JPH07300666A - Production of molecular beam source for silicon evaporation and crucible used for the same - Google Patents

Abstract

PURPOSE:To produce a molecular beam source for silicon evaporation, which is unreactive to silicon of high reactivity or causes no melting even if it reacts with it and causes no deterioration in heat resistance, and a crucible used for it. CONSTITUTION:A crucible 22 for holding silicon consists of an outer crucible 22a formed of a refractory material having higher melting point than silicon and an inner crucible 22b provided to the inside of the outer crucible 22a and formed of silicon carbide or carbon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a molecular beam crystal growth apparatus (hereinafter referred to as M
The present invention relates to a molecular beam source (referred to as BE apparatus) and a method for manufacturing a crucible used for the molecular beam source, and particularly to improvement of a crucible suitable for evaporating highly reactive silicon as a molecular beam raw material.

[0002]

2. Description of the Related Art A molecular beam crystal growth method (hereinafter referred to as MBE method) irradiates a semiconductor substrate with a molecular beam emitted from a molecular beam source in a vacuum chamber to grow a semiconductor thin film crystal on the semiconductor substrate. It is a method to let. The MBE method is a method suitable for growing a crystal that requires a high degree of controllability, especially a steep heterojunction interface and a thin semiconductor crystal layer. The semiconductor thin film crystal grown by the MBE method provides a semiconductor device having excellent characteristics. , For example, high electron mobility transistors (HEM
T) is put to practical use.

FIG. 11 shows an example of a conventional MBE device.
In the ultra-high vacuum container 1, for example, a plurality of molecular beam sources 2, 3
Is installed. A desired molecular beam is emitted from the molecular beam sources 2 and 3, and a semiconductor thin film crystal is grown on a sample 4, which is a semiconductor substrate, for example, which is arranged at a position facing the molecular beam sources 2 and 3. The molecular beams emitted from the molecular beam sources 2 and 3 are interrupted intermittently by shutters 5 and 6 provided in the openings of the molecular beam sources 2 and 3, respectively, and their emission is controlled. Further, these molecular beam sources 2, 3, shutter 5,
6 is surrounded by a liquid nitrogen shroud 7 for keeping the inside of the vacuum container 1 at an ultrahigh vacuum.

FIG. 12 shows a cross-sectional view of the main part of the molecular beam source indicated by 2 (or 3) in FIG. Usually, the molecular beam source 2 (3) is provided with a molecular beam raw material 21, for example, a crucible 22 made of pyrolytic boron nitride (PBN) or tantalum (Ta), and is arranged on the outer periphery of the crucible 22. A heater 23 for heating the molecular beam raw material 21, a heat reflection plate 24 arranged so as to cover the outer periphery of the heater 23 for improving heating efficiency, and a temperature for monitoring the temperature of the molecular beam generating raw material 21. It is composed of a thermocouple 25.

By heating the molecular beam raw material 21 with the heater 23 through the crucible 22, molecules are injected into the vacuum container 1 through the opening 26 of the crucible 22. In addition, the opening 26
By opening and closing the shutter 5 arranged in the vicinity, the molecular beam can be emitted or blocked. The opening and closing of the shutter 5 is usually performed by rotating a shaft 51 that supports one end of the shutter 5. 27 in the figure
Is a lead wire for supplying electric power to the heater 23 from a power source (not shown).

By the way, in this type of MBE apparatus,
When, for example, silicon (Si) is evaporated as the molecular beam raw material 21, the crucible 22 with the shutter 5 closed.
Silicon, which is the molecular beam raw material 21, is housed therein, and the heater 23 is energized to heat it to a high temperature of about 1500 ° C. to melt the silicon. To start the growth, the shutter 5 is opened, and the evaporated silicon element is ejected into the vacuum through the opening 26 of the molecular beam source 2 to grow a silicon thin film on the sample 4.

