JPH06173011A - Vaporization vessel - Google Patents

Abstract

PURPOSE:To provide the vaporization vessel for org. metal compd. capable of efficiently and stably vaporizing a solid org. metal compd. with a simple structure. CONSTITUTION:In the vaporization vessel of this invention, a carrier gas introducing pipe 2 and a mixed gas discharging pipe 3 are respectively opened in the vessel 1 and a heating pipe 4 pierces through the vessel 1. The number of the heating pipe 4 is 2-5, and they may be disposed parallel to a base wall, and the carrier gas introducing pipe 2 may be opened at the bottom part and the mixed gas discharging pipe 3 may be opened above it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid metalorganic compound vaporization vessel for producing a compound semiconductor.

[0002]

2. Description of the Related Art Recently, III-V and II-VI group compound semiconductors have come to be used in a wide range of fields such as semiconductor light emitting devices and microwave transistors. Integrated circuits for computers,
Optoelectronic integrated circuits have also been developed.

When manufacturing III-V compound semiconductors, metal chemical vapor deposition (MOCVD Metalorg) is often used.
anic Chemical Vapor Deposition) is adopted. In this method, a liquid or solid organometallic compound is vaporized,
The crystal is epitaxially grown on the substrate. A change in the mixing ratio of the organometallic compound in the carrier gas supplied to the substrate during epitaxial growth has a significant adverse effect on the electrical or optical properties of the resulting semiconductor. In order to obtain a high performance device, it is necessary that a constant concentration of the organometallic compound is stably supplied from the vaporization container.

To vaporize the liquid organometallic compound, a vaporization vessel in which a carrier gas introducing dip tube and a gas mixture exhaust tube are connected to a sealed vessel is used. When hydrogen gas or the like is bubbled through the liquid organometallic compound through the carrier gas introducing dip tube, hydrogen gas saturated by vaporization of the liquid organometallic compound is discharged from the gas mixture discharge pipe.

Thus, not only the liquid organometallic compound but also the solid organometallic compound such as trimethylindium vaporizes when exposed to the carrier gas. The above method can be applied to a solid organometallic compound.

[0006]

When applied to solid organometallic compounds, there are several problems. When a solid organometallic compound is filled in a vaporization container for a liquid organometallic compound and a carrier gas is introduced into the container through a carrier gas introduction dip tube, the vaporization amount also changes as the remaining amount of the solid organometallic compound in the container decreases. Come on. If it is attempted to use it in a range where the vaporization amount hardly changes, the solid organometallic compound cannot be exhausted until the remaining amount of the solid organometallic compound filled in the vaporization container becomes almost zero.
That is, there is a problem that the efficiency is low.

In addition to the above, as a method of recovering the solid organometallic compound by vaporization, there is also a method of heating the inside of the vaporization container to liquefy the solid organometallic compound and vaporize it by bubbling. Japanese Unexamined Patent Publication (Kokai) No. 4-74523 discloses a method of heating a vaporization container filled with a solid organometallic compound, in which fin-shaped projections are installed therein. The fin-shaped protrusion has good thermal conductivity. However, if it is attempted to vaporize the solid organic metal in such a vaporization container, it is first difficult to fill the sample. Even if the vaporization container that was once used to vaporize a specific solid organometal was filled with a specific organometallic compound again and then tried to be reused, the number of protrusions was too large to clean and it was almost unusable. there were. The publication also discloses a vaporization container having hollow fins. In that case, although the improvement effect is recognized as compared with the case without the fin, the vaporized organometallic compound cannot be obtained at a stable concentration.

In order to solve the above problems, it is an object of the present invention to provide an organometallic compound vaporization container having a simple structure and capable of efficiently and stably vaporizing a solid organometallic compound.

[0009]

A vaporization container of the present invention made to achieve the above object will be described with reference to FIG. 1 corresponding to an embodiment.

In the vaporization container of the present invention, a carrier gas introduction pipe 2 and a mixture gas discharge pipe 3 are opened in the container 1, and a heat transfer pipe 4 penetrates the container 1. It is preferable that the number of the heat transfer tubes 4 is 2 to 5, and that they are provided in parallel with the bottom wall, the carrier gas introduction tube 2 is opened at the bottom, and the mixture discharge tube 3 is opened above it. .

[0011]

In the vaporization container, a solid organometallic compound such as trimethylindium is filled in a form in which it is widely solidified and adhered to the entire inner surface of the container 1 including the surface of the heat transfer tube 4. When the carrier gas is discharged into the container 1 through the carrier gas introduction pipe 2, the solid organometallic compound 6 attached thereto comes into contact with the carrier gas over a wide area and immediately sublimes to the saturation concentration of the carrier gas to form a carrier gas flow. The air-fuel mixture is discharged from the air-fuel mixture discharge pipe 3.

The vaporization container as described above can be easily manufactured by passing the heat transfer tube 4 through a conventional vaporization container for liquid organic metal compound.

[0013]

EXAMPLES Examples of the present invention will be described below. FIG. 1 is a partial cutaway view of an embodiment of the vaporization container of the present invention. A carrier gas introducing pipe 2 penetrates the upper end wall of the vertically sealed cylindrical container 1 and opens at the bottom of the cylindrical container 1. Further, an air-fuel mixture discharge pipe 3 is connected to the same upper end wall and opened.

