JPH03238714A - Manufacture of transparent conductive film - Google Patents

Abstract

PURPOSE:To obtain a transparent conductive film of low resistance with good reproducibility, by adding to an inert gas a specific amount of gas including an element that works as a donor of at least one species that controls the resistance value of the transparent conductive film through the combination with oxygen. CONSTITUTION:A target electrode 2 that supports a metal oxide target 3 formed out of indium oxide to which tin oxide is added, and a substrate holder 4 that supports a substrate 5 on which a transparent conductive film is to be coated, are arranged in a manner that they are opposed to each other, in a vacuum container 1 in which a vacuum exhaust system (b) in a sputtering device and a sputter gas introducing pipe 1a are connected with each other. A gas including an element that works as a donor of at least one species that controls the resistance value of the transparent conductive layer through the combination with oxygen, to an inert gas by 0.01-10volum%. Even when an impurity gas including an oxygen gas that is adsorbed by the target electrode 2 and the substrate holder 4, etc., causes effect during sputtering, a transparent conductive film of low resistance can be obtained with good reproducibility.

Description

[Detailed Description of the Invention] [Summary] A method for forming a transparent conductive film used as a transparent electrode of various display panels, particularly a method for forming a transparent conductive film using low resistance ITO (IndiumT
Regarding the method of forming a transparent conductive film consisting of 0x in oxide) with good reproducibility, even if impurity gases including oxygen gas (0□) adsorbed on the walls of the vacuum chamber, the target electrode, the substrate holder, etc. are involved in sputtering. With the aim of obtaining a low-resistance transparent conductive film with good reproducibility, a metal oxide target consisting of indium oxide and tin oxide is sputtered in an inert gas, and a metal oxide target consisting of indium and tin oxide is sputtered onto an opposing substrate. In the method of forming a transparent conductive film, in the inert gas, 0.0% of a gas containing at least one donor element that combines with oxygen to control the resistance value of the transparent conductive film is added.
The composition is such that 1 to 10% by volume is added.

[Industrial application field]

The present invention relates to a method of forming a transparent conductive film used as a transparent electrode of various display panels, and particularly relates to a method of forming a transparent conductive film used as a transparent electrode of various display panels, and particularly relates to a method of forming a transparent conductive film used as a transparent electrode of various display panels.
The present invention relates to a method for forming a transparent conductive film made of ndium tin oxide) with good reproducibility.

Transparent conductive films made of ITO are now indispensable for forming transparent electrodes in flat display devices such as EL display panels, liquid crystal display panels, and gas discharge display panels. In order to stabilize display drive characteristics, etc., low resistance is required.

Therefore, there is a need for a method for easily forming a transparent conductive film made of ITO for transparent electrodes with a low sheet resistance value with good reproducibility.

[Conventional technology]

The conventional method for forming a transparent conductive film made of ITO is as follows:
For example, as shown in FIG. 2, indium oxide (Inz
A metal oxide target 3 in which approximately 10% by weight of tin oxide (SnO The inside of the vacuum container l is once heated to around 200° C. and evacuated to a high vacuum.

Thereafter, a sputtering gas consisting of argon gas (Ar) to which approximately 0.1% of oxygen gas (0□) was added is introduced into the container 1 from the sputtering gas introduction pipe 1a to a predetermined gas pressure, and the substrate holder 4 By supplying a predetermined power from the high frequency power source 6 between the metal oxide target 3 and the metal oxide target 3 to cause a discharge, and performing sputtering, InzO is deposited on the substrate 5.
A transparent conductive film made of ITO mainly composed of ITO is deposited.

[Problem to be solved by the invention]

By the way, in the above-described conventional method for forming a transparent conductive film, the oxygen gas added to the sputtering gas is sufficiently incorporated into the transparent conductive film made of ITO formed on the substrate 5, thereby increasing the transmittance of the transparent conductive film. Although the resistance value is good, the resistance value is not necessarily low at around 4X10-'Ω・cm. Therefore, the amount of oxygen gas added to the sputtering gas is adjusted, but the resistance value of the transparent conductive film to be formed is It was not easy to control lower.

In particular, once the inside of the vacuum container 1 is exposed to the atmosphere, the walls of the vacuum container 1, the target electrode 2 and the substrate holder 4
Impurity gas including oxygen gas (0□) is adsorbed on the substrate, and this impurity gas is released during sputtering and participates in film formation, so that the resistance value of the formed transparent conductive film made of ITO is 4X10-'Ω. - There was a problem in that the resistance was higher than cm, and it was not possible to obtain a low-resistance transparent conductive film with good reproducibility due to variations.

In view of the above-mentioned conventional problems, the present invention has been developed to provide a transparent, low-resistance film that can be used even if impurity gases including oxygen gas (OX) adsorbed on the walls of the vacuum chamber, target electrodes, substrate holders, etc. are involved during sputtering. The object of the present invention is to provide a novel method for forming a transparent conductive film that makes it possible to obtain a conductive film with good reproducibility.

