JPH11189491A - Vaporization vessel for liquid stock for vapor growth - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vaporization vessel of simple structure enabling a liquid stock for vapor growth to be vaporized and withdrawn at stable gas concentrations until the remaining liquid in the vessel is nearly gone. SOLUTION: This vaporization vessel has a closed vessel 1 with a groove 4 at the bottom, a carrier gas introduction tube 2 with the lower end 7 reached to the groove 4 and the upper portion penetrated through the upper part of the closed vessel and opened outside the closed vessel, and a gas withdrawal tube 3 with the lower end penetrated through the upper part of the closed vessel and opened inside the closed vessel and the upper portion opened outside the closed vessel. A liquid stock for vapor growth filled in the closed vessel is vaporized and withdrawn via the gas withdrawal tube 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an MOCVD (Metalorganic) for manufacturing a compound semiconductor.
Chemical-al Vapor Deposition
The present invention relates to a container for vaporizing a liquid source for epitaxial vapor phase growth according to n).

[0002]

2. Description of the Related Art In recent years, III-V and II-VI compound semiconductors have been used in a wide range of fields such as semiconductor light emitting devices and microwave transistors. It has also been used for integrated circuits for computers, integrated circuits for optoelectronics, and the like.

[0003] As a crystal growth method for producing a compound semiconductor used for such a wide variety of uses, an MOCVD method using an organometallic compound or the like is mainly employed. MOC
The VD method is one of crystal growth methods often used for forming an epitaxial thin film of a compound semiconductor or a mixed crystal semiconductor. For example, an organic metal compound such as trimethylgallium, trimethylaluminum, dimethylzinc,
Organic V such as alkyl phosphine and alkyl arsine
This is a method in which a group III compound is vaporized and crystal growth of a thin film is performed using a thermal decomposition reaction on a substrate.

In this method, if the mixing ratio of an organometallic compound or the like in a carrier gas supplied to a substrate fluctuates during epitaxial growth, the electrical or optical characteristics of the obtained semiconductor are significantly adversely affected. Occurs. In order to obtain a high-performance element, it is necessary to stably supply a constant concentration of a raw material for vapor phase growth.

[0005] In order to vaporize a liquid raw material, usually, a vaporization vessel in which a carrier gas introduction pipe and a gas discharge pipe are connected to a closed vessel is used. When a carrier gas such as hydrogen gas is introduced from the carrier gas introduction pipe into the closed container and bubbled in the liquid raw material, the mixed gas saturated with the carrier gas is vaporized from the liquid raw material and discharged from the gas discharge pipe.

[0006] Conventionally, as a container for entraining these liquid materials for vapor phase growth by bubbling with a carrier gas, for example, JP-A-59-191699, JP-A-62-46639,
A vaporization container having a flat bottom as described in Japanese Utility Model Application Laid-Open No. 62-196331 has been used. However, when bubbling is carried out with a carrier gas using a vaporization container having such a flat bottom, when the remaining amount of the liquid material for vapor phase growth in the container decreases, the mixed gas is discharged until the remaining amount is almost exhausted. There was a disadvantage that it could not be exhausted. This is presumed to be due to insufficient gas-liquid contact between the carrier gas and the liquid source.

In order to solve the above-mentioned problem, Japanese Unexamined Utility Model Publication No. 6-20951 discloses a vaporization container having a spherical bottom portion.
8. Japanese Patent Application Laid-Open No. Hei 2-26017 proposes a vaporizing container or the like having a shape in which the diameter of the lower portion from the center of the container body is gradually reduced in a tapered shape.

[0008]

However, in recent years, large-sized vaporizing containers have been used, and the above-mentioned problems have become more remarkable. The above-mentioned conventional vaporizing containers still cannot be solved. For example, in the case of a vaporization container having a shape in which the diameter of the lower portion from the center of the container body is tapered, if the liquid material inside decreases and the liquid level falls on the tapered portion, the concentration of the liquid material to be vaporized gradually increases. However, there is a drawback that it becomes lower. This is thought to be because the surface area of the liquid surface was reduced. In addition, since the amount of the liquid raw material that can be filled is smaller than that of other containers having the same size due to the presence of the tapered portion, there is also a problem that the effect of increasing the filling amount by increasing the size of the container cannot be sufficiently obtained. there were.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to vaporize and extract a liquid material for vapor phase growth at a stable gas concentration until almost no residual liquid remains in a container with a simple structure. It is an object of the present invention to provide a vaporization container which can be used.

