JPS60205909A - Light permeabile conductive 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 The present invention relates to a light-transmitting conductive film, particularly a low-resistance light-transmitting conductive film made of a metal oxide.

Conventionally, light-transmitting conductive films or light-transmitting conductive laminates have been used, for example, for electrodes for liquid crystal displays, electrodes for electroluminescence, electrodes for photoconductive photoreceptors, and windows for cathode ray tubes and various measuring instruments. Electrostatic shielding layer, antistatic layer,
Widely used in electrical and electronic fields such as heating elements. Among these, transparent shielding films having selective light transmittance are used as window materials for collectors for solar energy utilization or as window materials for buildings due to their infrared light reflecting ability.

In addition, with the development of information processing, various solid-state displays using electroluminescent, mineral, liquid crystal, plasma, and ferroelectric materials have been developed as display devices to replace cathode ray tubes, and these displays have translucent electrodes. is always used. Furthermore, new electro-optical elements and recording materials based on the interaction or mutual exchange of electrical and optical signals are becoming useful for information processing technology, and these also require films that are both transparent and conductive. is required. On the other hand, such a light-transmitting conductive film can also be used as a light-transmitting heat-insulating window for preventing solidification in automobiles, airplanes, etc.

In particular, in recent years, there has been an increasing demand for high-pixel displays in liquid crystal displays, electroluminescent displays, plasma displays, electrochromic displays, fluorescent display devices, etc., and along with this, pixel portions are formed using electrodes made of transparent conductive layers. At the same time, it has been proposed to form signal application lines using electrodes made of metal layers to improve the display speed of pixels and improve images.

In this case, a laminate structure of a metal layer and a transparent conductive layer may be formed on a transparent substrate.

Transparent conductive films as described above can be broadly classified into metal thin films and metal oxide thin films.

The former is made by vapor-depositing gold, palladium, etc. to a thickness of several hundred layers, and has good electrical conductivity, but is generally said to have poor light transmittance.

On the other hand, the latter is made of indium oxide, soot oxide, a mixture of both, or a mixture of cadmium and tin oxide, and is formed by chemical film forming methods (e.g. spray method,
Chemical vapor deposition method (CVD>.

It is formed by a coating method) or a physical film forming method (e.g., vacuum evaporation method, ion blating method, spankling method).

In the chemical film forming method, the temperature of the substrate to be deposited is generally 500 - 500℃.
The temperature is high at 600℃, which is bad for productivity, but the temperature of the 4IJ2 salmon 3 methods is low - the temperature of the blue salmon and the warm slender anus can be improved in early spring.
In the case of a physical film forming method, the temperature of the substrate may be relatively low at 250 to 300''C.

In contrast, the present invention provides a light-transmitting conductive film characterized in that, when forming the conductive film, two or more types of metal oxides containing at least one different element are alternately laminated. Regarding.

That is, when forming a transparent conductive film on an insulating substrate, an insulating layer, or a semiconductor layer formed thereon, after forming a first metal oxide layer, the first metal oxide layer is formed. A third metal oxide layer having at least one element different from that of the metal oxide layer is deposited.

From now on, metal oxides containing different elements may be added as necessary.
Different types of materials may be alternately stacked, or three types of materials may be alternately stacked. Note that at least one of these metal oxides is electrically conductive.

By stacking different types of metal oxides in this way, it was possible to have a light-transmitting conductive film with low resistance without increasing the film thickness.

In this way, some of the elements constituting each layer react at the layer interface, such as the first layer and second layer, second layer and third layer, etc. of different metal oxides, forming a metal compound. In order to
It is thought that the resistance will be low.

However, when laminated alternately, the In in the first layer and the second
sb in the layer reacts to form a 1-V group compound semiconductor layer, which is a direct transition type semiconductor, at the interface, and therefore the effective mass of electrons is large and the electron mobility is large. Therefore, it is thought that the resistance value will decrease.

As described above, according to the present invention, a light-transmitting conductive film with low resistance can be obtained without increasing the film thickness.

Examples are shown below.

Example 1 A glass substrate and a stainless steel substrate on which an insulating film was formed were used as substrates. ITO (5wt% S) as the first layer
n) by vacuum evaporation at 200°C and oxygen partial pressure 2X1
Approximately 1,000 layers of SnO (containing 7.5 wt% SB) were formed as a second layer under the same conditions using a vacuum evaporation method, and then a third layer was formed. As a fourth layer, rTO was laminated under the same conditions as the first layer, and then SnO was laminated as a fourth layer under the same conditions as the second layer, resulting in a total film thickness of approximately 2400.
A human translucent conductive film was obtained. -The total sheet resistance value (according to the four-terminal method) and the glass substrate are 500
The transmittance in nm (using an automatic spectrometer) is shown in Table 1.

Table 1 Sheet resistance value Transmittance (Ω/hole) (%) 1st layer (I-TO) 64.4 84.0 2nd layer (ITO)
+SnO) 45.8 72.0 3rd layer (ITO+S
nO+ITO) 33.4 83.0 4th layer (ITO
+SNO+ITO+SnO) 21.9 74.5 ratio relationship is shown in FIG.

As shown in Figure 1, the resistance value decreases as the number of layers is increased, but after a certain number of times, the rate of decrease gradually becomes smaller (Also, regarding transmittance, when SnO is layered, it becomes worse When ITO was laminated next, the results were better, but this is because the SnO crotch grains i created under the conditions of this example were large, which caused light to scatter, resulting in this result. Conceivable.

Example 2 Lamination was performed in exactly the same manner and under the same conditions as in Example 1, except that the first layer was ITO and the second layer was SiO.

Even in this case, as seen in FIG. 2, it can be seen that the resistance value decreases as the layers are stacked. When the last layer was made of SiO and laminated on a non-single crystal semiconductor as in this example, the last layer could be used as a protective film for the semiconductor.

In this way, according to the present invention, a light-transmitting conductive film with low resistance could be obtained without increasing the film thickness.

Note that the method for forming the conductive film is not limited to the vacuum evaporation method, but may also be a sputtering method, an ion blating method, a plasma CVD method, or a photoCVD method.

Insulating substrates include glass substrates, ceramic substrates,
A flexible organic film may also be used.

[Brief explanation of the drawing]

FIG. 1 shows the relationship between the C/resistance value, the transmittance, and the number of laminations when the first layer is ITO and the second layer is SnO. FIG. 2 shows the relationship between resistance, transmittance, and number of laminations when the first layer is ITO and the second layer is SiO. Patent applicant Figure 7/z3 left 49 times (1 town seedling map

Claims (1)

[Claims] 1. When forming a transparent conductive film on an insulating substrate or an insulating layer and a non-single-crystal semiconductor layer provided on the substrate or insulating layer, at least one A translucent conductive film characterized by alternately laminating two or more types of metal oxides containing different elements. 2. A transparent conductive film according to claim 1, characterized in that two or more metal oxides containing at least one different element are alternately laminated three or more times. . 3. The light-transmitting conductive film according to claim 1, wherein at least one of the metal oxides has high conductivity.