JPH09118544A - Transparent electrically conductive film, its production and material for production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce specific resistance without deteriorating transparency by laminating a film consisting of one or more kinds of group III or IV metals of the Periodic Table, O and N and a film consisting of In, Sn and O. SOLUTION: In a device shown by the drawing, a transparent substrate of plate glass, acrylic resin, polycarbonate resin, etc., is used as a substrate 1 on which a transparent electrically conductive film is formed. The substrate 1 is conveyed from a preliminary chamber into a chamber 4 through a door valve 6. Two cathodes disposed at positions confronting the substrate 1 are properly used. The chamber 4 is evacuated to 5×10<-6> Torr by a vacuum pump through an exhaust port 5 and sputtering gas is introduced from a gas introducing hole 15. A film consisting of In, Sn and O is formed on the substrate 1 by DC reactive sputtering with a target A7, a film consisting of In, Sn, O and N is laminated with a target B9 and a film having the same compsn. as the 1st film is further laminated as a 3rd film with the target A7 in a thickness different from that of the 1st film.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to indium, tin,
By laminating a film made of oxygen and a film made of at least one metal of group III or group IV of the periodic table, oxygen, and nitrogen, a transparent conductive film having reduced electrical resistivity while maintaining transparency, and The present invention relates to a manufacturing method thereof and a material for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, transparent conductive films have been used in solar cells, liquid crystal display devices, touch panels, antistatic clothing, infrared reflective films, electromagnetic shield materials and the like. Among them, films made of indium oxide and tin oxide are widely used. Especially, the spread of liquid crystal display devices is remarkable. However, in recent years, due to the finer electrodes, the larger size of devices, and the colorization of devices, a film having low resistance and high transmittance has been required even when forming a film at low temperature. Conventionally used transparent conductive film (ITO film) containing 9 to 10 wt% of tin oxide
Has a specific resistance of about 1.5 to 2.0 × 10 ⁻⁴ Ω · cm when the film is formed at a high temperature (about 400 ° C.), and the ITO film on the organic resin-based color filter formed at a low temperature. Is about 2.5 to 3.0 × 10 ⁻⁴ Ω · cm, a film having the same film thickness and lower resistance is required.

[0003]

[PROBLEMS TO BE SOLVED BY THE INVENTION] To provide a transparent conductive film having a reduced electrical resistivity without impairing transparency, a method for producing the same, and a material for producing the transparent conductive film.

[0004]

A material for producing a transparent conductive film is a sintered body composed of at least one metal of Group III or IV of the periodic table and oxygen and nitrogen, or an introduced gas is inert. A mixed gas of gas, oxygen and nitrogen, or
The method is characterized in that a film made of indium, tin, oxygen, and nitrogen is formed by both methods to form a laminate with a conventional film made of indium, tin, and oxygen.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The transparent conductive film according to the present invention has a very activated film formed by adding nitrogen to a film made of indium, tin and oxygen. By forming a boundary with a film that does not contain nitrogen, oxygen in the ITO film is taken in, oxygen defects in the ITO film increase, and the number of donors at the boundary of the laminated film increases, so that the entire film becomes Mobility and carrier concentration are increased, and moreover, by using the conventional ITO film as the surface of the whole film, it is possible to realize stable low resistance as a comprehensive film.

[0006]

EXAMPLE The present invention is a planer type magnetron sputtering apparatus in which a target is a sintered body (IT) containing indium oxide and tin oxide having a tin content of 10 wt%.
As O), when a sputtering gas is a mixed gas of argon, oxygen, and nitrogen, and DC power is supplied to the target to perform sputtering, the formed film is formed of indium, tin,
A film consisting of oxygen and nitrogen, which is a very activated film, despite being stored at room temperature in the atmosphere,
Acceleration of membrane oxidation was observed in the course of about 2 o'clock,
It is due to the discovery that the resistivity changes several times.

FIG. 1 shows a cross-sectional view of the film structure in the embodiment of the present invention, and FIG. 2 shows a schematic view of the apparatus used for forming the film. Details will be described with reference to the drawings. The chamber 4 is kept vacuum through an exhaust port 5 by an exhaust system such as a vacuum pump (not shown). The substrate 1 on which the transparent conductive film is formed is made of a transparent material such as plate glass, acrylic resin, polycarbonate resin, etc., and is passed from a spare chamber (not shown) through the door valve 6 into the chamber 4.
Similarly, it is carried in by a carrying mechanism not shown. Further, two cathodes are installed at a position facing the substrate 1, and there are cases where only the cathode A is used and cases where both cathodes are used depending on the film forming method. The cathode is generally known as a planar magnetron cathode. Here, the target A7 was used when forming the first layer film and the third layer film of all the examples, and the sintered body made of indium oxide and tin oxide was used as the material, and the material of the target B9 was Selection is made according to the examples as shown in Table 1. A Naoshima power source 13 is connected to each target. Sputter gas is introduced into the chamber 4 through a gas inlet 15 by a sputter gas supply system (not shown). The substrate heating heater 16 is used to release the adsorbed gas or improve the film characteristics. Further, the anode 11 is grounded together with the earth shield 10.

