JPS6026658A - Formation of thin film - Google Patents

Abstract

PURPOSE:To form selectively a thin film of an additive layer only on the surface of the thin film of a prototype in the stage of forming the thin film of the additive layer on the thin film of the prototype formed on a part of a substrate and specifying the critical atom supplying rate of a material necessary for forming the thin film of the additive layer. CONSTITUTION:A thin film of a photoelectric transducer, etc. is manufactured by forming further a thin film (II-VI group compd. semiconductor) as an additive layer on the thin film (transparent electrode film) of the prototype formed on at least one layer in a part of a substrate (glass). The critical atom or molecular supplying rate alphaf necessary for forming the thin film of the additive layer on the surface of the thin film of the prototype is set smaller than the critical atom or molecular supplying speed alphas necessary for forming the thin film of the additive layer on the surface of the substrate in the above-mentioned stage. The material for forming the thin film of the additive layer is at the same time supplied at the atom or molecule supplying rate alpha to satisfy the condition alphaf<alpha<alphas. The number of etching stage is thus decreased without requiring a mask.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for forming a thin film that can be used to manufacture a thin film device such as a photoelectric conversion element, and particularly relates to a method for forming a thin film that can be used to manufacture a thin film device such as a photoelectric conversion element. ill on the thin film
) A thin film forming method for forming four films as d.

Conventional structure and points of escape When manufacturing a multilayer thin film device, when forming a thin film on an imitation M that has been previously formed on a part of a substrate, conventionally a mask is used or Alternatively, after forming a thin film of the second layer on the entire surface of the substrate 1 including the thin film of the first layer, unnecessary parts are removed by etching or the like, leaving the second thin film τ only on the desired parts. It was used. However, the method of using the mask 7 is not necessarily suitable when the pattern=<m, since problems such as alignment and wrapping of material during thin film formation arise. In addition, the etching method often uses acids, alkalis, etc., which has the disadvantage that necessary parts may be attacked and the performance of the device may be degraded, and the number of steps increases.

OBJECTS OF THE INVENTION The present invention solves the drawbacks of the above-mentioned conventional example, and an object thereof is to provide a thin film forming method that makes it possible to reliably manufacture a desired R film device τ with a small number of steps.

In order to achieve the above-mentioned objective τ, the structure of the notch is to further form a thin film as an additional layer on the original R film formed at least 1 part on a part of the substrate. In this case, the critical atom or molecule supply rate α required for forming an additional thin film on the surface of the original thin film is set to be smaller than the critical atom or molecule supply required for forming an additional layer on the surface of the substrate α 7 , and the additional Layer (L) Material for forming a thin film By introducing the conditions of i:J plus atoms or molecules to form the thin film, an additional layer can be selectively formed only on the surface of the original thin film. A thin film forming method capable of forming a film is provided.

In general, vapor deposition? In the thin film formation process by sputtering, etc., in order for the thin film to grow stably on the substrate, the substrate temperature and the rate of supply of atoms or molecules of the thin film forming material (which can be a single substance or a compound) to the substrate are important. There exists a certain critical value.

In other words, at a certain substrate temperature, film formation will only occur at an atom or molecule supply rate above a certain value, or conversely, at a certain atom or molecule supply rate, film formation will not occur unless the substrate temperature is below a certain value. . The 1m limit value for such a n0 film formation greatly depends on the surface condition of the substrate material, and if the substrate material is different,
Naturally, the critical values will also differ. Therefore, some parts of the substrate
A prototype thin film (which can be considered as a substrate of different materials) consisting of a layer of 1 m or more is exposed to a mouse at °C.
Then, the critical atom or molecule supply rate α required for forming an additional layer of thin film in two times of the original thin film is
If f is smaller than the critical atom or molecule supply rate α3 required for forming a thin film of the additional layer on the substrate surface, then 1 of the additional layer
By supplying the material for the τ-type film at an atom or molecule supply rate σ that satisfies the conditions αf, α, α8, it is possible to selectively form four additional layers only on the original thin film surface. It is something.

Description of examples An embodiment of the present invention will be described below.

First, a transparent electrode film of 1/i'] is formed on the entire surface of a glass substrate as an original thin film by evaporation or sputtering of In20a or SnO2, and then etched so that the necessary parts remain, and +IJ4 Part of the glass is exposed. On this transparent electrode film, an additional 1 m thick thin film is formed by vapor deposition or sputtering of l-IV group compound semiconductor.

For example, if CdS is used as a CdS group compound semiconductor,
In this case, an additional layer is formed on the transparent electrode film by the thin film chamber sputtering method.In the case U, a glass substrate on which a transparent electrode film is partially formed is placed on a turntable rotating at about 5 rpm. and intermittently exposed to plasma. The board temperature is 250'C! .

The argon gas pressure is 5×10 TOrr% and the sputtering power is about 200W. When a CdS thin film is formed under such conditions, the CdS thin film is selectively formed only on the transparent electrode where the critical molecule supply rate is low, and is not formed on the substrate surface where the glass is exposed.

Incidentally, in the above-mentioned embodiment, the case a was explained in which an additional thin film layer is formed on one original thin film layer formed on a glass substrate. It goes without saying that it is possible to fabricate an N-film device formed from a thin film of 8 or more times the thickness of the film.

In addition, materials other than those used in this embodiment can be used as materials for the substrate, the original thin film, and the thin film of the follow-up skin.

Effects of investigation As explained above, in the thin film forming method according to the present invention,
The critical atom or molecule supply rate αfτ necessary for the thin film shape of the additional layer to fall on the original thin film surface ζ
By supplying atoms or molecules at a supply rate α that satisfies the conditions for forming the additional thin film, the material is selectively applied only to the surface of the original thin film. Since three additional layers are formed, there is no need for mass dandruff, which not only eliminates the need for mask alignment and concerns about the thin spreadable material wrapping around the etching process.
In addition to reducing the amount of release caused by the etching process (
It is possible to improve the yield by reducing the occurrence of damage to the necessary parts, etc.), and it is possible to reduce the cost.

Agent Yoshihiro Gunmoto

Claims (1)

[Claims] 1. When further forming an additional layer on the original thin film formed in at least one area on a part of the substrate, the original thin film 5 (for forming the additional layer on the surface) The necessary critical atom or molecule supply rate αf is set to be smaller than the critical atom or molecule supply rate α required for forming a thin film of the additional layer around the plate surface, and additionally, IIIJ
By supplying the material for forming the thin film of the layer at an atom or molecule supply rate a that satisfies the conditions tαf, α, and α8, it is possible to selectively form an impressive thin film only on the large surface of the original thin film. N film formation method. 2. A method for forming an N film according to claim 1, using glass as a substrate. 8. The thin film forming method according to claim 4i or 2, wherein the original 4 film is a part of the transparent ψ co-electrode film. 4. The thin film forming method according to any one of claims 1 to 8, wherein the thin film of the additional layer is composed of a 1-2 group compound semiconductor.