[0010]

According to the first aspect of the present invention, there is provided an airtight container having a groove formed in a bottom portion, a lower end reaching the groove in the airtight container bottom and opening, and an upper portion penetrating the upper portion of the airtight container. A carrier gas inlet pipe opened to the outside of the closed vessel and a gas outlet pipe whose lower end penetrates the upper part of the closed vessel and opens inside the closed vessel, and has an upper part opened to the outside of the closed vessel. The present invention provides a vaporization container for a vapor source for vapor phase growth, characterized in that the vaporized liquid source for vapor phase growth is vaporized and led out from a gas outlet pipe.

According to a second aspect of the present invention, there is provided the vaporization container according to the first aspect, wherein the groove formed at the bottom of the closed container is cylindrical. I will provide a.

According to a third aspect of the present invention, in the vaporization container according to the second aspect, the diameter of the cylindrical groove is 5 to 50 m.
Provided is a vaporization container for a liquid source for vapor phase growth, which has a diameter of mφ and a depth of 5 to 50 mm.

According to a fourth aspect of the present invention, there is provided the vaporization container according to the first aspect, wherein the groove formed at the bottom of the closed container has a polygonal column shape. I will provide a.

According to a fifth aspect of the present invention, in the vaporization container according to the fourth aspect, the polygonal column-shaped groove has a diagonal length of 5 mm.
Provided is a vaporization container for a liquid material for vapor phase growth, which is characterized by having a depth of 5 to 50 mm and a depth of 5 to 50 mm.

According to a sixth aspect of the present invention, in the vaporization container according to the first aspect, the liquid material for vapor phase growth filled in the vaporization container is represented by the general formula (I):

Embedded image (R _{1 to} R ₃ represent a group in which at least one of them is one or more alkyl groups having 1 to 3 carbon atoms and the other is a hydrogen atom, and M ₁ represents a trivalent metal element Or an organometallic compound represented by the general formula (II)

Embedded image (R ₄ and R ₅ represent a group in which one or two of them are one or two alkyl groups having 1 to 3 carbon atoms and the other is a hydrogen atom, and M ₂ represents a divalent metal element. An organic metal represented by the general formula (III)

Embedded image (R _{6 to} R ₈ represent a group of one or more of which are one or more alkyl groups having 1 to 10 carbon atoms and the other being a hydrogen atom, and M ₃ represents phosphorus or arsenic.) A vaporization container for a liquid material for vapor phase growth, which is an alkyl phosphine or an alkyl arsine represented by the formula:

[0016]

FIG. 1 shows an example of an embodiment of the present invention. The vaporization container includes a closed container 1 having a groove 4 formed at the bottom, a carrier gas introduction pipe 2 having a lower end 7 reaching the groove 4 at the bottom of the container and an upper end passing through the upper part of the container and opening to the outside of the container. And a gas outlet pipe 3 whose lower end passes through the upper part of the container and opens inside the container and whose upper part opens outside the container. Valves 6 and 5 are provided above the carrier gas inlet pipe 2 and the gas outlet pipe 3 (portions protruding outside the container), respectively.

The groove 4 provided at the bottom of the closed vessel 1 is preferably cylindrical or polygonal, and the open end 7 of the carrier gas introduction pipe 2 reaches near the bottom of the groove 4.

In order to vaporize and supply the liquid material for vapor phase growth by the vaporization container having such a configuration, first, the liquid material for vapor phase growth is charged into the container 1, the valve 6 is opened, and the gas is supplied from the carrier gas introduction pipe 2. When a carrier gas such as hydrogen is introduced and the liquid material for vapor phase growth is bubbled, the liquid material for vapor phase growth is vaporized. Here, when the valve 5 of the gas outlet pipe 3 is opened, the vaporized raw material for vapor phase growth is led out of the gas outlet pipe 3 together with the carrier gas.

When the vaporization of the liquid material for vapor phase growth is continued, the liquid material gradually decreases, and when the liquid level falls to the vicinity of the tip 7 of the carrier gas introduction pipe 2 in the groove 4, the vaporization of the liquid material cannot be further performed. However, the remaining amount of the liquid material for vapor phase growth remaining in the groove 4 is extremely small.

Although the size of the whole closed container is not particularly limited, a container usually used in this field has a diameter of 30.
mmφ to 500 mmφ, and the height may be selected in the range of 50 mm to 500 mm.

The size of the groove 4 is 5 mm in the case of a cylindrical shape.
~ 50mmφ, diagonal length is 5 in case of polygonal column
It is preferably about 50 mm to 50 mm. When the dimension of the groove 4 is smaller than 5 mm in diameter or 5 mm in diagonal length,
When the bubbling is strong, the liquid material may be scattered by the bubbling, and a better effect may not be obtained. On the other hand, even if the dimension of the groove 4 is larger than the diameter 50 mmφ or the diagonal length 50 mm, the residual liquid amount increases, which is uneconomical. The depth of the groove 4 may be such that the carrier gas and the liquid material for vapor phase growth can have a liquid depth sufficient to make gas-liquid contact, but is preferably 5 mm to 50 mm. If the depth is smaller than 5 mm, sufficient gas-liquid contact may not be performed, and it is expected that a saturated mixed gas cannot be obtained. On the other hand, even if it is deeper than 50 mm, the container dimensions are unnecessarily elongated vertically, which is uneconomical and cannot be said to be effective.