In the apparatus having the above-described structure, the chamber 4 is evacuated to 5 × 10 ⁻⁶ Torr, and then, while being evacuated through the exhaust port 5 by a vacuum pump or the like, a mixed gas according to the embodiment is used as a sputtering gas. The gas inlet 1
5, the film 2 made of indium, tin and oxygen is first formed by the target A7 on the substrate 1 by DC reactive sputtering, and then the film 3 made of indium, tin, oxygen and nitrogen is formed by the target B9. Was further laminated, and further, the film 2 initially formed as the third film layer by the target A7 was laminated by changing the film thickness. Table 2 shows the sputtering conditions other than those mentioned above at this time.

[0009]

[0010]

[0011]

Examples 1 to 8 As a result of Examples 1 to 8 as described above, the mobility is 1.2 to 1.7 times that of a normal ITO film and the carrier concentration is 1.1 to 1.5. It was doubled, and the target resistivity of the film could be significantly improved without impairing the transmittance. This means that in the conventional ITO film, Sn introduced as an impurity in the film partially forms O ₂ in the same film and SnO ₂ of a stable molecule, and thus is not effective as a donor. On the other hand, in the embodiment, N ₂
Are introduced, the In existing at the boundary of the film
^{---, Sn ----, O ++,} N +++ is, effectively acts as a donor, is considered to have contributed to the particular to increase the mobility. This means that, in the state of the film surface observed by an electron microscopic photograph of the film formed at about 100 ° C., the mobility was about 23 cm ² / Vs, although the crystal grain size was not large. It is estimated from the fact that Further, as described above, since the film 3 made of indium, tin, oxynitride, and nitrogen is a highly activated film, oxygen is removed from the film 2 made of indium, tin, and oxygen at the interface between the films. By incorporating, the conventional I
It is considered that there is also an effect of increasing oxygen defects in the TO film and consequently increasing the carrier concentration.

[0012]

Ninth Embodiment Target B in the above first to eighth embodiments
The material of No. 9 is changed to a nitride of indium and tin, and aluminum and silicon are used as one or more metals of group III or group V of the periodic table of elements, and the nitride and oxides of indium and tin are used. The same experiment was conducted using the sintered body of and as a material.

FIG. 3 shows a cross-sectional view of the membrane structure embodied in the ninth embodiment. In this example as well, the same results as in Examples 1 to 8 were obtained, so that as described in Examples 1 to 8, the film 2 made of indium, tin, and oxygen was used.
And I existing at the boundary of the film 3'consisting of at least one metal of group III or group IV of the periodic table, oxygen, and nitrogen.
^{n ---, Sn ----, Al ---} , Si ----,
O ^++, as if N ⁺⁺⁺ is Examples 1-8, serves as an effective donor with valence of the dispersion is believed that a similar effect. It can be easily presumed that the same phenomenon naturally occurs in other elements as long as it is one or more metals of group III or group IV of the periodic table, and that it has the same effect on the film characteristics.

[0014]

As described above, indium,
Film consisting of tin and oxygen and Group III or IV of the periodic table
A transparent conductive film, which is a laminated film of clothes composed of one or more metals of the group, oxygen, and nitrogen, lowers specific resistance without impairing transparency. Further, by using a sintered body of an oxide of indium and tin and a nitride of at least one metal of Group III or IV of the periodic table as a material for producing a transparent conductive film, a low resistivity can be obtained. The transparent conductive film is inexpensively and stably supplied.

[Brief description of the drawings]

FIG. 1 is a sectional view of a film structure according to Examples 1 to 8 of the present invention.

FIG. 2 is a schematic configuration diagram of a vacuum device according to an embodiment of the present invention.

FIG. 3 is a sectional view of a film structure according to Example 9 of the present invention.

[Explanation of symbols]

1 ... Substrate 2 ... Indium, tin, oxygen film 3 ... Indium, tin, oxygen, nitrogen film 3 '... Group III or IV metal, oxygen, Membrane made of nitrogen 4 ‥‥‥‥ Chamber 5 ‥‥‥‥ Exhaust port 6 ‥‥‥ Door valve 7 ‥‥‥‥‥ Target A 8 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ Shield 11 ‥‥‥‥ Anode 12 ‥‥‥‥‥‥‥‥‥ Magnet Magnet 13 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ Gas inlet 16 ‥‥‥‥‥‥

Claims (6)

[Claims] 1. A film made of at least one metal selected from Group III and Group IV of the Periodic Table of Elements, oxygen, and nitrogen, and indium,
A transparent conductive film comprising a stack of films of tin and oxygen. 2. The element according to claim 1, wherein at least one metal selected from group III or group IV of the periodic table of the elements is indium and tin. The transparent conductive film described. 3. Indium and tin oxides and periodic table I
A material for producing a transparent conductive film, comprising a sintered body of a nitride of at least one metal selected from the group II and the group IV. 4. The element according to claim 3, wherein at least one metal of group III or group IV of the periodic table of the elements is indium and tin. The material for producing a transparent conductive film as described above. 5. A manufacturing method characterized in that the material for producing a transparent conductive film is used as a material according to claim 2 and a film according to claim 1 is formed by a vacuum film forming apparatus. Method. 6. A material for producing a transparent conductive film is indium,
As a sintered body composed of tin and oxygen, and a gas introduced when forming a film by a vacuum film forming apparatus as a mixed gas of an inert gas and oxygen or a mixed gas of an inert gas, oxygen and nitrogen, A manufacturing method comprising forming the film according to claim 1.