JPS62242314A - Nonlinear resistance element and manufacture of the same - 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 Field of Industrial Application The present invention relates to a nonlinear resistance element having a function such as conductive switching and a method for manufacturing the same.
Can be used in the electronics industry.

Conventional technology Non-linear resistance elements such as conductive switching are 0V
It is known as an ONIC element and uses an amorphous semiconductor mainly composed of chalcogen elements as its material. It is also known that transition metal oxides have similar electrical properties, such as hematite, magnetite, nickel ferrite, nickel zinc ferrite, and nickel oxide. In these conventional nonlinear resistance elements, materials are used in the form of thin films or sintered bodies, but N
It is advantageous to use a thin film from the viewpoint of low voltage value, and most amorphous semiconductor devices exhibiting relatively stable characteristics are of the thin film type.

The basic structure of this is shown in FIGS. 2 and 3.

As described above, it can be divided into a sandwich type (FIG. 2) in which the formed film is used in the direction of the film thickness and a Brenna type (FIG. 3) in which the film is used in the direction of its surface. In either case, the active layer is usually formed by vacuum evaporation or sputtering.

In FIG. 2, 1 and 3 are electrodes, 2 is an active layer, and 4 is a substrate. Further, in FIG. 3, 5 is an active layer, 6 and 7 are electrodes, and 8 is a base.

Problems to be Solved by the Invention As mentioned above, in conventional nonlinear resistance elements exhibiting switching characteristics, the active layer is formed by a vacuum method.
Not only is this disadvantageous in terms of manufacturing yield and productivity, but it is also expensive for applications that require devices to be constructed on very large substrates. I can't. The purpose of the present invention is to
It is an object of the present invention to provide a nonlinear resistance element having switching characteristics that solves these problems, and a method for manufacturing the same, so that these elements can be manufactured with high productivity and at low cost.

Means for Solving the Problems In order to achieve the above object, the present invention adopts a method of applying a solution of a metal compound and thermal decomposition to form an active layer. Furthermore, any metal compound may be used as long as it dissolves in a suitable solvent and forms a film when the solution is applied and dried.

For example, inorganic acid salts such as nitrates, organic acid salts such as acetates, complexes, and organic metals with an alkyl group attached to the metal can be used. There are many compounds that can be used to form thin films using this method, but the inventors discovered a mixture of manganese oxide, nickel oxide, and bismuth oxide as a compound that exhibits switching properties, and used this for the active layer.

According to the present invention, a thin film of a mixture of manganese oxide, nickel oxide and bismuth oxide is prepared by mixing and dissolving compounds of manganese, nickel and bismuth in a solvent and coating the mixture on a substrate.
It is easily obtained by thermal decomposition. At this time, by considering the combination of the compound and the solvent, a very stable solution can be obtained, and the ink and 1- can be stored for a long period of time.

In order to introduce such formation methods, dip, dip, spray,
Since construction methods such as printing can be used, 5 ・, −
7. A uniform film can be manufactured over a large area with high productivity and at low cost. In addition, the thin film obtained by pyrolysis is
It exhibits switching characteristics in which the threshold voltage and sustaining current change depending on the film thickness, distance between electrodes, composition, etc., and the stability of these characteristics is very good.

Example The present invention will be described in detail below with reference to Examples.

<Example 1> In order to make the sandwich type element shown in FIG. 2, a coating solution for forming a thin film of a mixture of manganese oxide, nickel oxide and bismuth oxide was prepared with the composition shown in Table 1 below. Here, 2-ethylhexanoate, which is very easy to form into a film, was used as the compound of manganese, nickel, and bismuth, and methyl isobutyl ketone was used as the solvent. Then, these coating solutions were spin-coded onto a glass substrate on which a thin gold film was formed as an electrode, and then dried at room temperature.
An active layer was formed by heating and baking at 550"C for 60 minutes in the air, and a thin gold film was further formed on this thin film. When the I-v characteristics of these devices were measured with a curve tracer when voltage was applied, A knee curve as shown in Figure 1 is obtained.The measurement results are also shown in Table 1 below, but in this table, vth (threshold voltage) and
(threshold current), vh (sustaining voltage), and h (maintaining current) are shown as numerical values. These values are all obtained when swept at a frequency of 5012. The thickness of the active layer was measured by etching a part of this thin film to form a step and using a contact type surface roughness meter.

(Margin below) 71, -1 9. ,,-.

