JPS63245893A - Method of forming insulating film - 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 (Industrial Field of Application) The present invention is used in a light emitting element that extracts light through a transparent conductive film, a light receiving element that takes in light, and the like. The present invention relates to a method of forming an insulating film on a transparent substrate on which a transparent conductive film is formed.

(Prior Art) Conventionally, silicon nitride, silicon oxide,
The method for forming a silicon oxynitride film is as follows:
Resistance heating vacuum evaporation method, electron beam heating vacuum evaporation method, sputtering method and plasma CVD (Chemical
There was a vapor deposition method.

(Problems to be solved by the invention) In the vacuum evaporation method, many low-resistance parts occur in the manufactured film due to pinholes and compositional deviations, and between the transparent conductive film and the conductive film formed on the back side of the insulating film. When an electric field is applied to these insulating films, leakage current flowing through the insulating films becomes large, and when the electric field becomes large, dielectric breakdown occurs at the defective portions. In addition, step coverage is poor for protrusions existing on the transparent conductive film, end faces of the patterned transparent conductive film, and minute dust on the transparent conductive film, and the insulating film becomes thin or one composition deviation occurs in these areas. This causes problems such as a decrease in electrical resistance, an increase in leakage current, and dielectric breakdown.

In addition, although the sputtering method has better step coverage than the vacuum evaporation method, it is still not sufficient, the film formation time is long and productivity is poor, and the transparent conductive film is exposed to high-energy plasma, so it cannot be damaged by electricity. There are many problems such as increased resistance.

Furthermore, although most of the above problems are solved by film formation by plasma CVD, the film often becomes opaque. This is because the leakage current is abnormally large in this part and the film is not uniform.

The present invention provides a method for forming an insulating film that has excellent insulating properties and is transparent and uniform.

(Means for Solving the Problems) The present invention involves depositing silicon nitride, silicon oxide, or silicon onto the transparent substrate using a plasma CVD method after evaporating an insulator by one to ten people onto a transparent substrate on which a transparent conductive film is formed. It is characterized by depositing a thin film of at least one type of oxynitride.

The plasma CVD method is a method that activates one or more compounds or single gases of the elements constituting the thin film material to be formed at a lower temperature than using heat by exposing them to plasma discharge. This is a vapor deposition method that forms a desired thin film by causing a reaction in the gas phase or on the surface of a substrate.

Silicon nitride formed by plasma CVD method,
Insulating films made of silicon oxide and silicon oxynitride often exhibit a whitening phenomenon (opacity). As a result of examining this whitening using an electron microscope, it was found that particles of abnormal particle size grew on the transparent conductive film, and a uniform film did not grow. This phenomenon is often seen when the transparent conductive film is thoroughly cleaned, and is considered to be a reaction that occurs on the very surface of the transparent conductive film. Furthermore, the higher the substrate temperature, the more frequently the whitening phenomenon appears. This is thought to be due to the above-mentioned reaction being promoted, but the cause of particle growth is not clear.

The present invention was made based on the discovery that the whitening phenomenon can be suppressed by depositing 1 to 10 times of an insulator on a transparent conductive film.

In such vapor deposition, the insulating material does not cover the transparent conductive film uniformly, but is scattered in an island-like structure. Such an island-like structure can eliminate the whitening phenomenon, and it can be seen that this whitening phenomenon is a special phenomenon on the substrate surface. In addition, when depositing a thin insulating film regardless of its type, for example, when forming a silicon nitride film by plasma CVD, first, about a few angstroms of silicon nitride is deposited on the substrate by plasma CVD, and then the input power is turned off. Even if a silicon nitride film of a predetermined thickness is formed thereon, the whitening phenomenon will not occur. Other than this.

The insulator may be an insulating film of silicon oxide or silicon oxynitride formed by plasma CVD, or a 3-10 evaporated film of Al2O3.

To make the surface of the transparent substrate 200 to 550℃, 0℃ to 5℃.
This can be done by controlling the temperature of a metal plate of about 2 to 5 Qmm to tightly fix a transparent substrate of about mm to 200 to 550°C.

Furthermore, when heating the transparent substrate surface with radiant heat, the temperature of the transparent substrate surface can be measured and controlled with a thermocouple.

