since the light collection efficiency is greatly improved, efficient heating can be achieved.

FIG. 18 is an external view of the configuration shown in FIG. 17 in an actual disk-type plasma image heating apparatus. Reference numeral 32 designates an atmosphere control device, which has an airtight structure with a sample handling door for exchanging the sample. Since it is configured in this way, it can be used for microgravity experiments in space such as the space shuttle.

[0037]

Since the present invention is constructed as described above, the emission spectrum can be selected from the ultraviolet region to the infrared region, so that a wide range of samples 8 can be heated. In particular, since it can be melted by image heating at wavelengths in the absorption band of glass, it is extremely effective for the space and terrestrial production of pure infrared glass, which dramatically improves the efficiency of fiber cables. In addition, in the production of laser crystals such as YIG, 2
Crystals with large diameters of centimeters or larger can be produced using the floating melt zone transfer method, making it possible to dramatically improve the performance of conventional crystals. In other words, if crystal impurities are completely controlled and a large aperture diameter free from crystal defects can be created, it will be possible to increase the output of the laser. As described above, this is an innovative device for producing materials, and can contribute to the production of new materials on the ground or in space.

Furthermore, as described above, since the light emitting shape of the disc-shaped plasma lamp 2 is disc-shaped, the temperature gradient of the sample 8 can be adjusted to be steeper or gentler by rotating the direction of the disc-shaped plasma lamp 2. , a heating region suitable for crystal growth can be selected. Therefore, high quality crystals without cracks can be obtained.

Furthermore, since the sample 8 can be heated uniformly, there is no need for much rotation, and crystal growth is possible with low speed rotation, so there is no need to stir the solution to a temperature, which has a good effect on crystal growth. In particular, it becomes possible to remove crystal bubbles in microgravity. In other words, bubbles can be moved outward by convection due to thermal gradients.

Furthermore, since electrodeless discharge is utilized, the life of the lamp is extremely long and can last for more than 10,000 hours, making it possible to provide a furnace with a life 100 times longer than conventional lamps. Furthermore, since the lamp is small and lightweight and the ellipsoidal mirror can be made small, the entire device can be constructed compactly, which is an extremely important advantage in space.

Furthermore, in another invention related to this invention, since the cavity resonator is cup-shaped, it is not affected by the shape and size of the ellipsoidal mirror, and the same disc-shaped plasma lamp can be used in various shapes. It can be made compatible with ellipsoidal mirrors. In addition, the shape and emission spectrum of the disc-shaped plasma lamp can be easily changed to suit the sample 8, making it a very effective means for processing materials.

Furthermore, in another invention, in addition to the above-mentioned effects, since the sample 8 is moved on the long axis of the ellipsoidal mirror, the light collection efficiency is high and the light distribution is extremely uniform.
Helps prevent crystal defects.

Furthermore, in another invention related to this invention, in addition to the above-mentioned effects, since the cavity resonator is cup-shaped, it is not affected by the shape and size of the ellipsoidal mirror, and the same disk-shaped plasma can be generated. The lamp can be adapted to ellipsoidal mirrors of various shapes. In addition, the shape and emission spectrum of the disc-shaped plasma lamp can be easily changed to suit the sample 8, making it a very effective means for processing materials.

Furthermore, in another invention, in addition to the above-mentioned effects, the temperature of the sample 8 can be measured via the reactor core tube.
temperature can be determined. Suppressing temperature fluctuations has the effect of preventing crystal defects and is therefore effective in producing high quality products.

Furthermore, in another invention related to this invention, in addition to the above-mentioned effects, since the cavity resonator is cup-shaped, it is not affected by the shape and size of the ellipsoidal mirror, and the same disk-shaped plasma can be generated. The lamp can be adapted to ellipsoidal mirrors of various shapes.

Furthermore, in another invention, in addition to the above-mentioned effects, the temperature of the sample 8 can be made uniform, and further suppressing temperature fluctuations has the effect of preventing crystal defects, which is effective in producing high quality products. be.

In addition to the above-mentioned effects, in another invention related to this invention, since the cavity resonator is cup-shaped, it is not affected by the shape and size of the ellipsoidal mirror, and the same disk-shaped plasma can be generated. The lamp can be adapted to ellipsoidal mirrors of various shapes.

[0048] In the above explanation, the shape of the disc-shaped plasma lamp was limited to a disc-shape, but this shape can be set to any shape such as a sphere, cylinder, oval, ellipsoid, cube, or triangular pyramid. Each has its own effect.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating the configuration of a disk-shaped plasma lamp.

FIG. 3 is an analysis result of the light intensity distribution on the surface of the sample.

FIG. 4 is data from a heating experiment.

FIG. 5 is an analysis result of the maximum temperature reached.

FIG. 6 is a diagram showing the emission spectrum of a disc-shaped plasma lamp.

FIG. 7 is a diagram showing the shape of a solid solution layer boundary surface in a conventional floating melt zone movement method.

FIG. 8 is a diagram showing the shape of a solid solution layer boundary surface in the floating melt zone movement method of the present invention.

FIG. 9 is a sectional view showing another embodiment of the invention.