The liquid raw material for gas-liquid growth used here is represented by the general formula (I)

Embedded image (R _{1 to} R ₃ represent a group in which at least one of them is one or more alkyl groups having 1 to 3 carbon atoms and the other is a hydrogen atom, and M ₁ represents a trivalent metal element Or an organometallic compound represented by the general formula (II)

Embedded image (R ₄ and R ₅ represent a group in which one or two of them are one or two alkyl groups having 1 to 3 carbon atoms and the other is a hydrogen atom, and M ₂ represents a divalent metal element. An organic metal represented by the general formula (III)

Embedded image (R _{6 to} R ₈ represent a group of one or more of which are one or more alkyl groups having 1 to 10 carbon atoms and the other being a hydrogen atom, and M ₃ represents phosphorus or arsenic.) And an alkyl phosphine or an alkyl arsine represented by

More specifically, examples of the organometallic compound include trimethylaluminum, triethylaluminum, trimethylgallium, triethylgallium, dimethylzinc, diethylzinc, triethylindium and the like. In addition, tertiary butyl phosphine is exemplified as alkyl phosphine, and tertiary butyl arsine is exemplified as alkyl arsine.

As described above, the liquid source such as trimethylgallium is vaporized and entrained by the carrier gas using the vaporization container for the liquid source for vapor phase growth of the present invention, thereby performing the epitaxial growth, so that the vaporization amount does not fluctuate. In addition, a stable gas concentration can be supplied until the remaining amount becomes almost zero.

[0025]

Examples of the present invention will be described below.

Example 1 Using the vaporization container shown in FIG. 1, a test was conducted to determine whether stable supply of the liquid raw material was possible using this vaporization container. In this vaporization container, the main body of the closed container 1 has a cylindrical shape with an outer diameter of 90 mmφ and a height of 160 mm, and has a space capacity of about 700 ml. In addition, diameter 20mm in the bottom
It has a cylindrical groove 4 having a diameter of φ and a depth of 20 mm. Closed container 1
The carrier gas introduction pipe 2 penetrates the upper end wall of the
Is opened at a position 5 mm above the bottom of the cylindrical groove 4. Further, a gas outlet pipe 3 penetrates and opens on the upper end wall of the closed casing 1. Valves 6 and 5 are provided above the carrier gas inlet pipe 2 and the gas outlet pipe 3, respectively.

In this vaporization vessel, trimethylgallium 50
0 g was charged. The vaporization container containing the trimethylgallium is mounted in a thermostat, high-purity helium is used as a carrier gas, high-purity helium is introduced from the carrier gas inlet pipe 2 and bubbling is performed, and the high-purity helium is entrained from the gas outlet pipe 3. To derive trimethylgallium. The gas phase obtained from the gas outlet pipe 3 was measured with a gas concentration meter (Apriori).

FIG. 5 shows the relationship between the amount of feed (the ratio of the amount of feed to the total amount of trimethylgallium) and the concentration of trimethylgallium. The feed amount increases with time, and the closer to 100%, the smaller the remaining amount. As shown in Embodiment 1 of FIG. 5, according to the vaporization container of this embodiment, the concentration can be stably supplied for a long time,
It was confirmed that the amount of liquid remaining unusable due to a decrease in the amount of vaporization was extremely small. 8g of liquid left unusable
(About 2% based on the filling amount).

(Example 2) In the vaporizing container shown in Fig. 1, the same vaporizing container as in Example 1 was used except that the bottom groove 4 was formed in a cylindrical shape having a diameter of 30mmφ and a depth of 30mm. The same test was performed. As a result, as in Example 1, the liquid could be supplied stably for a long time, and there was almost no liquid that could not be used and remained. The remaining liquid amount was as small as 12 g (about 2% based on the filling amount).

Example 3 In the vaporizing container shown in FIG. 1, the same vaporizing container as that of Example 1 was used except that the closed container 1 had an outer diameter of 165 mmφ and a height of 205 mm. The test was performed. As a result, as in Example 1, the liquid could be supplied stably for a long time, and there was almost no liquid that could not be used and remained. The remaining liquid amount was as small as 10 g (about 2% based on the filling amount).

(Example 4) In the vaporization container shown in Fig. 1, the same vaporization container as that of Example 1 was used except that the bottom groove 4 was formed as a square column having a diagonal length of 30mm and a depth of 30mm. The same test as in Example 1 was performed. As a result, as in Example 1, the liquid could be supplied stably for a long time, and there was almost no liquid that could not be used and remained. The remaining liquid amount was as small as 13 g (about 3% based on the filling amount).