The heating medium inlet / outlet is opened at two locations vertically on the tubular wall of the tubular container 1, and two locations at the opposite side are also opened vertically. Two heat transfer tubes 4 penetrating the inside of the cylindrical container 1 are provided vertically and horizontally orthogonal to the center line of the cylindrical body and parallel to the bottom wall, and each is directly connected to each heat medium inlet / outlet on the upper side. , Is directly connected to each heat medium inlet / outlet on the lower side.

The diameter of the heat transfer tube 4 is preferably 1/2 or less, preferably 1/3 to 1/4 of the inner diameter of the cylindrical container 1. The number of heat transfer tubes 4 is preferably 5 or less, and particularly preferably 2 to 3. If the number is 6 or more, not only the production becomes difficult, but also when the organometallic compound is vaporized and the remaining amount becomes small, the concentration recovered from the gas mixture discharge pipe 3 fluctuates. It is not preferable because it becomes easier. If you increase the number, you have to reduce the thickness of each one,
It is considered that the organometallic compound attached to the wall surface of the heat transfer tube 4 is easily peeled off. The heat transfer tube 4 is provided parallel to the bottom surface of the container 1. If the pipes are not parallel, it is expected that the pipes will be slanted and the penetration distance will be longer, and the adhesion area of the organometallic compound will increase. When this happens, the organometallic compound easily peels off, and the recovery concentration easily fluctuates, which is not preferable.

In the case of the present embodiment, since the carrier gas introduction pipe 2 is open at the bottom and the air-fuel mixture discharge pipe 3 is opened above it, even if a gas having a low specific gravity is used as the carrier gas, it has a relatively high specific gravity. The sublimation gas can be efficiently discharged.

Example 1 A trimethylindium crystal 6 was adhered to the inside of the container 1 such as the surface of the heat transfer tube 4 in a vaporization container as shown in FIG. 1 with a substantially uniform thickness as shown by the chain line.

The temperature inside the container is maintained at 40 ° C. in the water bath 5, helium gas is fed from the carrier gas introducing pipe 2 at a flow rate of 100 ml / min, trimethylindium is sublimated, and in the form of a mixed gas with helium gas. Trimethylindium gas was taken out from the gas mixture discharge pipe 3.

The amount of trimethylindium in the discharged mixed gas was detected by comparison with the residual amount of trimethylindium in the container 1 by using a gas chromatography spectrometer. The measurement result is shown in FIG. From FIG. 3, it was found that the trimethylindium gas can be stably recovered at a constant concentration until the remaining amount of trimethylindium in the container 1 becomes almost empty.

COMPARATIVE EXAMPLE A conventional example as shown in FIG. 2 in which a carrier gas introducing pipe 2 is provided so as to penetrate therethrough, and a mixture discharging pipe is connected to provide a mixture discharging pipe 3. A type of vaporization vessel was used. Others were the same as in Example 1. The results are shown in Fig. 4. From FIG. 4, it was reconfirmed that the concentration in the mixed gas fluctuates when the remaining amount decreases when recovering trimethylindium.

[0021]

As described above in detail, in the vaporization container of the present invention, the solid organometallic compound can be brought into contact with the carrier gas in a wide range within the container. The solid organometallic compound sublimes and becomes saturated in the carrier gas, and is discharged at its saturated concentration. Therefore, the mixing ratio of the carrier gas and the sublimation gas is constant, and an organometallic compound gas having a constant concentration can be obtained efficiently and stably.

Since the concentration of the sublimation gas in the mixed gas obtained from the mixed gas discharge pipe maintains the saturated concentration and hardly decreases even when the remaining amount decreases, the crystal of the solid organometallic compound is stabilized on the substrate. It is possible to epitaxially grow the semiconductor, and it is possible to manufacture a semiconductor having highly reliable characteristics. It has an extremely useful effect in industry.

In the production of the vaporization container, a conventional vaporization container for a liquid organometallic compound may be applied and can be easily obtained.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an embodiment of a vaporization container to which the present invention is applied.

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

FIG. 3 is a graph showing the results of Example 1.

FIG. 4 is a graph showing the results of a comparative example.

[Explanation of symbols]

Reference numeral 1 is a cylindrical container, 2 is a carrier gas introduction pipe, 3 is a mixture discharge pipe, 4 is a heat transfer pipe, 5 is a water bath, and 6 is trimethylindium attached.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiromi Osaki, Hiromi Osaki, 28, Nishi-Fukushima, Chugiki-mura, Nakakubiki-gun, Niigata Prefecture, Shinsei Chemical Industry Co., Ltd. 28, Nishi-Fukushima, Kikugi-mura, Gunma 1 Shin-Etsu Chemical Co., Ltd. Synthetic Technology Laboratory

Claims (3)

[Claims] 1. A vaporization container characterized in that a carrier gas introduction pipe and a mixture gas discharge pipe are each opened in the container, and a heat transfer pipe penetrates through the container. 2. The vaporization container according to claim 1, wherein the number of the heat transfer tubes is 2 to 5, and the heat transfer tubes are provided in parallel with the bottom wall. 3. The vaporization container according to claim 1, wherein the carrier gas introduction pipe is opened at the bottom, and the air-fuel mixture discharge pipe is opened above it.