Silicon nitride using plasma CVD method.

When forming a thin film of silicon oxide or silicon oxynitride, the gas species as a silicon source are:
Hydride such as SiH, 5t2Hb.

Halides such as SiF4, 5iC14, etc. are used as nitrogen sources, NH3, N, etc. are used as nitrogen sources, and N, 0.02 as oxygen sources.
etc., but N2. Ar or the like is used. S
The t/N ratio and 5t10 ratio are each a volume ratio of 1 nitrogen gas.
0.5 to 80 parts of silicon source gas per 100 parts of oxygen source gas, and 20 to 300 parts of silicon source gas per 100 parts of oxygen source gas. The total pressure of the gas is 0.1 to 5 t o r r
, input power is 0.05-10W/cm2. The frequency is 10
Conditions from KHz to 50 GHz are used.

Silicon nitride formed by plasma CVD method,
The thickness of the silicon oxide or silicon oxynitride thin film is 0.1 to 3 μm.

As the transparent conductive film, rn20z (Sn) is used.

Snug (Sb), Sno□ (P), Snug (Te)
.

5nOz (W), Sno□ (CI), 5nOz (F).

Oxide semiconductor films such as Cdz5nOa, CdSn0++, CdO, Au, Ag, Cu, Pd,
Pt.

A metal film such as AI, Cr, Rh, etc. is used.

When depositing an insulating film of silicon nitride, silicon oxide, or silicon oxynitride using the plasma CVD method, by keeping the temperature of the transparent substrate at 350 to 550°C, even if heat treatment is performed in the post-process, the film will not peel off or crack. It will no longer occur.

In addition, silicon nitride is produced using the plasma CVD method.
When depositing an insulating film of silicon oxide or silicon oxynitride, thermal CV
Side reactions caused by D can be suppressed.

The transparent conductive film on the transparent substrate can be striped or
Even those formed on the entire surface of a transparent substrate.

Any shape is fine.

Example: Approximately 20 I nz 03 (S n) was added to borosilicate glass.
After forming a film by electron beam heating vacuum evaporation method,
A substrate etched into stripes was used. The substrate was cleaned and placed in the plasma CVD equipment using the deposit down method, the substrate temperature was set to 400°C, and the inside of the chamber was heated to 1.
．． The pressure was reduced to 5×10 −6 torr. After that S I H
A, Nz, and NH3 were introduced at a volume ratio of 1:2, and silicon nitride was deposited for about 5 minutes at a total pressure of 0.8 torr and an input power of 0.18 W/cm.The obtained silicon nitride film is transparent and has a film thickness of about 3000 mm, so the leakage current is small (10-
5μA/mm2)1. OXl 0? No dielectric breakdown was observed even when an electric field of V/cm was applied.

After Al2O was vapor-deposited on the substrate by electron beam heating vacuum evaporation for about 3 seconds (5 people in terms of monitors).

Each film was formed in the same manner as above. Prior to each of the above film formations, plasma was generated for about 2 seconds with the same gas composition and input power as above, and then each film was formed as described above.

By these pretreatments, no whitening phenomenon was observed at all, and a film with excellent electrical properties similar to those obtained by nitrogen plasma treatment was obtained.

(Effects of the Invention) According to the present invention, it is possible to obtain silicon nitride, silicon oxide, and silicon oxynitride films by plasma CVD that do not cause whitening and have good electrical properties. Moreover, this method is excellent in mass production.

Claims (3)

[Claims] 1. 1 to 1 insulators are applied to a transparent substrate on which a transparent conductive film is formed.
1. A method for forming an insulating film, which comprises depositing a thin film of at least one of silicon nitride, silicon oxide, or silicon oxynitride on a transparent substrate by plasma CVD after 0 Å deposition. 2. 2. The method of forming an insulating film according to claim 1, wherein the insulator is at least one of silicon nitride, silicon oxide, silicon oxynitride, or alumina. 3. The insulation according to claim 1 or 2, characterized in that a thin film of at least one of silicon nitride, silicon oxide, or silicon oxynitride is deposited on the transparent substrate at a temperature below 350° C. by plasma CVD method. Membrane formation method.