JPS60121272A - Production of transparent conductive film - Google Patents

Abstract

PURPOSE:To form a transparent oxide film which has conductivity and is dense and chemically stable by bringing fluoride of Sn, Sb or In contg. no Cl and Br into reaction with a gaseous mixture composed of O2 and hydride or nitride of O2 in a reaction vassel. CONSTITUTION:Gaseous N2 is heated by a ribbon heater 20 and is introduced into a reaction vassel 1 and thereafter SnF2 or SbF3, InF3 or the like contg. no Cl and Br is introduced therein. Atm. air 18 is supplied to the vessel in succession thereto and a substrate 2 in the vessel is heated by a heater 3 to 100- 400 deg.C. The N2, SnF2, etc. and the atm. air supplied into the vessel are mixed with a mixer 4 and the mixture thereof enters the space 17 in which plasma is closed by stainless steel meshes 16, 16'. A high-frequency voltage is impressed from a high-frequency power source 5 to electrodes 6, 6' to induce plasma reaction thereby forming the transparent, conductive and chemically stable film consisting of SnO2, Sb2O3 or In2O on the surface of the body 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a transparent conductive film (hereinafter referred to as CT (1)) containing tin oxide, indium oxide, or antimony oxide as a main component.

This invention uses CTO as a starting material of tin, antimony, or indium fluoride that does not contain chlorine or bromine, and combines it with oxygen (including air), a hydride of oxygen such as water, or a nitride such as N, O, No□. The reaction is carried out using the reduced pressure gas phase method.
It is carried out using a plasma vapor phase method or a charged gas phase method, and fluorine is added to CTO, for example, tin oxide, to produce a transparent oxide with high electrical conductivity.

This invention is a CTO to which fluorine is added without the addition or residual of chlorine, bromine, or iodine, and which has electrical conductivity, mechanically dense, and chemically stable characteristics. This is what we do.

Although TCO produced by the conventional CVD method or spray method using SnC contains residual chlorine, the present invention aims to produce a thermally stable TCO free from contamination with chlorine impurities.

Conventionally, CTO is produced by adding antimony or indium in addition to the reaction between tin chloride and oxygen, and its production methods include CVD method (a gas phase reaction method using only thermochemical reactions) and spray method. was the main thing.

For this reason, such a coating had chlorine remaining in the coating, and in addition had a sheet resistance of 300 Ω/mouth or more at a thickness of 1000 mm, and its transmittance was only up to 83%.

When a photoelectric conversion device is fabricated using a plasma vapor phase method using a non-single crystal semiconductor on the top surface of the chlorine etc. in the TCO,
It has been found that impurities are mixed into the P or - type semiconductor layer and this creates recombination centers. Chlorine and bromine, which have large atomic radii, have extremely bad properties that kill electron and hole carriers. In the present invention, only fluorine remains as an impurity and is added instead of a halogen element having a large atomic radius such as chlorine or bromine, in order to improve electrical conductivity.

Furthermore, the present invention uses tin oxide that is free of chlorine and bromine and is doped with fluorine, and uses a flexible transparent organic resin or silicon nitride on the substrate instead of glass that can withstand high temperatures. In order to be able to fabricate at a low temperature of 150 to 400 degrees Celsius on a substrate formed by the PCVII method to a thickness of 300 to 2,500 degrees Celsius, that is, a substrate that has heat resistance only up to 350 degrees Celsius, This relates to a plasma vapor phase method in which electrical energy is simultaneously applied.

For this reason, the chemical bonds in the activated species are strong;
It was possible to form an extremely dense film.

Furthermore, since the present invention mainly uses the PCVD method, it is characterized in that a non-chlorinated gas is used as the starting material. That is, 5nCI, , 5nC1,
.

5bC1j, InCl J cannot be used. If these are used as reactive gases for PCVD, they will be mixed into CTF as impurities such as chlorine and bromine, causing devitrification and transmittance of 10~
This is because it will drop to 30%.

That is, in addition to being pcvo, the present invention also uses tin fluoride, 5n, which is a non-chlorine and bromide as its reactive gas.
FL, 5n14 + Sn (CII7), KyouPI
Sn (C1lj), F, +5nCI5 F)
Tin fluoride and oxygen, nitrogen oxides or water are used as reactive gases. For this reason, for example, even if a transparent conductive film is made at 300°C, its transmittance is 85 (30
00 people) to 93 (1000 people)%.

The present invention uses PCVD or 400 chemical reaction (Photo CVD method), which forms a film at a low temperature of 100 to 400°C, yet has a dense film, and the starting material is non-chlorine or brominated. It is.

As a result, as shown in the example below, the sheet resistance was 7.
0~300Ω/portion (thickness ±1000 people transmission rate 85~9
It was possible to produce a film having a concentration of 3%.

