JP3007703B2 - Method for producing sulfide thin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a sulfide thin film capable of simultaneously depositing sulfur having a high vapor pressure and another deposition material in a vacuum deposition apparatus to form a film.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a sulfide thin film using a vacuum film forming apparatus, an MSD method, a CVD method, an electron beam evaporation method, a sputtering method and the like are known.

In the CVD method, the electron beam evaporation method, and the sputtering method, for example, a sulfur compound gas such as hydrogen sulfide gas and another thin film forming gas are introduced from outside into a vacuum chamber, and these are combined on a substrate. To form a film.

In the MSD method, a plurality of vapor deposition sources contained in a vacuum chamber are filled with vapor deposition materials, the vapor deposition materials are independently controlled to evaporate, and these vapors are deposited on a substrate to form a film.

[0005]

However, the CVD method,
The electron beam evaporation method and the sputtering method have a disadvantage that decomposition products such as a sulfur compound gas are taken into the thin film, thereby impairing the performance of the thin film. For this reason, a device for recovering the decomposition product is required, and there is a disadvantage that the entire device becomes complicated.

[0006] The MSD method has a disadvantage that when there is a large difference between the vapor deposition pressure of sulfur and the vapor deposition pressure of another vapor deposition material, the jetting amount of sulfur tends to fluctuate due to radiant heat from other vapor deposition sources.

For example, ZnS: M which is a light emitting layer of an EL element
n or CaS: Eu or SrS: Ce or CdS, CdS / InP or P which is a photo sensor, a solar cell or a TFT.
In the case of forming a thin film such as bS, sulfur is used as another vapor deposition material Z.
n, Mn, Ca, Eu, Sr, Ce, Cd, In, Pb
The probability of adhesion to the substrate is smaller than that of
It is necessary to evaporate more than other evaporation materials.

[0008] As a result, the liquid level of the molten sulfur in the crucible greatly changes, and there is a disadvantage that the evaporation amount is not constant. Also, the frequency of material supply to the crucible increases,
Each time replenishment is performed, the inside of the vacuum film forming container 1 is exposed to the atmosphere, and maintenance is troublesome.

Further, as described above, sulfur has a higher vapor pressure than other vapor deposition materials, and therefore, has a relatively low temperature (300 ° C.).
However, since the evaporation source of another evaporation material is at a high temperature, the amount of sulfur evaporation changes under the influence of the heat, and the reproducibility of film formation is reduced. Has also occurred.

The present invention has been made in view of the above-mentioned problems of the prior art,
An object of the present invention is to provide a method for producing a sulfide thin film capable of forming a film by simultaneously vapor-depositing a plurality of vapor deposition materials having different vapor deposition conditions by utilizing the fact that the vapor pressure of sulfur is high.

[0011]

In order to achieve the above object, a method for producing a sulfide thin film according to the present invention comprises the steps of: generating sulfur vapor by an evaporation source separately provided outside a vacuum chamber;
The sulfur vapor is introduced into the vacuum chamber to make the inside of the vacuum chamber a sulfur atmosphere, and the sulfur vapor is supplied to the vacuum chamber together with the vapor of another evaporation material generated by another evaporation source in the vacuum chamber. The film was formed by being attached to a substrate provided inside.

[0012]

According to the above construction, sulfur vapor is generated outside, and this vapor is introduced into the film forming chambers of a CVD apparatus, an electron beam evaporation apparatus and a sputtering apparatus, and a film is formed by each method. Problems caused by decomposition products generated when film formation is performed by introducing a gas or the like do not occur.

[0013] Even when used in an MSD apparatus, since vaporization occurs externally, it is not affected by heat from other evaporation sources.

That is, the method having the above structure is applicable to a CVD apparatus, an electron beam evaporation apparatus, and a sputtering apparatus.
Alternatively, the present invention can be applied to any vacuum deposition apparatus, even an MSD apparatus.

[0015]

FIG. 1 shows a first embodiment of the present invention. FIG. 1 shows M
FIG. 2 is a process chart of the present embodiment for an SD vacuum film forming apparatus, and FIG. 2 shows an example of the MSD vacuum film forming apparatus.

First, the example of the MSD vacuum film forming apparatus shown in FIG. 2 includes a plurality of evaporation sources 2 and 3, a substrate holder 4 and a substrate heater 5, and includes an exhaust valve 9 and a vacuum pump 10. A container 6 is separately arranged below the outside of the vacuum tank 1, and a straight steam introduction pipe 7 is introduced into the vacuum tank 1 from above the container 6.

The evaporation sources 2 and 3 referred to herein are a crucible,
The configuration includes a vapor deposition material and a heater. However,
The heater 8 of the outer container 6 is configured so as to ring around the container 6 (the same applies to the following drawings).

Other examples of the MSD vacuum film forming apparatus include an apparatus in which the outer container 6 is provided on the vacuum vessel 1 (FIG. 3) and an apparatus in which the heater 8 is provided in the outer container 6 (FIG. 6). It can be selected as appropriate.

In this example of the MSD vacuum film forming apparatus, the embodiments are as follows: (a) The vapor deposition sources 2 and 3 in the vacuum chamber 1 are filled with a vapor deposition material;
Further, the container 6 is filled with sulfur, and (b) the substrate is fixedly mounted on the substrate holder 4 in the vacuum tank 1, and the air in the vacuum tank 1 and the inside of the container 6 is discharged to the atmosphere using a vacuum pump 10. (C) heating the vapor deposition sources 2 and 3 and the container 6 in the vacuum chamber 1 independently by controlling them; (d) generating vapor for each vapor deposition material and sulfur vapor via the vapor introduction pipe 7 (E) Each vapor chemically bonds on the substrate in a sulfur atmosphere,
Thus, a sulfide thin film is formed on the substrate.

