JPH05271912A - Method for generating vapor and device therefor - Google Patents

Abstract

PURPOSE:To improve the efficiency in vaporizing a raw material by applying a current to the liq.-film raw material to produce Joule heat and heating the raw material with the heat to generate the vapor. CONSTITUTION:A power source 17 is connected to an upper vessel 11 and a lower vessel 13, the upper vessel 11 and the lower vessel 13 are short-circuited by a liq. film 16 when the film 16 flows down on the surface of an insulating member 14 and reaches the lower vessel 13, and an electrical closed circuit is formed. Consequently, a current is passed through the film 16 by the power source 17, Joule heat is produced by the electric resistance of the film 16, hence the film 16 is vaporized, and the generated vapor 18 is radially diffused. Since an electron beam is not used, a current is applied to the film 16, and the film is heated and vaporized by the Joule heat, a vessel to keep the molten raw material at high temp. or cooling equipment is not needed, and the entire device is simplified. Besides, since almost all the supplied energy is used to vaporize the raw material, the vaporization efficiency is remarkably enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for generating a vapor of a substance by electric heating, and more particularly to a method and an apparatus for producing a vapor for stable steam supply.

[0002]

2. Description of the Related Art Optical device manufacturing processes, semiconductor film forming processes,
In the industrial field such as development of functional materials, film forming technology by vaporization of substances represented by vacuum vapor deposition method, chemical vapor deposition method, molecular beam epitaxy method and the like has been conventionally used.
In these techniques, the substance to be film-formed or the composition raw material of the substance is vaporized and vapor-deposited on a solid wall, and as means for vaporizing or sublimating the substance, heater heating, high-frequency heating are used. , Beam heating and the like. Among them, the beam heating uses a laser beam, a neutral particle beam, and a charged particle beam as an energy driver to directly and locally heat only the surface of the substance. Not many have advantages. In particular, the electron beam as an energy driver is widely used because it is easy to generate a beam source, propagate the beam, and focus the beam, and the cost of the entire device is low. It is the current situation. A conventional method for producing a vapor of a substance by heating an electron beam and a conventional apparatus therefor will be described below with reference to FIGS. 3 and 4.

FIG. 3 is a system diagram schematically showing the structure of a conventional vapor generator of a substance by heating an electron beam.
FIG. 4 is a vertical cross-sectional view showing the configuration of the vapor generator of the substance shown in FIG. The substance 1 to be evaporated is contained in a container 2 having thermochemical resistance, such as a crucible. next,
An electron beam 4 emitted from the electron gun 3 is deflected by a DC magnetic field 5 applied by an external magnetic field coil (not shown), and is irradiated onto the surface of the substance 1 contained in the container 2. The substance 1 irradiated with the electron beam 4 is heated only to the beam irradiation portion 6 to a high temperature above the evaporation temperature, and a vapor 7 of the substance 1 is generated from the portion. The vapor 7 is vapor-deposited on the solid wall surface 8 arranged on the upper part of the container 2, and a thin film 9 of the substance 1 is formed on the surface.

On the other hand, the substance 1 contained in the container 2 is
Since it decreases as the steam 7 is generated, it is necessary to sequentially supply the substance 1 to the container 2. However, since the apparatus main parts such as the electron gun 3 including the container 2 are all placed in a vacuum atmosphere, there is no steady raw material supply means to the container 2, and the apparatus operation must be stopped each time. . Further, not only the container 2 which contains the substance 1 to which the electron beam 4 is irradiated, but also the reflection beam 10 generated by the surface reflection at the beam irradiation unit 6 heats the surrounding structures not shown. Therefore, a separate means for cooling these parts is required.

[0005]

As described above, in the steam generator having such a structure as described above, the following problems are caused by the use of the electron beam as the energy driver. Points have been pointed out.

(1) The electron beam is easily reflected on the surface of the material to be heated, and only about half of the input power contributes to heating the material. Other power is reflected as invalid power,
It will be dissipated and cause energy efficiency to drop.

(2) Since the liquefied substance is contained in the container and the surface thereof is locally heated, the vapor generation source is limited to the electron beam irradiation part. Therefore, the steam is generated from this portion as if it were jetted from the nozzle, and it is difficult to generate spatially uniform steam.

(3) Due to the influence of the generated steam, a trouble such as dielectric breakdown is likely to occur in the electron gun, which causes a problem in maintenance and inspection of the device. Further, this limits the operation time of the device, which is a factor of reducing the economical efficiency.

The present invention has been made in order to solve the above problems, and eliminates the above-mentioned drawbacks of the prior art, and makes it possible to stably supply steam to a wide area. It is an object to provide a method and an apparatus thereof.

[0010]

According to a first aspect of the present invention, there is provided at least one pair of upper and lower containers for containing a liquefied substance, and the upper and lower containers forming the pair are connected by a cylindrical insulating member. Then, by causing the liquefied substance in the upper container to flow down along the surface of the cylindrical insulating member,
A liquid film of a liquefied substance is formed on the surface of this cylindrical insulating member,
When a voltage is applied by connecting both electrodes of the power supply circuit to the liquefied substance of the upper and lower containers or the upper and lower containers, the liquid film reaches the lower end of the cylindrical insulating member, and when the power supply circuit is in a short circuit state, An electric current flows through the liquid film,
It is characterized in that the liquid film is evaporated by heating.