Example 1 FIG. 1 shows an outline of a PCVO device used in the present invention.

In the drawing, a reaction vessel (1) has a heater (3), two preheaters (4), a high frequency power source (5), and a film forming substrate (two input/exhaust systems (9), four doping systems (10)).

A pair of electrodes (fl+>, <6'
), high frequency energy, here 13.56 MHz, was applied.

The doping system (10) is hydrogen fluoride (liver 13), nitrogen (
N ) < 14), tin fluoride (155, atmosphere (18) (N
Other oxides such as LO, No, NOl may be added),
Flow needle (11).

The amount was controlled by a valve (12).

The valve was opened, nitrogen was introduced from (14) at 100 cc/min, and tin fluoride heated to 200-300°C, for example, 250°C, was introduced. This doping system is 200~300℃
Then, heating was performed using a ribbon heater (20). Furthermore, 200 cc of air was added starting from 7 minutes (13). The temperature of the substrate (2) is variable between 100 and 400°C, for example 350°C.
And so. These reactive gases were mixed together in the prespace (7) by a mixer (8). In addition, preheat (4
) to prevent solidification.

Furthermore, the mixed reactive gas is mixed with stainless steel mesh (1
6), <16'), the plasma is confined and introduced into the reaction space ITjl (t7), and electrical energy is applied by a pair of electrodes (6), <6') to cause a plasma reaction,
A coating was formed on the substrate (2). For example, assuming a thickness of 3000 mm, the sea 1 resistance was 23Ω and the light transmittance was 87%. Furthermore, when we fabricated an amorphous solar cell having a PIN junction on its upper surface by the PCVO method, this was an extremely remarkable progress considering that it was impossible to obtain it.

Example 2 In the example of FIG.
A reduced pressure gas phase method was used with the furnace pressure set at 10 torr.

As a result, a sheet resistance of 18 Ω/hole was obtained by depositing tin oxide on a glass substrate to a thickness of 6000 mm, and the light transmittance was also 85% (50 Ω/mm).
0r+m) was obtained. In addition, the surface has serrated irregularities (height difference 3
00 people).

Example 3 This invention uses the apparatus of Example 1, in which the substrate is a transparent organic film such as a polyimide film and a silicon nitride film with a thickness of 300%
A flexible substrate formed to a thickness of ~2000 mm was used.

A material on which ITO (indium tin oxide) was formed in a flat or fibrous shape with a height difference of 300 to 1200 was used.

Sheet resistance of ITO increases when heat treated at 350° C. or higher. For this purpose, the SnO layer was formed by PCVD at a substrate temperature of 150 to 350°C, here 200°C. SnO,
It was estimated that there were 400 to 800 people. As a result, the sheet resistance of ITO alone was 15 Ω/hole, but this value hardly changed to 18 Ω/hole, and it was possible to create extremely mechanically and chemically stable fluoride tin oxide legs on the surface. Ta.

The transmittance was 91% on average, and silicon was formed on the fiber. Furthermore, the reflection by the integrating sphere in the wavelength range of 400 to 600 nm was extremely low (7%).

In the present invention, 185 or 254
Ultraviolet light of nm wavelength was irradiated simultaneously or independently using 11 ultra-high pressure mercury lamps, and a photo plasma vapor phase method (PPCVD method) or a charged gas phase method (Photo CVD method) could be performed. Furthermore, by passing the light through a mercury bubbler, it was possible to create a CTF with even higher efficiency of light energy.

The present invention mainly focuses on tin fluoride. However, these include tin, antimony, or indium fluorides such as tin fluoride (SnF, 5nF4), antimony fluoride (S
bF, ), fluorine-doped rTO, InLO, and Sbρ may be prepared using indium fluoride (InF, ).

[Brief explanation of drawings]

FIG. 1 shows an outline of an apparatus for producing a transparent conductive film according to the present invention. patent applicant

Claims (1)

[Claims] 1. A mixed gas of tin, antimony or indium fluoride and oxygen or oxygen hydride or nitride, which does not contain chlorine and bromine, is introduced into a reaction vessel, and the mixed gas is supplied with thermal energy or A method for producing a transparent conductive film, which comprises forming a transparent oxide conductive film containing fluorine but not chlorine or bromine by applying thermal energy and electricity or light energy. 2. The method for producing a transparent conductive film according to claim 1, characterized in that the fluoride of tin, antimony or indium is soot fluoride, antimony fluoride or indium fluoride. 3. In claim 1, the mixed gas of tin fluoride and atmosphere is in the range of 0.01 to 10 torr,
A method for producing a transparent conductive film, which comprises forming a tin oxide film containing fluorine on a surface to be formed by high-frequency discharge under reaction conditions in a temperature range of 150 to 400°C.