[Means to solve the problem]

In order to achieve the above object, the present invention sputters a metal oxide target made of indium oxide and tin oxide in an inert gas to form a transparent conductive film made of indium and tin oxide on an opposing substrate. In the method, a gas containing at least one donor element that combines with oxygen to control the resistance value of the transparent conductive film is added to the inert gas. The composition is such that 1 to 10% by volume of O is added.

[For production]

In the formation method of the present invention, ITO is formed by sputtering.
A gas consisting of tin hydride (SnH4) containing, for example, tin (Sn), which serves as at least one type of donor that combines with oxygen, is added to the sputtering gas consisting of argon gas (Ar) used when forming a transparent conductive film consisting of By adding 1 to 10% by volume of O, oxygen gas (0□) in the adsorbed impurity gas released into the vacuum chamber during sputtering is combined with the tin hydride (SnFI4) to form tin oxide (Snow).
) and acts as a donor when incorporated into the transparent conductive film being formed, so the amount of oxygen incorporated into the Bib bright conductive film (oxidation reaction) is significantly reduced, resulting in a low-resistance I
It becomes possible to form a transparent conductive film made of TO with good reproducibility.

〔Example〕

An embodiment of the method for forming a transparent conductive film according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing an example of a sputtering apparatus applied to the method of forming a transparent conductive film of the present invention.

Indium oxide (InzO:+) containing about 10% by weight of tin oxide (Snug) is placed in a vacuum container (sputtering chamber) l in which a vacuum evacuation system and a sputtering gas introduction pipe 1a are connected in a sputtering apparatus as shown in the figure. A target electrode 2 supporting a metal oxide target 3 and a substrate holder 4 supporting a substrate 5 to which a transparent conductive film is to be deposited are placed facing each other.

Then, with the substrate 5 heated to around 200° C., the inside of the vacuum container 1 is evacuated to a high vacuum of 10-' Torr or less.
A sputtering gas made of argon gas (Ar) to which about 1% by volume of a gas made of tin hydride (SnHn) containing
After introducing the gas to a pressure of about
Sputtering is performed by supplying a power of 00 W and discharging it.

In this way, the 02 gas in the adsorbed impurity gas released from the wall surface in the vacuum chamber 1, the target electrode 2, the substrate holder 4, etc. during sputtering is the gas consisting of tin hydride (SnHa) in the sputtering gas. It combines with the metal oxide target to form tin oxide (SnO□), which is deposited on the opposing substrate 5 surface together with sputtered particles of indium tin oxide sputtered from the 3 surfaces of the metal oxide target and acts as a donor. Sputtered particles and I deposited on the substrate 5
Since the amount of oxygen that directly oxidizes with the transparent conductive film made of TO is significantly reduced, 1.5 to 2.0
It becomes possible to easily form a transparent conductive film made of ITO with a low resistance of x10-4 Ω·cm.

Note that the A
A gas consisting of tin hydride (SnH4) containing tin (Sn) as a donor to be added to the sputtering gas consisting of r gas is
．． 01 to 10% by volume, and the sputtering gas pressure in the vacuum chamber 1 is 5×10−3 to 5×10” Tor.
By controlling the range of r and the high frequency power supplied between the metal oxide target 3 and the substrate holder 4 in the range of 300 to 700 W, sputtering is performed.
1.5~2.0×l0-4Ω・Cl11 on the substrate 5
It is possible to easily form a transparent conductive film made of ITO with a low resistivity and a transmittance comparable to conventional ones with good reproducibility.

Furthermore, in the above embodiments, tin, which serves as a donor, is added to the sputtering gas consisting of Ar gas, and contains at least one element that becomes a donor when combined with 0□ to control the resistance value of the transparent conductive film. (Sn) containing tin hydride (S
Although an example in which 5xHt) is applied has been described, the present invention is not limited to this example; for example, 5xHt
, HtS+ NLIL, COI PH31 or ■
Gases such as the above may also be used, and similar effects can be obtained.

〔Effect of the invention〕

As is clear from the above description, according to the method for forming a transparent conductive film according to the present invention, the film is made of ITO that is adsorbed in a vacuum container and adheres to the substrate surface with oxygen gas in the impurity gas released during sputtering. When used in the formation of a transparent conductive film, it has the excellent advantage of suppressing oxidation of the transparent conductive film and making it possible to obtain a low-resistance transparent conductive film with good reproducibility. When applied to a method of forming a transparent conductive film using an in-line film formation method, the effect is extremely remarkable.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an example of a sputtering apparatus applied to the method of forming a transparent conductive film of the present invention, and FIG. 2 is a schematic configuration diagram illustrating a conventional method of forming a transparent conductive film. In FIG. 1, 1 is a vacuum vessel, 1a is a sputtering gas introduction tube, 2 is a target electrode, 3 is a metal oxide target, 4 is a substrate holder, 5 is a substrate, and 6 is a high frequency power source. Figure 2

Claims (1)

[Claims] Sputtering a metal oxide target (3) made of indium oxide and tin oxide in an inert gas to form a transparent conductive film made of indium and tin oxide on an opposing substrate (5). The method is characterized in that 0.01 to 10% by volume of a gas containing an element that becomes at least one type of donor that combines with oxygen to control the resistance value of the transparent conductive film is added to the inert gas. A method for forming a transparent conductive film.