JPS637621A - Apparatus for vaporizing volatile material - Google Patents

Abstract

PURPOSE:To find the depletion of a volatile material instantly, by providing a gas inlet tube whose tip part is inserted to the volatile material, a gas outlet tube including vaporized volatile material, and a monitoring gas tube whose tip part is inserted to the lowest level of the available liquid surface of the volatile material. CONSTITUTION:A container 3 is sufficiently filled with a volatile material 2. When the surface of the liquid is positioned higher than a tip part 7 of a monitoring gas tube 6, a carrier gas including the volatile material flows out of the container 3 through a gas outlet tube 5. Therefore, the gas does not flow in the monitoring gas tube 6, and a flowmeter 8 does not detect the gas. Meanwhile when the volatile material 2 is depleted and the liquid surface is positioned beneath the tip part 7 of the monitoring gas tube 6, the carrier gas, which is inputted through a gas inlet tube 1, flows through the tip part 7 of the monitoring gas tube 6. The gas flows in the monitoring gas tube. Therefore, the flowmeter 8 detects the flow of the gas, and the depletion of the volatile gas can be found.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus for vaporizing liquid volatile substances having high vapor pressure.

Conventional techniques: Vapor phase growth of compound semiconductors (e.g. halide vapor phase epitaxial growth method and organometallic vapor phase epitaxy method).

BACKGROUND ART In crystal growth and processes for semiconductor devices, such as electrode formation by CVD (for example, formation of molybdenum electrodes), volatile substances are often vaporized and used as raw materials.

One example is metal-organic vapor phase epitaxy (Met), which uses volatile organic metals (alkylated substances) as raw materials.
al Organic Vapor PhaseEp
itaxy), abbreviated as MOVPE. In this case, a carrier gas is generally poured into the organic metal, which is a liquid with a high vapor pressure, and the organic metal is supplied to the furnace with the vapor contained therein. The organometallic vaporization apparatus at this time has a structure as shown in FIG. Carrier gas is passed through mass flow controller-6 1. The gas is introduced into a gas inlet pipe 1 and flows into a container 3 containing a volatile substance 2 which is an organic metal. Since the tip 4 of the gas inflow pipe 1 is inserted into the volatile substance 2, the carrier gas that has flowed in forms bubbles and rises within the volatile substance 2 to the liquid level. This is called bubbling. The bubbled carrier gas contains the vapor of the vaporized volatile substance 2 and exits the container 3 through the gas outlet pipe 5. The gas outflow pipe 5 is connected to a gas pipe on the side of the growth reaction section of the vapor growth apparatus, and the vaporized volatile substance is introduced into the vapor growth reaction section while being contained in the carrier gas, and crystals are grown. Ru.

Problems to be Solved by the Invention Organic metals, which are generally volatile substances, are easily denatured by light and have very strong reactivity with oxygen and the like. Therefore, the inside of a container containing such a volatile substance must be shielded from external light, and strict leakage countermeasures are required for this container and piping system. However, when this volatile substance is depleted, there is no way to directly know the remaining amount of the volatile substance from the outside world. Additionally, the amount of volatile substances remaining can be determined by removing the piping system of the container containing the volatile substance and measuring the weight of the entire container, but it is extremely difficult to remove the piping system of the container. , there is also a strong possibility that it will cause a leak.

Means for Solving the Problems The technical means of the present invention for solving the above problems is that the tip of the gas inflow pipe for introducing the carrier gas is inserted into the volatile material, and the vaporized volatile material is It is equipped with a gas outflow pipe for discharging gas containing volatile substances, and is further equipped with a monitoring gas pipe whose tip is inserted to the lowest level of the usable liquid level of volatile substances. Further, a means for detecting gas flowing through the monitoring gas pipe, such as a flow meter or a differential pressure gauge, is connected to the monitoring gas pipe.

For production The effect of this technical means is as follows.

When the liquid level of the volatile substance is located higher than the tip of the monitoring gas tube, bubbles flowing out from the tip of the gas inflow tube are blocked by the inflow prevention cover and are prevented from flowing into the tip of the monitoring gas tube. It will rise to the liquid level. However, when the liquid level becomes lower than the monitoring gas pipe, the carrier gas that has flowed in through the gas inflow pipe also flows through the monitoring gas pipe and flows through the monitoring gas pipe. Therefore, by detecting the flow, it is possible to know whether volatile substances are depleted.

Example Embodiments of the present invention will be described below with reference to the accompanying drawings.

In this example, the volatile substance is an organic metal (alkylated substance), and the volatile substance is an organic metal (alkylated substance), and the volatile substance is an organic metal (alkylated substance), and the volatile substance is
However, volatile substances are not limited to organic metals, and the present invention is applicable to any device connected to this vaporization device as long as it vaporizes and uses volatile substances. be done.

An embodiment of the present invention is shown in FIG. 1 is a gas inflow pipe for carrier gas. 2 is a volatile substance and is contained in container 3. The tip 4 of the gas inlet tube 1 is inserted into the volatile substance 2. - side 5 is a gas outflow pipe through which the carrier gas containing the vaporized volatile substance 2 flows out. 6 is a monitoring gas pipe for monitoring the liquid level of the volatile substance 2. The distal end 7 of this monitoring gas tube is inserted into the volatile substance 2, and is placed at a liquid level position where it is determined that the volatile substance has been depleted. In this embodiment, the monitoring gas pipe 6 is integrally connected to the flow meter 8, so that it can be detected when gas flows through the monitoring gas pipes.
It may be provided on the device main body side and separated from the serious vaporization device. Reference numeral 9 denotes an inflow prevention cover installed to prevent bubbles flowing out from the tip 4 of the gas inflow tube 1 during bubbling from flowing into the tip 7 of the monitoring gas tube 6.