FIG. 10 is a diagram illustrating the configuration of a disk-shaped plasma lamp according to another invention.

FIG. 11 is a block diagram showing the configuration of yet another embodiment of the invention.

FIG. 12 is a block diagram showing the configuration of yet another embodiment of the invention.

FIG. 13 is a diagram showing the distribution of light when the sample is placed on the long axis.

FIG. 14 is a block diagram showing the configuration of yet another embodiment of the invention.

FIG. 15 is a block diagram showing the configuration of yet another embodiment of the invention.

FIG. 16 is a block diagram showing the configuration of yet another embodiment of the invention.

FIG. 17 is a block diagram showing the configuration of yet another embodiment of the invention.

FIG. 18 is a configuration external view of an embodiment of another invention.

FIG. 19 is a block diagram showing the configuration of a conventional disk-type plasma image heating device.

[Explanation of symbols]

1 Ellipsoidal mirror 2 Disc-shaped plasma lamp 3 Support equipment 4 Radio wave shielding plate 5 Cavity resonator 6 Waveguide 7 High frequency oscillator 8 Sample 9. Light 10 Cup-shaped radio wave shielding plate 11 xenon lamp 12 Power supply 13 Wire 14 Window 15 Rotating tool 16 Melting part 17 Solid solution layer interface 18 Furnace core tube 19 Motor 20 Mobile device 21 Radiation thermometer 22 Temperature observation window 23 Control computer 24 Heating power supply 25 Magnetron 26 Gas cylinder 27 Valve 28 Flow regulator 29 Vacuum pump 30 Screen 31　Sample operation door 32 Atmosphere control device

Claims (5)

[Claims] 1. An ellipsoidal mirror having an ellipsoidal reflective surface inside and one sample insertion hole provided at its second focal point side end with the long axis as the center; 1st
a disk-shaped plasma lamp placed at the focal point, and a first focal point side end of the ellipsoidal mirror that houses the plasma lamp;
A disk-shaped plasma image characterized by comprising a bowl-shaped cavity resonator formed by a radio wave shielding plate attached to the inner surface, and a high-frequency oscillator that injects microwave power into the cavity resonator. heating device. 2. An ellipsoidal mirror having an ellipsoidal reflective surface on the inside and one sample insertion hole provided at the end on the second focal point side centered on the long axis; 1st
a disk-shaped plasma lamp placed at the focal point, and a first focal point side end of the ellipsoidal mirror that houses the plasma lamp;
A disk-shaped plasma image characterized by comprising a cavity resonator formed by a cup-shaped radio wave shield attached to the inner surface thereof, and a high-frequency oscillator that injects microwave power into the cavity resonator. heating device. 3. A rotating device that grips and rotates the sample at the end of the sample inserted into the sample insertion hole in the longitudinal direction, a moving device that moves the sample in the longitudinal direction, and a reactor core tube that houses the sample. , an atmosphere control device connected to the reactor core tube, a radiation thermometer placed facing the sample, and a control device connected to the radiation thermometer and a heating power source. 3. The disc-shaped plasma image heating device according to item 1 or 2. 4. An ellipsoidal mirror having an ellipsoidal reflective surface inside, a disk-shaped plasma lamp placed at the first focal point of the ellipsoidal mirror, and a disk-shaped plasma lamp placed at the first focal point of the ellipsoidal mirror; The ellipsoid is provided with a bowl-shaped cavity resonator formed by a radio wave shielding plate attached to the inner surface thereof at the focal point side end, and a high frequency oscillator for injecting microwave power into the cavity resonator. In a disk-shaped plasma image heating device having two sample insertion holes formed at the second focal point side end of the mirror around a perpendicular to the long axis passing through the second focal point,
A rotating device that grips and rotates the sample at the end of the sample inserted into the sample insertion hole in the short axis direction, a moving device that moves the sample in the short axis direction, a reactor core tube that stores the sample, and this reactor core tube. A disk-shaped plasma image heating device characterized by comprising an atmosphere control device connected to the sample, a radiation thermometer placed facing the sample, and a control device connected to the radiation thermometer and a heating power source. . 5. An ellipsoidal mirror having an ellipsoidal reflective surface inside, a disk-shaped plasma lamp placed at the first focal point of the ellipsoidal mirror, and a disk-shaped plasma lamp that houses the plasma lamp and is located at the first focal point of the ellipsoidal mirror. The ellipsoid is provided with a cavity resonator formed of a cup-shaped radio wave shielder attached to the inner surface of the focal-side end, and a high-frequency oscillator for injecting microwave power into the cavity resonator. In a disk-type plasma image heating device having two sample insertion holes drilled at the second focal point side end of the mirror centered on a perpendicular line to the long axis passing through the second focal point, the sample insertion holes are inserted into the sample insertion holes in the short axis direction. A rotating device that grips and rotates the sample at the end of the sample, a moving device that moves the sample in the short axis direction, a reactor core tube that stores the sample, an atmosphere control device connected to the reactor core tube, 1. A disk-shaped plasma image heating device comprising: a radiation thermometer placed opposite to the heating source; and a control device to which the radiation thermometer and a heating power source are connected.