Example 5 The same test as in Example 1 was performed except that the same vaporization vessel as in Example 1 was used and tertiary butylphosphine was used instead of trimethylgallium. As a result, as in Example 1, the liquid could be supplied stably for a long time, and there was almost no liquid that could not be used and remained. The remaining liquid amount was as small as 7 g (about 1% based on the filling amount).

(Comparative Example 1) As shown in FIG. 2, a supply test using trimethylgallium was performed in the same manner as in Example 1 using a vaporization container having a flat bottom and a structure without grooves. As a result, as shown in Comparative Example 1 in FIG. 5, stable supply was not possible to the end, and the amount of the remaining liquid was as large as 83 g (about 17% with respect to the filling amount).

Comparative Example 2 As shown in FIG. 3, a vaporization container similar to that of Example 1 was used except that the bottom had a structure having a spherical inner surface 8, and trimethylgallium was used in the same manner as in Example 1. A supply test was performed. As a result, Comparative Example 1
Although the improvement was observed as compared with the vaporization container having a flat bottom, the liquid could not be supplied stably to the end, and the amount of the remaining liquid was as large as 34 g (about 7% based on the charged amount).

(Comparative Example 3) As shown in FIG. 4, the same vaporizing container as that of Example 1 was used except that the inner diameter of the bottom portion was gradually reduced to have a tapered inner surface 9.
A supply test using trimethylgallium was performed in the same manner as in Example 1. As a result, as shown in Comparative Example 3 in FIG. 5, although an improvement is observed as compared with the vaporization container having a flat bottom of Comparative Example 1, when the residual liquid decreases and the liquid level falls on the tapered inner surface 9. The concentration gradually decreased and could not be supplied stably until the end. The remaining liquid amount was as large as 25 g (about 5% based on the filling amount).

[0036]

As described above, according to the present invention, a liquid material for vapor phase growth can be vaporized and derived at a stable gas concentration with a simple structure until almost no residual liquid remains in the container.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a vaporization container of the present invention.

FIG. 2 is a sectional view showing an example of a conventional vaporization container.

FIG. 3 is a sectional view showing an example of a conventional vaporization container.

FIG. 4 is a sectional view showing an example of a conventional vaporization container.

FIG. 5 is a graph showing a relationship between a feed amount (a ratio of a derived amount to a total filling amount of trimethylgallium) and a concentration of trimethylgallium.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Closed container 2 Carrier gas introduction pipe 3 Gas outlet pipe 4 Groove 5, 6 Valve 7 Lower end of carrier gas introduction pipe

Claims (6)

[Claims] A closed gas container having a groove formed in a bottom portion, a carrier gas inlet pipe having a lower end reaching a groove in a closed container bottom portion and opening, and an upper portion penetrating a container upper end wall and opening to the outside of the sealed container; A gas outlet pipe whose lower end passes through the upper part of the closed vessel and opens inside the closed vessel, and has a gas outlet pipe whose upper part is opened outside the closed vessel. A vaporization container for a liquid material for vapor phase growth, which is derived from a tube. 2. The vaporization container for vapor-phase growth liquid material according to claim 1, wherein the groove formed in the bottom of the closed container is cylindrical. 3. The vaporization container for a liquid material for vapor phase growth according to claim 2, wherein the diameter of the cylindrical groove is 5 to 50 mmφ and the depth is 5 to 50 mm. 4. The container for vaporizing a liquid material for vapor phase growth according to claim 1, wherein the groove formed at the bottom of the closed container has a polygonal column shape. 5. The diagonal length of the polygonal column-shaped groove is 5 to 50 m.
5. The vaporization container for a liquid material for vapor phase growth according to claim 4, wherein m and the depth are 5 to 50 mm. 6. The liquid material for vapor phase growth to be charged in a vaporization container is represented by the general formula (I): (R _{1 to} R ₃ represent a group in which at least one of them is one or more alkyl groups having 1 to 3 carbon atoms and the other is a hydrogen atom, and M ₁ represents a trivalent metal element Or an organometallic compound represented by the general formula (II): (R ₄ and R ₅ represent a group in which one or two of them are one or two alkyl groups having 1 to 3 carbon atoms and the other is a hydrogen atom, and M ₂ represents a divalent metal element. Or an organic metal represented by the general formula (III): (R _{6 to} R ₈ represent a group of one or more of which are one or more alkyl groups having 1 to 10 carbon atoms and the other being a hydrogen atom, and M ₃ represents phosphorus or arsenic.) 2. The vaporization container for a liquid material for vapor phase growth according to claim 1, which is an alkyl phosphine or an alkyl arsine represented by the formula: