JP3412853B2 - Semiconductor crystal manufacturing equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing semiconductor crystals, and more particularly to an apparatus for producing semiconductor crystals by a solution growth method.

[0002]

2. Description of the Related Art As a method of growing a bulk crystal of a semiconductor, a solution growth method is known in which a solute dissolved in a solvent is deposited to grow a crystal. This solution growth method includes a heater transfer method and a solvent transfer method.

Heater transfer method (THM: Travelli)
ng Heater Method) arranges the crystal raw material, the solvent that dissolves the crystal raw material, and the crystal that becomes the seed crystal in a straight line to locally heat the solvent, while slowly moving the heated portion toward the crystal raw material. In this method, the crystal raw material is sequentially dissolved in a solvent, and the crystal is sequentially deposited and grown on the seed crystal from the solvent.

Solvent transfer method (TSM: Travellin)
g Solvent Method) is a crystal raw material, a solvent that dissolves the crystal raw material, and a crystal that becomes a seed crystal are linearly arranged, and the crystal raw material side has a higher temperature, the seed crystal side has a lower temperature, and the solvent layer portion is steep. While heating so as to obtain a temperature gradient, the position of the steep temperature distribution is slowly moved in the direction of the crystal raw material, the crystal raw material is sequentially dissolved in the solvent, and the crystal is sequentially deposited and grown on the seed crystal from the solvent. It is a method of producing crystals.

The heater transfer method and the solvent transfer method do not use the process of heating the crystal raw material to the melting point and solidifying it from the molten state unlike the melt growth method, and the heating temperature is set to the melting point of the crystal raw material or less. Using a substance having a melting point lower than the melting point of the raw material as a solvent, dissolving the crystal raw material on the high temperature side of this solvent, and precipitating the crystal from the low temperature side of the solvent, the point of growing the crystal by the dissolution / precipitation process Therefore, it is basically different from the melt growth method.

Due to such characteristics, the heater transfer method and the solvent transfer method have a high melting point material which has a high melting point and is not easily heated, a material which is not melted and sublimes when heated, and has a high equilibrium vapor pressure and easily volatilizes. It has an advantage that crystals can be easily produced even from a raw material containing an element.

In most cases, the growth of crystals composed of multiple components is so-called growth in which there is no so-called congruent melt in which the compositions of the liquid phase and the solid phase in thermodynamic equilibrium are the same. In the case of such growth from a non-congruent melt, the precipitation of crystals causes a problem that the melt composition changes and the composition of the subsequently growing crystals changes.
The heater transfer method and the solvent transfer method are one of the solution growth methods of precipitating a solute dissolved in a solvent to perform crystal growth, and although the method is a method of growing from a non-congruent melt, Since the solid raw material is always present during the growth and the raw material crystals are dissolved as the growth progresses,
It is equipped with a mechanism in which a crystal that matches the composition of the raw material crystal grows automatically without changing the growth conditions according to the progress of growth. Therefore, it can be said that the heater transfer method and the solvent transfer method are growth methods particularly suitable for multi-component crystals, for example, solid solution crystals.

Binary compound semiconductor crystals, ie II
In the IV group compound semiconductor and the II-VI group compound semiconductor,
It is known that solid solutions are formed in a wide range between homologous compounds. This solid solution is generally called a mixed crystal. The lattice constants and forbidden band widths of these mixed crystal have properties that they are approximately averages of the lattice constants and forbidden band widths of the original binary crystal, respectively. A heterojunction is manufactured by laminating several mixed crystal semiconductor thin film crystals having substantially the same lattice constant and different forbidden band widths on a substrate crystal.

Utilizing the effect obtained from this heterojunction, various optical semiconductor devices such as semiconductor lasers, light emitting diodes, and photodiodes, various semiconductor devices such as bipolar transistors and field effect transistors operating at ultrahigh speed, Semiconductor sensors have been manufactured. However, the mixed crystal semiconductor crystals forming these heterojunctions are
Although a thin film crystal could be grown, a bulk crystal having a large diameter and long enough to be used as a substrate crystal could not be grown.

A bulk single crystal that has been industrially produced and used as a substrate crystal for manufacturing a semiconductor device is S
i, Ge, elemental semiconductors, GaAs, InAs,
It is a binary compound semiconductor such as GaP or InP. Each of these has been manufactured by the melt growth method represented by the Czochralski method and the Bridgman method. In each case, a seed crystal is immersed in a melt of a crystal raw material to grow the crystal. However, these melt-growing methods, which should be called established techniques, can produce bulk single crystals of elemental semiconductors and binary compound semiconductors, but bulk bulk crystals of ternary or higher compound semiconductors that are solid solutions of binary compounds. Crystals have hitherto not been able to be produced.

As described above, the reason why bulk single crystals of ternary or higher compound semiconductors cannot be produced by the melt growth method is that the binary compound semiconductor growth technique, which has been completed by the growth from the congruent melt, is used as it is for the non-congruent process. This is because even if it is applied to the crystal growth of a ternary or higher compound semiconductor that can only take the growth state from the luent melt, a problem occurs. This is considered to be largely because it is not possible to take effective measures against various problems caused by changes in melt composition due to growth and changes in composition of grown crystals.

On the other hand, the heater transfer method and the solvent transfer method are growth methods in which composition control is automatically realized, and are growth methods suitable for growing ternary or higher compound semiconductors. However, nevertheless, it has been impossible to grow a large bulk single crystal by the heater transfer method and the solvent transfer method.

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problem that a bulk single crystal of a mixed crystal semiconductor could not be manufactured by the heater transfer method and the solvent transfer method, and the heater transfer method and the solvent transfer method have been solved. To provide an apparatus for producing a bulk single crystal of a mixed crystal semiconductor.

[0014]

Manufacturing of the semiconductor device of the present invention, in order to solve the problems]
Forming apparatus, the seed crystal, the solvent layer in the container, and to growth sample crystalline material formed by arranging accommodated linearly crystal raw material is high-temperature side, the low-temperature side is the seed crystal, the solvent layer is temperature transition region or performing heating so as to be positioned, or means performing localized heating to the solvent layer, and semiconductors comprising means Ru is sequentially moved to the temperature transition region or localized heating position in the crystal raw material side
An apparatus manufacturing apparatus , wherein the container holds the seed crystal.
And the space for containing the crystal raw material is connected.
It is characterized by having a pipe line .

The semiconductor device manufacturing apparatus of the present invention is
The seed crystal, the solvent layer, and the growth sample in which the crystal raw material is linearly arranged and housed in the container are arranged so that the crystal raw material is on the high temperature side, the seed crystal is on the low temperature side, and the solvent layer is on the temperature transition region. Manufacturing of semiconductor device provided with means for performing heating or for locally heating the solvent layer, and means for sequentially moving the temperature transition region or local heating position to the crystal raw material side
A device , wherein the container comprises the seed crystal, a solvent layer, and
An inner container that contains the crystal raw material, and an outer container that surrounds this inner container
Has a double structure consisting of a side container, the inner container and the outer
Through the space between the container and the seed in the inner container
The space for storing the crystal and the space for storing the crystal raw material
It is characterized by being connected .

In the present invention, the gas occupying the space inside the container is preferably one that does not form a compound with the solvent and solute contained in the solvent layer. As such a gas, any one of He, Ne, Ar, Kr, Xe, hydrogen gas, nitrogen gas, or a mixed gas thereof can be used.

In the present invention, as means for making the pressures of the gas occupying the space inside the container around the seed crystal and the space inside the container around the raw material crystals substantially equal, the following specific means are mentioned. I can.

(1) The container is made of a material in which the container and the solvent layer are not wet, or the inner surface of the container is coated with a material in which the container and the solvent layer are not wet, or the inner surface of the container is roughened. Thus, the space inside the container surrounding the seed crystal and the space inside the container surrounding the crystal raw material are communicated with each other through a slight space formed between the solvent layer and the inner surface of the container. (2) The container structure surrounding the seed crystal and the container internal space surrounding the crystal raw material are connected to each other.

(3) The container is doubled, and the space between the seed crystal and the inner container and the space between the crystal raw material and the inner container are connected to each other by the space inside the outer container. .

(4) The pressure in the space between the seed crystal and the container in the container and the pressure in the space between the crystal raw material and the container are detected, and the pressures in the two spaces are adjusted to be substantially equal. To have means.

(5) Means for keeping the temperature of the space between the seed crystal in the container and the container and the container holding portion of the space between the crystal raw material and the container at a constant temperature are provided, and the temperatures of the two spaces are substantially maintained. Be equal to each other.

(6) The volume of the space inside the container where the temperature of the space between the container and the seed crystal is constant is set larger than that of the space between the container and the seed crystal, and The volume of the space inside the container, which is made constant, should be made larger than the volume of the gap between the container and the crystal raw material.

(7) Means for independently controlling the temperature of either or both of the space inside the container connected to the space between the container and the seed crystal, the space inside the container connected to the space between the container and the crystal raw material, and the solvent layer during growth. And means for monitoring bubbles in
According to the generation or growth of bubbles in the solvent layer detected, the temperature of the space inside the container is adjusted to control the bubbles.

(8) A means for controlling the pressure in the space between the seed crystal in the container and the container, the space between the crystal raw material and the container, or both, and the bubbles in the growing solvent layer. A means for monitoring, adjusting the pressure in the space in the container according to the detected bubble generation or bubble growth state of the solvent layer to control the bubbles.

[0025]

In general, a grown crystal has growth fringes caused by temporal fluctuations of incorporation of impurities into the crystal. The cross section of the crystal grown by the conventional heater transfer method and solvent transfer method was etched with an etching solution such that the etching rate depends on the impurity concentration, and when the growth stripes were observed, the curves were intricately entangled and The interval was changing greatly.

The growth fringes show how the growth interface changed moment by moment during crystal growth.
The complicated growth fringes found when the heater transfer method and the solvent transfer method are used means that the shape of the solid-liquid interface on the seed crystal side changes intricately during the growth. Further, the fact that the intervals of the growth stripes fluctuate means that the growth rate fluctuates greatly.

Such a complicated variation of the solid-liquid interface prevents the grown crystal from being correctly oriented with respect to the underlying crystal, and causes a planar crystal defect such as a twin crystal. It is presumed that this is the reason why crystals grown by the heater transfer method and the solvent transfer method have not become single crystals until now. Since the complicated variation of the shape of the solid-liquid interface between the seed crystal and the solvent layer during growth occurs even when using a growth apparatus in which the heating temperature is sufficiently controlled, it cannot be considered that the growth apparatus is the cause.

On the other hand, as a result of examining the sample grown by the heater transfer method and the solvent transfer method, it was found that air bubbles were taken into the solidified solvent layer portion. Also, if the container is made of transparent quartz glass and grown in a state where the surface condition of the sample inside the container can be observed, bubbles are generated in the molten solvent layer, and the state of the bubbles changes momentarily, It was found to grow into large bubbles over time. From these observations, it was confirmed that bubbles were present in the solvent layer during heating.

The heater transfer method and the solvent transfer method are solution growth methods and have a slower growth rate than the melt growth method. Although the crystal growth rate by the solution growth method increases in proportion to the solute concentration, there is a limit to increase the solute concentration in the solvent. For this reason, in the solution growth method, in order to increase the crystal growth rate, the thickness of the solvent layer is made as thin as possible, and especially in the case of the solvent transfer method, heating that realizes a steep stepwise temperature distribution is realized. On the other hand, in the case of the heat transfer method, heating is carried out so as to realize local heating with a width as narrow as possible in order to realize a temperature distribution as steep as possible.

On the other hand, in order to obtain a crystal having a diameter as large as possible with a thin solvent layer, it is necessary to realize uniform growth in the radial direction, and the growth sample axis is arranged parallel to the direction of gravity. It is necessary to grow in.

In order to achieve the above growth sample morphology and sample arrangement, in the solvent transfer method and the heater transfer method, a large temperature distribution is formed in the up and down direction of the solvent layer, and remarkable natural convection occurs in the solvent layer. Occur. This natural convection has a great influence on the transport of the solute dissolved on the raw material crystal side, that is, the crystal component to the seed crystal side.

Bubbles generated in the solvent layer adhere to the container wall. The bubbles once generated and attached to the container wall are extremely difficult to remove. When the bubbles adhere to the container wall, the shape of the solvent layer changes, and a new free surface is formed on the solvent layer. Such a change changes the heat conduction state between the solvent layer and the container wall, and changes the temperature distribution. Changes in the shape of the solvent layer and changes in the temperature distribution due to the adhesion of bubbles cause irregular changes in the natural convection pattern, and the formation of the free surface causes another type of convection called Marangoni convection. .

For this reason, when bubbles are generated, the temperature distribution is irregularly changed, and the material transport process due to natural convection is also irregularly changed, so that the solid-liquid interface shape and the crystal growth rate are irregularly changed. It is considered that the complicated growth fringes of the conventional crystal grown by the solvent transfer method or the heater transfer method are caused by such bubble generation. Therefore, it was found that it is necessary to suppress the generation of bubbles in the solvent layer in order to prevent the growth in the polycrystalline state.

As a result of advancing the growth experiments by the solvent transfer method and the heater transfer method, it was found that there are various causes for generating bubbles in the solvent layer. One is due to an adsorbed gas component such as moisture generated at the time of heating from a sample holding member such as graphite used when loading the sample into the sealed container. When heated to near the growth temperature, the gas component generated from the sample holding member penetrates into the solvent layer through the gap between the tube wall of the sealed container and the sample to form bubbles. In order to reduce the bubbles generated in this way, it is considered effective to subject the sample holding member to a high-temperature vacuum heat treatment at a temperature sufficiently higher than the crystal growth temperature in advance. It is difficult to prevent the generation of various adsorbed gas components in terms of work.

In addition to the high temperature vacuum heat treatment of the sample holding member, use of a material that is dense and emits little gas as the sample holding member. After loading the sample and the sample holding member in the sealed container,
Before sealing, the sample portion is heated from the outside of the container while the sample portion is being cooled, and degassing from the sample holding member is performed while preventing the sample from changing. It is effective in suppressing the generation of bubbles inside.