[0007]

However, in the above-mentioned structure, the crucible 22 made of pyrolytic boron nitride, which has high heat resistance, is used. When a highly reactive substance that reacts with various pyrolytic boron nitrides is used, when the silicon is accommodated in the crucible 22 made of pyrolytic boron nitride and heated, the pyrolytic boron nitride and silicon react.

As a result, there is a disadvantage that a material other than silicon which constitutes the crucible 22 evaporates together with silicon and grows on the sample 4.

According to the experimental results of the inventor, when a sample piece on which silicon was grown as a molecular beam raw material was analyzed by Auger electron spectroscopy, nitrogen (N), which is a constituent material of the crucible other than silicon, was detected. .

As another example, the thickness is 1 mm.
Store silicon in a tantalum crucible of 1500 ℃
When heated for 30 minutes to generate molecular beams, a part of the wall surface of the crucible melts and bulges into a convex shape. If more molecular beams are generated, holes will open and it will not be possible to withstand use. confirmed.

Therefore, the present invention provides a molecular beam source for vaporizing silicon, which does not react with highly reactive silicon, or does not melt and does not deteriorate heat resistance even if it reacts, and a method for producing a crucible used therefor. Is the main purpose.

[0012]

To achieve the above object, the molecular beam source of the present invention is a crucible for containing silicon as a molecular beam raw material, and a crucible arranged around the crucible for heating the silicon. A heater, a heat reflection plate arranged on the outer periphery of the heater, and a thermocouple for monitoring the temperature of the silicon, the crucible, an outer crucible formed of a high melting point material having a melting point higher than silicon, It is characterized in that it comprises an inner crucible provided inside thereof and formed of silicon carbide.

Further, the molecular beam source of the present invention is a crucible for containing silicon as a molecular beam raw material, a heater arranged on the outer circumference of the crucible for heating the silicon, and a heater arranged on the outer circumference of the heater. And a thermocouple for monitoring the temperature of the silicon, wherein the crucible is made of a high melting point material having a melting point higher than that of silicon, and an outer crucible, and carbon provided inside the crucible. It is characterized by consisting of an inner crucible.

Further, the molecular beam source of the present invention includes a crucible for containing silicon as a molecular beam raw material, a heater arranged on the outer circumference of the crucible for heating the silicon, and a heater arranged on the outer circumference of the heater. And a thermocouple for monitoring the temperature of the silicon.The crucible has an outer crucible formed of a high melting point material having a melting point higher than that of silicon, and a pyrolytic graphite layered inside the crucible. It is characterized by comprising an inner crucible formed by coating on.

In the production method of the present invention, boron trichloride and ammonia are reacted under reduced pressure at high temperature by a vapor phase growth method,
A pyrolytic boron nitride film is grown on the outer side of a cylindrical crucible-shaped material, and then the crucible-shaped material is removed to form an outer crucible made of a pyrolytic boron nitride molded body, and then under high temperature and reduced pressure by a vapor phase growth method. It is characterized in that an aliphatic hydrocarbon is made to react and pyrolytic graphite is grown inside the outer crucible to integrally form an inner crucible made of a pyrolytic graphite layer.

Further, in the manufacturing method of the present invention, boron trichloride and ammonia are reacted at a high temperature and a reduced pressure by a vapor phase growth method to grow a pyrolytic boron nitride film on the outside of a cylindrical crucible-shaped material, and thereafter. After forming the outer crucible composed of a pyrolytic boron nitride molded body by removing the crucible-shaped material, the aliphatic hydrocarbon is reacted under a high temperature and reduced pressure by a vapor phase growth method, and inside the outer crucible, pyrolytic graphite is formed. An inner crucible made of a pyrolytic graphite layer is integrally formed by growing, and thereafter, silicon is accommodated in the inner crucible and heated in vacuum to react the pyrolytic graphite and the silicon forming the inner crucible with each other,
A silicon carbide layer is formed at an interface between the pyrolytic graphite layer and silicon.

