JPS637620A - Apparatus for vaporizing volatile material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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. Ride vapor phase epitaxial growth method and organometallic vapor phase growth 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 PhaseEpi
There is a taxi (MOVPE for short). 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 mass flow controller 6
tjim is introduced into the inflow pipe 1 and flows into a container 3 containing a volatile substance 2 which is an organometallic substance. Since the tip 4 of the gas inflow pipe 1 is inserted into the volatile substance 2, the carrier gas that has flowed in becomes bubbles and flows into the volatile substance 2.
The inside rises 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 vaporization device for the volatile substance 2 sets the vapor pressure of the volatile substance 2 by keeping the inside of the container 3 at a certain temperature in a constant temperature bath, etc., and the vaporization of the volatile substance 2 is controlled by the flow rate of the carrier gas. Control the supply amount used for phase growth. 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 substances are introduced into the vapor growth reaction section while being contained in the carrier gas, and crystals are grown. be done.

Problems to be Solved by the Invention Usually, a volatile substance is kept at a certain temperature, and during bubbling, a volatile substance dissolves into a carrier gas such as H2 by an amount of saturated vapor corresponding to that temperature. However, keeping volatile substances warm is
Unless a container containing a volatile substance is kept warm, and heat is conducted indirectly from the outside, the volatile substance cannot be kept sufficiently uniformly warm. Furthermore, since the carrier gas is normally introduced into the container at room temperature, the heat from the carrier gas makes it difficult to maintain the volatile substance at the desired temperature sufficiently uniformly. Therefore, it becomes very difficult to control the supply amount of raw materials used for vapor phase growth.

Means for Solving the Problems The technical means of the present invention for solving the above problems is that in a vaporization device for vaporizing a volatile substance used in a vapor phase growth device, a container for accommodating the liquid raw material and a container for storing the liquid raw material, In order to increase the contact area of the carrier gas and lengthen the path through which the carrier gas bubbles pass through the liquid raw material during bubbling, the container is provided with obstacles for the bubbles.

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

When keeping a volatile substance at a certain temperature, since the contact area between the volatile substance and the container containing it is large, heat conduction from the container to the volatile substance is easy, and the volatile substance is kept at a very uniform temperature. In addition, the carrier gas bubbles have a long path through the volatile substance during bubbling, and the bubbles stay in the volatile substance for a long time, so temperature fluctuations in the volatile substance are extremely small.

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, the volatile substance is not limited to organic metals, and this vaporization device may be connected to any device as long as it is a device that vaporizes and uses a volatile substance.

One embodiment of the invention is shown in FIG. 1 is a carrier gas inflow pipe. 2 is a volatile substance, which is contained in a 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 carrier gas containing vaporized volatile substances flows out. Inside the container 3, several flat plates 7 made of the same material (SUS31e) protrude and are divided into classrooms. Adjacent chambers are connected at the end of the flat plate 7. The connecting portions are arranged alternately so that carrier gas bubbles pass through the volatile substance in a meandering manner. This increases the contact area between the volatile substance 2 and the container 3, and since the carrier gas bubbles meander through the volatile substance 2 and rise to the liquid level, the bubbling path becomes longer and the bubbles Since the residence time in the volatile substance 2 is increased, the volatile substance 2 is maintained in an extremely uniform and accurate heat-retaining state.

FIG. 2 shows an example of the use of a volatile substance vaporization device having the above-described structure. The volatile substance is the organometallic triethylindium-41 (TEI, (C2H5)3In).
and triethyl gallium 42 (TEG, (02H
5) 3Ga) and is used as a raw material for MOVPE growth of InGaAsP. A volatile substance vaporization device according to an embodiment of the present invention shown in FIG. 1 is connected to sections 43 and 44. Hydrogen (H2), which is a carrier gas, has mass flows of 35 and 46, respectively.
TE I through the gas inlet pipe 1 of each vaporizer, controlled at 0 CC/min and 80 CC/min.
41 and TEG 42, and is bubbled and vaporized. Hydrogen containing vaporized TEI and TEG is passed through each gas outlet pipe 5 to the MOVPE growth reactor 47.
supplied to - On the other hand, as raw materials for P and As, phosphine 48 (PH3) and arsine 49 (AsH3) diluted to 50% with hydrogen were used, with mass flows of 50 and 61, respectively, of 170 l/min and 10
After the flow rate was controlled to 0 l/min, the growth furnace 47
supplied to In the growth furnace 47, the substrate 52 is heated to 670° C., and an InGaAsP quaternary mixed crystal is epitaxially grown on the substrate 52 by a thermal decomposition reaction of the supplied raw material.

Even if the growth was performed many times in succession by this method, the fluctuations in composition and film thickness were extremely small.

The compositional variations and film thickness variations (growth time: 1 hour) of 40 runs in which the susceptor was replaced after each growth were x=0.27±0.03, 7=O, and chi0. A good quaternary mixed crystal with extremely good controllability of (1) and 1 μm±0.02 was obtained.

In addition, in the flat plate 7 of the present invention, the bubbling air bubbles are volatile substances 2.
It may have a certain degree of inclination upward so that it can easily rise to the liquid level. This embodiment is shown in FIG.

Components that are the same as those in FIG. 1 are given the same numbers as in FIG. 1.

Further, the inside of the container may be formed in a linear shape as an obstacle to the bubbles so that the bubbling path of the volatile substance 2 is linear. This embodiment is shown in FIG.

Furthermore, a mesh may be used as an obstacle to air bubbles. This embodiment is shown in FIG. 9 in the figure is a mesh.

Effects of the Invention As described above, according to the present invention, the volatile substances contained in the vaporizer are kept in an extremely uniform temperature state, and there is no temperature fluctuation, so the amount of vaporized volatile substances can be controlled very easily. It is accurate and extremely useful.

[Brief explanation of drawings]

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 the use of this embodiment apparatus, and FIG. 4 and 6 are schematic diagrams of a volatile substance vaporization apparatus according to other embodiments of the present invention, and FIG. 6 is a schematic diagram of a conventional volatile substance vaporization apparatus. 1... Gas inflow pipe, 2... Volatile substance, 3... Container, 4... Tip, 5...
...Gas outflow pipe, 7...Flat plate. Name of agent: Patent attorney Toshio Nakao and one other person”−
Tl entry゛kan 2-°1 go + 1 thing'W 5"゛1 suf 0-]nLll-ra 7-°乎sha Fig. 3 Fig. 4 Total -° 5 line Ig 脣 阜 g7 Fig. 5 9---Me 1.

Claims (4)

[Claims] (1) A device for vaporizing a volatile substance, in which a container containing the volatile substance is provided with an obstacle for carrier gas bubbles passing through the volatile substance. (2) During bubbling, the obstruction is flat so that carrier gas bubbles pass through the volatile substance in a meandering manner;
2. The device for vaporizing a volatile substance according to claim 1, wherein a plurality of the vaporizers are arranged in a comb shape so as to protrude from the inner wall of the container. (3) During bubbling, the inside of the container acts as an obstacle so that carrier gas bubbles pass linearly through the volatile substance.
The device for vaporizing a volatile substance according to claim 1, which has a spiral shape. (4) The volatile substance vaporization device according to claim 1, wherein the obstruction is a mesh.