In the case of manufacturing a multi-dimensional semiconductor crystal by a solvent transfer method or a heater transfer method, a solvent material is a metal material. It was found that the metallic material also melts and generates some bubbles when heated to the growth temperature. This bubble is considered to be a low boiling point impurity in the metal material or an oxide of the metal material. In order to suppress the generation of bubbles from the metallic material that is the solvent member, before encapsulating the encapsulated metallic material, it is necessary to melt and heat it in advance and perform high-temperature vacuum heat treatment until low boiling point impurities and evaporation of the metallic material oxide are not observed It is effective to load a high temperature vacuum heat-treated metallic material into a growth sample container.

Many of the multi-component compound semiconductor crystals have a non-negligible equilibrium vapor pressure at the growth temperature and evaporate from the solvent layer. In particular, when the group II, V, or VI element is included, the evaporation of the components becomes remarkable. In the heater transfer method and solvent transfer method,
When the solvent layer portion is heated, the crystalline component is dissolved in the solvent layer and the solute concentration increases. As the temperature of the solvent layer rises, the equilibrium vapor pressure of the solvent layer rises.However, in the case of a material in which the solute component is highly volatile, the equilibrium vapor pressure of the solvent layer part increases significantly with the temperature rise of the solvent layer. Become. When the equilibrium vapor pressure of the solvent layer becomes higher than the total pressure of the gas phase in the space surrounding the solvent layer, bubbles are formed in the solvent layer, and a phenomenon in which the solvent containing a solute is vigorously evaporated occurs in the bubbles. This is a kind of boiling phenomenon.

When the growth sample consisting of the seed crystal, the solvent layer and the crystal raw material is in the container, the solvent layer is in contact with the container wall. For this reason, the generated bubbles do not simply stop as bubbles, but as a result of expansion, the solvent is extruded into the gap between the seed crystal and the container or the gap between the crystal raw material and the container. In the worst case, the solvent layer disappears from the space where it should originally exist, and even a phenomenon occurs in which the seed crystal and the raw material crystal are separated.

The phenomenon that the solvent seeps out from the solvent layer portion into the gap between the seed crystal and the container or the gap between the crystal raw material and the container occurs only by the solvent transfer method and the heater transfer method. Not only because it contains components that easily evaporate. Even in the case of melt growth, the melt portion may contain a component that easily evaporates. However, in this case, even if the melt is about to ooze out due to the growth of bubbles, the oozeed melt solidifies in the low temperature part immediately ahead,
The effect of suppressing further bleeding of the melt is produced. In the heater transfer method and solvent transfer method, the liquid that exudes is a solvent, so even if the exuding point is a low temperature part, only the crystalline component solidifies from the exuding solvent, and the melting point is lower than the crystalline component. The solvent remains liquid. Therefore, in the heater transfer method or the solvent transfer method, remarkable oozing of the solvent occurs.

It was confirmed that the generation of bubbles due to the increase in the vapor pressure of the solute component from the solvent layer can be prevented by introducing gas into the container and increasing the total pressure in the container. In order for the solute components to evaporate and bubbles to form in the solvent layer, it is necessary that at least the equilibrium vapor pressure of the solvent containing the solute be equal to or higher than the pressure applied to the solvent layer. If this condition is not met, bubbles cannot grow. In this case, the equilibrium vapor pressure depends on the solute component and the growth temperature.

As a method of increasing the equilibrium vapor pressure of the solvent containing the solute to be equal to or higher than the pressure applied to the solvent layer, enclosing the gas in the container and introducing the gas into the container during the growth can be mentioned. Thus, if the gas is enclosed in the container, the temperature rises as the sample is heated, and the pressure of the enclosed gas also rises. The pressure of the gas introduced during the growth can be determined in consideration of the equilibrium vapor pressure of the solvent containing the solute at the growth temperature and the pressure change of the gas in the container.

The gas introduced into such a container needs to have a low reactivity with the sample and the container. When reacting, not only is it taken in as an impurity in the grown crystal, but the amount of enclosed gas decreases with the passage of time, the gas pressure decreases, and the bubble generation suppressing effect is lost. For many samples, He, Ne,
A rare gas such as Ar, Kr, or Xe, hydrogen gas, nitrogen gas, or the like is suitable as the enclosed or introduced gas.

When gas was sealed in the container, another kind of bubble generation phenomenon was observed in which bubbles were injected into the solvent layer from the seed crystal side or the crystal raw material side. This is the average temperature of the two spaces when the gas enclosed in the space inside the two containers sandwiching the solvent layer, that is, the seed crystal side space and the two spaces on the crystal raw material side expands due to heating. This is because if either of them is different, the pressure of either one becomes higher, and the enclosed gas may enter the solvent layer as bubbles from the side where the pressure becomes higher.