The steam generator according to the second aspect of the present invention is a cylindrical insulating member for transporting the liquefied substance from the upper container to the lower container, and means for accommodating the liquefied substance and at least one pair of upper and lower containers. And means for electrically heating the liquefied substance flowing down the surface of the cylindrical insulating member.

[0012]

According to the steam generating method and the apparatus thereof according to the present invention, it is not necessary to dispose a device having a complicated structure in which a high voltage is applied to a region filled with the steam unlike an electron gun.
Further, there is no need for a container for holding high temperature raw materials or a mechanism for supplying raw materials. As a result, the device configuration becomes very simple, and there is no fear of failure, and a highly reliable device can be obtained. Furthermore, since the material that has turned into a liquid film is vaporized by the electric current flowing through the jar heating, there is no need for container cooling, which is a cause of wasted energy, and almost all of the energy input is energy for evaporation. It is possible to improve the evaporation efficiency.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical sectional view showing a device configuration of an embodiment according to the present invention, and FIG. 2 is a sectional view taken along the line II of FIG.

1 and 2, a liquefied substance 12 is supplied to the upper container 11 by a separate means (not shown), and a lower container 13 is arranged so as to face the upper container 11. Upper container
11 and the lower container 13 are bridged by a cylindrical insulating member 14, and the liquid film 16 flowing down from the hole 15 at the bottom of the upper container 11 along the surface of the insulating member 14 flows back to the lower container 13. It is composed.

Further, in the upper container 11 and the lower container 13,
Power supply 17 is connected. When the liquid film 16 flows down the surface of the insulating member 14 and reaches the lower container 13, the liquid film 16 short-circuits the upper container 11 and the lower container 13 to form an electrically closed circuit. Therefore, a current flows through the liquid film 16 by the power source 17, and the liquid film 16
Due to the electric resistance of the liquid, a Jule heat is generated, and the liquid film 16 is evaporated to generate vapor 18 that diffuses in the radial direction.

Further, the liquid film 16 does not reach the lower container 13, or the liquid film 16 evaporates, and a cylindrical insulating member is formed.
When the surface of 14 is partly or wholly dried and an electric closed circuit including the power supply 17 is not formed, the jule heat is not generated.

As described above, in this embodiment, the electron beam is not used to evaporate the raw material, and a current is passed through the liquid film 16 to heat and evaporate the liquid film 16 by the Jule heat. As described above, a raw material container for holding the molten raw material in a high temperature state or a cooling facility for cooling the raw material container is not required, and the entire apparatus can be configured with a simple structure. Moreover, since almost all of the input energy can be used as energy for evaporating the raw material, the evaporation efficiency can be significantly increased. On the other hand, in this embodiment, a mechanism for supplying the liquefied substance 12 to the upper container 11 can be easily arranged, and addition of raw materials and maintenance / inspection can be performed relatively easily.

[0018]

As described above, according to the steam generating method and the apparatus therefor of the present invention, an electric current is passed through the liquid film-shaped raw material to generate jule heat, and the raw material is heated by the heat. Since the vapor is generated by heating and vaporization, almost all the input energy is effectively used as the energy for vaporization, and the vaporization efficiency of the raw material can be improved.

Further, the energized continuous flow supplied from the external power source is automatically adjusted according to the state of the liquid film, so that stable operation can be performed without unevenness in steam generation. Further, the failure of the electron gun, which has been a main cause of troubles in the past, is eliminated, and an additional device for cooling the raw material container is not required, so that simplification of the device and high reliability are guaranteed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing the structure of a steam generator according to the present invention.

FIG. 2 is a sectional view taken along the line I-I shown in FIG.

FIG. 3 is a system diagram schematically showing the configuration of a conventional substance vapor generator by electron beam heating.

FIG. 4 is a vertical cross-sectional view showing the configuration of a vapor generator of the substance shown in FIG.

[Explanation of symbols]

 1 ... Material 2 ... Container 3 ... Electron Gun 4 ... Electron Beam 5 ... DC Magnetic Field 6 ... Beam Irradiation Part 7 ... Vapor 8 ... Solid Wall 9 ... Thin Film 10 ... Reflective Beam 11 ... Upper Container 12 ... Liquefaction Material 13 ... Lower container 14 ... Insulation member 15 ... Hole 16 ... Liquid film 17 ... Power supply 18 ... Steam

Claims (2)

[Claims] 1. At least one pair of upper and lower containers for accommodating a liquefied substance, the upper and lower containers forming the pair are connected by a cylindrical insulating member, and the liquefied substance in the upper container is connected to the surface of the cylindrical insulating member. To form a liquid film of a liquefied substance on the surface of this cylindrical insulating member, and to apply a voltage by connecting both electrodes of the power supply circuit to the liquefied substance in the upper and lower containers or the upper and lower containers, When the liquid film reaches the lower end of the cylindrical insulating member and the power supply circuit is short-circuited, a continuous current flows through the liquid film, and the liquid film is heated by a jar to evaporate the liquid film. A method of generating steam characterized by. 2. A means for accommodating a liquefied substance and at least one pair of upper and lower containers, a cylindrical insulating member for transporting the liquefied substance in these containers from an upper container to a lower container, and a surface of this cylindrical insulating member to flow down. A vapor generator comprising means for electrically heating a liquefied substance.