Next, other embodiments will be listed. In the second embodiment, the present invention is applied to a vacuum deposition apparatus for sputtering (FIG. 5). In the third embodiment, the present invention is applied to a vacuum deposition apparatus for electron beam evaporation (FIG. 4). The embodiment is a case where the present invention is applied to a vacuum film forming apparatus (not shown) for CVD.

Embodiments of the second to fourth embodiments are as follows. (1) Sulfur vapor is generated by a vapor deposition source separately provided outside the vacuum chamber 1, (2) This sulfur vapor is introduced into the vacuum chamber 1, (3) The inside of the vacuum chamber 1 is made a sulfur atmosphere, 4) This sulfur vapor is provided inside the vacuum chamber 1 together with the vapor of another evaporation material generated by another evaporation source (12 in FIG. 4 or 13 in FIG. 5) in the vacuum chamber 1. This is a configuration in which a film is formed by being attached to a substrate that has been removed.

The experimental results of the first embodiment will be described below.
The experiment is an example in which ZnS: Mn, which is a light emitting layer of a thin film EL element, is formed. To explain this in order, the glass substrate is mounted on the substrate holder 4 in the vacuum chamber 1. The deposition source 2 has Z
n, Mn is filled in the evaporation source 3, and sulfur is filled in the evaporation source of the outer container 6. The vacuum pump 10 is driven to release the air in the vacuum chamber 1 and the container 6 into the atmosphere,
The internal pressure is 5 × 10 ⁻⁶ Torr.

Next, when the evaporation sources 2 and 3 and the evaporation source of the container 6 are heated while being controlled independently of each other, vapors of Zn and Mn are generated in the vacuum chamber 1, and the containers heated by the heater 8 are heated. In 6, sulfur vapor is generated. This sulfur vapor is introduced into the vacuum chamber 1 through the steam introduction pipe 7. The pressure in the vacuum chamber 1 is adjusted by the valve 14 so as to be 3 × 10 ⁻⁴ Torr. The vapors Zn and Mn are chemically bonded on the substrate in a sulfur atmosphere to form a sulfide thin film ZnS: Mn.

The “sulfur atmosphere” refers to at least one particle (eg, atoms, molecules, clusters, etc.) evaporated from the crucible of the evaporation source or the external container 6 before reaching the substrate.
More than once, the atmosphere has a pressure such that it is scattered by the sulfur particles.

According to the effect of this experiment, it has been clarified that a vacuum film forming apparatus for MSD can be used even with an intractable material such as sulfur. Further, according to the second to fourth embodiments, it is possible to utilize a vacuum film forming apparatus such as an electron beam evaporation method, a sputtering method, or a CVD method without using a sulfur compound gas.

In terms of the performance of the product thin film, the thin film has better reproducibility than the conventional product. Furthermore, the method of the present invention itself is easy, and the number of times of replenishment of sulfur is small. In the above experiment, the number of times of replenishment is 1/8 of that of the prior art.

[0027]

As described above, according to the method for producing a sulfide thin film of the first invention, even if sulfur having a significantly different vapor pressure from that of a normal vapor deposition material is vapor-deposited simultaneously with the normal vapor deposition material, the film is formed. You can do it. In addition, the vacuum film forming apparatus to which the present invention is applied simply needs to provide a vapor deposition source for generating sulfide vapor outside the conventional vacuum film forming apparatus, and the electron beam vapor deposition method, the sputtering method, the CVD method, and the MSD method. Can be utilized without any trouble. Moreover, in any case, a film can be formed with higher reproducibility than the thin film quality according to the conventional technique. Further, the present invention has an effect that the control itself is easy and the number of times of replenishment of sulfur is small.

[Brief description of the drawings]

FIG. 1 shows a first example of application to a vacuum deposition apparatus for MSD.
It is process drawing of an Example.

FIG. 2 is a schematic configuration diagram of an example of a vacuum film forming apparatus to which the first embodiment is applied.

FIG. 3 is a schematic configuration diagram of another example of a vacuum film forming apparatus to which the first embodiment can be applied.

FIG. 4 is a view of an example of a vacuum film forming apparatus for electron beam evaporation to which the method of the present invention can be applied.

FIG. 5 is a schematic configuration diagram of an example of a vacuum deposition apparatus for a sputtering method to which the method of the present invention can be applied.

FIG. 6 is a schematic configuration diagram of another example of a vacuum film forming apparatus to which the first embodiment can be applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum tank 6 External container 7 Steam introduction pipe 11 Heater

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-1-301854 (JP, A) Japan Society for the Promotion of Science “Thin Film Engineering Handbook” (Application to Electronics) (Showa 39-5-25) Ohmsha p. . ▲ II ▼-145 (58) Field surveyed (Int. Cl. ⁷ , DB name) C23C 14/00-14/58

Claims (1)

(57) [Claims] In producing a sulfide thin film , sulfur vapor is generated by an evaporation source separately provided outside a vacuum chamber, and the sulfur vapor is introduced into the vacuum chamber to form a sulfur atmosphere in the vacuum chamber. A sulfide characterized in that a film is formed by attaching this sulfur vapor together with a vapor of another vapor deposition material generated by another vapor deposition source in the vacuum chamber to a substrate provided inside the vacuum chamber. Manufacturing method of thin film.