The bubbles generated by the pressure imbalance of the enclosed gas can be reduced by using a container structure in which two spaces, the seed crystal side space and the crystal raw material side space, are connected to each other. One of the container structures that connects the two spaces of the seed crystal side space and the crystal raw material side space to each other is a double container for the sample enclosure, and the seed container, the solvent layer, and the raw material crystal are loaded in the inner container, This is a structure in which the container is inserted into the outer container. With such a structure, it is possible to prevent bubbles from being generated due to a gas pressure imbalance in the sealed container.

Further, by controlling the temperature of the sample holding portion to be the same on the seed crystal side and the raw material crystal side, the gas pressure occupying the space on the seed crystal side and the raw material crystal side is set to the temperature of the sample holding portion. Is almost determined by the above, and the generation of bubbles can be reduced. Also, by taking a large space between the seed crystal side and the raw material crystal side, even if the temperature near the solvent layer changes,
Since the pressure change due to the temperature change is absorbed by the space, bubble generation can be reduced.

A method of manufacturing the container with a material having poor wetting with the solvent layer, or coating the inner surface of the container with a material having poor wetting with the solvent layer, or making the inner surface of the container a rough surface,
This is effective in preventing bubbles from being injected from the seed crystal side space or the raw material crystal side space. In this way, by realizing a poor wetting condition between the inner surface of the container that contacts the solvent layer and the solvent layer, the seed crystal side space and the raw material crystal side space are connected through a slight space on the surface of the solvent layer, and both spaces are connected. It is presumed that the bubbles are prevented from being injected from the seed crystal side space and the raw material crystal side space as a result of the pressures of 2) being balanced.

In addition to the above-mentioned methods, the pressure in the two spaces on the seed crystal side and the raw material crystal side is detected, and a positive control is performed by injecting or sucking gas so that the pressures in both spaces are equal. Also, the phenomenon that bubbles are injected into the solvent layer from the seed crystal side space or the raw material crystal side space can be prevented.

As control data, image data obtained by directly monitoring the bubble generation state in the solvent layer is also effective for precise control of bubble generation. When the container is an optically transparent material, it is possible to easily monitor the bubble generation state directly by visual observation or by a normal image taken by a TV camera, and when the container is opaque, the heated container is used. By appropriately selecting the wavelength of the electromagnetic wave emitted from the container and obtaining the distribution image of the radiation intensity on the container surface, it is possible to recognize the bubble generation and the generation site. Based on the direct monitoring data of these bubbles, the temperature of either or both of the seed crystal side space and the raw material crystal side space of the sample container in which the gas is sealed is changed, and the seed crystal side space and the raw material crystal side space are changed. A method of balancing the pressure, or a method of balancing the gas pressure by directly changing the gas pressure of the seed crystal side space or the raw material crystal side space in the container by injecting or sucking the gas. It is possible to prevent air bubbles from being injected into the solvent.

[0049]

EXAMPLES Examples in which the present invention is applied to the production of a single crystal of InGaP mixed crystal semiconductor will be described below with reference to the drawings. First, an example in which the present invention is applied to the production of a single crystal by the solvent transfer method will be described.

FIG. 1 shows InG according to one embodiment of the present invention.
It is a sample for manufacturing a single crystal of an aP mixed crystal semiconductor. <100>
Orientation GaP seed crystal 11, average composition is In _0.1 Ga
_0.9 P raw material polycrystal 13 and In with 85% In composition
The solvent layer 12 made of Ga alloy is housed in an inner cylindrical container 14 made of quartz glass, and both ends of the inner cylindrical container 14 are closed by graphite sample holding members 15 and 16. The inner cylindrical container 14 is enclosed in an outer cylindrical container 17 made of quartz glass.

Sample holding members 15 and 16 made of graphite
Does not seal the inner tubular container 14, but a small gap 18 existing between the inner tubular container 14 and the GaP seed crystal 11 and a large amount of raw material of the inner tubular container 14 and In _0.1 Ga _0.9 P. The slight gap 19 existing between the crystal 13 and
They are connected to each other through a slight gap between the inner cylindrical container 14 and the sample holding members 15 and 16 and a slight gap between the sample holding members 15 and 16 and the outer cylindrical container 17.

The sample holding members 15 and 16 are made of high density graphite having a bulk specific gravity of 2.0 or more, and the surface thereof is coated with pyrolytic graphite. When the growth sample shown in FIG. 1 is manufactured, the sample holding members 15 and 16 are vacuum heat-treated in advance at a vacuum degree of 10 ⁻⁶ Torr or higher and a high temperature of 1200 ° C. or higher to form the InGa alloy forming the solvent layer 12. No. 13 is also vacuum heat-treated at a high temperature of 700 ° C. or higher under a high vacuum of 10 ⁻⁶ Torr or higher in a quartz glass container.