[0017]

According to the above molecular beam source, the crucible itself is composed of the outer crucible and the inner crucible, and the outer crucible is made of a material having excellent mechanical strength and heat resistance. Is formed of silicon carbide, which is stable to highly reactive silicon, so that it does not react with the inner crucible when heated as a molecular beam source, and therefore the silicon reacts with the outer crucible. Can be prevented.

According to the above molecular beam source, the crucible itself is composed of the outer crucible and the inner crucible, and the outer crucible is made of a material having excellent mechanical strength and heat resistance. Since the inner crucible is made of carbon, silicon is put into the crucible as a molecular beam raw material and heated, and when this silicon is melted, carbon and silicon of the inner crucible react with each other, and the interface thereof has high reactivity. A silicon carbide layer that is stable with respect to silicon is formed, and further reaction is suppressed.
Therefore, it is possible to prevent the silicon from reacting with the outer crucible.

According to the above-mentioned molecular beam source, the crucible itself is composed of the outer crucible and the inner crucible, and the outer crucible is made of a material having excellent mechanical strength and heat resistance. Is formed integrally by coating pyrolytic graphite in layers inside the outer crucible, so when silicon is put into the crucible as a molecular beam raw material and heated, heat is transferred promptly, and the pyrolysis of the inner crucible is completed. Lytic graphite and silicon react with each other, a stable silicon carbide layer is formed at the interface with respect to highly reactive silicon, and further reaction is suppressed. Therefore, it is possible to prevent the silicon from reacting with the outer crucible.

Further, according to the above manufacturing method, the reaction between boron trichloride and ammonia under reduced pressure at high temperature in air,
A stable and dense pyrolytic boron nitride film grows on the outside of the cylindrical crucible material, and after removing the crucible material, an outer crucible composed of a pyrolytic boron nitride molded body can be formed, and then under high temperature and reduced pressure. At the inside of the outer crucible, pyrolytic graphite grows by the heating reaction of the aliphatic hydrocarbon, and the inner crucible composed of the pyrolytic graphite layer can be integrally formed.

Further, according to the above manufacturing method, a stable and dense pyrolytic boron nitride film grows on the outside of the cylindrical crucible-shaped material in the air by the reaction of boron trichloride and ammonia under reduced pressure at high temperature. Then, after removing the crucible shape material, an outer crucible composed of a pyrolytic boron nitride molded body can be formed, and thereafter, inside the outer crucible under a high temperature and reduced pressure, by a heating reaction of an aliphatic hydrocarbon, pyrolytic graphite is formed. Grow up,
An inner crucible composed of a dense pyrolytic graphite layer can be integrally formed, and thereafter, the silicon contained in the inner crucible and the pyrolytic graphite forming the inner crucible react with each other by heating in a vacuum to form the pyrolytic graphite. A silicon carbide layer stable to silicon is formed at the interface between the silicon and the silicon.

[0022]

【Example】

First Embodiment (see FIG. 1) FIG. 1 is a cross-sectional view of essential parts of a molecular beam source for silicon evaporation according to an embodiment of the present invention. It is to be noted that the portions denoted by the same reference numerals as those in the conventional example of FIGS. 11 and 12 indicate the same or corresponding portions. In the following, differences from the conventional example will be mainly described.

In this embodiment, the silicon evaporation molecular beam source 2 has a thickness of 0.5 mm to 5 m.
A double-structured crucible 22 is used which includes an outer crucible 22a having a size of about m and an inner crucible 22b having a thickness of about 10 μm to 1 mm, which is provided in close contact with the inner crucible 22a. The outer crucible 22a is formed by using a high melting point material having a melting point higher than that of silicon (Si) which is the molecular beam raw material 21. That is, since the melting point of silicon is 1412 ° C., for example, tantalum, molybdenum, tungsten or alloys thereof having a melting point of 1500 ° C. or higher,
Alternatively, pyrolytic boron nitride (PBN) or the like formed by a vapor phase growth method can be used.

