JPS604995Y2 - material evaporation equipment - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a material evaporation device.

In general, vapor deposition is an advantageous method for forming amorphous silicon films useful as components of solar cells, for example. When facing the substrate, there is a strong possibility that coarse particles of the material will be scattered due to boiling in the evaporation material and adhere to the evaporation substrate.

If these coarse grains adhere to the deposition substrate, the deposited film will become useless.

It goes without saying that the evaporation source container for storing the evaporation material should preferably be one that does not react with the material and is inexpensive.

This invention was made based on the above points,
The purpose is to provide a material evaporation device that does not cause scattering of coarse particles, is stable with respect to the material, and is low in cost.

An embodiment of the present invention will be described below with reference to the drawings.

In the present invention, as shown in FIGS. 1 and 2,
A cylindrical evaporation source container 12 having a vapor discharge port 11 at its upper end is provided with an inwardly projecting step 13 at a lower position on the inner peripheral surface thereof, and the evaporation The lower bottom of the source container 12 is filled with evaporative material 14 .

A cylindrical droplet blocking member 15 having an opening at its lower end is placed and supported on the stepped portion 13 via a ridge 16 provided on the outer periphery of its lower end. A vapor permeation port 17 formed by a plurality of through holes is formed in the peripheral wall facing the inner circumferential surface of the evaporation material 12 via a space, so that the upper surface of the evaporation material 14 directly faces the vapor release port 11. The vapor discharge port 1 is passed through the evaporation space 18 through a bent path to expose the upper surface of the evaporation material 14 surrounded by the splash blocking member 15 so as to be prevented from being exposed.
Connect to 1.

Further, a cylindrical sheet electric heater 19 made of molybdenum, tantalum, tungsten, graphite, etc., for example, is provided along the outer circumferential surface of the evaporation source container 12, and a circumferential wall that doublely surrounds the outer circumference of the heater 19 is provided. An outer container 21 having 20, 20 is provided.

22 is a flange projecting radially outward from the upper end of the evaporation source container 12;
This is a lead portion that extends through the peripheral wall 20 of No. 1.

The material of the evaporation source container 12 is boron nitride, and more preferably the material of the splash blocking member 15 and the outer container 21 is also boron nitride.

In the above, the droplet blocking member 15 specifically includes:
The straight line passing through the vapor transmission port 17 that is most vertical does not reach the vapor release port 11 of the evaporation source container 12 and
For this purpose, the position of the vapor transmission port 17 in the evaporation source container 12, its diameter, the peripheral wall of the droplet blocking member 15, and the inside of the evaporation source container 12 are required. The distance from the surrounding surface, the thickness of the splash blocking member 15, etc. may be set to appropriate values.

Since the evaporator of the present invention has the above-described configuration, when the electric heater 19 is energized to generate heat, the evaporation material 14 is heated and melted through the wall of the evaporation source container 12 by the heat, and the droplet blocking member 15 Evaporating into the enclosed evaporation space 18, this material vapor moves to its exterior via the vapor permeation port 17 and is discharged upwardly from within the evaporation source vessel 12 via the vapor outlet 11, thereby causing the vapor deposition to take place. It is done.

According to the present invention, the upper surface of the evaporation material 14 is not exposed to the steam release port 11 by the splash blocking member 15, so that boiling occurs in the molten evaporation material 14 and the droplets are scattered. Even if it does, it will not jump out from the steam outlet 11.

That is, the droplets collide with and adhere to the droplet blocking member 15, but return to the evaporation material 14 again or evaporate on the droplet blocking member 15.

In addition, droplets flying out from the evaporation space 18 through the vapor transmission port 17 always collide and adhere to the inner peripheral surface of the evaporation source container 12, where they evaporate and are released from the vapor release port 11. .

In this way, it is possible to completely prevent droplets of the molten material from scattering from the evaporation source container 12, so that coarse particles do not adhere to the resulting evaporated film, and as a result, the evaporation of the evaporation material is prevented. The speed can be increased, making it possible to perform the desired material deposition, and the material that has been scattered and attached to the inner peripheral surface of the evaporation source container 12 is further evaporated, contributing to the deposition. Therefore, evaporation material 1
4 will not be wasted.