On the other hand, GaP seed crystal 11, In _0.1 Ga
_The inner cylindrical container 14 containing the _0.9 P raw material polycrystal 13 and the InGa alloy solvent layer 12 is replaced with the outer cylindrical container 1 before sealing.
7 is loaded in an inert atmosphere, and the loaded outer cylindrical container 17 is attached to a vacuum sealing device. That is, after the inside of the outer cylindrical container 17 is vacuum-sucked, Ar gas is injected and sealed. The pressure of Ar gas injected into the outer cylindrical container 17 was 1 atm.

FIG. 2 shows a state in which the growth sample enclosed in the inner and outer quartz glass containers shown in FIG. 1 is heated using a two-temperature furnace 20 and crystal growth is performed by the solvent transfer method. Is. The sample was mounted with the sample axis parallel to gravity so that the solvent portion was located in the temperature transition region and the seed crystal was located below.

After the sample was set, the temperature was raised to 970 ° C. on the seed crystal side and 1020 ° C. on the crystal raw material side over 1 hour, and this state was maintained for 1 hour.
It was moved at a speed of m / hr for 100 hours and quenched. The temperature gradient in the temperature transition region was 30 ° C./cm.

The state of the sample during crystal growth was monitored by the television camera 21 through the sample observation window attached to the two-temperature furnace 20, and the solvent layer seen through the quartz glass container showed
No air bubbles were found. The length of the crystal grown in the above process is about 50 mm, and the mixed crystal composition of the crystal is approximately constant from the seed crystal boundary to the growth tail.
It was _0.1 Ga _0.9 P. In addition, the entire grown crystal was a single crystal.

FIG. 3 shows a growth sample used in another embodiment of the present invention. In this sample, a quartz glass cylindrical container 37 having an inner surface coated with a boron nitride film 40 was used in place of the double container, and a Kr gas was sealed in the container. It is similar to the sample shown in. That is, <1
00> orientation GaP seed crystal 31, average composition is In _0.1
Ga _0.9 P raw material polycrystal 33, In composition 85% In
Solvent layer 32 made of Ga alloy, and graphite sample holding members 35, 3 supporting the seed crystal 31 and the solvent layer 32.
6 is accommodated in the cylindrical container 37.

When crystals were grown by the solvent transfer method using the sample shown in FIG. 3 under the same conditions as in the first embodiment, bubbles were still observed in the solvent layer observed during the growth. There wasn't. Also in the case of this example, an In _0.1 Ga _0.9 P single crystal similar to that of the first example was obtained. This is because the boron nitride film 40 and the solvent layer 32 composed of In, Ga and P do not have good wetting, so that a narrow gap is created between the two and the seed crystal side space and the source crystal side space are separated from each other. This is because they are communicated with each other and the gas pressures are substantially equal.

FIG. 4 is a diagram showing a growth sample used in another embodiment of the present invention. In the sample container in this case, the inner surface of the cylindrical container 47 is covered with a boron nitride film, but the seed crystal side space 48 and the raw material crystal side space 49 are connected by a connecting pipe 50 outside the container. The sample is the same as the sample shown in FIG.

In the sample shown in FIG. 4, the connecting pipe 50
The gas pressures of the seed crystal side space 48 and the raw material crystal side space 49 are substantially equal to each other. In the case of this embodiment as well, under the same crystal growth conditions as in the first embodiment, In _0.1 Ga _0.9 P
We were able to grow a single crystal.

FIG. 5 shows I used in another embodiment of the present invention.
n is a diagram showing a _0.1 Ga _0.9 P mixed single crystal manufacturing apparatus.
In this apparatus, the gas introduction port 6 is provided in the seed crystal side space 58 and the raw material crystal side space 59 of the quartz glass sample cylindrical container 51.
0 and 61 are provided, the state of the solvent layer is monitored by the television camera 71 and the television monitor 72 on the side wall of the two-temperature heating furnace 70, and the gas introduction control valve 7 is operated according to the bubble generation state.
By operating 3, 74 and the gas suction control valves 75, 76, the bubbles generated in the solvent layer 62 are controlled. That is, according to the monitoring image 72 of the television camera 71, when bubbles are being injected into the solvent layer 62 from the crystal raw material 63 side, the gas introduction control valve 73 or the gas suction control valve 76 is opened and the crystal raw material 63 side is opened. When bubbles are being injected into the solvent layer 62, the gas introduction control valve 74 or the gas suction control valve 75.
Open and let the air bubbles disappear.