The operation of the volatile substance vaporization device having the above structure will be explained next. When the volatile substance 2 is sufficiently contained in the container 3 and its liquid level is located above the tip 7 of the monitoring gas tube 6, the air bubbles flowing out from the tip 4 of the gas inflow tube 1 are The gas does not flow into the tip 7 of the monitoring gas pipe 6 because it is blocked by the inflow prevention cover 9, and rises to the liquid level.

Then, the carrier gas containing volatile substances flows out of the container 3 through the gas outflow pipe 5. Therefore, no gas flows through the monitoring gas pipe 6, and the flow meter 8 does not detect it.

On the other hand, when the volatile substance 2 is depleted and the liquid level is located below the tip 7 of the monitoring gas tube 6, the carrier gas flowing in from the gas inflow tube 1 flows from the tip 7 of the monitoring gas tube 6. and flows through the monitoring gas pipe. Therefore, the flow meter 8 can detect the flow of gas and know the depletion of volatile substances.

Next, a second example of the use of such a volatile substance vaporization device will be explained.
As shown in the figure. The volatile substance is the organometallic triethylindium 41 (T E I , (C2H5)s In )
and triethylgallium-42 (TEG, (C2H5)
3Ga) and is used as a raw material for MOVPE growth of InGaAsP. The volatile substance vaporization apparatus according to one embodiment of the present invention shown in FIG.
It is connected to part 4. Hydrogen is a carrier gas (
H2) with mass flows 45 and 46 for 3 s respectively
o CC/gate and TEI41. through the gas inlet pipe 1 of each vaporizer controlled at 80 CC/m. Then, it flows into the TEG 42 and is bubbled and vaporized. The hydrogen containing vaporized TEI and TEG is then supplied to the MOVPE growth reactor 47 through its gas outlet pipe 6. - The raw material for P and A is 5% hydrogen.
Phosphine 48 (PH3) and arsine 4 diluted to
9(A s Hs ) was used with 17 o CC/lIm and 100 at mass flows of 6° and 51, respectively.
After the flow rate is controlled to CC/11M, it is supplied to the growth furnace 47.

The growth furnace 47 heats the substrate 52 to 670° C., and forms InGaAsP on the substrate 62 by a thermal decomposition reaction of the supplied raw material.
A quaternary mixed crystal grows epitaxially.

Even in such an example of use, the depletion state of the organic metal raw material can be immediately detected, and the growth process can be facilitated.

In addition, as a method of detecting the gas flow flowing through the monitoring gas pipe e, it can also be detected by knowing the gas pressure difference with the gas outflow pipe 5, and an example thereof is shown in FIG. Components that are the same as those in FIG. 1 are given the same numbers as in FIG. 1. 10 is a differential pressure gauge for detecting the gas pressure difference between the monitoring gas pipe 6 and the gas outflow pipe 5. In this embodiment, the differential pressure gauge 10 is integrated into the vaporizer, but it may be provided in the main body of the MOVPE device and separated from the vaporizer.

Further, in this embodiment, a flow meter and a differential pressure gauge are shown as methods for detecting the gas flow flowing through the monitoring gas pipe 6, but the present invention is not limited to this.

Effects of the Invention As described above, according to the present invention, it is possible to immediately and extremely easily know the depletion of volatile substances in a volatile substance vaporization device, and the process using the vaporization device can be performed very efficiently. It is extremely useful because it can be done.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of a volatile substance vaporization apparatus according to an embodiment of the present invention, Fig. 2 is a schematic gas system diagram of a vapor phase growth apparatus as an example of use of the apparatus of this embodiment, and the third characteristic diagram is FIG. 4 is a schematic diagram of a vaporizing device for nine volatile substances according to a second embodiment of the present invention, and FIG. 4 is a schematic diagram of a conventional vaporizing device for volatile substances. 1... Gas inflow pipe, 2... Volatile substance, 4... Tip, 6... Gas outflow pipe,
6... Gas pipe for monitoring, 7... Tip of gas pipe for monitoring, 8... Flow meter,
9...Inflow prevention cover. Name of agent: Patent attorney Toshio Nakao and 1 other person9-
--7 Ninety-eight limbs, sword bar, C-tsumi, purification of the proboscis drawing (no change in content) 5.3 Figure 4 Amendment to figure procedure (method) l Indication of the case Patent Application No. 152463 of 1985 2. Name of the invention Volatile substance vaporization device 3. Relationship with the amended person case Patent application Person address 1006 Oaza Kadoma, Kadoma City, Osaka Name (582) Representative of Matsushita Electric Industrial Co., Ltd.
Akio Tanii 4 Agent 571 Address 1006 Oaza Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. Date of 5 Amendment Order

Claims (4)

[Claims] (1) A gas inflow pipe whose tip end is inserted into a volatile substance; an outflow pipe which supplies gas containing the vaporized volatile substance; and a gas inflow pipe whose tip end is inserted into a volatile substance; A device for vaporizing volatile substances, which is equipped with a monitoring gas pipe into which a gas tube is inserted. (2) The volatile substance vaporization device according to claim 1, further comprising means for detecting gas flowing through the monitoring gas pipe. (3) The device for vaporizing volatile substances according to claim 2, wherein the means for detecting the gas flowing through the monitoring gas pipe is a flow meter. (4) The device for vaporizing volatile substances according to claim 2, wherein the means for detecting the gas flowing through the monitoring gas pipe is a differential pressure gauge that detects the pressure difference between the gas outflow pipe and the monitoring gas pipe. .