Furthermore, in the present invention, since the evaporation source container 12 is made of boron nitride, the molten material does not react with the substance in the evaporation source container 12, and no impurity gas is generated, so that a highly pure evaporated film is formed. Moreover, any remaining solidified lumps can be removed from the source container 12 very easily by applying an appropriate impact to the source container 12 after the required material has been deposited.

This is because the degree of wetting of the molten material to the boron nitride is low.

Therefore, the evaporation source container 12 can be used again for material evaporation, and since boron nitride is a processable material and the container 12 is easy to manufacture, the cost of evaporation is significantly reduced. be able to.

Furthermore, an electric heater 19 for heating the evaporation material 14
Since it is surrounded by the peripheral wall 20 of the outer container 21, this peripheral wall 20 acts as a heat reflecting member or as a secondary heating element when the temperature rises, thus efficiently heating the evaporation material. be able to.

If the outer container 21 and the splash blocking member 15 are also made of boron nitride, the same effects as described above can be obtained in these as well.

The flange 22 of the evaporation source container 12 is
This function serves to prevent steam from the heater 19 and the like from entering and adhering to the outer container 21 and the like, and also to prevent impure gas from the heater 19 and the like from entering the vapor deposition space.

FIG. 3 shows another embodiment of the present invention. In this example, instead of the cylindrical sheet heater 19, a coiled heating wire 24 made of, for example, tungsten is installed in a cylindrical shape that also serves as a heat reflecting plate. The heater holding member 25 is held on the inner peripheral surface thereof, and the outer container 21 is provided on the outer periphery thereof.

Even in such a configuration, the same effects as in the previously described example can be obtained.

Alternatively, as shown in FIG. 4, a cylindrical heater 26 having no leads may be made of, for example, graphite and placed therein, and the heater 26 may be heated by induction heating to generate heat and heat the evaporation material. good.

In vapor deposition using the device of the present invention, amorphous silicon can be doped with a substance, for example, ionized hydrogen from a hydrogen discharge tube is introduced into the vapor deposition space in order to introduce hydrogen into the amorphous silicon being formed. However, by introducing a P-type dopant such as boron, aluminum, gallium, or indium, or an N-type dopant such as antimony, arsenic, or phosphorus into the silicon film, a silicon film having desired characteristics can be obtained.

As described above, according to the present invention, with an extremely simple configuration,
It is possible to prevent the adhesion of coarse particles and form a deposited film with desired characteristics, and it is also possible to provide a material evaporation device that is inexpensive and reusable.

[Brief Description of the Drawings] Figure 1 is a longitudinal cross-sectional view of one embodiment of the material evaporator of the present invention, Figure 2 is a plan view of the heater and outer container, and Figure 3 is a longitudinal cross-section of another embodiment of the present invention. FIG. 4 is a plan view of a heater and an outer container of still another embodiment. 11... Steam release port, 12... Evaporation source container, 15... Splash blocking member 17...
・Vapor transmission port, 18... Evaporation space, 19, 26
...Heater 21 ...Outer container, 24
... Heating wire, 25 ... Heater holding member.

Claims (1)

[Scope of utility model registration request] an evaporation source container in which an evaporation material is stored; a particle scattering prevention member provided on the evaporation source container; a heater provided on the outer periphery of the evaporation source container for heating and evaporating the evaporation material; The evaporation source container has a cylindrical shape and has a vapor discharge port at its upper end and a step portion protruding inward at a lower position on the inner circumferential surface. , the particle scattering prevention member has a cylindrical shape, is provided on the stepped portion of the evaporation source container, and has a plurality of vapor permeation ports in its peripheral wall facing the inner peripheral surface of the evaporation source container with a space in between. A material evaporation device comprising: a material of the evaporation source container is boron nitride.