Further, the gas introduction control valves 73 and 74 and the gas suction control valves 75 and 76 are operated so that the gas pressures in the seed crystal side space 78 and the raw material crystal side space 79 are kept at 1 atm during the growth. Control was performed. The sample heating conditions are the same as those in the first embodiment, and as a result, In having a length of 50 mm can be obtained.
A mixed crystal single crystal of _0.1 Ga _0.9 P was obtained. The following examples are examples in which the present invention was applied to the production of single crystals by the heat transfer method.

FIG. 6 shows an example in which crystals are grown by a heater moving method using a growth sample enclosed in a quartz glass container and a focus heating furnace 23 having a halogen lamp as a light source according to the present invention. is there. FIG. 1 described above as a sample
Was used and the seed crystal was mounted vertically so that it was located below the sample. The initial heating position is set to the position of the solvent layer 12, and the lamp power value is increased over 1 hour to a lamp power value at which the thickness of the solvent layer during growth becomes 1.4 times the thickness of the solvent layer before heating, and the lamp power value is increased. Keep constant and after 3 hours holding time,
The heating position was moved to the raw material crystal side 13 side at a rate of 0.5 mm / hr, and after the furnace was moved for 100 hours, the lamp power was reduced over 2 hours to gradually cool the crystals to grow crystals. The estimated average temperature of the solvent layer at this lamp power setting condition is 1000 ° C.

The state of the sample during the crystal growth described above is observed through the sample observation window attached to the focus heating furnace 23 through the television camera 21.
No air bubbles were found in the solvent layer as seen through the quartz glass. The crystal length grown by the above process is about 50m.
It was m. The mixed crystal composition of the crystal was approximately constant from the seed crystal boundary to the growth tail and was In _0.1 Ga _0.9 P.
Moreover, the entire grown crystal was a single crystal.

When the crystal shown in FIG. 3 described above was used as a growth sample and crystal growth was carried out by the heater moving method under the same conditions as in the embodiment shown in FIG. 6, the solvent layer observed during the growth was also observed. No air bubbles were observed. Also in the case of this embodiment, In similar to the case of the embodiment shown in FIG.
_{A 0.1} Ga _0.9 P single crystal was obtained. This is because the boron nitride 40 and the solvent layer 32 made of In, Ga, P do not wet well, so that a narrow gap is created between the two, and the seed crystal side space and the source crystal side space communicate with each other, and This is because the pressures are substantially equal.

FIG. 7 shows a crystal growth state by a heater moving method according to another embodiment of the present invention. In this case as well, although the sample container is single, the seed crystal side 88 and the raw material crystal side 89 of the cylindrical container 87 are held by the supporting members 90 and 91 whose temperature is controlled to be constant, and growth is performed by the heater moving method. . Also in the case of this example, an In _0.1 Ga _0.9 P single crystal was grown as in the case of using the sample of FIG.

Using the sample shown in FIG. 4 described above, crystal growth was carried out by the heater transfer method under the same growth conditions as in the embodiment shown in FIG. 6, and an In _0.1 Ga _0.9 P single crystal was obtained.

FIG. 8 shows another embodiment of the present invention relating to the production of In _0.1 Ga _0.9 P mixed crystal single crystal. In this case,
Gas inlets 60 and 61 are provided in a seed crystal side space 58 and a raw material crystal side space 59 of a quartz glass sample container 51, and a TV camera 71 and a TV monitor 72 on a side wall of a focus heating furnace 70 are provided. The solvent layer state is monitored, and the gas introduction control valves 73 and 74 and the gas suction control valves 75 and 76 are operated according to the bubble generation state to control the bubbles generated in the solvent layer 52. That is, when air bubbles are being injected into the solvent layer 52 from the crystal raw material 53 side by the monitoring image 72 of the television camera 71, the gas introduction control valve 73 or the gas suction control valve 76 is opened and the crystal raw material 53 side is opened. When bubbles are being injected into the solvent layer 52, the gas introduction control valve 7
4, or the gas suction control valve 75 is opened to eliminate the bubbles. Further, the gas introduction control valves 73 and 74 and the gas suction control valves 75 and 76 are operated to perform control such that the gas pressures of the seed crystal side space 58 and the raw material crystal side space 59 always maintain 1 atm during growth. It was The sample heating conditions are the same as in the case of the embodiment shown in FIG. 6, whereby the In _0.1
A mixed crystal single crystal of Ga _0.9 P was obtained.