The inner crucible 22b has a thickness of 1 .mu.m-2 on the inner surface of the outer crucible 22a or the molded body formed of silicon carbide (SiC) by the vapor phase growth method.
It may be integrally formed by coating a silicon carbide layer having a thickness of about 00 μm.

According to the above construction, the outer crucible 22a
Is made of a material having excellent mechanical strength and heat resistance, and the inner crucible 22b is made of silicon carbide which is stable to highly reactive silicon. However, it does not react with the inner crucible 22b, so that it is possible to prevent the silicon from reacting with the outer crucible 22a.

Further, as described above, when the inner surface of the outer crucible 22a is coated with the inner crucible 22b made of silicon carbide, the adhesion between the two crucibles 22a and 22b is improved, so that the heat transfer between them is improved. Excellent and convenient.

Second Embodiment (See FIG. 2) FIG. 2 is a schematic sectional view of a crucible 22 showing another embodiment of the present invention. Only the differences from the first embodiment will be mainly described below. In the first embodiment, the inner crucible 22b is made of silicon carbide, but in this example, the inner crucible 22b is formed.
Are formed of carbon (C). Further, as the inner crucible 22b, on the inner surface of the outer crucible 22a,
Carbon is grown by a vapor phase growth method, etc., and the thickness is 1 μm.
~ 200μm Pyrolytic graphite (P
The G) layer may be coated and integrally formed.

According to the above structure, the outer crucible 22a
Is formed of a material having excellent mechanical strength and heat resistance as in the first embodiment. Since the inner crucible 22b is formed of carbon, silicon is used as the molecular beam raw material 21 in the crucible 22. , This crucible 22 is M
When the silicon is melted by setting it in a BE device, evacuating the device to a predetermined vacuum degree, and heating the crucible 22 to about 1500 ° C. by a heater to melt the silicon, the carbon forming the inner crucible 22b reacts with the silicon, A silicon carbide layer stable to highly reactive silicon is formed at the interface, and the reaction is prevented from further progressing. Therefore,
It is possible to prevent the silicon from reacting with the outer crucible 22a.

Further, as described above, when the inner crucible 22b is formed by coating the inner surface of the outer crucible 22a, the adhesion between the two crucibles 22a and 22b is improved, and therefore the heat transfer between them is excellent and convenient. Good.

Third Embodiment (See FIGS. 3 and 4) FIGS. 3 and 4 are explanatory views for explaining one embodiment of a method for manufacturing the crucible 22 according to the present invention. In this embodiment, a base material for forming the outer crucible 22a, for example, a cylindrical crucible member 10 made of graphite is placed on a mounting table 14 in a vacuum heating furnace 11 as shown in FIG. Operate a vacuum pump (not shown) in the heating furnace 11
The gas inlet 12 is heated to 1800 ° C. or higher, preferably 2000 ° C. or higher while maintaining a reduced pressure of Torr or lower
To boron trichloride (BCl ₃ ) as well as gas inlet 13
Ammonia (NH ₃ ) is introduced from the above to react them with each other under high temperature and reduced pressure.
While rotating, a pyrolytic boron nitride film is grown on the outside of the cylindrical crucible member 10 to a desired thickness, for example, about 0.5 mm to 2 mm. This becomes the outer crucible 22a.

Then, the crucible mold 10 and the outer crucible 22a made of pyrolytic boron nitride are taken out from the vacuum heating furnace 11 and the crucible mold 1 is obtained.
After removing 0, an outer crucible 22a made of a pyrolytic boron nitride molded body is formed, and then the outer crucible 22a is placed on the mounting table 17 in the vacuum heating furnace 15 as shown in FIG. While operating a vacuum pump (not shown) in the furnace 15 at a reduced pressure of 10 Torr or lower, while heating to 1800 ° C. or higher, preferably 2000 ° C. or higher, the aliphatic hydrocarbon (C _n H
_{2n + 2} ) is introduced and reacted under high temperature and reduced pressure, and a pyrolytic graphite film is grown inside the outer crucible 22a to a desired thickness, for example, about 1 μm to 200 μm, and the inner crucible 22b is formed of a pyrolytic graphite layer. Are integrally formed. With this, crucible 2
2 is formed.