Furthermore, we applied a sawtooth wave of ±15 V at S[Z to these devices to examine the stability of their characteristics. Even after adjusting the temperature, no fluctuation of more than ±6% was observed in the values shown in Table 1, and the stability of the properties was considered to be sufficient for practical use.

<Example 2> Using a coating liquid having the same composition as in Example 1, a sandwich-type element was constructed by replacing the electrode with an indium oxide thin film doped with tin. The manufacturing method except for the electrodes is exactly the same as in Example 1. When these knee v characteristics were measured with a curve tracer, an IV curve as shown in FIG. 1 was similarly obtained, and the results are shown in Table 2 below. Sample numbers in the table correspond to those in Table 1, and the same numbers indicate that the active layer was formed using the same coating solution. Further, the sweep frequency is 50flz.

<Table 2> 11, (-5) From this table, it can be seen that although there are some variations, almost the same results as in Example 1 are obtained. In addition, the same stability test as in Example 1 was conducted, It was confirmed that the characteristics of these devices remained stable even after switching over approximately 4 million times.

<Example 3> A thin gold film was formed on a glass substrate, a part of this thin film was etched to create a gap of several tens of microns in width, the gold thin film separated by this was used as an electrode, and the Example was placed on top of this. An active layer was formed using the same coating solution as in Example 1. The formation conditions are the same as in Example 1. In this way, the planar type element shown in FIG. 3 was produced. When DC voltage was applied to these and the IV characteristics were measured, the first
A sharp knee 7 curve shown in the figure was obtained. The results are shown in Table 3 below. Similarly in this third table, sample No.
corresponds to No in the first embodiment.

(The following is a margin) <Table 3> 13. It can be seen that in this Brehner-type Example 3, the threshold voltage increases in response to the larger inter-electrode spacing compared to the sandwich-type element. It was confirmed that the stability of the characteristics in these cases is practically equivalent to that of light.

<Example 4> A stainless steel wire with a diameter of 1 thick was immersed in the 111o8 coating solution of Example 1, pulled up at a speed of about 5 mx/sec, dried, and fired at 500'C for 90 minutes.
A thin film of a mixture of manganese oxide, nickel oxide, and bismuth oxide was formed on the surface of a stainless steel wire, and a silver electrode was further formed on the surface of this film to construct an element.

In this case, vth is 6.0 at a sweep frequency of 50 Hz.
9V, Ith is 1.1 mA, VH is 5.5 V
, Ih power of 1.4 mA, switching characteristics similar to Examples 1 to 3 were observed.

In Examples 1 to 4, the firing temperature was 500 to 550°C in view of the heat resistance of the substrate and electrode materials used. However, when using a heat-resistant material such as alumina, The temperature can be raised up to the heat-resistant temperature of the substrate.

As for the compounds used, as long as they are soluble in an appropriate solvent, such as inorganic acid salts such as nitrates and sulfates, organic acid salts such as acetates, complex salts, and metal alkoxides, they can be used without any problems. can. Furthermore, electrode materials may include metals other than those used in this example, such as copper, aluminum, and zinc, conductive oxides such as cadmium stannate, and tin oxide doped with antimony, or mixtures of manganese oxide, nickel oxide, and bismuth oxide. Consisting of a thin film and an electrode from which to take electrical leads, a thin film of a mixture of manganese oxide, nickel oxide, and bismuth oxide is coated onto a substrate with a solution of a manganese compound, a nickel compound, and a bismuth compound mixed and dissolved in a solvent, and then dried. Then, by manufacturing by heating and firing in the atmosphere, a nonlinear resistance element with switching characteristics can be provided at low cost with good productivity, and can be manufactured over a large area. .

Its practical utility is great in that it is easy.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the current-voltage characteristics of the nonlinear resistance element of the present invention, Fig. 2 is a sectional view showing the structure of a Sandinch type element, and Fig. 3 is a sectional view showing the structure of a Brehner type element. . , ;? ,,1. ．． ．． ．． ．． ．． Name of agent for the 271st class: Patent attorney Toshio Nakao and one other person 1st trial current

Claims (2)

[Claims] (1) A nonlinear resistance element comprising a thin film of a mixture of manganese oxide, nickel oxide, and bismuth oxide and an electrode for taking electrical leads therefrom, and having conductive switching characteristics. (2) A solution of a manganese compound, a nickel compound, and a bismuth compound mixed and dissolved in a solvent is applied onto the substrate, dried, and then heated and fired to produce manganese oxide,
A method for manufacturing a nonlinear resistance element, comprising forming a thin film of a mixture of nickel oxide and bismuth oxide.