In each of the above examples, In _0.1 Ga _0.9
This is a case where the present invention is applied to the production of a P mixed crystal, even if it is not a mixed crystal and the values of the mixed crystal composition are different.
Alternatively, it is obvious that the present invention can be applied even if the semiconductor material is different, such as In _x Ga _{1 -x} As. The present invention relates to a semiconductor crystal containing an element that easily evaporates as a constituent element, for example, a compound containing a group II element such as Zn or Cd, a group VI element such as S, Se or Te, or a group V element such as N, P or As. The effect can be obtained even when various kinds of semiconductors are applied. As the gas to be sealed in the sample container, not only Ar and Kr gases but also rare gases such as He, Ne and Xe, hydrogen gas and nitrogen gas were effective. Not only quartz glass but also various materials such as alumina, graphite and boron nitride can be used as the container material. Also, the container coating material can be variously modified within the scope of the present invention in accordance with not only boron nitride but also other growth materials such as carbon.

When the solvent transfer method is used, the furnace used for growth does not necessarily have to be a two-temperature furnace, and may be a multi-temperature furnace. Further, a method of gradually cooling the furnace and moving the solvent layer in a furnace having a temperature gradient throughout the furnace may be used. The growth furnace can be variously modified within the scope of the present invention.

[0071]

As described above, according to the present invention,
It has become possible to grow a single crystal of a compound semiconductor, which has been difficult to manufacture by the solvent transfer method or the heater transfer method. In addition, bulk single crystals of mixed crystals of compound semiconductors, which have been difficult to grow by single crystals, can now be grown by the solvent transfer method and the heater transfer method. As a result, a semiconductor diode having a specific forbidden band and a specific lattice constant could not be manufactured because it could only be used as a substrate.
Optical amplifiers and photodetectors can now be manufactured. In this respect, the industrial value of the present invention is great.

[Brief description of drawings]

FIG. 1 is a sectional view showing a growth sample used in one embodiment of the present invention.

FIG. 2 is a diagram showing a crystal growth apparatus used in one embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a growth sample used in another embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a growth sample used in another embodiment of the present invention.

FIG. 5 is a diagram showing a crystal growth apparatus used in another embodiment of the present invention.

FIG. 6 is a diagram showing a crystal growth apparatus used in another embodiment of the present invention.

FIG. 7 is a diagram showing a crystal growth apparatus used in another embodiment of the present invention.

FIG. 8 is a diagram showing a crystal growth apparatus used in another embodiment of the present invention.

[Description of Reference Signs] 11, 31, 41, 51 ... Seed crystal 12, 32, 42, 52 ... In _0.1 Ga _0.9 P alloy solvent layer 13, 33, 43, 53 ... InGa raw material polycrystal 14 ... Quartz glass inner cylinder Vessels 15, 16, 35, 36, 45, 46, 55, 56 ... Graphite sample holding members 17, 37, 47, 57 ... Quartz glass tubular vessels 18, 38, 48, 58 ... Vessels and GaP seed crystals Gap 19,39,49,59 ... Gap between container and In _0.1 Ga _0.9 P raw material polycrystal 20, 70 ... 2 Temperature furnace 21, 71 ... TV camera 22, 72 ... TV monitor 40 ... Boron nitride film 50 ... Connection pipes 60, 61 ... Gas introduction ports 73, 74 ... Gas introduction control valves 75, 76 ... Gas exhaust control valve 77 ... Ar gas supply device 78 ... Vacuum exhaust device

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A 64-37489 (JP, A) JP-A 4-97993 (JP, A) JP-A 5-139884 (JP, A) JP-A 2- 85500 (JP, A) JP-A-4-224188 (JP, A) JP-A-5-17280 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C30B 1/00-35 / 00

Claims (2)

(57) [Claims] 1. A growth sample in which a seed crystal, a solvent layer, and a crystal raw material are linearly arranged and housed in a container, the crystal raw material is at a high temperature side, the seed crystal is at a low temperature side, and the solvent layer is at a temperature transition region. In the apparatus for manufacturing a semiconductor device, which is provided with a means for performing heating so that the solvent layer is locally located, or a means for locally heating the solvent layer, and a means for sequentially moving the temperature transition region or the local heating position toward the crystal raw material side. The apparatus for producing a semiconductor crystal is characterized in that the container comprises a conduit for connecting a space for accommodating the seed crystal and a space for accommodating the crystal raw material. 2. A growth sample, in which a seed crystal, a solvent layer, and a crystal raw material are linearly arranged and housed in a container, the crystal raw material is on the high temperature side, the seed crystal is on the low temperature side, and the solvent layer is on the temperature transition region. In the apparatus for manufacturing a semiconductor device, which is provided with a means for performing heating so that the solvent layer is locally located, or a means for locally heating the solvent layer, and a means for sequentially moving the temperature transition region or the local heating position toward the crystal raw material side. The container has a double structure consisting of an inner container for accommodating the seed crystal, the solvent layer, and a crystal raw material, and an outer container surrounding the inner container, and a space between the inner container and the outer container. A space for accommodating the seed crystal in the inner container and a space for accommodating the crystal raw material are connected to each other through the through hole.