According to the above method, a stable and dense pyrolytic boron nitride film grows on the outside of the cylindrical crucible member 10 in the air due to the reaction between boron trichloride and ammonia under high temperature and reduced pressure. After that, if the crucible mold material 10 is removed, an outer crucible 22a made of a pyrolytic boron nitride molded body can be formed, and thereafter, pyrolysis is performed inside the outer crucible 22a under high temperature and reduced pressure by a heating reaction of an aliphatic hydrocarbon. The lithic graphite film grows, and the inner crucible 22b made of a pyrolytic graphite layer can be integrally formed.

The pyrolytic boron nitride and the pyrolytic graphite are both hexagonal and have the same crystal structure, and the strain due to thermal expansion is small, and the pyrolytic boron nitride (P
The lattice constants of BN) and pyrolytic graphite (PG) are also very similar as shown in Table 1, and the compatibility is good. In particular, their heat transfer properties are excellent.

[0034]

[Table 1]

Fourth Embodiment (see FIG. 5) FIG. 5 is an explanatory view for explaining another embodiment of the method for manufacturing the crucible 22 according to the present invention. Only the differences from the third embodiment will be mainly described below. In this embodiment, the crucible 22 in which the outer crucible 22a made of the pyrolytic boron nitride molded body of the third embodiment and the inner crucible 22b made of the pyrolytic graphite layer are integrally formed is used. The crucible 22b is filled with the same silicon 30 used as a molecular beam raw material, placed on a mounting table 32 in a vacuum heating furnace 31, and a vacuum pump (not shown) connected to an exhaust port 33 is operated to perform vacuum heating. While maintaining the inside of the furnace 31 at a reduced pressure of 10 ⁻⁷ Torr or less, for example, the crucible 22 is heated to 1500 ° C. or more by supplying power from a power source (not shown) to the heater 34. Then, while the silicon 30 is melting, a part of the silicon 30 evaporates, the pyrolytic graphite forming the inner crucible 22b reacts with the silicon 30, and the interface between the pyrolytic graphite layer and the silicon 30 or Silicon carbide layer 22c is formed on the upper portion.

According to the above method, the outer crucible 22a made of a stable and dense pyrolytic boron nitride molded body and the inner crucible 22b made of a dense pyrolytic graphite layer can be integrally formed. The silicon 30 accommodated in the inner crucible 22b and the pyrolytic graphite forming the inner crucible 22b react with each other by heating in a vacuum, and at the interface between the pyrolytic graphite and the silicon 30 and the upper portion thereof,
A crucible 22 having a silicon carbide layer 22c that is stable to silicon can be formed.

Therefore, if the molecular beam source 2 for vaporizing silicon using the crucible 22 is attached to the MBE apparatus to vaporize silicon as a raw material for the molecular beam, a stable molecular beam can be immediately generated and the crystal can be obtained. It is convenient because the growth efficiency can be improved.

In the third and fourth embodiments described above, the crucible member 10 made of graphite for the outer crucible 22a is used.
Was used to form the outer crucible 22a, and then the inner crucible 22b was formed on the inner side by vapor phase growth. On the contrary, first, a crucible-shaped member made of graphite for the inner crucible was formed. Is used to form an inner crucible 22b made of a pyrolytic graphite film by a vapor growth method, and then an outer crucible 22a made of a pyrolytic boron nitride compact is formed on the outer side thereof by a vapor growth method. Of course, it is good.

According to this, as in the third and fourth embodiments described above, after forming the outer crucible 22a, the outer crucible 22a is taken out from the vacuum heating furnace 11, the crucible-shaped material is removed, and then the vacuum heating is performed again. It is not necessary to install the outer crucible 22a in the furnace 14 to form the inner crucible 22b, and the inner crucible 22b and the outer crucible 22a can be sequentially formed in the same vacuum heating furnace, and the manufacturing process can be shortened. So convenient.

Experimental Example In order to confirm the effect of the molecular beam source for vaporizing silicon according to the present invention, pyrolytic graphite is provided inside the crucible manufactured according to Example 3 described above, that is, the outer crucible made of the pyrolytic boron nitride compact. silicon evaporating molecular beam source using integrally formed crucible inner crucible consisting of a layer, and mounted in a vacuum chamber, accommodating the silicon in the crucible as a molecular beam material, then the vacuum vessel 10 ^- Evacuate to ⁷ Torr, raise the molecular beam source to 1500 ° C, and evaporate silicon for 30 minutes.
A silicon film was grown on a piece of tantalum.

When this sample piece was analyzed by Auger electron spectroscopy, it was confirmed that a highly pure silicon (Si) film was formed as shown in FIG. Also,
In the figure, carbon (C) and oxygen (O) are detected, but these are considered to have adhered after the sample piece was taken out into the atmosphere and before the analysis, and there is no particular problem.

Further, the crucible used in the above experimental example was cut, and the thickness of the silicon carbide layer which is the reaction layer of pyrolytic graphite and silicon was investigated.
It was less than 1 μm. Therefore, the thickness of the inner crucible should be at least 1 μm, and if it is too thick, the heat transfer will be poor, and it will take time to manufacture and it will be expensive. Therefore, it is generally preferable that the thickness be 200 μm or less. Is 5 μm to 50 μm.

Reference Example 1 For reference, under the same conditions as in the above-mentioned experimental example, the inside of the vacuum chamber was set to 1 without containing silicon, that is, using an empty crucible.
After vacuuming to 0 ⁻⁷ Torr, heating the molecular beam source to 1500 ° C. and holding for 30 minutes, a substrate made of tantalum was used as a sample piece and analyzed by Auger electron spectroscopy.
As shown in FIG. 7, tantalum (T
Only a) can be confirmed.

Reference Example 2 FIG. 8 shows the result of analyzing new tantalum before thin film formation by Auger electron spectroscopy. Comparing FIG. 7 and FIG. 8, both are almost the same analysis result, and also from this result, it can be confirmed that the molecular beam source for silicon evaporation according to the present invention has excellent heat resistance.

Comparative Example 1 For comparison, a molecular beam source using a conventional crucible made only of pyrolytic boron nitride was mounted in a vacuum container, and silicon was housed in the crucible as a molecular beam raw material. Then, the inside of the vacuum chamber was evacuated to 10 ⁻⁷ Torr, the molecular beam source was heated to 1500 ° C. to evaporate silicon for 30 minutes, and a silicon film was grown on a sample piece made of tantalum.

When this sample piece was analyzed by Auger electron spectroscopy, nitrogen (N) was detected in addition to silicon (Si) as shown in FIG. This is considered to be a result of nitrogen evaporating and growing on the sample piece due to the reaction between pyrolytic boron nitride, which is a constituent material of the crucible, and silicon.

Comparative Example 2 Under the same conditions as in Comparative Example 1 above, a crucible made of an empty pyrolytic boron nitride containing no silicon was used, and the inside of the vacuum vessel was evacuated to 10 ^-7 Torr to remove the molecules. After heating the radiation source to 1500 ° C. and holding it for 30 minutes, a sample piece made of tantalum was analyzed by Auger electron spectroscopy. As a result, as shown in FIG. 10, tantalum (Ta) which is a constituent material of the sample piece was I could only confirm.

Note that carbon (C) is also used in FIGS. 7 to 10.
Also, oxygen (O) is detected, which is considered to have been adhered after the sample piece was taken out into the atmosphere and before the analysis, as in the case of the above-described experimental example.

[0049]

As described above, according to the present invention, the following effects can be obtained.

According to the invention of claim 1, the outer crucible is formed of a high melting point material having a melting point higher than that of silicon,
Moreover, because the inner crucible is made of silicon carbide that is stable against highly reactive silicon, it has excellent mechanical strength and heat resistance, and it does not react with highly reactive silicon and does not deteriorate heat resistance. A molecular beam source can be realized.

According to the second aspect of the invention, the outer crucible is made of a high melting point material having a melting point higher than that of silicon,
Moreover, the inner crucible is made of carbon, and when silicon is put in it and heated and melted, the carbon and silicon of the inner crucible react with each other, and the silicon carbide layer that is highly reactive to silicon and has high reactivity at the interface. Thus, it is possible to realize a molecular beam source for vaporizing silicon, which is excellent in mechanical strength and heat resistance, and does not melt even if it reacts with silicon and the heat resistance does not deteriorate.

According to the invention of claim 3, since the inner crucible is integrally coated on the inner surface of the outer crucible in a layered manner, the adhesion between both is improved and the heat transfer between them is improved.

According to the invention of claim 4, the outer crucible is formed of a high melting point material having a melting point higher than that of silicon,
Since the inner crucible is formed by integrally coating layered pyrolytic graphite, the pyrolytic graphite of the inner crucible and silicon react with each other to form a stable silicon carbide layer for silicon, which has high reactivity. Thus, it is possible to realize a molecular beam source for vaporizing silicon, which is excellent in mechanical strength and heat resistance, and does not melt even if it reacts with silicon and the heat resistance does not deteriorate. Moreover, since the inner crucible is integrally coated on the inner side of the outer crucible in a layered manner, the adhesion between them and the heat transfer property are excellent.

According to the invention of claim 5, since the outer crucible is made of pyrolytic boron nitride, it is excellent in mechanical strength and heat resistance.

According to the invention of claim 6, since the outer crucible is one of tantalum, molybdenum, tungsten and alloys thereof, the mechanical strength and heat resistance are excellent.

According to the invention of claim 7, since the inner crucible made of the pyrolytic graphite layer can be integrally formed inside the outer crucible made of the pyrolytic boron nitride molded body, even if it reacts with silicon, It is possible to obtain a crucible which is not melted and whose heat resistance is not deteriorated and which has excellent heat transfer properties.

According to the invention of claim 8, an inner crucible made of a pyrolytic graphite layer is integrally formed inside an outer crucible made of a pyrolytic boron nitride molded body, and the pyrolytic graphite and the inside thereof are accommodated. Since a silicon carbide layer stable to silicon is formed at the interface with the formed silicon, it is possible to obtain a crucible that does not react with silicon and has excellent heat transfer properties.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a molecular beam source for vaporizing silicon according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a schematic configuration of a crucible used for a silicon evaporation molecular beam source according to another embodiment of the present invention.

FIG. 3 is an explanatory view for explaining one embodiment of the method for manufacturing a crucible according to the present invention.

FIG. 4 is an explanatory view for explaining one embodiment of the method for manufacturing a crucible according to the present invention.

FIG. 5 is an explanatory view for explaining another embodiment of the crucible manufacturing method according to the present invention.

FIG. 6 is a diagram showing an analysis result by Auger electron spectroscopy of a sample piece according to an experimental example of the present invention.

FIG. 7 is a diagram showing an analysis result of a sample piece according to Reference Example 1 by Auger electron spectroscopy.

FIG. 8 is a diagram showing the results of Auger electron spectroscopy analysis of tantalum, which is a sample piece before thin film formation according to Reference Example 2.

FIG. 9 is a diagram showing an analysis result of a sample piece according to Comparative Example 1 by Auger electron spectroscopy.

FIG. 10 is a diagram showing an analysis result of a sample piece according to Comparative Example 2 by Auger electron spectroscopy.

FIG. 11 is a cross-sectional view showing a schematic configuration of a conventional MBE device.

FIG. 12 is a cross-sectional view of essential parts showing a schematic configuration of a molecular beam source for vaporizing silicon used in a conventional MBE apparatus.

[Explanation of symbols]

 2 Molecular Beam Source 10 Crucible Type Material 21 Molecular Beam Raw Material 22 Crucible 22a Outer Crucible 22b Inner Crucible 22c Silicon Carbide Layer 23 Heater 24 Heat Reflector 25 Thermocouple 30 Silicon

Claims (8)

[Claims] 1. A crucible for containing silicon as a molecular beam raw material, a heater arranged on the outer periphery of the crucible for heating the silicon, a heat reflection plate arranged on the outer periphery of the heater, and the silicon. And a thermocouple for monitoring the temperature of the crucible, wherein the crucible comprises an outer crucible formed of a high melting point material having a melting point higher than that of silicon, and an inner crucible formed of silicon carbide inside the crucible. A characteristic molecular beam source for silicon evaporation. 2. A crucible containing silicon as a molecular beam raw material, a heater arranged on the outer periphery of the crucible for heating the silicon, a heat reflection plate arranged on the outer periphery of the heater, and the silicon. And a thermocouple for monitoring the temperature of the crucible, wherein the crucible comprises an outer crucible formed of a high melting point material having a melting point higher than that of silicon, and an inner crucible formed of carbon inside the crucible. A molecular beam source for silicon evaporation. 3. The molecular beam source for vaporizing silicon according to claim 1, wherein the inner crucible is integrally coated in a layered manner on the inner surface of the outer crucible. 4. A crucible for containing silicon as a molecular beam raw material, a heater arranged on the outer periphery of the crucible for heating the silicon, a heat reflection plate arranged on the outer periphery of the heater, and the silicon. A thermocouple for monitoring the temperature of the crucible, wherein the crucible comprises an outer crucible formed of a high melting point material having a melting point higher than that of silicon, and an inner crucible formed by integrally coating a layer of pyrolytic graphite inside the crucible. A molecular beam source for vaporizing silicon, comprising: 5. The molecular beam for vaporizing silicon according to claim 1, wherein the outer crucible formed of a high melting point material having a melting point higher than that of silicon is pyrolytic boron nitride. source. 6. The outer crucible formed of a high melting point material having a melting point higher than that of silicon is one of tantalum, molybdenum, tungsten and alloys thereof, and the outer crucible is any one of claims 1 to 4. A molecular beam source for vaporizing silicon according to item 1. 7. A pyrolytic boron nitride film is grown on the outside of a cylindrical crucible-shaped material by reacting boron trichloride with ammonia under a high temperature and reduced pressure by a vapor phase growth method, and then the crucible-shaped material is removed to remove the pyrolytic material. After forming an outer crucible consisting of a boron nitride molded body, an aliphatic hydrocarbon is reacted under a high temperature and reduced pressure by a vapor phase growth method, and pyrolytic graphite is grown inside the outer crucible to form a pyrolytic graphite layer. A method of manufacturing a crucible for a molecular beam source for vaporizing silicon, characterized in that the inner crucible is formed integrally. 8. A pyrolytic boron nitride film is grown on the outside of a cylindrical crucible-shaped material by reacting boron trichloride with ammonia under a high temperature and reduced pressure by a vapor phase growth method, and then the crucible-shaped material is removed to remove pyrolysis. After forming an outer crucible composed of a lithic boron nitride molded body, an aliphatic hydrocarbon is reacted under a high temperature and reduced pressure by a vapor phase growth method, and pyrolytic graphite is grown inside the outer crucible to form a pyrolytic graphite layer. An inner crucible consisting of is integrally formed, and thereafter, silicon is accommodated in the inner crucible and heated in vacuum to react the pyrolytic graphite forming the inner crucible with the silicon, and the pyrolytic graphite layer and the silicon. Characterized by forming a silicon carbide layer at the interface with A method for manufacturing a crucible of a molecular beam source for vaporizing silicon.